Merge branch '57115-just-in-time-k8s-resource-creation' into 'master'

Create project-specific Kubernetes resources just-in-time

See merge request gitlab-org/gitlab-ce!25586

54 files changed, 943 insertions, 51 deletions

diff --git a/app/assets/stylesheets/framework/icons.scss b/app/assets/stylesheets/framework/icons.scss
index 49b9b7014ae..3ab61cc5c47 100644
--- a/app/assets/stylesheets/framework/icons.scss
+++ b/app/assets/stylesheets/framework/icons.scss
@@ -31,6 +31,7 @@
   }
 }
 
+.ci-status-icon-preparing,
 .ci-status-icon-running {
   svg {
     fill: $blue-400;
diff --git a/app/assets/stylesheets/pages/merge_requests.scss b/app/assets/stylesheets/pages/merge_requests.scss
index df3a4be6559..7f8b8ea8100 100644
--- a/app/assets/stylesheets/pages/merge_requests.scss
+++ b/app/assets/stylesheets/pages/merge_requests.scss
@@ -166,6 +166,7 @@
       float: left;
 
       .accept-merge-request {
+        &.ci-preparing,
         &.ci-pending,
         &.ci-running {
           @include btn-blue;
diff --git a/app/assets/stylesheets/pages/pipelines.scss b/app/assets/stylesheets/pages/pipelines.scss
index ef9c87d0452..bb08440fda8 100644
--- a/app/assets/stylesheets/pages/pipelines.scss
+++ b/app/assets/stylesheets/pages/pipelines.scss
@@ -795,6 +795,7 @@
     @include mini-pipeline-graph-color($white, $orange-100, $orange-200, $orange-500, $orange-600, $orange-700);
   }
 
+  &.ci-status-icon-preparing,
   &.ci-status-icon-running {
     @include mini-pipeline-graph-color($white, $blue-100, $blue-200, $blue-500, $blue-600, $blue-700);
   }
diff --git a/app/assets/stylesheets/pages/status.scss b/app/assets/stylesheets/pages/status.scss
index f4d568d02ac..a59bb31bdcb 100644
--- a/app/assets/stylesheets/pages/status.scss
+++ b/app/assets/stylesheets/pages/status.scss
@@ -44,6 +44,7 @@
   }
 
   &.ci-info,
+  &.ci-preparing,
   &.ci-running {
     @include status-color($blue-100, $blue-500, $blue-600);
   }
diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index a629db82c19..59f47effff7 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -172,6 +172,10 @@ module Ci
     end
 
     state_machine :status do
+      event :enqueue do
+        transition [:created, :skipped, :manual, :scheduled] => :preparing, if: :any_unmet_prerequisites?
+      end
+
       event :actionize do
         transition created: :manual
       end
@@ -185,8 +189,12 @@ module Ci
       end
 
       event :enqueue_scheduled do
+        transition scheduled: :preparing, if: ->(build) do
+          build.scheduled_at&.past? && build.any_unmet_prerequisites?
+        end
+
         transition scheduled: :pending, if: ->(build) do
-          build.scheduled_at && build.scheduled_at < Time.now
+          build.scheduled_at&.past? && !build.any_unmet_prerequisites?
         end
       end
 
@@ -204,6 +212,12 @@ module Ci
         end
       end
 
+      after_transition any => [:preparing] do |build|
+        build.run_after_commit do
+          Ci::BuildPrepareWorker.perform_async(id)
+        end
+      end
+
       after_transition any => [:pending] do |build|
         build.run_after_commit do
           BuildQueueWorker.perform_async(id)
@@ -355,6 +369,16 @@ module Ci
       !retried?
     end
 
+    def any_unmet_prerequisites?
+      return false unless Feature.enabled?(:ci_preparing_state, default_enabled: true)
+
+      prerequisites.present?
+    end
+
+    def prerequisites
+      Gitlab::Ci::Build::Prerequisite::Factory.new(self).unmet
+    end
+
     def expanded_environment_name
       return unless has_environment?
 
diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index adffdc0355e..ae74f569415 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -82,10 +82,14 @@ module Ci
 
     state_machine :status, initial: :created do
       event :enqueue do
-        transition [:created, :skipped, :scheduled] => :pending
+        transition [:created, :preparing, :skipped, :scheduled] => :pending
         transition [:success, :failed, :canceled] => :running
       end
 
+      event :prepare do
+        transition any - [:preparing] => :preparing
+      end
+
       event :run do
         transition any - [:running] => :running
       end
@@ -118,7 +122,7 @@ module Ci
       # Do not add any operations to this state_machine
       # Create a separate worker for each new operation
 
-      before_transition [:created, :pending] => :running do |pipeline|
+      before_transition [:created, :preparing, :pending] => :running do |pipeline|
         pipeline.started_at = Time.now
       end
 
@@ -141,7 +145,7 @@ module Ci
         end
       end
 
-      after_transition [:created, :pending] => :running do |pipeline|
+      after_transition [:created, :preparing, :pending] => :running do |pipeline|
         pipeline.run_after_commit { PipelineMetricsWorker.perform_async(pipeline.id) }
       end
 
@@ -149,7 +153,7 @@ module Ci
         pipeline.run_after_commit { PipelineMetricsWorker.perform_async(pipeline.id) }
       end
 
-      after_transition [:created, :pending, :running] => :success do |pipeline|
+      after_transition [:created, :preparing, :pending, :running] => :success do |pipeline|
         pipeline.run_after_commit { PipelineSuccessWorker.perform_async(pipeline.id) }
       end
 
@@ -597,6 +601,7 @@ module Ci
       retry_optimistic_lock(self) do
         case latest_builds_status.to_s
         when 'created' then nil
+        when 'preparing' then prepare
         when 'pending' then enqueue
         when 'running' then run
         when 'success' then succeed
diff --git a/app/models/ci/stage.rb b/app/models/ci/stage.rb
index 0389945191e..098f5189517 100644
--- a/app/models/ci/stage.rb
+++ b/app/models/ci/stage.rb
@@ -39,10 +39,14 @@ module Ci
 
     state_machine :status, initial: :created do
       event :enqueue do
-        transition created: :pending
+        transition [:created, :preparing] => :pending
         transition [:success, :failed, :canceled, :skipped] => :running
       end
 
+      event :prepare do
+        transition any - [:preparing] => :preparing
+      end
+
       event :run do
         transition any - [:running] => :running
       end
@@ -76,6 +80,7 @@ module Ci
       retry_optimistic_lock(self) do
         case statuses.latest.status
         when 'created' then nil
+        when 'preparing' then prepare
         when 'pending' then enqueue
         when 'running' then run
         when 'success' then succeed
diff --git a/app/models/commit_status.rb b/app/models/commit_status.rb
index 7f6562b63e5..5f66a661324 100644
--- a/app/models/commit_status.rb
+++ b/app/models/commit_status.rb
@@ -66,7 +66,10 @@ class CommitStatus < ActiveRecord::Base
     end
 
     event :enqueue do
-      transition [:created, :skipped, :manual, :scheduled] => :pending
+      # A CommitStatus will never have prerequisites, but this event
+      # is shared by Ci::Build, which cannot progress unless prerequisites
+      # are satisfied.
+      transition [:created, :preparing, :skipped, :manual, :scheduled] => :pending, unless: :any_unmet_prerequisites?
     end
 
     event :run do
@@ -74,26 +77,26 @@ class CommitStatus < ActiveRecord::Base
     end
 
     event :skip do
-      transition [:created, :pending] => :skipped
+      transition [:created, :preparing, :pending] => :skipped
     end
 
     event :drop do
-      transition [:created, :pending, :running, :scheduled] => :failed
+      transition [:created, :preparing, :pending, :running, :scheduled] => :failed
     end
 
     event :success do
-      transition [:created, :pending, :running] => :success
+      transition [:created, :preparing, :pending, :running] => :success
     end
 
     event :cancel do
-      transition [:created, :pending, :running, :manual, :scheduled] => :canceled
+      transition [:created, :preparing, :pending, :running, :manual, :scheduled] => :canceled
     end
 
