docs: allow multiple Coder deployments to use single GitHub OAuth app (#8786)

matifali · web-flow · commit af036b440bd7 · 2023-07-31T10:00:48.000-04:00
* docs: Add instructions for using the same GitHub OAuth app for multiple Coder deployments

* fmt

* typo

* Update auth.md
diff --git a/docs/admin/auth.md b/docs/admin/auth.md
@@ -14,8 +14,10 @@ The following steps explain how to set up GitHub OAuth or OpenID Connect.
 
 First, [register a GitHub OAuth app](https://developer.github.com/apps/building-oauth-apps/creating-an-oauth-app/). GitHub will ask you for the following Coder parameters:
 
-- **Homepage URL**: Set to your Coder domain (e.g. `https://coder.domain.com`)
-- **User Authorization Callback URL**: Set to `https://coder.domain.com/api/v2/users/oauth2/github/callback`
+- **Homepage URL**: Set to your Coder deployments [`CODER_ACCESS_URL`](https://coder.com/docs/v2/latest/cli/server#--access-url) (e.g. `https://coder.domain.com`)
+- **User Authorization Callback URL**: Set to `https://coder.domain.com`
+
+> Note: If you want to allow multiple coder deployments hosted on subdomains e.g. coder1.domain.com, coder2.domain.com, to be able to authenticate with the same GitHub OAuth app, then you can set **User Authorization Callback URL** to the `https://domain.com`
 
 Note the Client ID and Client Secret generated by GitHub. You will use these
 values in the next step.
