Move ChatOps to Coremove_chatops_to_core

ChatOps used to be in the Ultimate tier.

38 files changed, 1231 insertions, 4 deletions

diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index acef5d2e643..cb61d2629ca 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -47,6 +47,8 @@ module Ci
     has_many :auto_canceled_pipelines, class_name: 'Ci::Pipeline', foreign_key: 'auto_canceled_by_id'
     has_many :auto_canceled_jobs, class_name: 'CommitStatus', foreign_key: 'auto_canceled_by_id'
 
+    has_one :chat_data, class_name: 'Ci::PipelineChatData'
+
     accepts_nested_attributes_for :variables, reject_if: :persisted?
 
     delegate :id, to: :project, prefix: true
diff --git a/app/models/ci/pipeline_chat_data.rb b/app/models/ci/pipeline_chat_data.rb
new file mode 100644
index 00000000000..8d37500fec5
--- /dev/null
+++ b/app/models/ci/pipeline_chat_data.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Ci
+  class PipelineChatData < ActiveRecord::Base
+    self.table_name = 'ci_pipeline_chat_data'
+
+    belongs_to :chat_name
+
+    validates :pipeline_id, presence: true
+    validates :chat_name_id, presence: true
+    validates :response_url, presence: true
+  end
+end
diff --git a/app/models/ci/pipeline_enums.rb b/app/models/ci/pipeline_enums.rb
index 2994aaae4aa..4be4fdb1ff2 100644
--- a/app/models/ci/pipeline_enums.rb
+++ b/app/models/ci/pipeline_enums.rb
@@ -22,6 +22,7 @@ module Ci
         schedule: 4,
         api: 5,
         external: 6,
+        chat: 8,
         merge_request: 10
       }
     end
diff --git a/app/models/project_services/deployment_service.rb b/app/models/project_services/deployment_service.rb
index 6dae4f3a4a6..80aa2101509 100644
--- a/app/models/project_services/deployment_service.rb
+++ b/app/models/project_services/deployment_service.rb
@@ -11,7 +11,7 @@ class DeploymentService < Service
     %w()
   end
 
-  def predefined_variables
+  def predefined_variables(project:)
     []
   end
 
diff --git a/app/models/project_services/slack_slash_commands_service.rb b/app/models/project_services/slack_slash_commands_service.rb
index 6c82e088231..6a454070fe2 100644
--- a/app/models/project_services/slack_slash_commands_service.rb
+++ b/app/models/project_services/slack_slash_commands_service.rb
@@ -22,6 +22,10 @@ class SlackSlashCommandsService < SlashCommandsService
     end
   end
 
+  def chat_responder
+    ::Gitlab::Chat::Responder::Slack
+  end
+
   private
 
   def format(text)
diff --git a/app/services/ci/create_pipeline_service.rb b/app/services/ci/create_pipeline_service.rb
index 699b3e8555e..cd06643f27f 100644
--- a/app/services/ci/create_pipeline_service.rb
+++ b/app/services/ci/create_pipeline_service.rb
@@ -36,6 +36,7 @@ module Ci
         project: project,
         current_user: current_user,
         push_options: params[:push_options],
+        chat_data: params[:chat_data],
         **extra_options(**options))
 
       sequence = Gitlab::Ci::Pipeline::Chain::Sequence
diff --git a/app/workers/all_queues.yml b/app/workers/all_queues.yml
index 85c123c2704..052c0ffc18e 100644
--- a/app/workers/all_queues.yml
+++ b/app/workers/all_queues.yml
@@ -100,6 +100,7 @@
 
