Spring cloud-config-server Git-Backend on AWS ECS

I am able to resolve this.

1. Create a new Policy named GetParameters and attach it to current task role.

2. IAM -> create policy -> select 'System Manager' as service -> 'GetParameters' as Action(read type only) -> all Resources and create policy.

3. Go to Systems Manager -> Parameter Store for storing sensitive details as SecureString.

4. Go to Task -> Container Definitions -> Environment Variables: provide

The value should be in the form for arn:aws:ssm:::parameter/name

GITLAB_USERNAME, ValueFrom , arn:aws:ssm:::parameter/dev/my-config-server/GITLAB_USERNAME
GITLAB_PASSWORD, ValueFrom , arn:aws:ssm:::parameter/dev/my-config-server/GITLAB_PASSWORD
As per convention Name should be in the form of ///

And that's it. You are done. Wait for task to be provisioned and config-server would be able to connect to your remote repo.

    spring:
      profiles: dev
      cloud:
        config:
          server:
              git:
                uri: https://gitlab.com/<group>/<project>.git
                clone-on-start: true
                default-label: gitlabci-test
                searchPaths: '{profile}'
                username: ${GITLAB_USERNAME}
                password: ${GITLAB_PASSWORD}