Store Docker Hub Credentials in AWS Secrets Manager

This skill guides you through creating (or rotating) Docker Hub credentials and storing them in AWS Secrets Manager (mockserver-build/dockerhub) for use by Buildkite pipelines.

Prerequisites

• AWS CLI installed and configured with the mockserver-build SSO profile
• Authenticated to AWS: aws sso login --profile mockserver-build
• Docker Hub account with push access to the mockserver/mockserver repository
• Terraform resources deployed (the aws_secretsmanager_secret.dockerhub resource

in terraform/buildkite-agents/build-secrets.tf must exist)

Step 1: Try Local Docker Credentials (Optional Shortcut)

Before asking the user to create a new token, check if Docker Hub credentials are already available locally:

# Check what credential store is configured
cat ~/.docker/config.json | python3 -c "import sys,json; print(json.load(sys.stdin).get('credsStore','none'))"

# Try to extract credentials (the helper name comes from credsStore above)
echo "https://index.docker.io/v1/" | docker-credential-desktop get 2>/dev/null

If credentials are found, ask the user if they want to use them. Note that credentials from Docker Desktop may be session tokens rather than reusable PATs — prefer creating a dedicated PAT in Step 2 for production use.

Step 2: Create a Docker Hub Personal Access Token

If no local credentials are available (or the user wants a fresh token):

1. Instruct the user to navigate to Docker Hub:

• URL: https://app.docker.com/settings/personal-access-tokens
• Or: Docker Hub → Avatar → Account Settings → Personal Access Tokens

1. Click Generate New Token
2. Settings:

• Description: mockserver-ci (or similar)
• Permissions: Read & Write (needed to push images)
• Expiration: Choose based on rotation policy (recommended: 1 year)

1. Copy the generated token (format: dckr_pat_...)

Ask the user to provide:

• Docker Hub username
• Personal Access Token

Step 3: Validate Credentials

Test the credentials before storing them:

echo "<token>" | docker login --username "<username>" --password-stdin 2>&1

If login succeeds, proceed. If it fails, ask the user to verify the token.

After validation, log out to avoid leaving credentials in the local Docker config:

docker logout

Step 4: Store in AWS Secrets Manager

aws secretsmanager put-secret-value \
    --secret-id mockserver-build/dockerhub \
    --secret-string '{"username":"<username>","token":"<token>"}' \
    --profile mockserver-build \
    --region eu-west-2

IMPORTANT: Never log or echo the token value. Use the AWS CLI directly.

Step 5: Verify Storage

Confirm the secret was stored correctly by checking the JSON structure (not the token value):

aws secretsmanager get-secret-value \
    --secret-id mockserver-build/dockerhub \
    --profile mockserver-build \
    --region eu-west-2 \
    --query 'SecretString' \
    --output text | python3 -c "import sys,json; d=json.load(sys.stdin); print(f'✓ Secret contains username: {\"username\" in d}'); print(f'✓ Secret contains token: {\"token\" in d}'); print(f'✓ Username: {d.get(\"username\", \"MISSING\")}'); print(f'✓ Token length: {len(d.get(\"token\", \"\"))} chars')"

SECURITY: Never print any part of the token value (not even the first N characters). Verify by checking the JSON structure and token length only.

Troubleshooting

Security Notes

• Never commit Docker Hub tokens to the repository
• Never log the full token value in CI output
• The secret in AWS Secrets Manager is encrypted at rest using the default KMS key
• Access is scoped: only the Buildkite agent EC2 instance role can read the secret (via buildkite-read-dockerhub-secret IAM policy)
• Rotate the token if it may have been exposed