Authenticate with Dex
Dex is an OpenID Connect identity hub. Dex can be used to expose a consistent
OpenID Connect interface to your applications while allowing your users to authenticate using their existing credentials
from various back-ends, including LDAP, SAML, and other OIDC providers. Using an identity hub like Dex has the advantage
of allowing you to change your authentication back-ends without affecting the rest of the system.
You can also use Dex for authentication to the Kubernetes API server itself; for example, to allow LDAP logins to work
kubectl. This is outside the scope of this document, but you can read more about it
In this guide we will see how to authenticate users with your application via an OIDC flow that uses Dex as an identity provider. This guide is just an example to get you started and does not cover all aspects of a complete setup, like setting up a domain and SSL certificates.
This guide assumes that you have deployed Gloo to the
gloo-system namespace and that the
glooctl command line utility
is installed on your machine.
glooctl provides several convenient functions to view, manipulate, and debug Gloo resources;
in particular, it is worth mentioning the following command, which we will use each time we need to retrieve the URL of
the Gloo Gateway that is running inside your cluster:
glooctl proxy url
Deploy sample application
petclinic application deploys a MySql server. If you are using
minikube v1.5 to run this guide, this
service is likely to crash due a
To get around this, you can start
minikube with the following flag:
minikube start --docker-opt="default-ulimit=nofile=102400:102400"
Let’s deploy a sample web application that we will use to demonstrate these features:
kubectl apply -f https://raw.githubusercontent.com/solo-io/gloo/v0.8.4/example/petclinic/petclinic.yaml
Creating a Virtual Service
Now we can create a Virtual Service that routes all requests (note the
/ prefix) to the
apiVersion: gateway.solo.io/v1 kind: VirtualService metadata: name: petclinic namespace: gloo-system spec: virtualHost: domains: - '*' routes: - matchers: - prefix: / routeAction: single: kube: ref: name: petclinic namespace: default port: 80
To verify that the Virtual Service has been accepted by Gloo, let’s port-forward the Gateway Proxy service so that it is
reachable from your machine at
kubectl -n gloo-system port-forward svc/gateway-proxy 8080:80
If you open your browser and navigate to http://localhost:8080 you should see the following page (you might need to wait a minute for the containers to start):
Securing the Virtual Service
As we just saw, we were able to reach our application without having to provide any credentials. This is because by default Gloo allows any request on routes that do not specify authentication configuration. Let’s change this behavior. We will update the Virtual Service so that each request to the sample application is authenticated using an OpenID Connect flow.
To implement the authentication flow, we need an OpenID Connect provider to be running in your cluster. To this end, we will deploy the Dex identity service, as it easy to install and configure.
Let’s start by defining a
dex-values.yaml Helm values file with some bootstrap configuration for Dex:
cat > dex-values.yaml <<EOF config: # The base path of dex and the external name of the OpenID Connect service. # This is the canonical URL that all clients MUST use to refer to dex. If a # path is provided, dex's HTTP service will listen at a non-root URL. issuer: http://dex.gloo-system.svc.cluster.local:32000 # Instead of reading from an external storage, use this list of clients. staticClients: - id: gloo redirectURIs: - 'http://localhost:8080/callback' name: 'GlooApp' secret: secretvalue # A static list of passwords to login the end user. By identifying here, dex # won't look in its underlying storage for passwords. staticPasswords: - email: "email@example.com" # bcrypt hash of the string "password" hash: "\$2a\$10\$2b2cU8CPhOTaGrs1HRQuAueS7JTT5ZHsHSzYiFPm1leZck7Mc8T4W" username: "admin" userID: "08a8684b-db88-4b73-90a9-3cd1661f5466" EOF
This configures Dex with a static users. Notice how we choose a client secret with value
for the client named
gloo. Gloo will need to provide this secret when connecting to Dex in order to confirm its identity.