 - authorized_projects
 - background_migration
+- chat_notification
 - create_gpg_signature
 - delete_merged_branches
 - delete_user
diff --git a/app/workers/build_finished_worker.rb b/app/workers/build_finished_worker.rb
index ae853ec9316..adc38226405 100644
--- a/app/workers/build_finished_worker.rb
+++ b/app/workers/build_finished_worker.rb
@@ -30,5 +30,6 @@ class BuildFinishedWorker
     # We execute these async as these are independent operations.
     BuildHooksWorker.perform_async(build.id)
     ArchiveTraceWorker.perform_async(build.id)
+    ChatNotificationWorker.perform_async(build.id) if build.pipeline.chat?
   end
 end
diff --git a/app/workers/chat_notification_worker.rb b/app/workers/chat_notification_worker.rb
new file mode 100644
index 00000000000..25a306e94d8
--- /dev/null
+++ b/app/workers/chat_notification_worker.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+class ChatNotificationWorker
+  include ApplicationWorker
+
+  RESCHEDULE_INTERVAL = 2.seconds
+
+  # rubocop: disable CodeReuse/ActiveRecord
+  def perform(build_id)
+    Ci::Build.find_by(id: build_id).try do |build|
+      send_response(build)
+    end
+  rescue Gitlab::Chat::Output::MissingBuildSectionError
+    # The creation of traces and sections appears to be eventually consistent.
+    # As a result it's possible for us to run the above code before the trace
+    # sections are present. To better handle such cases we'll just reschedule
+    # the job instead of producing an error.
+    self.class.perform_in(RESCHEDULE_INTERVAL, build_id)
+  end
+  # rubocop: enable CodeReuse/ActiveRecord
+
+  def send_response(build)
+    Gitlab::Chat::Responder.responder_for(build).try do |responder|
+      if build.success?
+        output = Gitlab::Chat::Output.new(build)
+
+        responder.success(output.to_s)
+      else
+        responder.failure
+      end
+    end
+  end
+end
diff --git a/changelogs/unreleased/move_chatops_to_core.yml b/changelogs/unreleased/move_chatops_to_core.yml
new file mode 100644
index 00000000000..7a75efedfa8
--- /dev/null
+++ b/changelogs/unreleased/move_chatops_to_core.yml
@@ -0,0 +1,5 @@
+---
+title: Move ChatOps to Core
+merge_request: 24780
+author:
+type: changed
diff --git a/config/sidekiq_queues.yml b/config/sidekiq_queues.yml
index 1e094c03171..90cd787d5ac 100644
--- a/config/sidekiq_queues.yml
+++ b/config/sidekiq_queues.yml
@@ -86,3 +86,4 @@
   - [delete_stored_files, 1]
   - [remote_mirror_notification, 2]
   - [import_issues_csv, 2]
+  - [chat_notification, 2]
diff --git a/lib/gitlab/chat/command.rb b/lib/gitlab/chat/command.rb
new file mode 100644
index 00000000000..49b7dcf4bbe
--- /dev/null
+++ b/lib/gitlab/chat/command.rb
@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Chat
+    # Class for scheduling chat pipelines.
+    #
+    # A Command takes care of creating a `Ci::Pipeline` with all the data
+    # necessary to execute a chat command. This includes data such as the chat
+    # data (e.g. the response URL) and any environment variables that should be
+    # exposed to the chat command.
+    class Command
+      include Utils::StrongMemoize
+
+      attr_reader :project, :chat_name, :name, :arguments, :response_url,
+                  :channel
+
+      # project - The Project to schedule the command for.
+      # chat_name - The ChatName belonging to the user that scheduled the
+      #             command.
+      # name - The name of the chat command to run.
+      # arguments - The arguments (as a String) to pass to the command.
+      # channel - The channel the message was sent from.
+      # response_url - The URL to send the response back to.
+      def initialize(project:, chat_name:, name:, arguments:, channel:, response_url:)
+        @project = project
+        @chat_name = chat_name
+        @name = name
+        @arguments = arguments
+        @channel = channel
+        @response_url = response_url
+      end
+
+      # Tries to create a new pipeline.
+      #
+      # This method will return a pipeline that _may_ be persisted, or `nil` if
+      # the pipeline could not be created.
+      def try_create_pipeline
+        return unless valid?
+
+        create_pipeline
+      end
+
+      def create_pipeline
+        service = ::Ci::CreatePipelineService.new(
+          project,
+          chat_name.user,
+          ref: branch,
+          sha: commit,
+          chat_data: {
+            chat_name_id: chat_name.id,
+            command: name,
+            arguments: arguments,
+            response_url: response_url
+          }
+        )
+
+        service.execute(:chat) do |pipeline|
+          build_environment_variables(pipeline)
+          build_chat_data(pipeline)
+        end
+      end
+
+      # pipeline - The `Ci::Pipeline` to create the environment variables for.
+      def build_environment_variables(pipeline)
+        pipeline.variables.build(
+          [{ key: 'CHAT_INPUT', value: arguments },
+           { key: 'CHAT_CHANNEL', value: channel }]
+        )
+      end
+
+      # pipeline - The `Ci::Pipeline` to create the chat data for.
+      def build_chat_data(pipeline)
+        pipeline.build_chat_data(
+          chat_name_id: chat_name.id,
+          response_url: response_url
+        )
+      end
+
+      def valid?
+        branch && commit
+      end
+
+      def branch
+        strong_memoize(:branch) { project.default_branch }
+      end
+
+      def commit
+        strong_memoize(:commit) do
+          project.commit(branch)&.id if branch
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat/output.rb b/lib/gitlab/chat/output.rb
new file mode 100644
index 00000000000..411b1555a7d
--- /dev/null
+++ b/lib/gitlab/chat/output.rb
@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Chat
+    # Class for gathering and formatting the output of a `Ci::Build`.
+    class Output
+      attr_reader :build
+
+      MissingBuildSectionError = Class.new(StandardError)
+
+      # The primary trace section to look for.
+      PRIMARY_SECTION = 'chat_reply'
+
+      # The backup trace section in case the primary one could not be found.
+      FALLBACK_SECTION = 'build_script'
+
+      # build - The `Ci::Build` to obtain the output from.
+      def initialize(build)
+        @build = build
+      end
+
+      # Returns a `String` containing the output of the build.
+      #
+      # The output _does not_ include the command that was executed.
+      def to_s
+        offset, length = read_offset_and_length
+
+        trace.read do |stream|
+          stream.seek(offset)
+
+          output = stream
+            .stream
+            .read(length)
+            .force_encoding(Encoding.default_external)
+
