Set a [JWT](https://tools.ietf.org/html/rfc7519) signature to a random string. This is needed for all OAuth2 providers that you choose to configure. *Keep this random string around!*
You'll need it each time you start a chronograf server because it is used to verify user authorization. If you are running multiple chronograf servers in an HA configuration set the `TOKEN_SECRET` on each to allow users to stay logged in.
To create a Github OAuth Application follow the [Register your app](https://developer.github.com/guides/basics-of-authentication/#registering-your-app) instructions.
Essentially, you'll register your application [here](https://github.com/settings/applications/new)
The `Homepage URL` should be Chronograf's full server name and port. If you are running it locally for example, make it `http://localhost:8888`
You will need to obtain a client ID and an application secret by following the steps under "Basic Steps" [here](https://developers.google.com/identity/protocols/OAuth2). Chronograf will also need to be publicly accessible via a fully qualified domain name so that Google properly redirects users back to the application.
Similar to Github's organization restriction, Google authentication can be restricted to permit access to Chronograf from only specific domains. These are configured using the `GOOGLE_DOMAINS` ENV or the `--google-domains` switch. Multiple domains are separated with a comma. For example, if we wanted to permit access only from biffspleasurepalace.com and savetheclocktower.com the ENV would be set as follows:
To obtain a client ID and application secret for Heroku, you will need to follow the guide posted [here](https://devcenter.heroku.com/articles/oauth#register-client). Once your application has been created, those two values should be inserted into the following ENVs:
Like the other OAuth2 providers, access to Chronograf via Heroku can be restricted to members of specific Heroku organizations. This is controlled using the `HEROKU_ORGS` ENV or the `--heroku-organizations` switch and is comma-separated. If we wanted to permit access from the `hill-valley-preservation-society` orgization and `the-pinheads` organization, we would use the following ENV: