# This is stripped down version of the .gitlab-ci.yml found
# here: https://gitlab.com/joshlambert/autodevops-deploy.
#
# It performs only the deploy stage.

image: alpine:latest

variables:
  # AUTO_DEVOPS_DOMAIN is the application deployment domain and should be set as a variable at the group or project level.
  AUTO_DEVOPS_DOMAIN: $AUTO_DEVOPS_DOMAIN

  POSTGRES_USER: user
  POSTGRES_PASSWORD: testing-password
  POSTGRES_ENABLED: 'false'
  POSTGRES_DB: $CI_ENVIRONMENT_SLUG

  KUBERNETES_VERSION: 1.11.6
  HELM_VERSION: 2.12.2

  DOCKER_DRIVER: overlay2

stages:
  - production

# This job continuously deploys to staging/production on every push to `master`.

production:
  stage: production
  script:
    - check_kube_domain
    - install_dependencies
    - download_chart
    - ensure_namespace
    - initialize_tiller
    - create_secret
    - deploy
    - persist_environment_url
  environment:
    name: production
    url: http://$CI_PROJECT_PATH_SLUG.$AUTO_DEVOPS_DOMAIN
  artifacts:
    paths: [environment_url.txt]
  only:
    refs:
      - master
    kubernetes: active

# ---------------------------------------------------------------------------

.auto_devops: &auto_devops |
  # Auto DevOps variables and functions
  [[ "$TRACE" ]] && set -x
  auto_database_url=postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${CI_ENVIRONMENT_SLUG}-postgres:5432/${POSTGRES_DB}
  export DATABASE_URL=${DATABASE_URL-$auto_database_url}
  export CI_APPLICATION_REPOSITORY=$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG
  export CI_APPLICATION_TAG=$CI_COMMIT_SHA
  export CI_CONTAINER_NAME=ci_job_build_${CI_JOB_ID}
  export TILLER_NAMESPACE=$KUBE_NAMESPACE
  # Extract "MAJOR.MINOR" from CI_SERVER_VERSION and generate "MAJOR-MINOR-stable" for Security Products
  export SP_VERSION=$(echo "$CI_SERVER_VERSION" | sed 's/^\([0-9]*\)\.\([0-9]*\).*/\1-\2-stable/')


  function get_replicas() {
    track="${1:-stable}"
    percentage="${2:-100}"

    env_track=$( echo $track | tr -s  '[:lower:]'  '[:upper:]' )
    env_slug=$( echo ${CI_ENVIRONMENT_SLUG//-/_} | tr -s  '[:lower:]'  '[:upper:]' )

    if [[ "$track" == "stable" ]] || [[ "$track" == "rollout" ]]; then
      # for stable track get number of replicas from `PRODUCTION_REPLICAS`
      eval new_replicas=\$${env_slug}_REPLICAS
      if [[ -z "$new_replicas" ]]; then
        new_replicas=$REPLICAS
      fi
    else
      # for all tracks get number of replicas from `CANARY_PRODUCTION_REPLICAS`
      eval new_replicas=\$${env_track}_${env_slug}_REPLICAS
      if [[ -z "$new_replicas" ]]; then
        eval new_replicas=\${env_track}_REPLICAS
      fi
    fi

    replicas="${new_replicas:-1}"
    replicas="$(($replicas * $percentage / 100))"

    # always return at least one replicas
    if [[ $replicas -gt 0 ]]; then
      echo "$replicas"
    else
      echo 1
    fi
  }


  # Extracts variables prefixed with K8S_SECRET_
  # and creates a Kubernetes secret.
  #
  # e.g. If we have the following environment variables:
  #   K8S_SECRET_A=value1
  #   K8S_SECRET_B=multi\ word\ value
  #
  # Then we will create a secret with the following key-value pairs:
  #   data:
  #     A: dmFsdWUxCg==
  #     B: bXVsdGkgd29yZCB2YWx1ZQo=
  function create_application_secret() {
    track="${1-stable}"
    export APPLICATION_SECRET_NAME=$(application_secret_name "$track")

    env | sed -n "s/^K8S_SECRET_\(.*\)$/\1/p" > k8s_prefixed_variables

    kubectl create secret \
      -n "$KUBE_NAMESPACE" generic "$APPLICATION_SECRET_NAME" \
      --from-env-file k8s_prefixed_variables -o yaml --dry-run |
      kubectl replace -n "$KUBE_NAMESPACE" --force -f -

