How to pass environment variables to other processes in AWS Codebuild, e.g docker compose commands

buildspec.yaml

{
  "version": 0.2,
  "phases": {
    "build": {
      "commands": [
        "curl 169.254.170.2$AWS_CONTAINER_CREDENTIALS_RELATIVE_URI > creds_json",
        "export AWS_ACCESS_KEY_ID=$(cat creds_json | jq .AccessKeyId |tr -d '\"')",
        "export AWS_SECRET_ACCESS_KEY=$(cat creds_json | jq .SecretAccessKey | tr -d '\"')",
        "export AWS_SESSION_TOKEN=$(cat creds_json | jq .Token |tr -d '\"')",
        "export CDK_DEFAULT_ACCOUNT=$CDK_DEFAULT_ACCOUNT",
        "export CDK_DEFAULT_REGION=$CDK_DEFAULT_REGION",
        "docker-compose up --build"
      ]
    }
  }
}