-    before_transition [:created, :skipped, :manual, :scheduled] => :pending do |commit_status|
+    before_transition [:created, :preparing, :skipped, :manual, :scheduled] => :pending do |commit_status|
       commit_status.queued_at = Time.now
     end
 
-    before_transition [:created, :pending] => :running do |commit_status|
+    before_transition [:created, :preparing, :pending] => :running do |commit_status|
       commit_status.started_at = Time.now
     end
 
@@ -180,6 +183,10 @@ class CommitStatus < ActiveRecord::Base
     false
   end
 
+  def any_unmet_prerequisites?
+    false
+  end
+
   def auto_canceled?
     canceled? && auto_canceled_by_id?
   end
diff --git a/app/models/commit_status_enums.rb b/app/models/commit_status_enums.rb
index 152105d9429..45e08fa18fe 100644
--- a/app/models/commit_status_enums.rb
+++ b/app/models/commit_status_enums.rb
@@ -14,7 +14,8 @@ module CommitStatusEnums
       runner_unsupported: 6,
       stale_schedule: 7,
       job_execution_timeout: 8,
-      archived_failure: 9
+      archived_failure: 9,
+      unmet_prerequisites: 10
     }
   end
 end
diff --git a/app/models/concerns/has_status.rb b/app/models/concerns/has_status.rb
index 0d2be4c61ab..8882f48c281 100644
--- a/app/models/concerns/has_status.rb
+++ b/app/models/concerns/has_status.rb
@@ -5,14 +5,14 @@ module HasStatus
 
   DEFAULT_STATUS = 'created'.freeze
   BLOCKED_STATUS = %w[manual scheduled].freeze
-  AVAILABLE_STATUSES = %w[created pending running success failed canceled skipped manual scheduled].freeze
+  AVAILABLE_STATUSES = %w[created preparing pending running success failed canceled skipped manual scheduled].freeze
   STARTED_STATUSES = %w[running success failed skipped manual scheduled].freeze
-  ACTIVE_STATUSES = %w[pending running].freeze
+  ACTIVE_STATUSES = %w[preparing pending running].freeze
   COMPLETED_STATUSES = %w[success failed canceled skipped].freeze
-  ORDERED_STATUSES = %w[failed pending running manual scheduled canceled success skipped created].freeze
+  ORDERED_STATUSES = %w[failed preparing pending running manual scheduled canceled success skipped created].freeze
   STATUSES_ENUM = { created: 0, pending: 1, running: 2, success: 3,
                     failed: 4, canceled: 5, skipped: 6, manual: 7,
-                    scheduled: 8 }.freeze
+                    scheduled: 8, preparing: 9 }.freeze
 
   UnknownStatusError = Class.new(StandardError)
 
@@ -26,6 +26,7 @@ module HasStatus
       success = scope_relevant.success.select('count(*)').to_sql
       manual = scope_relevant.manual.select('count(*)').to_sql
       scheduled = scope_relevant.scheduled.select('count(*)').to_sql
+      preparing = scope_relevant.preparing.select('count(*)').to_sql
       pending = scope_relevant.pending.select('count(*)').to_sql
       running = scope_relevant.running.select('count(*)').to_sql
       skipped = scope_relevant.skipped.select('count(*)').to_sql
@@ -37,12 +38,14 @@ module HasStatus
         WHEN (#{builds})=(#{skipped}) THEN 'skipped'
         WHEN (#{builds})=(#{success}) THEN 'success'
         WHEN (#{builds})=(#{created}) THEN 'created'
+        WHEN (#{builds})=(#{preparing}) THEN 'preparing'
         WHEN (#{builds})=(#{success})+(#{skipped}) THEN 'success'
         WHEN (#{builds})=(#{success})+(#{skipped})+(#{canceled}) THEN 'canceled'
         WHEN (#{builds})=(#{created})+(#{skipped})+(#{pending}) THEN 'pending'
         WHEN (#{running})+(#{pending})>0 THEN 'running'
         WHEN (#{manual})>0 THEN 'manual'
         WHEN (#{scheduled})>0 THEN 'scheduled'
+        WHEN (#{preparing})>0 THEN 'preparing'
         WHEN (#{created})>0 THEN 'running'
         ELSE 'failed'
       END)"
@@ -70,6 +73,7 @@ module HasStatus
 
     state_machine :status, initial: :created do
       state :created, value: 'created'
+      state :preparing, value: 'preparing'
       state :pending, value: 'pending'
       state :running, value: 'running'
       state :failed, value: 'failed'
@@ -81,6 +85,7 @@ module HasStatus
     end
 
     scope :created, -> { where(status: 'created') }
+    scope :preparing, -> { where(status: 'preparing') }
     scope :relevant, -> { where(status: AVAILABLE_STATUSES - ['created']) }
     scope :running, -> { where(status: 'running') }
     scope :pending, -> { where(status: 'pending') }
@@ -90,14 +95,14 @@ module HasStatus
     scope :skipped, -> { where(status: 'skipped') }
     scope :manual, -> { where(status: 'manual') }
     scope :scheduled, -> { where(status: 'scheduled') }
-    scope :alive, -> { where(status: [:created, :pending, :running]) }
+    scope :alive, -> { where(status: [:created, :preparing, :pending, :running]) }
     scope :created_or_pending, -> { where(status: [:created, :pending]) }
     scope :running_or_pending, -> { where(status: [:running, :pending]) }
     scope :finished, -> { where(status: [:success, :failed, :canceled]) }
     scope :failed_or_canceled, -> { where(status: [:failed, :canceled]) }
 
     scope :cancelable, -> do
-      where(status: [:running, :pending, :created, :scheduled])
+      where(status: [:running, :preparing, :pending, :created, :scheduled])
     end
   end
 
diff --git a/app/models/deployment.rb b/app/models/deployment.rb
index 811e623b7f7..428edfd88de 100644
--- a/app/models/deployment.rb
+++ b/app/models/deployment.rb
@@ -78,6 +78,10 @@ class Deployment < ActiveRecord::Base
     Commit.truncate_sha(sha)
   end
 
+  def cluster
+    project.deployment_platform(environment: environment.name)&.cluster
+  end
+
   def last?
     self == environment.last_deployment
   end
diff --git a/app/presenters/commit_status_presenter.rb b/app/presenters/commit_status_presenter.rb
index 0cd77da6303..28a25c8b7a3 100644
--- a/app/presenters/commit_status_presenter.rb
+++ b/app/presenters/commit_status_presenter.rb
@@ -11,7 +11,8 @@ class CommitStatusPresenter < Gitlab::View::Presenter::Delegated
     runner_unsupported: 'Your runner is outdated, please upgrade your runner',
     stale_schedule: 'Delayed job could not be executed by some reason, please try again',
     job_execution_timeout: 'The script exceeded the maximum execution time set for the job',
-    archived_failure: 'The job is archived and cannot be run'
+    archived_failure: 'The job is archived and cannot be run',
+    unmet_prerequisites: 'The job failed to complete prerequisite tasks'
   }.freeze
 
   private_constant :CALLOUT_FAILURE_MESSAGES
diff --git a/app/services/ci/prepare_build_service.rb b/app/services/ci/prepare_build_service.rb
new file mode 100644
index 00000000000..32f11438b79
--- /dev/null
+++ b/app/services/ci/prepare_build_service.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Ci
+  class PrepareBuildService
+    attr_reader :build
+
+    def initialize(build)
+      @build = build
+    end
+
+    def execute
+      prerequisites.each(&:complete!)
+
+      unless build.enqueue
+        build.drop!(:unmet_prerequisites)
+      end
+    end
+
+    private
+
+    def prerequisites
+      build.prerequisites
+    end
+  end
+end
diff --git a/app/workers/all_queues.yml b/app/workers/all_queues.yml
index b2d88567e0e..6ebd756d3da 100644
--- a/app/workers/all_queues.yml
+++ b/app/workers/all_queues.yml
@@ -71,6 +71,7 @@
 - pipeline_hooks:build_hooks
 - pipeline_hooks:pipeline_hooks
 - pipeline_processing:build_finished
+- pipeline_processing:ci_build_prepare
 - pipeline_processing:build_queue
 - pipeline_processing:build_success
 - pipeline_processing:pipeline_process
diff --git a/app/workers/ci/build_prepare_worker.rb b/app/workers/ci/build_prepare_worker.rb
new file mode 100644
index 00000000000..1a35a74ae53
--- /dev/null
+++ b/app/workers/ci/build_prepare_worker.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Ci
+  class BuildPrepareWorker
+    include ApplicationWorker
+    include PipelineQueue
+
+    queue_namespace :pipeline_processing
+
+    def perform(build_id)
+      Ci::Build.find_by_id(build_id).try do |build|
+        Ci::PrepareBuildService.new(build).execute
+      end
+    end
+  end
+end
diff --git a/app/workers/cluster_configure_worker.rb b/app/workers/cluster_configure_worker.rb
index 63e6cc147be..b984dee5b21 100644
--- a/app/workers/cluster_configure_worker.rb
+++ b/app/workers/cluster_configure_worker.rb
@@ -5,6 +5,8 @@ class ClusterConfigureWorker
   include ClusterQueue
 
   def perform(cluster_id)
+    return if Feature.enabled?(:ci_preparing_state, default_enabled: true)
+
     Clusters::Cluster.find_by_id(cluster_id).try do |cluster|
       Clusters::RefreshService.create_or_update_namespaces_for_cluster(cluster)
     end
diff --git a/app/workers/cluster_project_configure_worker.rb b/app/workers/cluster_project_configure_worker.rb
index 497e57c0d0b..d7bea69a01c 100644
--- a/app/workers/cluster_project_configure_worker.rb
+++ b/app/workers/cluster_project_configure_worker.rb
@@ -5,6 +5,8 @@ class ClusterProjectConfigureWorker
   include ClusterQueue
 
   def perform(project_id)
+    return if Feature.enabled?(:ci_preparing_state, default_enabled: true)
+
     project = Project.find(project_id)
 
     ::Clusters::RefreshService.create_or_update_namespaces_for_project(project)
diff --git a/changelogs/unreleased/57115-just-in-time-k8s-resource-creation.yml b/changelogs/unreleased/57115-just-in-time-k8s-resource-creation.yml
new file mode 100644
index 00000000000..2141c75ec72
--- /dev/null
+++ b/changelogs/unreleased/57115-just-in-time-k8s-resource-creation.yml
@@ -0,0 +1,5 @@
+---
+title: Create Kubernetes resources for projects when their deployment jobs run.
+merge_request: 25586
+author:
+type: changed
diff --git a/doc/topics/autodevops/index.md b/doc/topics/autodevops/index.md
index 43aa4163ab1..fb3f9711711 100644
--- a/doc/topics/autodevops/index.md
+++ b/doc/topics/autodevops/index.md
@@ -1022,6 +1022,10 @@ planned for a subsequent release.
   buildpack](#custom-buildpacks).
 - Auto Test may fail because of a mismatch between testing frameworks. In this
   case, you may need to customize your `.gitlab-ci.yml` with your test commands.
+- Auto Deploy may fail if it is unable to create a Kubernetes namespace and
+  service account for your project. See the
+  [troubleshooting failed deployments](../../user/project/clusters/index.md#troubleshooting-failed-deployment-jobs)
+  section to debug why these resources were not created.
 
 ### Disable the banner instance wide
 
diff --git a/doc/user/project/clusters/index.md b/doc/user/project/clusters/index.md
index b05e8777b40..44b9e5cccb5 100644
--- a/doc/user/project/clusters/index.md
+++ b/doc/user/project/clusters/index.md
@@ -556,26 +556,27 @@ NOTE: **NOTE:**
 Prior to GitLab 11.5, `KUBE_TOKEN` was the Kubernetes token of the main
 service account of the cluster integration.
 
-### Troubleshooting missing `KUBECONFIG` or `KUBE_TOKEN`
+### Troubleshooting failed deployment jobs
 
-GitLab will create a new service account specifically for your CI builds. The
-new service account is created when the cluster is added to the project.
-Sometimes there may be errors that cause the service account creation to fail.
+GitLab will create a namespace and service account specifically for your
+deployment jobs. These resources are created just before the deployment
+job starts. Sometimes there may be errors that cause their creation to fail.
 
-In such instances, your build will not be passed the `KUBECONFIG` or
-`KUBE_TOKEN` variables and, if you are using Auto DevOps, your Auto DevOps
-pipelines will no longer trigger a `production` deploy build. You will need to
-check the [logs](../../../administration/logs.md) to debug why the service
-account creation failed.
+In such instances, your job will fail with the message:
+
+```The job failed to complete prerequisite tasks```
+
+You will need to check the [logs](../../../administration/logs.md) to debug
+why the namespace and service account creation failed.
 
 A common reason for failure is that the token you gave GitLab did not have
 [`cluster-admin`](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#user-facing-roles)
 privileges as GitLab expects.
 
-Another common problem for why these variables are not being passed to your
-builds is that they must have a matching
+Another common problem is caused by a missing `KUBECONFIG` or `KUBE_TOKEN`.
+To be passed to your job, it must have a matching
 [`environment:name`](../../../ci/environments.md#defining-environments). If
-your build has no `environment:name` set, it will not be passed the Kubernetes
+your job has no `environment:name` set, it will not be passed the Kubernetes
 credentials.
 
 ## Monitoring your Kubernetes cluster **[ULTIMATE]**
diff --git a/lib/gitlab/badge/pipeline/template.rb b/lib/gitlab/badge/pipeline/template.rb
index 64c3dfcd10b..2c5f9654496 100644
--- a/lib/gitlab/badge/pipeline/template.rb
+++ b/lib/gitlab/badge/pipeline/template.rb
@@ -15,6 +15,7 @@ module Gitlab
           failed: '#e05d44',
           running: '#dfb317',
           pending: '#dfb317',
+          preparing: '#dfb317',
           canceled: '#9f9f9f',
           skipped: '#9f9f9f',
           unknown: '#9f9f9f'
diff --git a/lib/gitlab/ci/build/prerequisite/base.rb b/lib/gitlab/ci/build/prerequisite/base.rb
new file mode 100644
index 00000000000..156aa22d95b
--- /dev/null
+++ b/lib/gitlab/ci/build/prerequisite/base.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Build
+      module Prerequisite
+        class Base
+          include Utils::StrongMemoize
+
+          attr_reader :build
+
+          def initialize(build)
+            @build = build
+          end
+
+          def unmet?
+            raise NotImplementedError
+          end
+
+          def complete!
+            raise NotImplementedError
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/build/prerequisite/factory.rb b/lib/gitlab/ci/build/prerequisite/factory.rb
new file mode 100644
index 00000000000..60cdf7af418
--- /dev/null
+++ b/lib/gitlab/ci/build/prerequisite/factory.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Build
+      module Prerequisite
+        class Factory
+          attr_reader :build
+
+          def self.prerequisites
+            [KubernetesNamespace]
+          end
+
+          def initialize(build)
+            @build = build
+          end
+
+          def unmet
+            build_prerequisites.select(&:unmet?)
+          end
+
+          private
+
+          def build_prerequisites
+            self.class.prerequisites.map do |prerequisite|
+              prerequisite.new(build)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/build/prerequisite/kubernetes_namespace.rb b/lib/gitlab/ci/build/prerequisite/kubernetes_namespace.rb
new file mode 100644
index 00000000000..41135ae62bb
--- /dev/null
+++ b/lib/gitlab/ci/build/prerequisite/kubernetes_namespace.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Build
+      module Prerequisite
+        class KubernetesNamespace < Base
+          def unmet?
+            deployment_cluster.present? && kubernetes_namespace.new_record?
+          end
+
+          def complete!
+            return unless unmet?
+
+            create_or_update_namespace
+          end
+
+          private
+
+          def deployment_cluster
+            build.deployment&.cluster
+          end
+
+          def kubernetes_namespace
+            strong_memoize(:kubernetes_namespace) do
+              deployment_cluster.find_or_initialize_kubernetes_namespace_for_project(build.project)
+            end
+          end
+
+          def create_or_update_namespace
+            Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService.new(
+              cluster: deployment_cluster,
+              kubernetes_namespace: kubernetes_namespace
+            ).execute
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/status/build/factory.rb b/lib/gitlab/ci/status/build/factory.rb
index 6e4bfe23f2b..f7d0715e617 100644
--- a/lib/gitlab/ci/status/build/factory.rb
+++ b/lib/gitlab/ci/status/build/factory.rb
@@ -11,6 +11,7 @@ module Gitlab
               Status::Build::Manual,
               Status::Build::Canceled,
               Status::Build::Created,
+              Status::Build::Preparing,
               Status::Build::Pending,
               Status::Build::Skipped],
              [Status::Build::Cancelable,
diff --git a/lib/gitlab/ci/status/build/failed.rb b/lib/gitlab/ci/status/build/failed.rb
index d40454df737..76dfe7b7639 100644
--- a/lib/gitlab/ci/status/build/failed.rb
+++ b/lib/gitlab/ci/status/build/failed.rb
@@ -15,7 +15,8 @@ module Gitlab
             runner_unsupported: 'unsupported runner',
             stale_schedule: 'stale schedule',
             job_execution_timeout: 'job execution timeout',
-            archived_failure: 'archived failure'
+            archived_failure: 'archived failure',
+            unmet_prerequisites: 'unmet prerequisites'
           }.freeze
 
           private_constant :REASONS
diff --git a/lib/gitlab/ci/status/build/preparing.rb b/lib/gitlab/ci/status/build/preparing.rb
new file mode 100644
index 00000000000..1fddcb05f79
--- /dev/null
+++ b/lib/gitlab/ci/status/build/preparing.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Status
+      module Build
+        class Preparing < Status::Extended
+          ##
+          # TODO: image is shared with 'pending'
+          # until we get a dedicated one
+          #
+          def illustration
+            {
+              image: 'illustrations/job_not_triggered.svg',
+              size: 'svg-306',
+              title: _('This job is preparing to start'),
+              content: _('This job is performing tasks that must complete before it can start')
+            }
+          end
+
+          def self.matches?(build, _)
+            build.preparing?
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/status/preparing.rb b/lib/gitlab/ci/status/preparing.rb
new file mode 100644
index 00000000000..62985d0a9f9
--- /dev/null
+++ b/lib/gitlab/ci/status/preparing.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Status
+      class Preparing < Status::Core
+        def text
+          s_('CiStatusText|preparing')
+        end
+
+        def label
+          s_('CiStatusLabel|preparing')
+        end
+
+        ##
+        # TODO: shared with 'created'
+        # until we get one for 'preparing'
+        #
+        def icon
+          'status_created'
+        end
+
+        ##
+        # TODO: shared with 'created'
+        # until we get one for 'preparing'
+        #
+        def favicon
+          'favicon_status_created'
+        end
+      end
+    end
+  end
+end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 53235ee7444..e096725be42 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -1518,6 +1518,9 @@ msgstr ""
 msgid "CiStatusLabel|pending"
 msgstr ""
 
+msgid "CiStatusLabel|preparing"
+msgstr ""
+
 msgid "CiStatusLabel|skipped"
 msgstr ""
 
@@ -1551,6 +1554,9 @@ msgstr ""
 msgid "CiStatusText|pending"
 msgstr ""
 
+msgid "CiStatusText|preparing"
+msgstr ""
+
 msgid "CiStatusText|skipped"
 msgstr ""
 
@@ -7879,6 +7885,12 @@ msgstr ""
 msgid "This job is in pending state and is waiting to be picked by a runner"
 msgstr ""
 
+msgid "This job is performing tasks that must complete before it can start"
+msgstr ""
+
+msgid "This job is preparing to start"
+msgstr ""
+
 msgid "This job is stuck because you don't have any active runners online with any of these tags assigned to them:"
 msgstr ""
 
diff --git a/spec/factories/ci/builds.rb b/spec/factories/ci/builds.rb
index 0b3e67b4987..067391c1179 100644
--- a/spec/factories/ci/builds.rb
+++ b/spec/factories/ci/builds.rb
@@ -75,6 +75,10 @@ FactoryBot.define do
       status 'created'
     end
 
+    trait :preparing do
+      status 'preparing'
+    end
+
     trait :scheduled do
       schedulable
       status 'scheduled'
diff --git a/spec/factories/ci/pipelines.rb b/spec/factories/ci/pipelines.rb
index ee5d27355f1..aa5ccbda6cd 100644
--- a/spec/factories/ci/pipelines.rb
+++ b/spec/factories/ci/pipelines.rb
@@ -50,6 +50,14 @@ FactoryBot.define do
         failure_reason :config_error
       end
 
+      trait :created do
+        status :created
+      end
+
+      trait :preparing do
+        status :preparing
+      end
+
       trait :blocked do
         status :manual
       end
diff --git a/spec/factories/clusters/clusters.rb b/spec/factories/clusters/clusters.rb
index a2e5f4862db..1cc3c0e03d8 100644
--- a/spec/factories/clusters/clusters.rb
+++ b/spec/factories/clusters/clusters.rb
@@ -12,7 +12,7 @@ FactoryBot.define do
       cluster_type { Clusters::Cluster.cluster_types[:project_type] }
 
       before(:create) do |cluster, evaluator|
-        cluster.projects << create(:project, :repository)
+        cluster.projects << create(:project, :repository) unless cluster.projects.present?
       end
     end
 
