action.yml

name: Create PR Preview
description: 'Spins up an Ephemeral Instance for a PR Preview'

inputs:
  github-token:
    description: 'Github token used to create PR comments'
    required: true
  localstack-api-key:
    description: 'LocalStack Auth Token used to create the preview environment'
    required: false
  preview-cmd:
    description: 'Command(s) used to create a preview of the PR (can use $AWS_ENDPOINT_URL)'
    required: false
    default: ''
  auto-load-pod:
    description: 'The pod to load on startup of LocalStack, the env var AUTO_LOAD_POD'
    required: false
    default: ''
  extension-auto-install:
    description: 'The extension(s) to automatically install on startup of LocalStack, the env var EXTENSION_AUTO_INSTALL'
    required: false
    default: ''
  lifetime:
    description: 'The lifetime of the ephemeral instance, how long the instance should be available for'
    required: false
    default: '30'
  

runs:
  using: composite
  steps:
    - name: Initial PR comment
      if: inputs.github-token
      uses: jenseng/dynamic-uses@5175289a9a87978dcfcb9cf512b821d23b2a53eb # v1
      with:
        uses: ${{ env.GH_ACTION_ROOT }}/prepare
        with: |-
          {
            "github-token": ${{ toJSON(inputs.github-token) }}
          }

    - name: Download PR artifact
      uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
      with:
        name: pr-id

    - name: Setup preview name
      shell: bash
      id: preview-name
      run: |
        prId=$(<pr-id.txt)
        repoName=$GITHUB_REPOSITORY
        repoNameCleaned=$(echo -n "$repoName" | tr -c '[:alnum:]' '-')
        previewName=preview-$repoNameCleaned-$prId
        echo "previewName=$previewName" >> $GITHUB_ENV
        echo "name=$previewName" >> $GITHUB_OUTPUT

    - name: Create preview environment
      shell: bash
      id: create-instance
      run: |
        AUTH_HEADER="ls-api-key: ${LOCALSTACK_AUTH_TOKEN:-${LOCALSTACK_API_KEY:-${{ inputs.localstack-api-key }}}}"
        CONTENT_TYPE_HEADER="content-type: application/json"
        API_URL_BASE="https://api.localstack.cloud/v1/compute/instances"

        source ${{ github.action_path }}/../retry-function.sh

        fetch_instances() {
            local list_response
            list_response=$(curl --fail-with-body -s -X GET \
              -H "$AUTH_HEADER" \
              -H "$CONTENT_TYPE_HEADER" \
              "$API_URL_BASE")
            if [ $? -ne 0 ]; then echo "curl command failed while fetching instances. Response: $list_response" >&2; return 1; fi
            if ! check_for_api_error "$list_response" "fetch instances"; then return 1; fi
            echo "$list_response"
        }

        if ! list_response=$(retry fetch_instances); then
          echo "Error: Failed to fetch instances after multiple retries."
          exit 1
        fi

        autoLoadPod="${AUTO_LOAD_POD:-${{ inputs.auto-load-pod }}}"
        extensionAutoInstall="${EXTENSION_AUTO_INSTALL:-${{ inputs.extension-auto-install }}}"
        lifetime="${{ inputs.lifetime }}"

        instance_exists=$(echo "$list_response" | jq --arg NAME "$previewName" '.[] | select(.instance_name == $NAME)')

        delete_instance() {
            # We expect a 200 on success or 404 if it's already gone. Other codes are errors.
            local response
            response=$(curl --fail-with-body -s -w "\n%{http_code}" -X DELETE \
                -H "$AUTH_HEADER" \
                -H "$CONTENT_TYPE_HEADER" \
                "$API_URL_BASE/$previewName")
            local exit_code=$?
            local http_code=$(echo "$response" | tail -n1)
            local body=$(echo "$response" | sed '$d')

            if [ $exit_code -ne 0 ]; then echo "curl command failed while deleting instance. Response: $body" >&2; return 1; fi
            if ! check_for_api_error "$body" "delete instance"; then return 1; fi