    export APPLICATION_SECRET_CHECKSUM=$(cat k8s_prefixed_variables | sha256sum | cut -d ' ' -f 1)

    rm k8s_prefixed_variables
  }

  function deploy_name() {
    name="$CI_ENVIRONMENT_SLUG"
    track="${1-stable}"

    if [[ "$track" != "stable" ]]; then
      name="$name-$track"
    fi

    echo $name
  }

  function application_secret_name() {
    track="${1-stable}"
    name=$(deploy_name "$track")

    echo "${name}-secret"
  }


  function deploy() {
    track="${1-stable}"
    percentage="${2:-100}"
    name=$(deploy_name "$track")

    replicas="1"
    service_enabled="true"
    postgres_enabled="$POSTGRES_ENABLED"

    # if track is different than stable,
    # re-use all attached resources
    if [[ "$track" != "stable" ]]; then
      service_enabled="false"
      postgres_enabled="false"
    fi

    replicas=$(get_replicas "$track" "$percentage")

    if [[ "$CI_PROJECT_VISIBILITY" != "public" ]]; then
      secret_name='gitlab-registry'
    else
      secret_name=''
    fi

    create_application_secret "$track"

    env_slug=$(echo ${CI_ENVIRONMENT_SLUG//-/_} | tr -s '[:lower:]' '[:upper:]')
    eval env_ADDITIONAL_HOSTS=\$${env_slug}_ADDITIONAL_HOSTS
    if [ -n "$env_ADDITIONAL_HOSTS" ]; then
      additional_hosts="{$env_ADDITIONAL_HOSTS}"
    elif [ -n "$ADDITIONAL_HOSTS" ]; then
      additional_hosts="{$ADDITIONAL_HOSTS}"
    fi

    if [[ -n "$DB_INITIALIZE" && -z "$(helm ls -q "^$name$")" ]]; then
      echo "Deploying first release with database initialization..."
      helm upgrade --install \
        --wait \
        --set service.enabled="$service_enabled" \
        --set releaseOverride="$CI_ENVIRONMENT_SLUG" \
        --set image.repository="registry.gitlab.com/joshlambert/ruby-gke/master" \
        --set image.tag="63492726c2264a0277141d6a6573c3d22ecd7de3" \
        --set image.pullPolicy=IfNotPresent \
        --set image.secrets[0].name="$secret_name" \
        --set application.track="$track" \
        --set application.database_url="$DATABASE_URL" \
        --set application.secretName="$APPLICATION_SECRET_NAME" \
        --set application.secretChecksum="$APPLICATION_SECRET_CHECKSUM" \
        --set service.url="$CI_ENVIRONMENT_URL" \
        --set service.additionalHosts="$additional_hosts" \
        --set replicaCount="$replicas" \
        --set postgresql.enabled="$postgres_enabled" \
        --set postgresql.nameOverride="postgres" \
        --set postgresql.postgresUser="$POSTGRES_USER" \
        --set postgresql.postgresPassword="$POSTGRES_PASSWORD" \
        --set postgresql.postgresDatabase="$POSTGRES_DB" \
        --set application.initializeCommand="$DB_INITIALIZE" \
        --set gitlab.app="$CI_PROJECT_PATH_SLUG" \
        --set gitlab.env="$CI_ENVIRONMENT_SLUG" \
        --namespace="$KUBE_NAMESPACE" \
        "$name" \
        chart/

