> ## Documentation Index
> Fetch the complete documentation index at: https://cloudanix.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Codepipeline region fanout remediation

### Triage and Remediation

<Tabs>
  <Tab title="Remediation">
    ### Remediation

    <AccordionGroup>
      <Accordion title="Using Console" defaultOpen="true">
        You remediate this by making your build/deploy pipeline *multi‑region* using cross‑region actions in AWS CodePipeline with regional CodeBuild projects. CodeBuild itself is regional; the fan‑out is done by CodePipeline. Below are the minimal console steps.

        ***

        ### 1. Plan your “primary” and “secondary” regions

        1. Choose a **primary region** for your pipeline (e.g. `us-east-1`).
        2. List the **target regions** where you want builds/deployments to run (e.g. `us-west-2`, `eu-west-1`).

        ***

        ### 2. Create artifact S3 buckets and KMS keys (per region)

        Do this for **each** target region (including primary):

        1. In the **S3 console**
           * Create a bucket (e.g. `my-pipeline-artifacts-us-east-1`, `my-pipeline-artifacts-us-west-2`).
           * Keep bucket in the target region; block public access; enable encryption.

        2. In the **KMS console (optional but recommended)**
           * Create a CMK for encrypting pipeline artifacts in that region.
           * Add IAM permissions for CodePipeline and CodeBuild to use it.

        ***

        ### 3. Create regional CodeBuild projects

        Do this in **each region** where you want to run builds:

        1. Switch console to the **target region** (top-right region selector).

        2. Open **CodeBuild → Build projects → Create build project**.

        3. Configure:
           * **Project name**: e.g. `my-app-build-us-east-1`, `my-app-build-us-west-2`.
           * **Source**: Same repo/provider in all regions (CodeCommit, GitHub, etc.) or “CodePipeline” if you use CodePipeline as the source.
           * **Environment**: Select image, compute, IAM role with:
             * `s3:*` on that region’s artifact bucket (or at least `GetObject/PutObject`).
             * Any additional permissions needed for builds.
           * **Buildspec**: inline or from repo (`buildspec.yml`).
           * **Artifacts**:
             * Type: `CodePipeline` (if using CodePipeline) or S3 bucket in that region.

        4. Save the project. Repeat for each region.

        ***

        ### 4. Create / modify a CodePipeline to fan out

        You can’t fan out from CodeBuild alone; configure CodePipeline to call multiple regional CodeBuild projects.

        1. In **primary region**, open **CodePipeline → Create pipeline** (or edit an existing one).

        2. **Pipeline settings**:
           * Artifact store:
             * Use a **custom location** and specify the S3 bucket for primary region.
             * For **advanced** (cross‑region), choose “Override the default location” per region if prompted, and select the per‑region buckets you created.

        3. **Source stage**: configure as usual (CodeCommit/GitHub/S3).

        4. **Build stage (fan‑out)**:
           * Add a build stage (e.g. `Build-MultiRegion`).
           * Inside this stage, add **one action per region**:
             * Action provider: **CodeBuild**.
             * Region: select the **target region** (e.g. `us-east-1`, `us-west-2`).
             * Input artifact: from Source stage.
             * Output artifact: different name per region (e.g. `BuildUS_EAST_1`, `BuildUS_WEST_2`).
             * Choose the **regional CodeBuild project** you created.
           * Ensure “Region” (top-right of action config) matches the target region; this is what creates a **cross-region action**.

        5. (Optional) **Deploy stages per region**:
           * Add Deploy stages (one or more) with actions targeting each region (CodeDeploy, CloudFormation, ECS, Lambda, etc.), again setting **Region** to the desired region and using the regional build artifacts.

        6. Save the pipeline.

        ***

        ### 5. Fix IAM permissions for cross‑region access

        1. **CodePipeline role** (in primary region):
           * Allow `codebuild:StartBuild`, `codebuild:BatchGetBuilds` **in all target regions** for the specific projects.
           * Allow `s3:GetObject/PutObject` in **all** regional artifact buckets.
           * Allow `kms:Encrypt/Decrypt/GenerateDataKey` for the KMS keys you created (if used).