Using this configuration, we can deploy Dex to our cluster using Helm.
help repo list doesn’t list the
stable repo, invoke:
helm repo add stable https://kubernetes-charts.storage.googleapis.com
And then install dex (helm 3 command follows):
helm install dex --namespace gloo-system stable/dex -f dex-values.yaml
Make the client secret accessible to Gloo
To be able to act as our OIDC client, Gloo needs to have access to the client secret we defined in the Dex configuration,
so that it can use it to identify itself with the Dex authorization server. Gloo expects the client secret to be stored
in a specific format inside of a Kubernetes
Let’s create the secret and name it
glooctl create secret oauth --client-secret secretvalue oauth
apiVersion: v1 kind: Secret type: Opaque metadata: annotations: resource_kind: '*v1.Secret' name: oauth namespace: gloo-system data: # The value is a base64 encoding of the following YAML: # client_secret: secretvalue # Gloo expects OAuth client secrets in this format. oauth: Y2xpZW50U2VjcmV0OiBzZWNyZXR2YWx1ZQo=
Create an AuthConfig
The auth configuration format shown on this page was introduced with Gloo Enterprise, release 0.20.1. If you are using an earlier version, please refer to this page to see which configuration formats are supported by each version.
Now that all the necessary resources are in place we can create the
AuthConfig resource that we will use to secure our
apiVersion: enterprise.gloo.solo.io/v1 kind: AuthConfig metadata: name: oidc-dex namespace: gloo-system spec: configs: - oauth: app_url: http://localhost:8080/ callback_path: /callback client_id: gloo client_secret_ref: name: oauth namespace: gloo-system issuer_url: http://dex.gloo-system.svc.cluster.local:32000/ scopes: - email
The above configuration instructs Gloo to use its extauth OIDC module to authenticate the incoming request. Notice how the configuration references the client secret we created earlier and compare the configuration values with the ones we used to bootstrap Dex.
Update the Virtual Service
Once the AuthConfig has been created, we can use it to secure our Virtual Service:
apiVersion: gateway.solo.io/v1 kind: VirtualService metadata: name: petclinic namespace: gloo-system spec: virtualHost: domains: - '*' routes: - matchers: - prefix: / routeAction: single: kube: ref: name: petclinic namespace: default port: 80 options: extauth: configRef: name: oidc-dex namespace: gloo-system
Note this is a simplistic example that has a
/ catch-all path prefix route. Gloo needs to handle the
/callback route and does so in the External Auth service. If you don’t have a matching route (ie, either using a
/callback) for the
callback setting, you’ll see
404s when the Identity Provider tries to callback to Gloo with the correct tokens. Please reach out to us on the Slack if you run into trouble here.
Testing our configuration
The OIDC flow redirects the client (in this case, your browser) to a login page hosted by Dex. Since Dex is running in your cluster and is not publicly reachable, we need some additional configuration to make our example work. Please note that this is just a workaround to reduce the amount of configuration necessary for this example to work.
Port-forward the Dex service so that it is reachable from your machine at
kubectl -n gloo-system port-forward svc/dex 32000:32000 & portForwardPid1=$! # Store the port-forward pid so we can kill the process later
Add an entry to the
/etc/hostsfile on your machine, mapping the
dex.gloo-system.svc.cluster.localhostname to your
localhost(the loopback IP address
echo "127.0.0.1 dex.gloo-system.svc.cluster.local" | sudo tee -a /etc/hosts
Port-forward the Gloo Gateway Proxy service so that it is reachable from your machine at
kubectl -n gloo-system port-forward svc/gateway-proxy 8080:80 & portForwardPid2=$! # Store the port-forward pid so we can kill the process later
Now we are ready to test our complete setup! Open you browser and navigate to http://localhost:8080. You should see the following login page:
If you login as the
firstname.lastname@example.org user with the password
password, Gloo should redirect you to the main page
of our sample application!
You can clean up the resources created in this guide by running:
sudo sed '/127.0.0.1 dex.gloo-system.svc.cluster.local/d' /etc/hosts # remove line from hosts file kill $portForwardPid1 kill $portForwardPid2 rm dex-values.yaml helm delete --purge dex kubectl delete -n gloo-system secret oauth dex-grpc-ca dex-grpc-client-tls dex-grpc-server-tls dex-web-server-ca dex-web-server-tls kubectl delete virtualservice -n gloo-system petclinic kubectl delete authconfig -n gloo-system oidc-dex kubectl delete -f https://raw.githubusercontent.com/solo-io/gloo/v0.8.4/example/petclinic/petclinic.yaml