@@ -20,7 +20,7 @@ FactoryBot.define do
       cluster_type { Clusters::Cluster.cluster_types[:group_type] }
 
       before(:create) do |cluster, evalutor|
-        cluster.groups << create(:group)
+        cluster.groups << create(:group) unless cluster.groups.present?
       end
     end
 
diff --git a/spec/factories/commit_statuses.rb b/spec/factories/commit_statuses.rb
index 381bf07f6a0..848a31e96c1 100644
--- a/spec/factories/commit_statuses.rb
+++ b/spec/factories/commit_statuses.rb
@@ -33,6 +33,10 @@ FactoryBot.define do
       status 'pending'
     end
 
+    trait :preparing do
+      status 'preparing'
+    end
+
     trait :created do
       status 'created'
     end
diff --git a/spec/features/projects/badges/pipeline_badge_spec.rb b/spec/features/projects/badges/pipeline_badge_spec.rb
index dee81898928..4ac4e8f0fcb 100644
--- a/spec/features/projects/badges/pipeline_badge_spec.rb
+++ b/spec/features/projects/badges/pipeline_badge_spec.rb
@@ -41,6 +41,25 @@ describe 'Pipeline Badge' do
       end
     end
 
+    context 'when the pipeline is preparing' do
+      let!(:job) { create(:ci_build, status: 'created', pipeline: pipeline) }
+
+      before do
+        # Prevent skipping directly to 'pending'
+        allow(Ci::BuildPrepareWorker).to receive(:perform_async)
+        allow(job).to receive(:prerequisites).and_return([double])
+      end
+
+      it 'displays the preparing badge' do
+        job.enqueue
+
+        visit pipeline_project_badges_path(project, ref: ref, format: :svg)
+
+        expect(page.status_code).to eq(200)
+        expect_badge('preparing')
+      end
+    end
+
     context 'when the pipeline is running' do
       it 'shows displays so on the badge' do
         create(:ci_build, pipeline: pipeline, name: 'second build', status_event: 'run')
diff --git a/spec/features/projects/pipelines/pipeline_spec.rb b/spec/features/projects/pipelines/pipeline_spec.rb
index 5d2a99f40b7..9fdf78baa1e 100644
--- a/spec/features/projects/pipelines/pipeline_spec.rb
+++ b/spec/features/projects/pipelines/pipeline_spec.rb
@@ -24,6 +24,11 @@ describe 'Pipeline', :js do
              pipeline: pipeline, stage: 'test', name: 'test')
     end
 
+    let!(:build_preparing) do
+      create(:ci_build, :preparing,
+             pipeline: pipeline, stage: 'deploy', name: 'prepare')
+    end
+
     let!(:build_running) do
       create(:ci_build, :running,
              pipeline: pipeline, stage: 'deploy', name: 'deploy')
@@ -109,6 +114,24 @@ describe 'Pipeline', :js do
         end
       end
 
+      context 'when pipeline has preparing builds' do
+        it 'shows a preparing icon and a cancel action' do
+          page.within('#ci-badge-prepare') do
+            expect(page).to have_selector('.js-ci-status-icon-preparing')
+            expect(page).to have_selector('.js-icon-cancel')
+            expect(page).to have_content('prepare')
+          end
+        end
+
+        it 'cancels the preparing build and shows retry button' do
+          find('#ci-badge-deploy .ci-action-icon-container').click
+
+          page.within('#ci-badge-deploy') do
+            expect(page).to have_css('.js-icon-retry')
+          end
+        end
+      end
+
       context 'when pipeline has successful builds' do
         it 'shows the success icon and a retry action for the successful build' do
           page.within('#ci-badge-build') do
diff --git a/spec/features/projects/pipelines/pipelines_spec.rb b/spec/features/projects/pipelines/pipelines_spec.rb
index 88d7c9ef8bd..9dc505573d4 100644
--- a/spec/features/projects/pipelines/pipelines_spec.rb
+++ b/spec/features/projects/pipelines/pipelines_spec.rb
@@ -282,6 +282,30 @@ describe 'Pipelines', :js do
       end
 
       context 'for generic statuses' do
+        context 'when preparing' do
+          let!(:pipeline) do
+            create(:ci_empty_pipeline,
+              status: 'preparing', project: project)
+          end
+
+          let!(:status) do
+            create(:generic_commit_status,
+              :preparing, pipeline: pipeline)
+          end
+
+          before do
+            visit_project_pipelines
+          end
+
+          it 'is cancelable' do
+            expect(page).to have_selector('.js-pipelines-cancel-button')
+          end
+
+          it 'shows the pipeline as preparing' do
+            expect(page).to have_selector('.ci-preparing')
+          end
+        end
+
         context 'when running' do
           let!(:running) do
             create(:generic_commit_status,
diff --git a/spec/lib/gitlab/badge/pipeline/template_spec.rb b/spec/lib/gitlab/badge/pipeline/template_spec.rb
index 20fa4f879c3..bcef0b7e120 100644
--- a/spec/lib/gitlab/badge/pipeline/template_spec.rb
+++ b/spec/lib/gitlab/badge/pipeline/template_spec.rb
@@ -59,6 +59,16 @@ describe Gitlab::Badge::Pipeline::Template do
       end
     end
 