      echo "Deploying second release..."
      helm upgrade --reuse-values \
        --wait \
        --set application.initializeCommand="" \
        --set application.migrateCommand="$DB_MIGRATE" \
        --namespace="$KUBE_NAMESPACE" \
        "$name" \
        chart/
    else
      echo "Deploying new release..."
      helm upgrade --install \
        --wait \
        --set service.enabled="$service_enabled" \
        --set releaseOverride="$CI_ENVIRONMENT_SLUG" \
        --set image.repository="registry.gitlab.com/joshlambert/ruby-gke/master" \
        --set image.tag="63492726c2264a0277141d6a6573c3d22ecd7de3" \
        --set image.pullPolicy=IfNotPresent \
        --set image.secrets[0].name="$secret_name" \
        --set application.track="$track" \
        --set application.database_url="$DATABASE_URL" \
        --set application.secretName="$APPLICATION_SECRET_NAME" \
        --set application.secretChecksum="$APPLICATION_SECRET_CHECKSUM" \
        --set service.url="$CI_ENVIRONMENT_URL" \
        --set service.additionalHosts="$additional_hosts" \
        --set replicaCount="$replicas" \
        --set postgresql.enabled="$postgres_enabled" \
        --set postgresql.nameOverride="postgres" \
        --set postgresql.postgresUser="$POSTGRES_USER" \
        --set postgresql.postgresPassword="$POSTGRES_PASSWORD" \
        --set postgresql.postgresDatabase="$POSTGRES_DB" \
        --set application.migrateCommand="$DB_MIGRATE" \
        --set gitlab.app="$CI_PROJECT_PATH_SLUG" \
        --set gitlab.env="$CI_ENVIRONMENT_SLUG" \
        --namespace="$KUBE_NAMESPACE" \
        "$name" \
        chart/
    fi

    kubectl rollout status -n "$KUBE_NAMESPACE" -w "deployment/$name"
  }


  function install_dependencies() {
    apk add -U openssl curl tar gzip bash ca-certificates git
    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub
    wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.23-r3/glibc-2.23-r3.apk
    apk add glibc-2.23-r3.apk
    rm glibc-2.23-r3.apk

    curl "https://kubernetes-helm.storage.googleapis.com/helm-v${HELM_VERSION}-linux-amd64.tar.gz" | tar zx
    mv linux-amd64/helm /usr/bin/
    mv linux-amd64/tiller /usr/bin/
    helm version --client
    tiller -version

    curl -L -o /usr/bin/kubectl "https://storage.googleapis.com/kubernetes-release/release/v${KUBERNETES_VERSION}/bin/linux/amd64/kubectl"
    chmod +x /usr/bin/kubectl
    kubectl version --client
  }

  function download_chart() {
    if [[ ! -d chart ]]; then
      auto_chart=${AUTO_DEVOPS_CHART:-gitlab/auto-deploy-app}
      auto_chart_name=$(basename $auto_chart)
      auto_chart_name=${auto_chart_name%.tgz}
    else
      auto_chart="chart"
      auto_chart_name="chart"
    fi

    helm init --client-only
    helm repo add gitlab https://charts.gitlab.io
    if [[ ! -d "$auto_chart" ]]; then
      helm fetch ${auto_chart} --untar
    fi
    if [ "$auto_chart_name" != "chart" ]; then
      mv ${auto_chart_name} chart
    fi

    helm dependency update chart/
    helm dependency build chart/
  }

  function ensure_namespace() {
    kubectl describe namespace "$KUBE_NAMESPACE" || kubectl create namespace "$KUBE_NAMESPACE"
  }

  function check_kube_domain() {
    if [ -z ${AUTO_DEVOPS_DOMAIN+x} ]; then
      echo "In order to deploy or use Review Apps, AUTO_DEVOPS_DOMAIN variable must be set"
      echo "You can do it in Auto DevOps project settings or defining a secret variable at group or project level"
      echo "You can also manually add it in .gitlab-ci.yml"
      false
    else
      true
    fi
  }

  function initialize_tiller() {
    echo "Checking Tiller..."

    export HELM_HOST="localhost:44134"
    tiller -listen ${HELM_HOST} -alsologtostderr > /dev/null 2>&1 &
    echo "Tiller is listening on ${HELM_HOST}"

    if ! helm version --debug; then
     echo "Failed to init Tiller."
     return 1
    fi
    echo ""
  }

  function create_secret() {
    echo "Create secret..."
    if [[ "$CI_PROJECT_VISIBILITY" == "public" ]]; then
      return
    fi

    kubectl create secret -n "$KUBE_NAMESPACE" \
      docker-registry gitlab-registry \
      --docker-server="$CI_REGISTRY" \
      --docker-username="$CI_REGISTRY_USER" \
      --docker-password="$CI_REGISTRY_PASSWORD" \
      --docker-email="$GITLAB_USER_EMAIL" \
      -o yaml --dry-run | kubectl replace -n "$KUBE_NAMESPACE" --force -f -
  }

  function persist_environment_url() {
      echo $CI_ENVIRONMENT_URL > environment_url.txt
  }

before_script:
  - *auto_devops