One of the login options for dex uses the GitHub OAuth2 flow to identify the end user through their GitHub account.
When a client redeems a refresh token through dex, dex will re-query GitHub to update user information in the ID Token. To do this, __dex stores a readonly GitHub access token in its backing datastore.__ Users that reject dex's access through GitHub will also revoke all dex clients which authenticated them through GitHub.
## Caveats
* A user must explicitly [request][github-request-org-access] an [organization][github-orgs] give dex [resource access][github-approve-org-access]. Dex will not have the correct permissions to determine if the user is in that organization otherwise, and the user will not be able to log in. This request mechanism is a feature of the GitHub API.
## Configuration
Register a new application with [GitHub][github-oauth2] ensuring the callback URL is `(dex issuer)/callback`. For example if dex is listening at the non-root path `https://auth.example.com/dex` the callback would be `https://auth.example.com/dex/callback`.
The following is an example of a configuration for `examples/config-dev.yaml`:
```yaml
connectors:
- type: github
# Required field for connector id.
id: github
# Required field for connector name.
name: GitHub
config:
# Credentials can be string literals or pulled from the environment.
Running Dex with HTTPS enabled requires a valid SSL certificate, and the API server needs to trust the certificate of the signing CA using the `--oidc-ca-file` flag.
For our example use case, the TLS assets can be created using the following command:
```
$ ./examples/k8s/gencert.sh
```
This will generate several files under the `ssl` directory, the important ones being `cert.pem` ,`key.pem` and `ca.pem`. The generated SSL certificate is for 'dex.example.com', although you could change this by editing `gencert.sh` if required.