+    context 'when status is preparing' do
+      before do
+        allow(badge).to receive(:status).and_return('preparing')
+      end
+
+      it 'has expected color' do
+        expect(template.value_color).to eq '#dfb317'
+      end
+    end
+
     context 'when status is unknown' do
       before do
         allow(badge).to receive(:status).and_return('unknown')
diff --git a/spec/lib/gitlab/ci/build/prerequisite/factory_spec.rb b/spec/lib/gitlab/ci/build/prerequisite/factory_spec.rb
new file mode 100644
index 00000000000..5187f99a441
--- /dev/null
+++ b/spec/lib/gitlab/ci/build/prerequisite/factory_spec.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Ci::Build::Prerequisite::Factory do
+  let(:build) { create(:ci_build) }
+
+  describe '.for_build' do
+    let(:kubernetes_namespace) do
+      instance_double(
+        Gitlab::Ci::Build::Prerequisite::KubernetesNamespace,
+        unmet?: unmet)
+    end
+
+    subject { described_class.new(build).unmet }
+
+    before do
+      expect(Gitlab::Ci::Build::Prerequisite::KubernetesNamespace)
+        .to receive(:new).with(build).and_return(kubernetes_namespace)
+    end
+
+    context 'prerequisite is unmet' do
+      let(:unmet) { true }
+
+      it { is_expected.to eq [kubernetes_namespace] }
+    end
+
+    context 'prerequisite is met' do
+      let(:unmet) { false }
+
+      it { is_expected.to be_empty }
+    end
+  end
+end
diff --git a/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb b/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb
new file mode 100644
index 00000000000..62dcd80fad7
--- /dev/null
+++ b/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb
@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Ci::Build::Prerequisite::KubernetesNamespace do
+  let(:build) { create(:ci_build) }
+
+  describe '#unmet?' do
+    subject { described_class.new(build).unmet? }
+
+    context 'build has no deployment' do
+      before do
+        expect(build.deployment).to be_nil
+      end
+
+      it { is_expected.to be_falsey }
+    end
+
+    context 'build has a deployment' do
+      let!(:deployment) { create(:deployment, deployable: build) }
+
+      context 'and a cluster to deploy to' do
+        let(:cluster) { create(:cluster, projects: [build.project]) }
+
+        before do
+          allow(build.deployment).to receive(:cluster).and_return(cluster)
+        end
+
+        it { is_expected.to be_truthy }
+
+        context 'and a namespace is already created for this project' do
+          let!(:kubernetes_namespace) { create(:cluster_kubernetes_namespace, cluster: cluster, project: build.project) }
+
+          it { is_expected.to be_falsey }
+        end
+      end
+
+      context 'and no cluster to deploy to' do
+        before do
+          expect(deployment.cluster).to be_nil
+        end
+
+        it { is_expected.to be_falsey }
+      end
+    end
+  end
+
+  describe '#complete!' do
+    let!(:deployment) { create(:deployment, deployable: build) }
+    let(:service) { double(execute: true) }
+
+    subject { described_class.new(build).complete! }
+
+    context 'completion is required' do
+      let(:cluster) { create(:cluster, projects: [build.project]) }
+
+      before do
+        allow(build.deployment).to receive(:cluster).and_return(cluster)
+      end
+
+      it 'creates a kubernetes namespace' do
+        expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService)
+          .to receive(:new)
+          .with(cluster: cluster, kubernetes_namespace: instance_of(Clusters::KubernetesNamespace))
+          .and_return(service)
+
+        expect(service).to receive(:execute).once
+
+        subject
+      end
+    end
+
+    context 'completion is not required' do
+      before do
+        expect(deployment.cluster).to be_nil
+      end
+
+      it 'does not create a namespace' do
+        expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService).not_to receive(:new)
+
+        subject
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/ci/status/build/preparing_spec.rb b/spec/lib/gitlab/ci/status/build/preparing_spec.rb
new file mode 100644
index 00000000000..4d8945845ba
--- /dev/null
+++ b/spec/lib/gitlab/ci/status/build/preparing_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Ci::Status::Build::Preparing do
+  subject do
+    described_class.new(double('subject'))
+  end
+
+  describe '#illustration' do
+    it { expect(subject.illustration).to include(:image, :size, :title, :content) }
+  end
+
+  describe '.matches?' do
+    subject { described_class.matches?(build, nil) }
+
+    context 'when build is preparing' do
+      let(:build) { create(:ci_build, :preparing) }
+
+      it 'is a correct match' do
+        expect(subject).to be true
+      end
+    end
+
+    context 'when build is not preparing' do
+      let(:build) { create(:ci_build, :success) }
+
+      it 'does not match' do
+        expect(subject).to be false
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/ci/status/preparing_spec.rb b/spec/lib/gitlab/ci/status/preparing_spec.rb
new file mode 100644
index 00000000000..7211c0e506d
--- /dev/null
+++ b/spec/lib/gitlab/ci/status/preparing_spec.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Ci::Status::Preparing do
+  subject do
+    described_class.new(double('subject'), nil)
+  end
+
+  describe '#text' do
+    it { expect(subject.text).to eq 'preparing' }
+  end
+
+  describe '#label' do
+    it { expect(subject.label).to eq 'preparing' }
+  end
+
+  describe '#icon' do
+    it { expect(subject.icon).to eq 'status_created' }
+  end
+
+  describe '#favicon' do
+    it { expect(subject.favicon).to eq 'favicon_status_created' }
+  end
+
+  describe '#group' do
+    it { expect(subject.group).to eq 'preparing' }
+  end
+end
diff --git a/spec/models/ci/build_spec.rb b/spec/models/ci/build_spec.rb
index 9ca4241d7d8..7500e6ae5b1 100644
--- a/spec/models/ci/build_spec.rb
+++ b/spec/models/ci/build_spec.rb
@@ -186,6 +186,37 @@ describe Ci::Build do
     end
   end
 
+  describe '#enqueue' do
+    let(:build) { create(:ci_build, :created) }
+
+    subject { build.enqueue }
+
+    before do
+      allow(build).to receive(:any_unmet_prerequisites?).and_return(has_prerequisites)
+      allow(Ci::PrepareBuildService).to receive(:perform_async)
+    end
+
+    context 'build has unmet prerequisites' do
+      let(:has_prerequisites) { true }
+
+      it 'transitions to preparing' do
+        subject
+
+        expect(build).to be_preparing
+      end
+    end
+
+    context 'build has no prerequisites' do
+      let(:has_prerequisites) { false }
+
+      it 'transitions to pending' do
+        subject
+
+        expect(build).to be_pending
+      end
+    end
+  end
+
   describe '#actionize' do
     context 'when build is a created' do
       before do
@@ -344,6 +375,18 @@ describe Ci::Build do
 
         expect(build).to be_pending
       end
+
+      context 'build has unmet prerequisites' do
+        before do
+          allow(build).to receive(:prerequisites).and_return([double])
+        end
+
+        it 'transits to preparing' do
+          subject
+
+          expect(build).to be_preparing
+        end
+      end
     end
   end
 
@@ -2876,6 +2919,36 @@ describe Ci::Build do
     end
   end
 
+  describe '#any_unmet_prerequisites?' do
+    let(:build) { create(:ci_build, :created) }
+
+    subject { build.any_unmet_prerequisites? }
+
+    context 'build has prerequisites' do
+      before do
+        allow(build).to receive(:prerequisites).and_return([double])
+      end
+
+      it { is_expected.to be_truthy }
+
+      context 'and the ci_preparing_state feature is disabled' do
+        before do
+          stub_feature_flags(ci_preparing_state: false)
+        end
+
+        it { is_expected.to be_falsey }
+      end
+    end
+
+    context 'build does not have prerequisites' do
+      before do
+        allow(build).to receive(:prerequisites).and_return([])
+      end
+
+      it { is_expected.to be_falsey }
+    end
+  end
+
   describe '#yaml_variables' do
     let(:build) { create(:ci_build, pipeline: pipeline, yaml_variables: variables) }
 
@@ -2928,6 +3001,20 @@ describe Ci::Build do
     end
   end
 
+  describe 'state transition: any => [:preparing]' do
+    let(:build) { create(:ci_build, :created) }
+
+    before do
+      allow(build).to receive(:prerequisites).and_return([double])
+    end
+
+    it 'queues BuildPrepareWorker' do
+      expect(Ci::BuildPrepareWorker).to receive(:perform_async).with(build.id)
+
+      build.enqueue
+    end
+  end
+
   describe 'state transition: any => [:pending]' do
     let(:build) { create(:ci_build, :created) }
 
diff --git a/spec/models/ci/pipeline_spec.rb b/spec/models/ci/pipeline_spec.rb
index 7eeaa7a18ef..2ac056f63b2 100644
--- a/spec/models/ci/pipeline_spec.rb
+++ b/spec/models/ci/pipeline_spec.rb
@@ -1201,16 +1201,28 @@ describe Ci::Pipeline, :mailer do
     end
 
     describe '#started_at' do
-      it 'updates on transitioning to running' do
-        build.run
+      let(:pipeline) { create(:ci_empty_pipeline, status: from_status) }
+
+      %i[created preparing pending].each do |status|
+        context "from #{status}" do
+          let(:from_status) { status }
 
