docs: git auth (#4902)

docs/admin/git-providers.md

@@ -0,0 +1,80 @@
+# Git Providers
+
+Coder integrates with git providers so developers can authenticate with repositories within their workspace.
+
+## How it works
+
+When developers use `git` inside their workspace, they are first prompted to authenticate. After that, Coder will store/refresh tokens for future operations. 
+
+<video autoplay playsinline loop>
+  <source src="https://github.com/coder/coder/blob/main/site/static/gitauth.mp4?raw=true" type="video/mp4">
+Your browser does not support the video tag.
+</video>
+
+## Configuration
+
+To add a git provider, you'll need to create an OAuth application. The following providers are supported:
+
+- [GitHub](https://docs.github.com/en/developers/apps/building-oauth-apps/creating-an-oauth-app) (GitHub apps are also supported)
+- [GitLab](https://docs.gitlab.com/ee/integration/oauth_provider.html)
+- [BitBucket](https://support.atlassian.com/bitbucket-cloud/docs/use-oauth-on-bitbucket-cloud/)
+- [Azure DevOps](https://learn.microsoft.com/en-us/azure/devops/integrate/get-started/authentication/oauth?view=azure-devops)
+
+Example callback URL: `https://coder.example.com/gitauth/primary-github/callback`. Use an arbitrary ID for your provider (e.g. `primary-github`).
+
+Set the following environment variables to [configure the Coder server](./configure.md):
+
+```sh
+CODER_GITAUTH_0_ID="primary-github"
+CODER_GITAUTH_0_TYPE=github|gitlab|azure-devops|bitbucket
+CODER_GITAUTH_0_CLIENT_ID=xxxxxx
+CODER_GITAUTH_0_CLIENT_SECRET=xxxxxxx
+```
+
+### Self-managed git providers
+
+Custom authentication and token URLs should be
+used for self-managed Git provider deployments.
+
+```sh
+CODER_GITAUTH_0_AUTH_URL="https://github.example.com/oauth/authorize"
+CODER_GITAUTH_0_TOKEN_URL="https://github.example.com/oauth/token"
+```
+
+### Custom scopes
+
+Optionally, you can request custom scopes:
+
+```sh
+CODER_GITAUTH_0_SCOPES="repo:read repo:write write:gpg_key"
+```
+
+### Multiple git providers (enterprise)
+
+Multiple providers are an Enterprise feature. [Learn more](../enterprise.md).
+
+A custom regex can be used to match a specific repository or organization to limit auth scope. Here's a sample config:
+
+```sh
+# Provider 1) github.com
+CODER_GITAUTH_0_ID=primary-github
+CODER_GITAUTH_0_TYPE=github
+CODER_GITAUTH_0_CLIENT_ID=xxxxxx
+CODER_GITAUTH_0_CLIENT_SECRET=xxxxxxx
+CODER_GITAUTH_0_REGEX=github.com/orgname
+
+# Provider 2) github.example.com
+CODER_GITAUTH_1_ID=secondary-github
+CODER_GITAUTH_1_TYPE=github
+CODER_GITAUTH_1_CLIENT_ID=xxxxxx
+CODER_GITAUTH_1_CLIENT_SECRET=xxxxxxx
+CODER_GITAUTH_1_REGEX=github.example.com
+CODER_GITAUTH_1_AUTH_URL="https://github.example.com/oauth/authorize"
+CODER_GITAUTH_1_TOKEN_URL="https://github.example.com/oauth/token"
+```
+
+To support regex matching for paths (e.g. github.com/orgname), youll need to add this to the [Coder agent startup script](https://registry.terraform.io/providers/coder/coder/latest/docs/resources/agent#startup_script):
+
+```sh
+git config --global credential.useHttpPath true
+```

docs/manifest.json

@@ -235,6 +235,12 @@
           "path": "./admin/configure.md",
           "icon_path": "./images/icons/toggle_on.svg"
         },
+        {
+          "title": "Git Providers",
+          "description": "Learn how connect Coder with external git providers",
+          "icon_path": "./images/icons/git.svg",
+          "path": "./admin/git-providers.md"
+        },
         {
           "title": "Upgrading",
           "description": "Learn how to upgrade Coder",