        2. **CodeBuild service roles** (per region):
           * Allow access to that region’s artifact S3 bucket.
           * Any resource access needed by the build (ECR, CloudWatch Logs, etc.).

        ***

        ### 6. Test the fan‑out

        1. Push a change to your source repository.
        2. Watch the pipeline:
           * Source stage succeeds in primary region.
           * Build stage shows **parallel actions**, one per region.
           * Each CodeBuild project runs in its own region.

        When all builds succeed, your pipeline now fans out across regions instead of relying on a single-region CodeBuild run.
      </Accordion>

      <Accordion title="Using CLI">
        To “fan out” your deployments across regions with AWS CodeBuild/CodePipeline using the AWS CLI, you:

        1. **Create (or reuse) a primary pipeline in one region**
        2. **Create CodeBuild projects in multiple regions**
        3. **Configure a cross‑region deployment stage that triggers those regional builds in parallel**

        Below are concise, CLI‑oriented steps.

        ***

        ## 1. Prerequisites

        * You already have:
          * A source repository (CodeCommit / GitHub / S3).
          * An existing CodePipeline + CodeBuild in a **primary region** (e.g., `us-east-1`) that builds artifacts.
        * S3 artifact bucket in the primary region (e.g., `my-artifact-bucket-us-east-1`).
        * An S3 artifact bucket in each **target region** (e.g., `my-artifact-bucket-eu-west-1`, `my-artifact-bucket-ap-southeast-1`).
        * IAM roles:
          * Pipeline service role (with `codebuild:StartBuild`, `s3:*` on the artifact buckets, etc.).
          * CodeBuild service roles in each region.

        ***

        ## 2. Create CodeBuild Projects in Each Target Region

        Do this once for each region you want to deploy to.

        Example for `eu-west-1`:

        ```bash theme={null}
        aws codebuild create-project \
          --region eu-west-1 \
          --name my-app-deploy-eu-west-1 \
          --source type=CODEPIPELINE \
          --artifacts type=CODEPIPELINE \
          --environment type=LINUX_CONTAINER,computeType=BUILD_GENERAL1_SMALL,image=aws/codebuild/standard:7.0,privilegedMode=false \
          --service-role arn:aws:iam::123456789012:role/codebuild-service-role-eu-west-1
        ```

        Repeat for other regions (change `--region`, `--name`, and service role ARN).

        Your `buildspec.yml` for these projects should do the **regional deployment**, e.g.:

        * `aws cloudformation deploy --region eu-west-1 ...`
        * or `aws ecs update-service --region eu-west-1 ...`
        * etc.

        ***

        ## 3. Add Cross-Region Action Configuration to the Pipeline

        You will modify the pipeline JSON so that the **deploy stage** has multiple parallel **CodeBuild actions**, each in a different region.

        1. **Get the current pipeline definition** (primary region, e.g., `us-east-1`):

        ```bash theme={null}
        aws codepipeline get-pipeline \
          --region us-east-1 \
          --name my-app-pipeline \
          > pipeline.json
        ```

        2. **Edit `pipeline.json`**:
           * Find or create a stage named `"Deploy"` (or similar).
           * Under `stages[].actions`, add one `CodeBuild` action per region.
           * Specify `region` in `actionTypeId` and `configuration` as needed.