+          without_executed_command_line(output)
+        end
+      end
+
+      # Returns the offset to seek to and the number of bytes to read relative
+      # to the offset.
+      def read_offset_and_length
+        section = find_build_trace_section(PRIMARY_SECTION) ||
+          find_build_trace_section(FALLBACK_SECTION)
+
+        unless section
+          raise(
+            MissingBuildSectionError,
+            "The build_script trace section could not be found for build #{build.id}"
+          )
+        end
+
+        length = section[:byte_end] - section[:byte_start]
+
+        [section[:byte_start], length]
+      end
+
+      # Removes the line containing the executed command from the build output.
+      #
+      # output - A `String` containing the output of a trace section.
+      def without_executed_command_line(output)
+        # If `output.split("\n")` produces an empty Array then the slicing that
+        # follows it will produce a nil. For example:
+        #
+        #     "\n".split("\n")        # => []
+        #     "\n".split("\n")[1..-1] # => nil
+        #
+        # To work around this we only "join" if we're given an Array.
+        if (converted = output.split("\n")[1..-1])
+          converted.join("\n")
+        else
+          ''
+        end
+      end
+
+      # Returns the trace section for the given name, or `nil` if the section
+      # could not be found.
+      #
+      # name - The name of the trace section to find.
+      def find_build_trace_section(name)
+        trace_sections.find { |s| s[:name] == name }
+      end
+
+      def trace_sections
+        @trace_sections ||= trace.extract_sections
+      end
+
+      def trace
+        @trace ||= build.trace
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat/responder.rb b/lib/gitlab/chat/responder.rb
new file mode 100644
index 00000000000..6267fbc20e2
--- /dev/null
+++ b/lib/gitlab/chat/responder.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Chat
+    module Responder
+      # Returns an instance of the responder to use for generating chat
+      # responses.
+      #
+      # This method will return `nil` if no formatter is available for the given
+      # build.
+      #
+      # build - A `Ci::Build` that executed a chat command.
+      def self.responder_for(build)
+        service = build.pipeline.chat_data&.chat_name&.service
+
+        if (responder = service.try(:chat_responder))
+          responder.new(build)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat/responder/base.rb b/lib/gitlab/chat/responder/base.rb
new file mode 100644
index 00000000000..f1ad0e36793
--- /dev/null
+++ b/lib/gitlab/chat/responder/base.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Chat
+    module Responder
+      class Base
+        attr_reader :build
+
+        # build - The `Ci::Build` that was executed.
+        def initialize(build)
+          @build = build
+        end
+
+        def pipeline
+          build.pipeline
+        end
+
+        def project
+          pipeline.project
+        end
+
+        def success(*)
+          raise NotImplementedError, 'You must implement #success(output)'
+        end
+
+        def failure
+          raise NotImplementedError, 'You must implement #failure'
+        end
+
+        def send_response(output)
+          raise NotImplementedError, 'You must implement #send_response(output)'
+        end
+
+        def scheduled_output
+          raise NotImplementedError, 'You must implement #scheduled_output'
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat/responder/slack.rb b/lib/gitlab/chat/responder/slack.rb
new file mode 100644
index 00000000000..0cf02c92a67
--- /dev/null
+++ b/lib/gitlab/chat/responder/slack.rb
@@ -0,0 +1,80 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Chat
+    module Responder
+      class Slack < Responder::Base
+        SUCCESS_COLOR = '#B3ED8E'
+        FAILURE_COLOR = '#FF5640'
+        RESPONSE_TYPE = :in_channel
+
+        # Slack breaks messages apart if they're around 4 KB in size. We use a
+        # slightly smaller limit here to account for user mentions.
+        MESSAGE_SIZE_LIMIT = 3.5.kilobytes
+
+        # Sends a response back to Slack
+        #
+        # output - The output to send back to Slack, as a Hash.
+        def send_response(output)
+          Gitlab::HTTP.post(
+            pipeline.chat_data.response_url,
+            {
+              headers: { Accept: 'application/json' },
+              body: output.to_json
+            }
+          )
+        end
+
+        # Sends the output for a build that completed successfully.
+        #
+        # output - The output produced by the chat command.
+        def success(output)
+          return if output.empty?
+
+          send_response(
+            text: message_text(limit_output(output)),
+            response_type: RESPONSE_TYPE
+          )
+        end
+
+        # Sends the output for a build that failed.
+        def failure
+          send_response(
+            text: message_text("<#{build_url}|Sorry, the build failed!>"),
+            response_type: RESPONSE_TYPE
+          )
+        end
+
+        # Returns the output to send back after a command has been scheduled.
+        def scheduled_output
+          # We return an empty message so that Slack still shows the input
+          # command, without polluting the channel with standard "The job has
+          # been scheduled" (or similar) responses.
+          { text: '' }
+        end
+
+        private
+
+        def limit_output(output)
+          if output.bytesize <= MESSAGE_SIZE_LIMIT
+            output
+          else
+            "<#{build_url}|The output is too large to be sent back directly!>"
+          end
+        end
+
+        def mention_user
+          "<@#{pipeline.chat_data.chat_name.chat_id}>"
+        end
+
+        def message_text(output)
+          "#{mention_user}: #{output}"
+        end
+
+        def build_url
+          ::Gitlab::Routing.url_helpers.project_build_url(project, build)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/pipeline/chain/command.rb b/lib/gitlab/ci/pipeline/chain/command.rb
index e62d547d862..e4ed1424865 100644
--- a/lib/gitlab/ci/pipeline/chain/command.rb
+++ b/lib/gitlab/ci/pipeline/chain/command.rb
@@ -10,7 +10,8 @@ module Gitlab
           :origin_ref, :checkout_sha, :after_sha, :before_sha,
           :trigger_request, :schedule, :merge_request,
           :ignore_skip_ci, :save_incompleted,
-          :seeds_block, :variables_attributes, :push_options
+          :seeds_block, :variables_attributes, :push_options,
+          :chat_data
         ) do
           include Gitlab::Utils::StrongMemoize
 
