1. Download [Prebuilt Binary](https://github.com/bitly/oauth2_proxy/releases) (current release is `v2.0.1`) or build with `$ go get github.com/bitly/oauth2_proxy` which will put the binary in `$GOROOT/bin`
You will need to register an OAuth application with a Provider (Google, Github or another provider), and configure it with Redirect URI(s) for the domain you intend to run `oauth2_proxy` on.
#### Restrict auth to specific Google groups on your domain. (optional)
1. Create a service account: https://developers.google.com/identity/protocols/OAuth2ServiceAccount and make sure to download the json file.
2. Make note of the Client ID for a future step.
3. Under "APIs & Auth", choose APIs.
4. Click on Admin SDK and then Enable API.
5. Follow the steps on https://developers.google.com/admin-sdk/directory/v1/guides/delegation#delegate_domain-wide_authority_to_your_service_account and give the client id from step 2 the following oauth scopes:
6. Follow the steps on https://support.google.com/a/answer/60757 to enable Admin API access.
7. Create or choose an existing administrative email address on the Gmail domain to assign to the ```google-admin-email``` flag. This email will be impersonated by this client to make calls to the Admin SDK. See the note on the link from step 5 for the reason why.
8. Create or choose an existing email group and set that email to the ```google-group``` flag. You can pass multiple instances of this flag with different groups
and the user will be checked against all the provided groups.
9. Lock down the permissions on the json file downloaded from step 1 so only oauth2_proxy is able to read the file and set the path to the file in the ```google-service-account-json``` flag.
10. Restart oauth2_proxy.
Note: The user is checked against the group members list on initial authentication and every time the token is refreshed ( about once an hour ).
The GitHub auth provider supports two additional parameters to restrict authentication to Organization or Team level access. Restricting by org and team is normally accompanied with `--email-domain=*`
To authorize by email domain use `--email-domain=yourcompany.com`. To authorize individual email addresses use `--authenticated-emails-file=/path/to/file` with one email per line. To authorize all email addresse use `--email-domain=*`.
`oauth2_proxy` can be configured via [config file](#config-file), [command line options](#command-line-options) or [environment variables](#environment-variables).
An example [oauth2_proxy.cfg](contrib/oauth2_proxy.cfg.example) config file is in the contrib directory. It can be used by specifying `-config=/etc/oauth2_proxy.cfg`
`oauth2_proxy` supports having multiple upstreams, and has the option to pass requests on to HTTP(S) servers or serve static files from the file system. HTTP and HTTPS upstreams are configured by providing a URL such as `http://127.0.0.1:8080/` for the upstream parameter, that will forward all authenticated requests to be forwarded to the upstream server. If you instead provide `http://127.0.0.1:8080/some/path/` then it will only be requests that start with `/some/path/` which are forwarded to the upstream.
Static file paths are configured as a file:// URL. `file:///var/www/static/` will serve the files from that directory at `http://[oauth2_proxy url]/var/www/static/`, which may not be what you want. You can provide the path to where the files should be available by adding a fragment to the configured URL. The value of the fragment will then be used to specify which path the files are available at. `file:///var/www/static/#/static/` will ie. make `/var/www/static/` available at `http://[oauth2_proxy url]/static/`.
Multiple upstreams can either be configured by supplying a comma separated list to the `-upstream` parameter, supplying the parameter multiple times or provinding a list in the [config file](#config-file). When multiple upstreams are used routing to them will be based on the path they are set up with.
The environment variables `OAUTH2_PROXY_CLIENT_ID`, `OAUTH2_PROXY_CLIENT_SECRET`, `OAUTH2_PROXY_COOKIE_SECRET`, `OAUTH2_PROXY_COOKIE_DOMAIN` and `OAUTH2_PROXY_COOKIE_EXPIRE` can be used in place of the corresponding command-line arguments.
OAuth2 Proxy responds directly to the following endpoints. All other endpoints will be proxied upstream when authenticated. The `/oauth2` prefix can be changed with the `--proxy-prefix` config variable.
* /oauth2/auth - only returns a 202 Accepted response or a 401 Unauthorized response; for use with the [Nginx `auth_request` directive](#nginx-auth-request)
## <a name="nginx-auth-request"></a>Configuring for use with the Nginx `auth_request` directive
The [Nginx `auth_request` directive](http://nginx.org/en/docs/http/ngx_http_auth_request_module.html) allows Nginx to authenticate requests via the oauth2_proxy's `/auth` endpoint, which only returns a 202 Accepted response or a 401 Unauthorized response without proxying the request through. For example:
