Add automation to create a gitlab project

[dave-shawley]

This PR builds on top of #72 by adding the imbi.automations.gitlab.create_project function that can be used as an automation callable. It does required that you have an OAuth 2 application defined in GitLab that is used to authorize Imbi to act as a specific GitLab user. You will need the OAuth 2 Client ID and Client Secret for that application to continue (details below).

Once you have the GitLab connection configured and a user connected, creating a new project of a project type that has automations enabled will add toggles for each available automation to the display.

After creating the Imbi project, the project creation endpoint will run the selected automations (8400ff4). If none of the automations fail, then the endpoint responds with a 👍 to the client. If any automation fails, then any successful automations are rolled back, the Imbi project is deleted, and a 👎 is returned to the client. The only automation implemented in this PR is one to create a GitLab project (e775720). The project location is determined by the namespace.gitlab_group_name and project_type.gitlab_project_prefix. If either is missing, then the slug is substituted. There are a few interesting error conditions that can pop up:

1. since the GitLab creation request is done as the connected GitLab user, you might not have access to create projects in the target -- this one is handled with a reasonable message IIRC
2. if the target GitLab parent doesn't exist, a "configuration error" is displayed -- made this decision since the namespace or project-type data in Imbi is misconfigured
3. you can configure interesting combinations of GitLab group and sub-group permissions that could result in really strange errors

Feel free to play around with different settings. The error handling can be changed fairly easily... as long as we can determine what to do programatically.

You will also need AWeber-Imbi/imbi-ui#73 running to see the new UI options.

Guru meditations

• should we make the project defaults configurable under automations:gitlab: in the configuration file?
• is using a default of slugs appropriate instead of explicit configuration?
• should we send automation dependency information to the client? Attempts to create a project with unmet dependencies will fail today but I didn't spend a lot of time thinking through alternatives.

Enabling the OAuth 2 connection and automation

GitLab OAuth 2 Application Details

Confidential ☑️
Scopes api
Redirect URI (one per line)

http://localhost:8000/gitlab/auth
http://127.0.0.1:8000/gitlab/auth

Script to enable GitLab OAuth 2 integration & automation

#!/usr/bin/env python3

import contextlib
import getpass
import http.client
import json
import os
import sys
import textwrap
import urllib.parse


def get_string(prompt, secret=False):
    env_var = prompt.replace(' ', '_').upper()
    with contextlib.suppress(KeyError):
        return os.environ[env_var]

    try:
        if secret:
            return getpass.getpass(prompt + ': ')
        return input(prompt + ': ')
    except (IOError, KeyboardInterrupt):
        sys.exit('Canceled')


def post(conn, path, body, allow_statuses=None):
    allow_statuses = allow_statuses or []
    headers = {'Private-Token': imbi_api_token,
               'Content-Type': 'application/json'}
    conn.request('POST', path,
                 json.dumps(body).encode(),
                 headers=headers)
    rsp = conn.getresponse()
    rsp_body = rsp.read()
    if rsp.code >= 400:
        print('Imbi API Failure: POST {} -> {}'.format(
            path, rsp.code))
        if rsp.code in allow_statuses:
            print('Failure ignored here')
            print('')
        else:
            if rsp_body:
                json.dump(json.loads(rsp_body), sys.stdout, indent=2)
                print('')
            sys.exit(1)
    return json.loads(rsp_body) if rsp_body else None


if not os.environ.get('IMBI_API_TOKEN'):
    os.environ['IMBI_API_TOKEN'] =  '00000000-0000-0000-0000-000000000000'
imbi_api_token = get_string('Imbi API Token', secret=True)
gitlab_client_id = get_string('GitLab Client ID')
gitlab_client_secret = get_string('GitLab Client Secret', secret=True)
gitlab_url = get_string('GitLab URL')
imbi_url = get_string('Imbi URL')

parsed = urllib.parse.urlparse(gitlab_url)
gitlab_url = parsed.scheme + '://' + parsed.netloc

parsed = urllib.parse.urlparse(imbi_url)
if parsed.scheme == 'http':
    conn = http.client.HTTPConnection(parsed.hostname, parsed.port or 80)
elif parsed.scheme == 'https':
    conn = http.client.HTTPSConnection(parsed.hostname, parsed.port or 443)
else:
    sys.exit('Unhandled scheme: ' + parsed.scheme)
imbi_url = parsed.scheme + '://' + parsed.netloc

with contextlib.closing(conn):
    print('Created HTTP API project type')
    post(conn, '/project-types', {
        'name': 'HTTP API',
        'plural_name': 'HTTP APIs',
        'slug': 'api',
        'icon_class': 'fas cog',
        'environment_urls': True,
        'gitlab_project_prefix': 'api',
    }, allow_statuses=[409])

    print('Creating GitLab integration')
    post(conn, '/integrations', {
        'name': 'gitlab2',
        'api_endpoint': gitlab_url + '/api/v4',
        'api_secret': None,
    })

    print('Configuring GitLab OAuth2 connection')
    post(conn, '/integrations/gitlab2/oauth2', {
        'authorization_endpoint': gitlab_url + '/oauth/authorize',
        'token_endpoint': gitlab_url + '/oauth/token',
        'revoke_endpoint': None,
        'callback_url': imbi_url + '/gitlab/auth',
        'client_id': gitlab_client_id,
        'client_secret': gitlab_client_secret,
        'use_pkce': True,
    })

    print('Creating Create GitLab Project automation')
    post(conn, '/integrations/gitlab2/automations', {
        'name': 'Create GitLab Project',
        'callable': 'imbi.automations.gitlab.create_project',
        'categories': ['create-project'],
        'applies_to': ['api']
    })


term_size = os.get_terminal_size()

def display(*paragraphs):
    print()
    for p in paragraphs:
        msg = textwrap.dedent(p.format(**globals()))
        for line in textwrap.wrap(msg, term_size.columns * 0.7):
            print(line.strip())
        print()

display(
'''
    Your Imbi instance has been configured to connect to {gitlab_url}.
    Please open {imbi_url}/ui/user/profile and click the "Connect to
    GitLab" button.
''', '''
    If the button is not showing, reload the page. If that doesn't work
    then restart your Imbi instance.
'''
)