A minimal forward authentication service that provides OAuth/SSO login and authentication for the traefik reverse proxy/load balancer.
Why?
- Seamlessly overlays any http service with a single endpoint (see:
url-path
in Configuration) - Supports multiple providers including Google and OpenID Connect (supported by Azure, Github, Salesforce etc.)
- Supports multiple domains/subdomains by dynamically generating redirect_uri's
- Allows authentication to be selectively applied/bypassed based on request parameters (see
rules
in Configuration)) - Supports use of centralised authentication host/redirect_uri (see
auth-host
in Configuration)) - Allows authentication to persist across multiple domains (see Cookie Domains)
- Supports extended authentication beyond Google token lifetime (see:
lifetime
in Configuration)
Contents
Releases
We recommend using the 2
tag on docker hub.
You can also use the latest incremental releases found on docker hub and github.
Upgrade Guide
v2 was released in June 2019, whilst this is fully backwards compatible, a number of configuration options were modified, please see the upgrade guide to prevent warnings on startup and ensure you are using the current configuration.
Usage
Simple:
See below for instructions on how to setup your Provider Setup.
docker-compose.yml:
version: '3'
services:
traefik:
image: traefik:1.7
ports:
- "8085:80"
volumes:
- ./traefik.toml:/traefik.toml
- /var/run/docker.sock:/var/run/docker.sock
traefik-forward-auth:
image: thomseddon/traefik-forward-auth:2
environment:
- PROVIDERS_GOOGLE_CLIENT_ID=your-client-id
- PROVIDERS_GOOGLE_CLIENT_SECRET=your-client-secret
- SECRET=something-random
- INSECURE_COOKIE=true # Example assumes no https, do not use in production
whoami:
image: emilevauge/whoami:latest
labels:
- "traefik.frontend.rule=Host:whoami.mycompany.com"
traefik.toml:
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.auth.forward]
address = "http://traefik-forward-auth:4181"
authResponseHeaders = ["X-Forwarded-User"]
[docker]
endpoint = "unix:///var/run/docker.sock"
network = "traefik"
Advanced:
Please see the examples directory for a more complete docker-compose.yml and full traefik.toml.
Also in the examples directory is docker-compose-auth-host.yml which shows how to configure a central auth host, along with some other options.
Provider Setup
Head to https://console.developers.google.com and make sure you've switched to the correct email account.
Create a new project then search for and select "Credentials" in the search bar. Fill out the "OAuth Consent Screen" tab.
Click "Create Credentials" > "OAuth client ID". Select "Web Application", fill in the name of your app, skip "Authorized JavaScript origins" and fill "Authorized redirect URIs" with all the domains you will allow authentication from, appended with the url-path
(e.g. https://app.test.com/_oauth)
You must set the providers.google.client-id
and providers.google.client-secret
config options.
OpenID Connect
Any provider that supports OpenID Connect 1.0 can be configured via the OIDC config options below.
You must set the providers.oidc.issuer-url
, providers.oidc.client-id
and providers.oidc.client-secret
config options.