            if [ "$http_code" -eq 200 ]; then
                echo "Instance '$previewName' deleted successfully."
            fi
        }

        if [ -n "$instance_exists" ]; then
          echo "Found existing instance using '$previewName', trying to delete the old one..."
          if ! retry delete_instance; then
            echo "Error: Failed to delete existing instance after multiple retries."
            exit 1
          fi
        fi

        create_instance_func() {
            local response
            response=$(curl --fail-with-body -s -X POST -d "{\"instance_name\": \"${previewName}\", \"lifetime\": ${lifetime} ,\"env_vars\": {\"AUTO_LOAD_POD\": \"${autoLoadPod}\", \"EXTENSION_AUTO_INSTALL\": \"${extensionAutoInstall}\"}}"\
                -H "$AUTH_HEADER" \
                -H "$CONTENT_TYPE_HEADER" \
                "$API_URL_BASE")
            if [ $? -ne 0 ]; then echo "curl command failed while creating instance. Response: $response" >&2; return 1; fi
            if ! check_for_api_error "$response" "create instance"; then return 1; fi
            if ! echo "$response" | jq -e 'has("endpoint_url") and (.endpoint_url | test(".+"))' > /dev/null; then
              echo "Invalid response from instance creation API: $response" >&2; return 1;
            fi
            echo "$response"
        }

        echo "Creating preview environment ..."
        if ! response=$(retry create_instance_func); then
          echo "Error: Failed to create preview environment after multiple retries."
          exit 1
        fi
        
        endpointUrl=$(echo "$response" | jq -r .endpoint_url)

        echo "Created preview environment with endpoint URL: $endpointUrl"

        echo $endpointUrl > ./ls-preview-url.txt
        echo "LS_PREVIEW_URL=$endpointUrl" >> $GITHUB_ENV
        echo "AWS_ENDPOINT_URL=$endpointUrl" >> $GITHUB_ENV

    - name: Upload preview instance URL
      uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
      with:
        name: preview-instance-url
        path: ./ls-preview-url.txt

    - name: Run preview deployment
      if: ${{ inputs.preview-cmd != '' }}
      shell: bash
      run: |
        ${{ inputs.preview-cmd }}

    - name: Print logs of ephemeral instance
      if: ${{ !cancelled() && steps.create-instance.outcome == 'success' }}
      shell: bash
      env:
        previewName: ${{ steps.preview-name.outputs.name }}
      run: |
        AUTH_HEADER="ls-api-key: ${LOCALSTACK_AUTH_TOKEN:-${LOCALSTACK_API_KEY:-${{ inputs.localstack-api-key }}}}"
        CONTENT_TYPE_HEADER="content-type: application/json"
        API_URL_BASE="https://api.localstack.cloud/v1/compute/instances"

        source ${{ github.action_path }}/../retry-function.sh
        fetch_logs() {
            local log_response
            log_response=$(curl --fail-with-body -s -X GET \
                -H "$AUTH_HEADER" \
                -H "$CONTENT_TYPE_HEADER" \
                "$API_URL_BASE/$previewName/logs")
            if [ $? -ne 0 ]; then echo "curl command failed while fetching logs. Response: $log_response" >&2; return 1; fi
            if ! check_for_api_error "$log_response" "fetch logs"; then return 1; fi

            # A valid log response must be a JSON array.
            if ! echo "$log_response" | jq -e 'if type == "array" then true else false end' > /dev/null; then
              echo "Invalid response from logs API (expected a JSON array): $log_response" >&2; return 1;
            fi

            # Check if the logs contain the "Ready." message, indicating the instance is fully started.
            if ! echo "$log_response" | jq -e '.[] | select(.content | contains("Ready."))' > /dev/null; then
              echo "Instance is not ready yet, waiting for 'Ready.' message in logs..." >&2
              return 1
            fi

            echo "$log_response"
        }
        echo "Fetching logs for $previewName ..."
        if ! log_response=$(retry fetch_logs); then
          echo "Error: Failed to fetch logs after multiple retries."
          exit 1
        fi
        echo "$previewName logs:"
        echo "$log_response" | jq -r '.[].content'