diff --git a/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs.rb b/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs.rb
index 0f687a4ce9b..1e09b417311 100644
--- a/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs.rb
+++ b/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs.rb
@@ -6,7 +6,13 @@ module Gitlab
       module Chain
         class RemoveUnwantedChatJobs < Chain::Base
           def perform!
-            # to be overriden in EE
+            return unless pipeline.config_processor && pipeline.chat?
+
+            # When scheduling a chat pipeline we only want to run the build
+            # that matches the chat command.
+            pipeline.config_processor.jobs.select! do |name, _|
+              name.to_s == command.chat_data[:command].to_s
+            end
           end
 
           def break?
diff --git a/lib/gitlab/slash_commands/application_help.rb b/lib/gitlab/slash_commands/application_help.rb
new file mode 100644
index 00000000000..0ea7554ba64
--- /dev/null
+++ b/lib/gitlab/slash_commands/application_help.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module SlashCommands
+    class ApplicationHelp < BaseCommand
+      def initialize(params)
+        @params = params
+      end
+
+      def execute
+        Gitlab::SlashCommands::Presenters::Help.new(commands).present(trigger, params[:text])
+      end
+
+      private
+
+      def trigger
+        "#{params[:command]} [project name or alias]"
+      end
+
+      def commands
+        Gitlab::SlashCommands::Command.commands
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/slash_commands/command.rb b/lib/gitlab/slash_commands/command.rb
index 474c09b9c4d..7c963fcf38a 100644
--- a/lib/gitlab/slash_commands/command.rb
+++ b/lib/gitlab/slash_commands/command.rb
@@ -9,7 +9,8 @@ module Gitlab
           Gitlab::SlashCommands::IssueNew,
           Gitlab::SlashCommands::IssueSearch,
           Gitlab::SlashCommands::IssueMove,
-          Gitlab::SlashCommands::Deploy
+          Gitlab::SlashCommands::Deploy,
+          Gitlab::SlashCommands::Run
         ]
       end
 
