Add cli tool to create GitLab application and permissions

[tmcgilchrist]

Background

GitLab is missing the integrated concept of an [GitHub Application]() that includes allowing access to a project/group, setup notifications of merge request/push events, and notifications of adding new projects to build. We would like a cli application that creates/maintains the correct set of web hooks and permissions.

Summary

1. Create the necessary token / application and project web hooks for tezos-ci. Given an existing token with permissions to create or update setup everything required for a tezos-ci instance.
2. Add signup process for adding new project to build and creating the right webhook callbacks, based off an existing access token with sufficient permissions.

The GitLab Application should have

• a descriptive name
• callback url (eg https://gitlab.tezos.ci.dev:8100/login)
• scopes of read_user (Read the authenticated user's personal information)

The web hooks are setup per project, so for each project it needs:

• Callback url to deliver web hooks to eg https://tezos.ci.dev/webhooks/gitlab
• Webhook secret that is shared between GitLab and the tezos-ci services, we use this to validate the web hooks really came from GitLab. This needs to be added to system configuration in ansible/docker.
• Add triggers for Push, Tag Push and Merge Request events
• Enable SSL verification.

Outcome

A cli application to

• setup a new tezos-ci installation in GitLab
• add a new project with the correct permissions, web hooks and configuration.

The CLI should look something like:

tezos-setup create --token <token>
tezos-setup add --project-id <project_id> | --project_name tezos/tezos --token <token>
tezos-setup add --projects "tezos/tezos, tmcgilchrist/ocaml-gitlab" --token <token>

[novemberkilo]

Also see https://github.com/tarides/tezos-ci/blob/main/doc/gitlab.md