-        expect(pipeline.reload.started_at).not_to be_nil
+          it 'updates on transitioning to running' do
+            pipeline.run
+
+            expect(pipeline.started_at).not_to be_nil
+          end
+        end
       end
 
-      it 'does not update on transitioning to success' do
-        build.success
+      context 'from created' do
+        let(:from_status) { :created }
+
+        it 'does not update on transitioning to success' do
+          pipeline.succeed
 
-        expect(pipeline.reload.started_at).to be_nil
+          expect(pipeline.started_at).to be_nil
+        end
       end
     end
 
@@ -1229,27 +1241,49 @@ describe Ci::Pipeline, :mailer do
     end
 
     describe 'merge request metrics' do
-      let(:project) { create(:project, :repository) }
-      let(:pipeline) { FactoryBot.create(:ci_empty_pipeline, status: 'created', project: project, ref: 'master', sha: project.repository.commit('master').id) }
-      let!(:merge_request) { create(:merge_request, source_project: project, source_branch: pipeline.ref) }
+      let(:pipeline) { create(:ci_empty_pipeline, status: from_status) }
 
       before do
         expect(PipelineMetricsWorker).to receive(:perform_async).with(pipeline.id)
       end
 
       context 'when transitioning to running' do
-        it 'schedules metrics workers' do
-          pipeline.run
+        %i[created preparing pending].each do |status|
+          context "from #{status}" do
+            let(:from_status) { status }
+
+            it 'schedules metrics workers' do
+              pipeline.run
+            end
+          end
         end
       end
 
       context 'when transitioning to success' do
+        let(:from_status) { 'created' }
+
         it 'schedules metrics workers' do
           pipeline.succeed
         end
       end
     end
 
+    describe 'merge on success' do
+      let(:pipeline) { create(:ci_empty_pipeline, status: from_status) }
+
+      %i[created preparing pending running].each do |status|
+        context "from #{status}" do
+          let(:from_status) { status }
+
+          it 'schedules pipeline success worker' do
+            expect(PipelineSuccessWorker).to receive(:perform_async).with(pipeline.id)
+
+            pipeline.succeed
+          end
+        end
+      end
+    end
+
     describe 'pipeline caching' do
       it 'performs ExpirePipelinesCacheWorker' do
         expect(ExpirePipelineCacheWorker).to receive(:perform_async).with(pipeline.id)
@@ -1768,6 +1802,18 @@ describe Ci::Pipeline, :mailer do
 
     subject { pipeline.reload.status }
 
+    context 'on prepare' do
+      before do
+        # Prevent skipping directly to 'pending'
+        allow(build).to receive(:prerequisites).and_return([double])
+        allow(Ci::BuildPrepareWorker).to receive(:perform_async)
+
+        build.enqueue
+      end
+
+      it { is_expected.to eq('preparing') }
+    end
+
     context 'on queuing' do
       before do
         build.enqueue
diff --git a/spec/models/commit_status_spec.rb b/spec/models/commit_status_spec.rb
index 8b7c88805c1..e2b7f5c6ee2 100644
--- a/spec/models/commit_status_spec.rb
+++ b/spec/models/commit_status_spec.rb
@@ -49,6 +49,16 @@ describe CommitStatus do
 
       commit_status.success!
     end
+
+    describe 'transitioning to running' do
+      let(:commit_status) { create(:commit_status, :pending, started_at: nil) }
+
+      it 'records the started at time' do
+        commit_status.run!
+
+        expect(commit_status.started_at).to be_present
+      end
+    end
   end
 
   describe '#started?' do
@@ -479,6 +489,12 @@ describe CommitStatus do
 
       it { is_expected.to be_script_failure }
     end
+
+    context 'when failure_reason is unmet_prerequisites' do
+      let(:reason) { :unmet_prerequisites }
+
+      it { is_expected.to be_unmet_prerequisites }
+    end
   end
 
   describe 'ensure stage assignment' do
@@ -555,6 +571,7 @@ describe CommitStatus do
 
     before do
       allow(Time).to receive(:now).and_return(current_time)
+      expect(commit_status.any_unmet_prerequisites?).to eq false
     end
 
     shared_examples 'commit status enqueued' do
@@ -569,6 +586,12 @@ describe CommitStatus do
       it_behaves_like 'commit status enqueued'
     end
 
+    context 'when initial state is :preparing' do
+      let(:commit_status) { create(:commit_status, :preparing) }
+
+      it_behaves_like 'commit status enqueued'
+    end
+
     context 'when initial state is :skipped' do
       let(:commit_status) { create(:commit_status, :skipped) }
 
diff --git a/spec/models/concerns/has_status_spec.rb b/spec/models/concerns/has_status_spec.rb
index 6b1038cb8fd..e8b1eba67cc 100644
--- a/spec/models/concerns/has_status_spec.rb
+++ b/spec/models/concerns/has_status_spec.rb
@@ -34,6 +34,22 @@ describe HasStatus do
         it { is_expected.to eq 'running' }
       end
 
+      context 'all preparing' do
+        let!(:statuses) do
+          [create(type, status: :preparing), create(type, status: :preparing)]
+        end
+
+        it { is_expected.to eq 'preparing' }
+      end
+
+      context 'at least one preparing' do
+        let!(:statuses) do
+          [create(type, status: :success), create(type, status: :preparing)]
+        end
+
+        it { is_expected.to eq 'preparing' }
+      end
+
       context 'success and failed but allowed to fail' do
         let!(:statuses) do
           [create(type, status: :success),
@@ -188,7 +204,7 @@ describe HasStatus do
       end
     end
 
-    %i[created running pending success
+    %i[created preparing running pending success
        failed canceled skipped].each do |status|
       it_behaves_like 'having a job', status
     end
@@ -234,7 +250,7 @@ describe HasStatus do
     describe '.alive' do
       subject { CommitStatus.alive }
 
-      %i[running pending created].each do |status|
+      %i[running pending preparing created].each do |status|
         it_behaves_like 'containing the job', status
       end
 
@@ -270,7 +286,7 @@ describe HasStatus do
     describe '.cancelable' do
       subject { CommitStatus.cancelable }
 
-      %i[running pending created scheduled].each do |status|
+      %i[running pending preparing created scheduled].each do |status|
         it_behaves_like 'containing the job', status
       end
 
diff --git a/spec/models/deployment_spec.rb b/spec/models/deployment_spec.rb
index a8d53cfcd7d..5fce9504334 100644
--- a/spec/models/deployment_spec.rb
+++ b/spec/models/deployment_spec.rb
@@ -356,4 +356,32 @@ describe Deployment do
       end
     end
   end
+
+  describe '#cluster' do
+    let(:deployment) { create(:deployment) }
+    let(:project) { deployment.project }
+    let(:environment) { deployment.environment }
+
+    subject { deployment.cluster }
+
+    before do
+      expect(project).to receive(:deployment_platform)
+        .with(environment: environment.name).and_call_original
+    end
+
+    context 'project has no deployment platform' do
+      before do
+        expect(project.clusters).to be_empty
+      end
+
+      it { is_expected.to be_nil }
+    end
+
+    context 'project has a deployment platform' do
+      let!(:cluster) { create(:cluster, projects: [project]) }
+      let!(:platform) { create(:cluster_platform_kubernetes, cluster: cluster) }
+
+      it { is_expected.to eq cluster }
+    end
+  end
 end
diff --git a/spec/requests/api/project_clusters_spec.rb b/spec/requests/api/project_clusters_spec.rb
index 9bab1f95150..4e42e233b4c 100644
--- a/spec/requests/api/project_clusters_spec.rb
+++ b/spec/requests/api/project_clusters_spec.rb
@@ -331,7 +331,6 @@ describe API::ProjectClusters do
 
         it 'should update cluster attributes' do
           expect(cluster.platform_kubernetes.namespace).to eq('new-namespace')
-          expect(cluster.kubernetes_namespace.namespace).to eq('new-namespace')
         end
       end
 
diff --git a/spec/requests/api/runner_spec.rb b/spec/requests/api/runner_spec.rb
index 9087cccb759..3ccedd8dd06 100644
--- a/spec/requests/api/runner_spec.rb
+++ b/spec/requests/api/runner_spec.rb
@@ -918,6 +918,15 @@ describe API::Runner, :clean_gitlab_redis_shared_state do
 
           it { expect(job).to be_job_execution_timeout }
         end
+
+        context 'when failure_reason is unmet_prerequisites' do
+          before do
+            update_job(state: 'failed', failure_reason: 'unmet_prerequisites')
+            job.reload
+          end
+
+          it { expect(job).to be_unmet_prerequisites }
+        end
       end
 
       context 'when trace is given' do
diff --git a/spec/services/ci/prepare_build_service_spec.rb b/spec/services/ci/prepare_build_service_spec.rb
new file mode 100644
index 00000000000..1797f8f964f
--- /dev/null
+++ b/spec/services/ci/prepare_build_service_spec.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Ci::PrepareBuildService do
+  describe '#execute' do
+    let(:build) { create(:ci_build, :preparing) }
+
+    subject { described_class.new(build).execute }
+
+    before do
+      allow(build).to receive(:prerequisites).and_return(prerequisites)
+    end
+
+    shared_examples 'build enqueueing' do
+      it 'enqueues the build' do
+        expect(build).to receive(:enqueue).once
+
+        subject
+      end
+    end
+
+    context 'build has unmet prerequisites' do
+      let(:prerequisite) { double(complete!: true) }
+      let(:prerequisites) { [prerequisite] }
+
+      it 'completes each prerequisite' do
+        expect(prerequisites).to all(receive(:complete!))
+
+        subject
+      end
+
+      include_examples 'build enqueueing'
+
+      context 'prerequisites fail to complete' do
+        before do
+          allow(build).to receive(:enqueue).and_return(false)
+        end
+
+        it 'drops the build' do
+          expect(build).to receive(:drop!).with(:unmet_prerequisites).once
+
+          subject
+        end
+      end
+    end
+
+    context 'build has no prerequisites' do
+      let(:prerequisites) { [] }
+
+      include_examples 'build enqueueing'
+    end
+  end
+end
diff --git a/spec/services/projects/create_service_spec.rb b/spec/services/projects/create_service_spec.rb
index d1b110b9806..e8418b09dc2 100644
--- a/spec/services/projects/create_service_spec.rb
+++ b/spec/services/projects/create_service_spec.rb
@@ -276,6 +276,7 @@ describe Projects::CreateService, '#execute' do
     before do
       group.add_owner(user)
 
+      stub_feature_flags(ci_preparing_state: false)
       expect(Clusters::Gcp::Kubernetes::CreateOrUpdateServiceAccountService).to receive(:namespace_creator).and_return(service_account_creator)
       expect(Clusters::Gcp::Kubernetes::FetchKubernetesTokenService).to receive(:new).and_return(secrets_fetcher)
     end
diff --git a/spec/services/projects/transfer_service_spec.rb b/spec/services/projects/transfer_service_spec.rb
index aae50d5307f..4efd360cb30 100644
--- a/spec/services/projects/transfer_service_spec.rb
+++ b/spec/services/projects/transfer_service_spec.rb
@@ -83,6 +83,7 @@ describe Projects::TransferService do
       subject { transfer_project(project, user, group) }
 
       before do
+        stub_feature_flags(ci_preparing_state: false)
         expect(Clusters::Gcp::Kubernetes::CreateOrUpdateServiceAccountService).to receive(:namespace_creator).and_return(service_account_creator)
         expect(Clusters::Gcp::Kubernetes::FetchKubernetesTokenService).to receive(:new).and_return(secrets_fetcher)
       end
diff --git a/spec/workers/ci/build_prepare_worker_spec.rb b/spec/workers/ci/build_prepare_worker_spec.rb
new file mode 100644
index 00000000000..9f76696ee66
--- /dev/null
+++ b/spec/workers/ci/build_prepare_worker_spec.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Ci::BuildPrepareWorker do
+  subject { described_class.new.perform(build_id) }
+
+  context 'build exists' do
+    let(:build) { create(:ci_build) }
+    let(:build_id) { build.id }
+    let(:service) { double(execute: true) }
+
+    it 'calls the prepare build service' do
+      expect(Ci::PrepareBuildService).to receive(:new).with(build).and_return(service)
+      expect(service).to receive(:execute).once
+
+      subject
+    end
+  end
+
+  context 'build does not exist' do
+    let(:build_id) { -1 }
+
+    it 'does not attempt to prepare the build' do
+      expect(Ci::PrepareBuildService).not_to receive(:new)
+
+      subject
+    end
+  end
+end
diff --git a/spec/workers/cluster_configure_worker_spec.rb b/spec/workers/cluster_configure_worker_spec.rb
index 6918ee3d7d8..83f76809435 100644
--- a/spec/workers/cluster_configure_worker_spec.rb
+++ b/spec/workers/cluster_configure_worker_spec.rb
@@ -4,6 +4,11 @@ require 'spec_helper'
 
 describe ClusterConfigureWorker, '#perform' do
   let(:worker) { described_class.new }
+  let(:ci_preparing_state_enabled) { false }
+
+  before do
+    stub_feature_flags(ci_preparing_state: ci_preparing_state_enabled)
+  end
 
   context 'when group cluster' do
     let(:cluster) { create(:cluster, :group, :provided_by_gcp) }
@@ -66,4 +71,15 @@ describe ClusterConfigureWorker, '#perform' do
       described_class.new.perform(123)
     end
   end
+
+  context 'ci_preparing_state feature is enabled' do
+    let(:cluster) { create(:cluster) }
+    let(:ci_preparing_state_enabled) { true }
+
+    it 'does not configure the cluster' do
+      expect(Clusters::RefreshService).not_to receive(:create_or_update_namespaces_for_cluster)
+
+      described_class.new.perform(cluster.id)
+    end
+  end
 end
diff --git a/spec/workers/cluster_project_configure_worker_spec.rb b/spec/workers/cluster_project_configure_worker_spec.rb
new file mode 100644
index 00000000000..afdea55adf4
--- /dev/null
+++ b/spec/workers/cluster_project_configure_worker_spec.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ClusterProjectConfigureWorker, '#perform' do
+  let(:worker) { described_class.new }
+
+  context 'ci_preparing_state feature is enabled' do
+    let(:cluster) { create(:cluster) }
+
+    before do
+      stub_feature_flags(ci_preparing_state: true)
+    end
+
+    it 'does not configure the cluster' do
+      expect(Clusters::RefreshService).not_to receive(:create_or_update_namespaces_for_project)
+
+      described_class.new.perform(cluster.id)
+    end
+  end
+end