diff --git a/lib/gitlab/slash_commands/presenters/error.rb b/lib/gitlab/slash_commands/presenters/error.rb
new file mode 100644
index 00000000000..442f8796338
--- /dev/null
+++ b/lib/gitlab/slash_commands/presenters/error.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module SlashCommands
+    module Presenters
+      class Error < Presenters::Base
+        def initialize(message)
+          @message = message
+        end
+
+        def message
+          ephemeral_response(text: @message)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/slash_commands/presenters/run.rb b/lib/gitlab/slash_commands/presenters/run.rb
new file mode 100644
index 00000000000..c4bbc231464
--- /dev/null
+++ b/lib/gitlab/slash_commands/presenters/run.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module SlashCommands
+    module Presenters
+      class Run < Presenters::Base
+        # rubocop: disable CodeReuse/ActiveRecord
+        def present(pipeline)
+          build = pipeline.builds.take
+
+          if build && (responder = Chat::Responder.responder_for(build))
+            in_channel_response(responder.scheduled_output)
+          else
+            unsupported_chat_service
+          end
+        end
+        # rubocop: enable CodeReuse/ActiveRecord
+
+        def unsupported_chat_service
+          ephemeral_response(text: 'Sorry, this chat service is currently not supported by GitLab ChatOps.')
+        end
+
+        def failed_to_schedule(command)
+          ephemeral_response(
+            text: 'The command could not be scheduled. Make sure that your ' \
+              'project has a .gitlab-ci.yml that defines a job with the ' \
+              "name #{command.inspect}"
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/slash_commands/run.rb b/lib/gitlab/slash_commands/run.rb
new file mode 100644
index 00000000000..78a2d531e96
--- /dev/null
+++ b/lib/gitlab/slash_commands/run.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module SlashCommands
+    # Slash command for triggering chatops jobs.
+    class Run < BaseCommand
+      def self.match(text)
+        /\Arun\s+(?<command>\S+)(\s+(?<arguments>.+))?\z/.match(text)
+      end
+
+      def self.help_message
+        'run <command> <arguments>'
+      end
+
+      def self.available?(project)
+        project.builds_enabled?
+      end
+
+      def self.allowed?(project, user)
+        can?(user, :create_pipeline, project)
+      end
+
+      def execute(match)
+        command = Chat::Command.new(
+          project: project,
+          chat_name: chat_name,
+          name: match[:command],
+          arguments: match[:arguments],
+          channel: params[:channel_id],
+          response_url: params[:response_url]
+        )
+
+        presenter = Gitlab::SlashCommands::Presenters::Run.new
+        pipeline = command.try_create_pipeline
+
+        if pipeline&.persisted?
+          presenter.present(pipeline)
+        else
+          presenter.failed_to_schedule(command.name)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/chat/command_spec.rb b/spec/lib/gitlab/chat/command_spec.rb
new file mode 100644
index 00000000000..46d23ab2b62
--- /dev/null
+++ b/spec/lib/gitlab/chat/command_spec.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Chat::Command do
+  let(:chat_name) { create(:chat_name) }
+
+  let(:command) do
+    described_class.new(
+      project: project,
+      chat_name: chat_name,
+      name: 'spinach',
+      arguments: 'foo',
+      channel: '123',
+      response_url: 'http://example.com'
+    )
+  end
+
+  describe '#try_create_pipeline' do
+    let(:project) { create(:project) }
+
+    it 'returns nil when the command is not valid' do
+      expect(command)
+        .to receive(:valid?)
+        .and_return(false)
+
+      expect(command.try_create_pipeline).to be_nil
+    end
+
+    it 'tries to create the pipeline when a command is valid' do
+      expect(command)
+        .to receive(:valid?)
+        .and_return(true)
+
+      expect(command)
+        .to receive(:create_pipeline)
+
+      command.try_create_pipeline
+    end
+  end
+
+  describe '#create_pipeline' do
+    let(:project) { create(:project, :test_repo) }
+    let(:pipeline) { command.create_pipeline }
+
+    before do
+      stub_repository_ci_yaml_file(sha: project.commit.id)
+
+      project.add_developer(chat_name.user)
+    end
+
+    it 'creates the pipeline' do
+      expect(pipeline).to be_persisted
+    end
+
+    it 'creates the chat data for the pipeline' do
+      expect(pipeline.chat_data).to be_an_instance_of(Ci::PipelineChatData)
+    end
+
+    it 'stores the chat name ID in the chat data' do
+      expect(pipeline.chat_data.chat_name_id).to eq(chat_name.id)
+    end
+
+    it 'stores the response URL in the chat data' do
+      expect(pipeline.chat_data.response_url).to eq('http://example.com')
+    end
+
+    it 'creates the environment variables for the pipeline' do
+      vars = pipeline.variables.each_with_object({}) do |row, hash|
+        hash[row.key] = row.value
+      end
+
+      expect(vars['CHAT_INPUT']).to eq('foo')
+      expect(vars['CHAT_CHANNEL']).to eq('123')
+    end
+  end
+end
diff --git a/spec/lib/gitlab/chat/output_spec.rb b/spec/lib/gitlab/chat/output_spec.rb
new file mode 100644
index 00000000000..b179f9e9d0a
--- /dev/null
+++ b/spec/lib/gitlab/chat/output_spec.rb
@@ -0,0 +1,101 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Chat::Output do
+  let(:build) do
+    create(:ci_build, pipeline: create(:ci_pipeline, source: :chat))
+  end
+
+  let(:output) { described_class.new(build) }
+
+  describe '#to_s' do
+    it 'returns the build output as a String' do
+      trace = Gitlab::Ci::Trace.new(build)
+
+      trace.set("echo hello\nhello")
+
+      allow(build)
+        .to receive(:trace)
+        .and_return(trace)
+
+      allow(output)
+        .to receive(:read_offset_and_length)
+        .and_return([0, 13])
+
+      expect(output.to_s).to eq('he')
+    end
+  end
+
+  describe '#read_offset_and_length' do
+    context 'without the chat_reply trace section' do
+      it 'falls back to using the build_script trace section' do
+        expect(output)
+          .to receive(:find_build_trace_section)
+          .with('chat_reply')
+          .and_return(nil)
+
+        expect(output)
+          .to receive(:find_build_trace_section)
+          .with('build_script')
+          .and_return({ name: 'build_script', byte_start: 1, byte_end: 4 })
+
+        expect(output.read_offset_and_length).to eq([1, 3])
+      end
+    end
+
+    context 'without the build_script trace section' do
+      it 'raises MissingBuildSectionError' do
+        expect { output.read_offset_and_length }
+          .to raise_error(described_class::MissingBuildSectionError)
+      end
+    end
+
+    context 'with the chat_reply trace section' do
+      it 'returns the read offset and length as an Array' do
+        trace = Gitlab::Ci::Trace.new(build)
+
+        allow(build)
+          .to receive(:trace)
+          .and_return(trace)
+
+        allow(trace)
+          .to receive(:extract_sections)
+          .and_return([{ name: 'chat_reply', byte_start: 1, byte_end: 4 }])
+
+        expect(output.read_offset_and_length).to eq([1, 3])
+      end
+    end
+  end
+
+  describe '#without_executed_command_line' do