        Example `Deploy` stage section (minimal illustration):

        ```json theme={null}
        {
          "name": "Deploy",
          "actions": [
            {
              "name": "Deploy-EU-West-1",
              "actionTypeId": {
                "category": "Build",
                "owner": "AWS",
                "provider": "CodeBuild",
                "version": "1"
              },
              "configuration": {
                "ProjectName": "my-app-deploy-eu-west-1"
              },
              "runOrder": 1,
              "inputArtifacts": [
                { "name": "BuildOutput" }
              ],
              "outputArtifacts": [],
              "region": "eu-west-1"
            },
            {
              "name": "Deploy-AP-Southeast-1",
              "actionTypeId": {
                "category": "Build",
                "owner": "AWS",
                "provider": "CodeBuild",
                "version": "1"
              },
              "configuration": {
                "ProjectName": "my-app-deploy-ap-southeast-1"
              },
              "runOrder": 1,
              "inputArtifacts": [
                { "name": "BuildOutput" }
              ],
              "outputArtifacts": [],
              "region": "ap-southeast-1"
            }
          ]
        }
        ```

        Key points:

        * Same `inputArtifacts` (e.g., `"BuildOutput"`) from your build stage.
        * Same `runOrder` so they run **in parallel**.
        * Each action has its **own region**.
        * Ensure your pipeline’s `artifactStore` / `artifactStores` section has entries per region:

        Example top-level `artifactStores` fragment:

        ```json theme={null}
        "artifactStores": {
          "us-east-1": {
            "type": "S3",
            "location": "my-artifact-bucket-us-east-1"
          },
          "eu-west-1": {
            "type": "S3",
            "location": "my-artifact-bucket-eu-west-1"
          },
          "ap-southeast-1": {
            "type": "S3",
            "location": "my-artifact-bucket-ap-southeast-1"
          }
        }
        ```

        Remove any existing single `artifactStore` key if you use `artifactStores`.

        3. **Update the pipeline**:

        ```bash theme={null}
        aws codepipeline update-pipeline \
          --region us-east-1 \
          --cli-input-json file://pipeline.json
        ```

        ***

        ## 4. Test the Fan‑Out

        Trigger a run:

        ```bash theme={null}
        aws codepipeline start-pipeline-execution \
          --region us-east-1 \
          --name my-app-pipeline
        ```

        Then check CodeBuild in each region:

        ```bash theme={null}
        aws codebuild list-builds-for-project \
          --region eu-west-1 \
          --project-name my-app-deploy-eu-west-1
        ```

        Repeat per region to verify builds (deployments) start in parallel.

        ***

        If you share your current `get-pipeline` JSON, I can give you an exact patch snippet tailored to your setup.
      </Accordion>

      <Accordion title="Using Python">
        To “fan out” a deployment pipeline across regions in AWS, you don’t actually make CodeBuild multi‑region; instead you:

        1. Build once in a primary region.
        2. Replicate the build artifact to other regions.
        3. Trigger region‑specific deployment actions.

        Below is a minimal, concrete pattern using Python (boto3) plus CodePipeline/CodeBuild.

        ***

        ## 1. High‑level architecture

        * Region A (primary):
          * CodePipeline:
            * Source → Build (CodeBuild) → Fan‑Out (Lambda or CodeBuild action)
        * Multiple regions (A, B, C…):
          * Region‑local S3 artifact buckets
          * Region‑local deployment mechanisms (CodeDeploy, CloudFormation, ECS, Lambda, etc.)

        Your “fan‑out” step copies the built artifact to S3 buckets in each target region and optionally triggers a deployment in those regions.

        ***

        ## 2. Prerequisites

        1. **Artifact bucket in each region**\
           Create an S3 bucket per region where you will deploy:

           * `my-artifacts-us-east-1`
           * `my-artifacts-eu-west-1`
           * etc.

        2. **IAM role for fan‑out step** with permissions:
           * `s3:GetObject` on primary artifact bucket
           * `s3:PutObject` on regional buckets
           * (optional) `codedeploy:*` / `cloudformation:*` / etc. to trigger regional deploys.

        ***

        ## 3. Configure your CodeBuild (Primary Region)

        Your CodeBuild project in the *primary* region:

        * `artifacts` → `type: CODEPIPELINE`
        * buildspec example (build once and bundle):

        ```yaml theme={null}
        version: 0.2
        phases:
          install:
            runtime-versions:
              python: 3.11
          build:
            commands:
              - pip install -r requirements.txt -t package/
              - cp -r src/* package/
              - cd package && zip -r ../build.zip .
        artifacts:
          files:
            - build.zip
        ```

        CodePipeline will store `build.zip` in the primary region’s artifact bucket.

