GitHub LDAP Team Sync

This utility is intended to enable synchronization between LDAP/Active Directory and GitHub. This is particularly useful for large organizations with many teams that either do not use LDAP for authentication, or else do not use the team sync feature for one reason or another. It supports both GitHub.com and GitHub Enterprise, but it will need to live in a location that can access your LDAP servers.

Features

This utility provides the following functionality:

Feature	Supported	Description
Sync Users	Yes	Add or remove users from Teams in GitHub to keep in sync with Active Directory groups
Dynamic Config	Yes	Utilize a settings file to derive Active Directory and GitHub settings
LDAP SSL	No	SSL or TLS connections. This is a WIP
Failure notifications	Yes	Presently supports opening a GitHub issue when sync failed. The repo is configurable.
Sync on new team	Yes	Synchronize users when a new team is created
Sync on team edit	No	This event is not processed currently
Custom team/group maps	Yes	The team slug and group name will be matched automatically, unless you define a custom mapping with syncmap.yml
Dry run / Test mode	Yes	Run and print the differences, but make no changes
Nested teams/groups	No	Synchronize groups within groups. Presently, if a group is a member of another group it is skipped

Creating the GitHub App on your GitHub instance

1. On your GitHub instance, visit the settings page on the Organization that you want to own the GitHub App, and navigate to the GitHub Apps section.
   • You can access this page by visiting the following url: https://<MY_GITHUB_HOSTNAME>/organizations/<MY_ORG_NAME>/settings/apps
2. Create a new GitHub App with the following settings:
   • Webhook URL: URL of the machine on which this app has been deployed (Example: http://ip.of.machine:3000)
   • Homepage URL: URL of the machine on which this app has been deployed (Example: http://ip.of.machine:3000)
   • Webhook Secret: The webhook secret that will be or has been defined as an environment variable in your deployment environment as WEBHOOK_SECRET
   • Permissions and Events: This application will need to be able to manage teams in GitHub, so the events and permissions listed below will be required. For more information on how to create a GitHub App, please visit https://developer.github.com/apps/building-github-apps/creating-a-github-app
3. Once these have been configured, select the Create GitHub App button at the bottom of the page to continue
4. Make a note of the APP ID on your newly-created GitHub App. You will need to set this as an environment variable when you configure the app.
5. Generate and download a private key from the new App page, and store it in your deployment environment. You can either do this by saving the file directly in the environment and specifying its path with the environment variable PRIVATE_KEY_PATH
6. After you have created the GitHub App, you will need to install it to the desired GitHub Organizations.
   • Select Install App
   • Select All Repositories or the desired repositories you wish to watch

Permissions and Events

Permissions

Category	Attribute	Permission
Organization permissions	Members	Read & write
User permissions	Email addresses	Read-only
Repository permissions	Issues	Read & write
Repostiroy permissions	Metadata	Read-only

Events

Event	Required?	Description
Team	Optional	Trigger when a new team is created, deleted, edited, renamed, etc.

Getting Started

To get started, ensure that you are using Python 3.4+. The following additional libraries are required:

• Flask
• github3.py
• python-ldap3
• APScheduler
• python-dotenv
• PyYAML
• msal

Install the required libraries.

pipenv install

Once you have all of the requirements installed, be sure to edit the .env to match your environment.

Sample .env for GitHub App settings

## GitHub App settings
WEBHOOK_SECRET=development
APP_ID=12345
PRIVATE_KEY_PATH=.ssh/team-sync.pem
GHE_HOST=github.example.com

Sample .env for choosing your backend

## AzureAD = AAD
## AD/LDAP = LDAP
USER_DIRECTORY=LDAP

Sample .env for Active Directory

LDAP_SERVER_HOST=dc1.example.com
LDAP_SERVER_PORT=389
LDAP_BASE_DN="DC=example,DC=com"
LDAP_USER_BASE_DN="CN=Users,DC=example,DC=example"
LDAP_GROUP_BASE_DN="OU=Groups,DC=example,DC=example"
LDAP_USER_FILTER="(objectClass=person)"
LDAP_USER_ATTRIBUTE=sAMAccountName
LDAP_USER_MAIL_ATTRIBUTE=mail
LDAP_GROUP_FILTER="(&(objectClass=group)(cn={group_name}))"
LDAP_GROUP_MEMBER_ATTRIBUTE=member
LDAP_BIND_USER="bind-user@example.com"
LDAP_BIND_PASSWORD="p4$$w0rd"
LDAP_SEARCH_PAGE_SIZE=1000

Sample .env for OpenLDAP

LDAP_SERVER_HOST=dc1.example.com
LDAP_SERVER_PORT=389
LDAP_BASE_DN="dc=example,dc=com"
LDAP_USER_BASE_DN="ou=People,dc=example,dc=com"
LDAP_GROUP_BASE_DN="ou=Groups,dc=example,dc=com"
LDAP_USER_FILTER="(&(objectClass=person)({ldap_user_attribute}={username}))"
LDAP_USER_ATTRIBUTE=uid
LDAP_USER_MAIL_ATTRIBUTE=mail
LDAP_GROUP_FILTER="(&(objectClass=posixGroup)(cn={group_name}))"
LDAP_GROUP_MEMBER_ATTRIBUTE=memberUid
LDAP_BIND_USER="cn=admin,dc=example,dc=com"
LDAP_BIND_PASSWORD="p4$$w0rd"
LDAP_SEARCH_PAGE_SIZE=1000

Sample .env for AzureAD

AZURE_TENANT_ID="<tenant_id>"
AZURE_CLIENT_ID="<client_id>"
AZURE_CLIENT_SECRET="<client_secret>"
AZURE_APP_SCOPE="default"
AZURE_API_ENDPOINT="https://graph.microsoft.com/v1.0"
USERNAME_ATTRIBUTE=userPrincipalName

Sample .env settings for additional settings

## Additional settings
CHANGE_THRESHOLD=25
OPEN_ISSUE_ON_FAILURE=true
REPO_FOR_ISSUES=github-demo/demo-repo
ISSUE_ASSIGNEE=githubber
SYNC_SCHEDULE=0 * * * *
TEST_MODE=false

Sample syncmap.yml custom mapping file

---
mapping:
  - github: demo-team
    ldap: ldap super users
  - github: demo-admin-2
    ldap: some other group

Usage Examples

Start the application from Pipenv

This example runs the app in a standard Flask environment

pipenv run flask run --host=0.0.0.0 --port=5000

Or you can run the app with Python directly

pipenv run python app.py

Credits

This project draws much from:

• Flask-GitHubApp
• github3.py