+    it 'returns the input without the first line' do
+      expect(output.without_executed_command_line("hello\nworld"))
+        .to eq('world')
+    end
+
+    it 'returns an empty String when the input is empty' do
+      expect(output.without_executed_command_line('')).to eq('')
+    end
+
+    it 'returns an empty String when the input consits of a single newline' do
+      expect(output.without_executed_command_line("\n")).to eq('')
+    end
+  end
+
+  describe '#find_build_trace_section' do
+    it 'returns nil when no section could be found' do
+      expect(output.find_build_trace_section('foo')).to be_nil
+    end
+
+    it 'returns the trace section when it could be found' do
+      section = { name: 'chat_reply', byte_start: 1, byte_end: 4 }
+
+      allow(output)
+        .to receive(:trace_sections)
+        .and_return([section])
+
+      expect(output.find_build_trace_section('chat_reply')).to eq(section)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/chat/responder/base_spec.rb b/spec/lib/gitlab/chat/responder/base_spec.rb
new file mode 100644
index 00000000000..7fa9bad9d38
--- /dev/null
+++ b/spec/lib/gitlab/chat/responder/base_spec.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Chat::Responder::Base do
+  let(:project) { double(:project) }
+  let(:pipeline) { double(:pipeline, project: project) }
+  let(:build) { double(:build, pipeline: pipeline) }
+  let(:responder) { described_class.new(build) }
+
+  describe '#pipeline' do
+    it 'returns the pipeline' do
+      expect(responder.pipeline).to eq(pipeline)
+    end
+  end
+
+  describe '#project' do
+    it 'returns the project' do
+      expect(responder.project).to eq(project)
+    end
+  end
+
+  describe '#success' do
+    it 'raises NotImplementedError' do
+      expect { responder.success }.to raise_error(NotImplementedError)
+    end
+  end
+
+  describe '#failure' do
+    it 'raises NotImplementedError' do
+      expect { responder.failure }.to raise_error(NotImplementedError)
+    end
+  end
+
+  describe '#send_response' do
+    it 'raises NotImplementedError' do
+      expect { responder.send_response('hello') }
+        .to raise_error(NotImplementedError)
+    end
+  end
+
+  describe '#scheduled_output' do
+    it 'raises NotImplementedError' do
+      expect { responder.scheduled_output }
+        .to raise_error(NotImplementedError)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/chat/responder/slack_spec.rb b/spec/lib/gitlab/chat/responder/slack_spec.rb
new file mode 100644
index 00000000000..a1553232b32
--- /dev/null
+++ b/spec/lib/gitlab/chat/responder/slack_spec.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Chat::Responder::Slack do
+  let(:chat_name) { create(:chat_name, chat_id: 'U123') }
+
+  let(:pipeline) do
+    pipeline = create(:ci_pipeline)
+
+    pipeline.create_chat_data!(
+      response_url: 'http://example.com',
+      chat_name_id: chat_name.id
+    )
+
+    pipeline
+  end
+
+  let(:build) { create(:ci_build, pipeline: pipeline) }
+  let(:responder) { described_class.new(build) }
+
+  describe '#send_response' do
+    it 'sends a response back to Slack' do
+      expect(Gitlab::HTTP).to receive(:post).with(
+        'http://example.com',
+        { headers: { Accept: 'application/json' }, body: 'hello'.to_json }
+      )
+
+      responder.send_response('hello')
+    end
+  end
+
+  describe '#success' do
+    it 'returns the output for a successful build' do
+      expect(responder)
+        .to receive(:send_response)
+        .with(hash_including(text: /<@U123>:.+hello/, response_type: :in_channel))
+
+      responder.success('hello')
+    end
+
+    it 'limits the output to a fixed size' do
+      expect(responder)
+        .to receive(:send_response)
+        .with(hash_including(text: /The output is too large/))
+
+      responder.success('a' * 4000)
+    end
+
+    it 'does not send a response if the output is empty' do
+      expect(responder).not_to receive(:send_response)
+
+      responder.success('')
+    end
+  end
+
+  describe '#failure' do
+    it 'returns the output for a failed build' do
+      expect(responder).to receive(:send_response).with(
+        hash_including(
+          text: /<@U123>:.+Sorry, the build failed!/,
+          response_type: :in_channel
+        )
+      )
+
+      responder.failure
+    end
+  end
+
+  describe '#scheduled_output' do
+    it 'returns the output for a scheduled build' do
+      output = responder.scheduled_output
+
+      expect(output).to eq({ text: '' })
+    end
+  end
+end
diff --git a/spec/lib/gitlab/chat/responder_spec.rb b/spec/lib/gitlab/chat/responder_spec.rb
new file mode 100644
index 00000000000..9893689cba9
--- /dev/null
+++ b/spec/lib/gitlab/chat/responder_spec.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Chat::Responder do
+  describe '.responder_for' do
+    context 'using a regular build' do
+      it 'returns nil' do
+        build = create(:ci_build)
+
+        expect(described_class.responder_for(build)).to be_nil
+      end
+    end
+
+    context 'using a chat build' do
+      it 'returns the responder for the build' do
+        pipeline = create(:ci_pipeline)
+        build = create(:ci_build, pipeline: pipeline)
+        service = double(:service, chat_responder: Gitlab::Chat::Responder::Slack)
+        chat_name = double(:chat_name, service: service)
+        chat_data = double(:chat_data, chat_name: chat_name)
+
+        allow(pipeline)
+          .to receive(:chat_data)
+          .and_return(chat_data)
+
+        expect(described_class.responder_for(build))
+          .to be_an_instance_of(Gitlab::Chat::Responder::Slack)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs_spec.rb b/spec/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs_spec.rb
new file mode 100644
index 00000000000..7c1c016b4bb
--- /dev/null
+++ b/spec/lib/gitlab/ci/pipeline/chain/remove_unwanted_chat_jobs_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Ci::Pipeline::Chain::RemoveUnwantedChatJobs do
+  let(:project) { create(:project, :repository) }
+
+  let(:pipeline) do
+    build(:ci_pipeline_with_one_job, project: project, ref: 'master')
+  end
+
+  let(:command) do
+    double(:command, project: project, chat_data: { command: 'echo' })
+  end
+
+  describe '#perform!' do
+    it 'removes unwanted jobs for chat pipelines' do
+      allow(pipeline).to receive(:chat?).and_return(true)
+
+      pipeline.config_processor.jobs[:echo] = double(:job)
+
+      described_class.new(pipeline, command).perform!
+
+      expect(pipeline.config_processor.jobs.keys).to eq([:echo])
+    end
+  end
+
+  it 'does not remove any jobs for non-chat pipelines' do
+    described_class.new(pipeline, command).perform!
+
+    expect(pipeline.config_processor.jobs.keys).to eq([:rspec])
+  end
+end
diff --git a/spec/lib/gitlab/import_export/all_models.yml b/spec/lib/gitlab/import_export/all_models.yml
index 6897ac8a3a8..c7e7dcde68b 100644
--- a/spec/lib/gitlab/import_export/all_models.yml
+++ b/spec/lib/gitlab/import_export/all_models.yml
@@ -131,6 +131,7 @@ ci_pipelines:
 - merge_request
 - deployments
 - environments
+- chat_data
 pipeline_variables:
 - pipeline
 stages:
diff --git a/spec/lib/gitlab/slash_commands/application_help_spec.rb b/spec/lib/gitlab/slash_commands/application_help_spec.rb
new file mode 100644
index 00000000000..b203a1ee79c