        ***

        ## 4. Add Fan‑Out Stage in CodePipeline

        In CodePipeline, after the Build stage add a new stage:

        * Action type: **Lambda** or **CodeBuild**
        * Purpose: run Python that:
          1. Reads the artifact location from the pipeline event.
          2. Copies artifact to regional buckets.
          3. (Optionally) triggers regional deployments.

        Using a **Lambda** is usually simplest.

        ***

        ## 5. Python Lambda to Fan Out Artifacts

        ### 5.1. Lambda IAM policy (core permissions)

        Attach a policy like:

        ```json theme={null}
        {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Effect": "Allow",
              "Action": ["s3:GetObject"],
              "Resource": "arn:aws:s3:::my-artifacts-us-east-1/*"
            },
            {
              "Effect": "Allow",
              "Action": ["s3:PutObject"],
              "Resource": [
                "arn:aws:s3:::my-artifacts-eu-west-1/*",
                "arn:aws:s3:::my-artifacts-ap-southeast-1/*"
              ]
            }
          ]
        }
        ```

        Add more regions as needed. Add deploy permissions if you’ll trigger CodeDeploy/CloudFormation.

        ### 5.2. Lambda Python code (copy artifacts to multiple regions)

        ```python theme={null}
        import json
        import os
        import boto3
        from urllib.parse import unquote_plus

        s3 = boto3.client("s3")

        # Map target regions to target buckets
        TARGET_BUCKETS = {
            "us-east-1": "my-artifacts-us-east-1",
            "eu-west-1": "my-artifacts-eu-west-1",
            "ap-southeast-1": "my-artifacts-ap-southeast-1"
        }

        def lambda_handler(event, context):
            # Event from CodePipeline
            job = event["CodePipeline.job"]
            artifact = job["data"]["inputArtifacts"][0]
            artifact_location = artifact["location"]["s3Location"]

            src_bucket = artifact_location["bucketName"]
            src_key = artifact_location["objectKey"]

            print(f"Source artifact: s3://{src_bucket}/{src_key}")

            # Copy to each target region's bucket
            for region, target_bucket in TARGET_BUCKETS.items():
                print(f"Copying to {target_bucket} in {region}")
                # Cross-region S3 copy is just bucket-to-bucket (endpoint auto-handled)
                copy_source = {"Bucket": src_bucket, "Key": src_key}
                s3.copy_object(
                    Bucket=target_bucket,
                    Key=src_key,
                    CopySource=copy_source
                )

            # Report success back to CodePipeline
            codepipeline = boto3.client("codepipeline")
            codepipeline.put_job_success_result(jobId=job["id"])

            return {"status": "OK"}
        ```

        Deploy this Lambda in the **primary region** and add it as an action in the fan‑out stage (with the pipeline’s artifact as input).

        ***

        ## 6. (Optional) Trigger Regional Deployments in Python

        In the same Lambda (or in a second Lambda/CodeBuild action per region), call the deployment service.

        Example: trigger a CloudFormation stack update per region:

        ```python theme={null}
        import boto3

        def trigger_regional_deploy(region, bucket, key):
            cf = boto3.client("cloudformation", region_name=region)
            template_url = f"https://{bucket}.s3.{region}.amazonaws.com/{key}"

            cf.update_stack(
                StackName="my-app-stack",
                TemplateURL=template_url,
                Capabilities=["CAPABILITY_NAMED_IAM"],
                Parameters=[
                    {"ParameterKey": "Environment", "ParameterValue": "prod"}
                ]
            )
        ```

        Call `trigger_regional_deploy` inside the loop after copying to each regional bucket.

