Unique ELBv2 Listener Rule Priority

Without any conflict, generate random priotity for a Elastic Load Balancer Listener Rule.

Usage

Prerequisites

For each kind of run, you will need to configure the credentials first, so consider adding the following step before each of the below approaches:

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: ${{ env.REGION }}

For this to work, you also need a user with (at least) the following policies (hopefully in a cloud formation template):

  GitHubActionsUser:
    Type: AWS::IAM::User
    Properties:
      UserName: !Ref GitHubActionsUserName

  # The permissions that the GitHub Actions deployment workflow will have
  GitHubActionsUserPolicy:
    Type: AWS::IAM::Policy
    Properties:
      Users:
        - !Ref GitHubActionsUser
      PolicyName: allow-github-actions-cloudformation-deploy
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Action:
              - "elasticloadbalancing:DescribeRules"
            Effect: Allow
            Resource: "*"

Produce only one priority

      - uses: licenseware/unique-elbv2-listener-rule-priority@v1
        name: Get unique listerner rule priority
        id: elb-priority
        with:
          listener-arn: ${{ secrets.LOAD_BALANCER_LISTENER_ARN }}

      - uses: aws-actions/aws-cloudformation-github-deploy@v1
        with:
          name: sample-elb-priority
          template: cloudformation-templates/myapp-dev.yml
          no-fail-on-empty-changeset: "1"
          role-arn: ${{ secrets.CLOUD_FORMATION_ROLE_ARN }}
          parameter-overrides: >-
            MyAppLBPriority=${{ steps.elb-priority.outputs.priorities }}

Produce multiple priorities

      - uses: licenseware/unique-elbv2-listener-rule-priority@v1
        name: Get unique listerner rule priority
        id: elb-priority
        with:
          listener-arn: ${{ secrets.LOAD_BALANCER_LISTENER_ARN }}
          sorted: true
          delimiter: " "
          count: 3

      - name: Get load balancer priorities
        run: |
          export PRIORITIES=$(echo ${{ steps.elb-priority.outputs.priorities }})

          cat << EOF >> $GITHUB_ENV
          MYAPP_LB_PR=$(echo $PRIORITIES | awk '{print $1}')
          YOURAPP_LB_PR=$(echo $PRIORITIES | awk '{print $2}')
          HISAPP_LB_PR=$(echo $PRIORITIES | awk '{print $3}')
          EOF

      - uses: aws-actions/aws-cloudformation-github-deploy@v1
        with:
          name: sample-elb-priority
          template: cloudformation-templates/myapp-dev.yml
          no-fail-on-empty-changeset: "1"
          role-arn: ${{ secrets.CLOUD_FORMATION_ROLE_ARN }}
          parameter-overrides: >-
            MyAppLBPriority=${{ env.MYAPP_LB_PR }},
            YourAppLBPriority=${{ env.YOURAPP_LB_PR }},
            HisAppLBPriority=${{ env.HISAPP_LB_PR }}

Inputs

Name	Description	Required	Default
listener-arn	The ARN of the ELBv2 Listener to generate the priority for.	true
count	The number of priorities to generate.	false	1
min-priority	The minimum priority to use.	false	-1000
max-priority	The maximum priority to use.	false	1000
max-try	The maximum number of tries to generate a unique priority.	false	10
log-level	The log level to use.	false	error
sorted	Whether to sort the resulting priorities.	false	true
delimiter	The delimiter to use on the resulting the priorities.	false	","

Outputs

Name	Description	Example
priorities	Comma-separated list of generated priorities.	1,2,3