Configuration
Overview
The following configuration options are supported:
Usage:
traefik-forward-auth [OPTIONS]
Application Options:
--log-level=[trace|debug|info|warn|error|fatal|panic] Log level (default: warn) [$LOG_LEVEL]
--log-format=[text|json|pretty] Log format (default: text) [$LOG_FORMAT]
--auth-host= Single host to use when returning from 3rd party auth [$AUTH_HOST]
--config= Path to config file [$CONFIG]
--cookie-domain= Domain to set auth cookie on, can be set multiple times [$COOKIE_DOMAIN]
--insecure-cookie Use insecure cookies [$INSECURE_COOKIE]
--cookie-name= Cookie Name (default: _forward_auth) [$COOKIE_NAME]
--csrf-cookie-name= CSRF Cookie Name (default: _forward_auth_csrf) [$CSRF_COOKIE_NAME]
--default-action=[auth|allow] Default action (default: auth) [$DEFAULT_ACTION]
--default-provider=[google|oidc] Default provider (default: google) [$DEFAULT_PROVIDER]
--domain= Only allow given email domains, can be set multiple times [$DOMAIN]
--lifetime= Lifetime in seconds (default: 43200) [$LIFETIME]
--url-path= Callback URL Path (default: /_oauth) [$URL_PATH]
--secret= Secret used for signing (required) [$SECRET]
--whitelist= Only allow given email addresses, can be set multiple times [$WHITELIST]
--rule.<name>.<param>= Rule definitions, param can be: "action", "rule" or "provider"
Google Provider:
--providers.google.client-id= Client ID [$PROVIDERS_GOOGLE_CLIENT_ID]
--providers.google.client-secret= Client Secret [$PROVIDERS_GOOGLE_CLIENT_SECRET]
--providers.google.prompt= Space separated list of OpenID prompt options [$PROVIDERS_GOOGLE_PROMPT]
OIDC Provider:
--providers.oidc.issuer-url= Issuer URL [$PROVIDERS_OIDC_ISSUER_URL]
--providers.oidc.client-id= Client ID [$PROVIDERS_OIDC_CLIENT_ID]
--providers.oidc.client-secret= Client Secret [$PROVIDERS_OIDC_CLIENT_SECRET]
Help Options:
-h, --help Show this help message
All options can be supplied in any of the following ways, in the following precedence (first is highest precedence):
- Command Arguments/Flags - As shown above
- Environment Variables - As shown in square brackets above
- File
- Use INI format (e.g.
url-path = _oauthpath
) - Specify the file location via the
--config
flag or$CONFIG
environment variable - Can be specified multiple times, each file will be read in the order they are passed
- Use INI format (e.g.
Option Details
-
auth-host
When set, when a user returns from authentication with a 3rd party provider they will always be forwarded to this host. By using one central host, this means you only need to add this
auth-host
as a valid redirect uri to your 3rd party provider.The host should be specified without protocol or path, for example:
--auth-host="auth.example.com"
For more details, please also read the Auth Host Mode, operation mode in the concepts section.
Please Note - this should be considered advanced usage, if you are having problems please try disabling this option and then re-read the Auth Host Mode section.
-
config
Used to specify the path to a configuration file, can be set multiple times, each file will be read in the order they are passed. Options should be set in an INI format, for example:
url-path = _oauthpath
-
cookie-domain
When set, if a user successfully completes authentication, then if the host of the original request requiring authentication is a subdomain of a given cookie domain, then the authentication cookie will be set for the higher level cookie domain. This means that a cookie can allow access to multiple subdomains without re-authentication. Can be specificed multiple times.
For example:
--cookie-domain="example.com" --cookie-domain="test.org"
For example, if the cookie domain
test.com
has been set, and a request comes in onapp1.test.com
, following authentication the auth cookie will be set for the wholetest.com
domain. As such, if another request is forwarded for authentication fromapp2.test.com
, the original cookie will be sent and so the request will be allowed without further authentication.Beware however, if using cookie domains whilst running multiple instances of traefik/traefik-forward-auth for the same domain, the cookies will clash. You can fix this by using a different
cookie-name
in each host/cluster or by using the samecookie-secret
in both instances. -
insecure-cookie
If you are not using HTTPS between the client and traefik, you will need to pass the
insecure-cookie
option which will mean theSecure
attribute on the cookie will not be set. -
cookie-name
Set the name of the cookie set following successful authentication.
Default:
_forward_auth
-
csrf-cookie-name
Set the name of the temporary CSRF cookie set during authentication.
Default:
_forward_auth_csrf
-
default-action
Specifies the behavior when a request does not match any rules. Valid options are
auth
orallow
.Default:
auth
(i.e. all requests require authentication) -
default-provider
Set the default provider to use for authentication, this can be overridden within rules. Valid options are currently
google
oroidc
.Default:
google
-
domain
When set, only users matching a given domain will be permitted to access.
For example, setting
--domain=example.com --domain=test.org
would mean that only users from example.com or test.org will be permitted. So thom@example.com would be allowed but thom@another.com would not.For more details, please also read User Restriction in the concepts section.
-
lifetime
How long a successful authentication session should last, in seconds.
Default:
43200
(12 hours) -
url-path
Customise the path that this service uses to handle the callback following authentication.
Default:
/_oauth
Please note that when using the default Overlay Mode requests to this exact path will be intercepted by this service and not forwarded to your application. Use this option (or Auth Host Mode) if the default
/_oauth
path will collide with an existing route in your application. -
secret
Used to sign cookies authentication, should be a random (e.g.
openssl rand -hex 16
) -
whitelist
When set, only specified users will be permitted.
For example, setting
--whitelist=thom@example.com --whitelist=alice@example.com
would mean that only those two exact users will be permitted. So thom@example.com would be allowed but john@example.com would not.For more details, please also read User Restriction in the concepts section.
-
rule
Specify selective authentication rules. Rules are specified in the following format:
rule.<name>.<param>=<value>
<name>
can be any string and is only used to group rules together<param>
can be:action
- same usage asdefault-action
, supported values:auth
(default)allow
provider
- same usage asdefault-provider
, supported values:google
oidc
rule
- a rule to match a request, this uses traefik's v2 rule parser for which you can find the documentation here: https://docs.traefik.io/v2.0/routing/routers/#rule, supported values are summarised here:Headers(`key`, `value`)
HeadersRegexp(`key`, `regexp`)
Host(`example.com`, ...)
HostRegexp(`example.com`, `{subdomain:[a-z]+}.example.com`, ...)
Method(methods, ...)
Path(`path`, `/articles/{category}/{id:[0-9]+}`, ...)
PathPrefix(`/products/`, `/articles/{category}/{id:[0-9]+}`)
Query(`foo=bar`, `bar=baz`)
For example:
# Allow requests that being with `/api/public` and contain the `Content-Type` header with a value of `application/json` rule.1.action = allow rule.1.rule = PathPrefix(`/api/public`) && Headers(`Content-Type`, `application/json`) # Allow requests that have the exact path `/public` rule.two.action = allow rule.two.rule = Path(`/public`) # Use OpenID Connect provider (must be configured) for requests that begin with `/github` rule.oidc.action = auth rule.oidc.provider = oidc rule.oidc.rule = PathPrefix(`/github`)
Concepts
User Restriction
You can restrict who can login with the following parameters:
domain
- Use this to limit logins to a specific domain, e.g. test.com onlywhitelist
- Use this to only allow specific users to login e.g. thom@test.com only
Note, if you pass whitelist
then only this is checked and domain
is effectively ignored.
Forwarded Headers
The authenticated user is set in the X-Forwarded-User
header, to pass this on add this to the authResponseHeaders
config option in traefik, as shown here.
Operation Modes
Overlay Mode
Overlay is the default operation mode, in this mode the authorisation endpoint is overlaid onto any domain. By default the /_oauth
path is used, this can be customised using the url-path
option.
The user flow will be:
- Request to
www.myapp.com/home
- User redirected to Google login
- After Google login, user is redirected to
www.myapp.com/_oauth
- Token, user and CSRF cookie is validated (this request in intercepted and is never passed to your application)
- User is redirected to
www.myapp.com/home
- Request is allowed
As the hostname in the redirect_uri
is dynamically generated based on the original request, every hostname must be permitted in the Google OAuth console (e.g. www.myappp.com
would need to be added in the above example)
Auth Host Mode
This is an optional mode of operation that is useful when dealing with a large number of subdomains, it is activated by using the auth-host
config option (see this example docker-compose.yml).
For example, if you have a few applications: app1.test.com
, app2.test.com
, appN.test.com
, adding every domain to Google's console can become laborious.
To utilise an auth host, permit domain level cookies by setting the cookie domain to test.com
then set the auth-host
to: auth.test.com
.
The user flow will then be:
- Request to
app10.test.com/home/page
- User redirected to Google login
- After Google login, user is redirected to
auth.test.com/_oauth
- Token, user and CSRF cookie is validated, auth cookie is set to
test.com
- User is redirected to
app10.test.com/home/page
- Request is allowed
With this setup, only auth.test.com
must be permitted in the Google console.
Two criteria must be met for an auth-host
to be used:
- Request matches given
cookie-domain
auth-host
is also subdomain of samecookie-domain
Please note: For Auth Host mode to work, you must ensure that requests to your auth-host are routed to the traefik-forward-auth container, as demonstrated with the service labels in the docker-compose-auth.yml example.
Copyright
2018 Thom Seddon