        ***

        ## 7. Summary of Remediation Steps

        1. Keep CodeBuild in one region; configure it to output a single artifact.
        2. Create S3 artifact buckets in each target region.
        3. Create a fan‑out Lambda (Python + boto3) that:
           * Reads the CodePipeline artifact location.
           * Copies the artifact to each regional bucket.
           * Optionally kicks off region‑specific deployment (CloudFormation/CodeDeploy/etc.).
        4. Add this Lambda as a stage/action in CodePipeline after the build stage.
        5. Ensure IAM roles allow cross‑bucket copy and regional deploy actions.

        This remediates the misconfiguration by ensuring a single build fans out to consistent, automated deployments across multiple regions.
      </Accordion>

      <Accordion title="Using Terraform">
        ```hcl theme={null}
        resource "aws_codepipeline" "APP_PIPELINE" {
          name     = "APP_PIPELINE_NAME"   # replace with your pipeline name
          role_arn = "CODEPIPELINE_ROLE_ARN" # replace with IAM role ARN for CodePipeline

          artifact_store {
            type     = "S3"
            location = "PRIMARY_REGION_ARTIFACT_BUCKET_NAME" # S3 bucket in primary region
          }

          # Existing stages (source, build, tests, primary-region deploy, etc.) go here
          # ...

          # New cross-region deployment stage - REGION 1
          stage {
            name = "Deploy_To_REGION_1"

            action {
              name             = "CodeDeploy_REGION_1"
              category         = "Deploy"
              owner            = "AWS"
              provider         = "CodeDeploy"
              version          = "1"
              input_artifacts  = ["BUILD_ARTIFACT_NAME"] # must match prior stage output
              run_order        = 1

              # This is the key field that fans the pipeline out across regions
              region = "REGION_1_CODEDEPLOY_REGION" # e.g., "us-west-2"

              configuration = {
                ApplicationName     = "CODEDEPLOY_APP_NAME_REGION_1"
                DeploymentGroupName = "CODEDEPLOY_DEPLOYMENT_GROUP_REGION_1"
              }
            }
          }

          # New cross-region deployment stage - REGION 2
          stage {
            name = "Deploy_To_REGION_2"

            action {
              name             = "CodeDeploy_REGION_2"
              category         = "Deploy"
              owner            = "AWS"
              provider         = "CodeDeploy"
              version          = "1"
              input_artifacts  = ["BUILD_ARTIFACT_NAME"]
              run_order        = 1

              region = "REGION_2_CODEDEPLOY_REGION" # e.g., "eu-central-1"

              configuration = {
                ApplicationName     = "CODEDEPLOY_APP_NAME_REGION_2"
                DeploymentGroupName = "CODEDEPLOY_DEPLOYMENT_GROUP_REGION_2"
              }
            }
          }
        }
        ```

        Substitute:

        * `APP_PIPELINE_NAME` with the existing CodePipeline name.
        * `CODEPIPELINE_ROLE_ARN` with the IAM role ARN used by CodePipeline.
        * `PRIMARY_REGION_ARTIFACT_BUCKET_NAME` with the S3 bucket for artifacts in the primary region.
        * `BUILD_ARTIFACT_NAME` with the artifact name output by your build stage (e.g., `"BuildOutput"`).
        * `REGION_1_CODEDEPLOY_REGION` / `REGION_2_CODEDEPLOY_REGION` with the additional AWS regions.
        * `CODEDEPLOY_APP_NAME_REGION_1` / `CODEDEPLOY_APP_NAME_REGION_2` and corresponding `*_DEPLOYMENT_GROUP_*` with existing CodeDeploy applications and deployment groups in those regions.

        This is an in-place update of the pipeline definition (no forced replacement) but is a complex behavioral change; test in a non-production pipeline first.

        Verification with `terraform plan`:

        * The existing `aws_codepipeline.APP_PIPELINE` resource should show updates adding the new `stage` blocks and `action.region` fields, with no `-/+` replacement, only `~` (update in-place).
      </Accordion>
    </AccordionGroup>
  </Tab>
</Tabs>