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/application_help_spec.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::ApplicationHelp do
+  let(:params) { { command: '/gitlab', text: 'help' } }
+
+  describe '#execute' do
+    subject do
+      described_class.new(params).execute
+    end
+
+    it 'displays the help section' do
+      expect(subject[:response_type]).to be(:ephemeral)
+      expect(subject[:text]).to include('Available commands')
+      expect(subject[:text]).to include('/gitlab [project name or alias] issue show')
+    end
+  end
+end
diff --git a/spec/lib/gitlab/slash_commands/presenters/error_spec.rb b/spec/lib/gitlab/slash_commands/presenters/error_spec.rb
new file mode 100644
index 00000000000..30ff81510c1
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/presenters/error_spec.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::Presenters::Error do
+  subject { described_class.new('Error').message }
+
+  it { is_expected.to be_a(Hash) }
+
+  it 'shows the error message' do
+    expect(subject[:response_type]).to be(:ephemeral)
+    expect(subject[:status]).to eq(200)
+    expect(subject[:text]).to eq('Error')
+  end
+end
diff --git a/spec/lib/gitlab/slash_commands/presenters/run_spec.rb b/spec/lib/gitlab/slash_commands/presenters/run_spec.rb
new file mode 100644
index 00000000000..f3ab01ef6bb
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/presenters/run_spec.rb
@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::Presenters::Run do
+  let(:presenter) { described_class.new }
+
+  describe '#present' do
+    context 'when no builds are present' do
+      it 'returns an error' do
+        builds = double(:builds, take: nil)
+        pipeline = double(:pipeline, builds: builds)
+
+        expect(presenter)
+          .to receive(:unsupported_chat_service)
+
+        presenter.present(pipeline)
+      end
+    end
+
+    context 'when a responder could be found' do
+      it 'returns the output for a scheduled pipeline' do
+        responder = double(:responder, scheduled_output: 'hello')
+        build = double(:build)
+        builds = double(:builds, take: build)
+        pipeline = double(:pipeline, builds: builds)
+
+        allow(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(build)
+          .and_return(responder)
+
+        expect(presenter)
+          .to receive(:in_channel_response)
+          .with('hello')
+
+        presenter.present(pipeline)
+      end
+    end
+
+    context 'when a responder could not be found' do
+      it 'returns an error' do
+        build = double(:build)
+        builds = double(:builds, take: build)
+        pipeline = double(:pipeline, builds: builds)
+
+        allow(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(build)
+          .and_return(nil)
+
+        expect(presenter)
+          .to receive(:unsupported_chat_service)
+
+        presenter.present(pipeline)
+      end
+    end
+  end
+
+  describe '#unsupported_chat_service' do
+    it 'returns an ephemeral response' do
+      expect(presenter)
+        .to receive(:ephemeral_response)
+        .with(text: /Sorry, this chat service is currently not supported/)
+
+      presenter.unsupported_chat_service
+    end
+  end
+
+  describe '#failed_to_schedule' do
+    it 'returns an ephemeral response' do
+      expect(presenter)
+        .to receive(:ephemeral_response)
+        .with(text: /The command could not be scheduled/)
+
+      presenter.failed_to_schedule('foo')
+    end
+  end
+end
diff --git a/spec/lib/gitlab/slash_commands/run_spec.rb b/spec/lib/gitlab/slash_commands/run_spec.rb
new file mode 100644
index 00000000000..ca3df57c1ca
--- /dev/null
+++ b/spec/lib/gitlab/slash_commands/run_spec.rb
@@ -0,0 +1,109 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::SlashCommands::Run do
+  describe '.available?' do
+    it 'returns true when builds are enabled for the project' do
+      project = double(:project, builds_enabled?: true)
+
+      expect(described_class.available?(project)).to eq(true)
+    end
+
+    it 'returns false when builds are disabled for the project' do
+      project = double(:project, builds_enabled?: false)
+
+      expect(described_class.available?(project)).to eq(false)
+    end
+  end
+
+  describe '.allowed?' do
+    it 'returns true when the user can create a pipeline' do
+      project = create(:project)
+
+      expect(described_class.allowed?(project, project.creator)).to eq(true)
+    end
+
+    it 'returns false when the user can not create a pipeline' do
+      project = create(:project)
+      user = create(:user)
+
+      expect(described_class.allowed?(project, user)).to eq(false)
+    end
+  end
+
+  describe '#execute' do
+    let(:chat_name) { create(:chat_name) }
+    let(:project) { create(:project) }
+
+    let(:command) do
+      described_class.new(project, chat_name, response_url: 'http://example.com')
+    end
+
+    context 'when a pipeline could not be scheduled' do
+      it 'returns an error' do
+        expect_any_instance_of(Gitlab::Chat::Command)
+          .to receive(:try_create_pipeline)
+          .and_return(nil)
+
+        expect_any_instance_of(Gitlab::SlashCommands::Presenters::Run)
+          .to receive(:failed_to_schedule)
+          .with('foo')
+
+        command.execute(command: 'foo', arguments: '')
+      end
+    end
+
+    context 'when a pipeline could be created but the chat service was not supported' do
+      it 'returns an error' do
+        build = double(:build)
+        pipeline = double(
+          :pipeline,
+          builds: double(:relation, take: build),
+          persisted?: true
+        )
+
+        expect_any_instance_of(Gitlab::Chat::Command)
+          .to receive(:try_create_pipeline)
+          .and_return(pipeline)
+
+        expect(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(build)
+          .and_return(nil)
+
+        expect_any_instance_of(Gitlab::SlashCommands::Presenters::Run)
+          .to receive(:unsupported_chat_service)
+
+        command.execute(command: 'foo', arguments: '')
+      end
+    end
+
+    context 'using a valid pipeline' do
+      it 'schedules the pipeline' do
+        responder = double(:responder, scheduled_output: 'hello')
+        build = double(:build)
+        pipeline = double(
+          :pipeline,
+          builds: double(:relation, take: build),
+          persisted?: true
+        )
+
+        expect_any_instance_of(Gitlab::Chat::Command)
+          .to receive(:try_create_pipeline)
+          .and_return(pipeline)
+
+        expect(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(build)
+          .and_return(responder)
+
+        expect_any_instance_of(Gitlab::SlashCommands::Presenters::Run)
+          .to receive(:in_channel_response)
+          .with(responder.scheduled_output)
+
+        command.execute(command: 'foo', arguments: '')
+      end
+    end
+  end
+end
diff --git a/spec/models/ci/pipeline_spec.rb b/spec/models/ci/pipeline_spec.rb
index 72a0df96a80..39d47ce0c2a 100644
--- a/spec/models/ci/pipeline_spec.rb
+++ b/spec/models/ci/pipeline_spec.rb
@@ -22,6 +22,7 @@ describe Ci::Pipeline, :mailer do
   it { is_expected.to have_many(:builds) }
   it { is_expected.to have_many(:auto_canceled_pipelines) }
   it { is_expected.to have_many(:auto_canceled_jobs) }
+  it { is_expected.to have_one(:chat_data) }
 
   it { is_expected.to validate_presence_of(:sha) }
   it { is_expected.to validate_presence_of(:status) }
diff --git a/spec/models/project_services/slack_slash_commands_service_spec.rb b/spec/models/project_services/slack_slash_commands_service_spec.rb
index 0d95f454819..5c4bce90ace 100644
--- a/spec/models/project_services/slack_slash_commands_service_spec.rb
+++ b/spec/models/project_services/slack_slash_commands_service_spec.rb
@@ -38,4 +38,11 @@ describe SlackSlashCommandsService do
       end
     end
   end
+
+  describe '#chat_responder' do
+    it 'returns the responder to use for Slack' do
+      expect(described_class.new.chat_responder)
+        .to eq(Gitlab::Chat::Responder::Slack)
+    end
+  end
 end
diff --git a/spec/workers/build_finished_worker_spec.rb b/spec/workers/build_finished_worker_spec.rb
index acd8da11d8d..ccb26849e67 100644
--- a/spec/workers/build_finished_worker_spec.rb
+++ b/spec/workers/build_finished_worker_spec.rb
@@ -26,5 +26,24 @@ describe BuildFinishedWorker do
           .not_to raise_error
       end
     end
+
+    it 'schedules a ChatNotification job for a chat build' do
+      build = create(:ci_build, :success, pipeline: create(:ci_pipeline, source: :chat))
+
+      expect(ChatNotificationWorker)
+        .to receive(:perform_async)
+        .with(build.id)
+
+      described_class.new.perform(build.id)
+    end
+
+    it 'does not schedule a ChatNotification job for a regular build' do
+      build = create(:ci_build, :success, pipeline: create(:ci_pipeline))
+
+      expect(ChatNotificationWorker)
+        .not_to receive(:perform_async)
+
+      described_class.new.perform(build.id)
+    end
   end
 end
diff --git a/spec/workers/chat_notification_worker_spec.rb b/spec/workers/chat_notification_worker_spec.rb
new file mode 100644
index 00000000000..91695674f5d
--- /dev/null
+++ b/spec/workers/chat_notification_worker_spec.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ChatNotificationWorker do
+  let(:worker) { described_class.new }
+  let(:chat_build) do
+    create(:ci_build, pipeline: create(:ci_pipeline, source: :chat))
+  end
+
+  describe '#perform' do
+    it 'does nothing when the build no longer exists' do
+      expect(worker).not_to receive(:send_response)
+
+      worker.perform(-1)
+    end
+
+    it 'sends a response for an existing build' do
+      expect(worker)
+        .to receive(:send_response)
+        .with(an_instance_of(Ci::Build))
+
+      worker.perform(chat_build.id)
+    end
+
+    it 'reschedules the job if the trace sections could not be found' do
+      expect(worker)
+        .to receive(:send_response)
+        .and_raise(Gitlab::Chat::Output::MissingBuildSectionError)
+
+      expect(described_class)
+        .to receive(:perform_in)
+        .with(described_class::RESCHEDULE_INTERVAL, chat_build.id)
+
+      worker.perform(chat_build.id)
+    end
+  end
+
+  describe '#send_response' do
+    context 'when a responder could not be found' do
+      it 'does nothing' do
+        expect(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(chat_build)
+          .and_return(nil)
+
+        expect(worker.send_response(chat_build)).to be_nil
+      end
+    end
+
+    context 'when a responder could be found' do
+      let(:responder) { double(:responder) }
+
+      before do
+        allow(Gitlab::Chat::Responder)
+          .to receive(:responder_for)
+          .with(chat_build)
+          .and_return(responder)
+      end
+
+      it 'sends the response for a succeeded build' do
+        output = double(:output, to_s: 'this is the build output')
+
+        expect(chat_build)
+          .to receive(:success?)
+          .and_return(true)
+
+        expect(responder)
+          .to receive(:success)
+          .with(an_instance_of(String))
+
+        expect(Gitlab::Chat::Output)
+          .to receive(:new)
+          .with(chat_build)
+          .and_return(output)
+
+        worker.send_response(chat_build)
+      end
+
+      it 'sends the response for a failed build' do
+        expect(chat_build)
+          .to receive(:success?)
+          .and_return(false)
+
+        expect(responder).to receive(:failure)
+
+        worker.send_response(chat_build)
+      end
+    end
+  end
+end