Keycloak Proxy

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Keycloak-proxy is a proxy service which at the risk of stating the obvious integrates with the Keycloak authentication service. The configuration and feature set is based on the actual java version of the proxy. The

[jest@starfury keycloak-proxy]$ bin/keycloak-proxy --help
Usage of bin/keycloak-proxy:
  -alsologtostderr         log to standard error as well as files
  -config string           the path to the configuration file for the keycloak proxy service, in yaml or json format
  -httptest.serve string   if non-empty, httptest.NewServer serves on this address and blocks
  -log_backtrace_at value  when logging hits line file:N, emit a stack trace (default :0)
  -log_dir string          If non-empty, write log files in this directory
  -logtostderr             log to standard error instead of files
  -stderrthreshold value   logs at or above this threshold go to stderr
  -v value                 log level for V logs
  -vmodule value           comma-separated list of pattern=N settings for file-filtered logging

Configuration

# is the url for retrieve the openid configuration - normally the <server>/auth/realm/<realm_name>
discovery_url: https://keycloak.example.com/auth/realms/<REALM_NAME>
# the client id for the 'client' application
clientid: <CLIENT_ID>
# the secret associated to the 'client' application
secret: <CLIENT_SECRET>
# the interface definition you wish the proxy to listen, all interfaces is specified as ':<port>'
listen: 127.0.0.1:3000
# whether to request offline access and use a refresh token
refresh_session: true
# assuming you are using refresh tokens, specify the maximum amount of time the refresh token can last
max_session: 1h
# the location of a certificate you wish the proxy to use for TLS support
tls_cert:
# the location of a private key for TLS
tls_private_key:
# the redirection url, essentially the site url, note: /oauth/callback is added at the end
redirection_url: http://127.0.0.3000
# the encryption key used to encode the session state
encryption_key: <ENCRYPTION_KEY>
# the upstream endpoint which we should proxy request
upstream: http://127.0.0.1:80
# additional scopes to add to add to the default (openid+email+profile)
scopes:
  - vpn-user

# a collection of resource i.e. urls that you wish to protect
resources:
  - url: /admin/test
    # the methods on this url that should be protected, if missing, we assuming all
    methods:
      - GET
    # a list of roles the user must have in order to accces urls under the above
    roles_allowed:
      - openvpn:vpn-user
      - openvpn:prod-vpn
      - test
  - url: /admin
    methods:
      - GET
    roles_allowed:
      - openvpn:vpn-user
      - openvpn:commons-prod-vpn

Example Usage

Assuming you have some web service you wish protected by Keycloak;

a) Create the client under the Keycloak GUI or CLI; the client protocol is 'openid-connect', access-type: confidential. b) Add a Valid Redirect URIs of http://127.0.0.1:3000/oauth/callback. c) Grab the client id and client secret. d) Create the various roles under the client or existing clients for authorization purposes.

The default config

discovery_url: https://keycloak.example.com/auth/realms/<REALM_NAME>
clientid: <CLIENT_ID>
secret: <CLIENT_SECRET>
listen: 127.0.0.1:3000
redirection_url: http://127.0.0.3000
refresh_session: false
encryption_key: AgXa7xRcoClDEU0ZDSH4X0XhL5Qy2Z2j
upstream: http://127.0.0.1:80

resources:
  - url: /admin
    methods:
      - GET
    roles_allowed:
      - <CLIENT_APP_NAME>:<ROLE_NAME>
      - <CLIENT_APP_NAME>:<ROLE_NAME>

Below is a sample kubeconfig file with two contexts for dev and prod clusters, the file is placed / located at ~/.kube/config by default. You can find a cheat-sheet for the kubectl command here

Upstream Headers

On protected resources the upstream endpoint will receive a number of headers added by the proxy;

cx.Request.Header.Add("KEYCLOAK_SUBJECT", id.preferredName)
cx.Request.Header.Add("KEYCLOAK_USERNAME", id.name)
cx.Request.Header.Add("KEYCLOAK_EMAIL", id.email)
cx.Request.Header.Add("KEYCLOAK_EXPIRES_IN", id.expiresAt.String())
cx.Request.Header.Add("KEYCLOAK_ACCESS_TOKEN", id.token.Encode())
cx.Request.Header.Add("KEYCLOAK_ROLES", strings.Join(id.roles, ","))

# plus the default
cx.Request.Header.Add("X-Forwarded-For", <CLIENT_IP>)
cx.Request.Header.Add("X-Forwarded-Proto", <CLIENT_PROTO>)

Encryption Key

In order to remain stateless and not have to rely on a central cache to persist the 'refresh_tokens', the refresh token is encrypted and added as a cookie using crypto/aes. Naturally the key must be the same if your running behind a load balancer etc.