Protecting Jaeger UI with a sidecar security proxy

A blog post by Juraci Paixão Kröhling

In a production deployment of Jaeger, it may be advantageous to restrict access to Jaeger’s Query service, which includes the UI. For instance, you might have internal security requirements to allow only certain groups to access trace data, or you might have deployed Jaeger into a public cloud. In a true microservices way, one possible approach is to add a sidecar to the Jaeger Query service, acting as a security proxy. Incoming requests hit our sidecar instead of reaching Jaeger’s Query service directly and the sidecar would be responsible for enforcing the authentication and authorization constraints.

Incoming HTTP requests arrive at the route ①, which uses the internal service ② to resolve and communicate with the security proxy ③. Once the request is validated and all security constraints are satisfied, the request reaches Jaeger ④.

A newer version of this blog post is available on Jaeger’s blog

For demonstration purposes we’ll make use of Keycloak as our security solution, but the idea can be adapted to work with any security proxy. This demo should also work without changes with Red Hat SSO. For this exercise, we’ll need:

A Keycloak (or Red Hat SSO) server instance running. We’ll call its location ${REDHAT_SSO_URL}
An OpenShift cluster, where we’ll run Jaeger backend components. It might be as easy as oc cluster up
A local clone of the Jaeger OpenShift Production template

Note that we are not trying to secure the communication between the components, like from the Agent to the Collector. For this scenario, there are other techniques that can be used, such as mutual authentication via certificates, employing istio or other similar tools.

Preparing Keycloak

For this demo, we’ll run Keycloak via Docker directly on the host machine. This is to stress that Keycloak does not need to be running on the same OpenShift cluster as our Jaeger backend.

The following command should start an appropriate Keycloak server locally. If you already have your own Keycloak or Red Hat SSO server, skip this step.

docker run --rm --name keycloak-server -e KEYCLOAK_USER=admin -e KEYCLOAK_PASSWORD=password -p 8080:8080 jboss/keycloak

Once the Keycloak server is up and running, let’s create a realm for Jaeger:

Login into Keycloak (http://<YOUR_IP>:8080/auth/admin/master/console) with admin as username and password as password
In the top left corner, mouse over the Select realm box and click Add realm. Name it jaeger and click Create
On Clients, click Create and set proxy-jaeger as the name and save it
Set the Access Type to confidential and * as Valid Redirect URIs and save it. You might want to fine tune this in a production environment, otherwise you might be open to an attack known as "Unvalidated Redirects and Forwards".
Open the Installation tab and select Keycloak OIDC JSON and copy the JSON that is shown. It should look like this, but the auth-server-url and secret will have different values.

{
  "realm": "jaeger",
  "auth-server-url": "http://192.168.2.111:8080/auth",
  "ssl-required": "external",
  "resource": "proxy-jaeger",
  "credentials": {
    "secret": "7f201319-1dfd-43cc-9838-057dac439046"
  }
}

And finally, let’s create a role and a user, so that we can log into Jaeger’s Query service:

Under the Configure left-side menu, open the Roles page and click Add role
As role name, set user and click Save
Under the Manage left-side menu, open the Users page and click Add user
Fill out the form as you wish and set Email verified to ON and click on Save
Open the Credentials tab for this user and set a password (temporary or not).
Open the Role mappings tab for this user, select the role user from the Available Roles list and click Add selected

Preparing OpenShift

For this demo, we assume you have an OpenShift cluster running already. If you don’t, then you might want to check out tools like minishift. If you are running a recent version of Fedora, CentOS or Red Hat Enterprise Linux you might want to install the package origin-clients and run oc cluster up --version=latest. This should get you a basic OpenShift cluster running locally.

To make it easier for our demonstration, we’ll add cluster-admin rights to our developer user and we’ll create the Jaeger namespace:

oc login -u system:admin
oc new-project jaeger
oc adm policy add-cluster-role-to-user cluster-admin developer -n jaeger
oc login -u developer

Preparing the Jaeger OpenShift template

We’ll use the Jaeger OpenShift Production template as the starting point: either clone the entire repository, or just get a local version of the template.

The first step is to add the sidecar container to the query-deployment object. Under the containers list, after we specify the jaeger-query, let’s add the sidecar:

        - image: jboss/keycloak-proxy
          name: ${JAEGER_SERVICE_NAME}-query-security-proxy
          volumeMounts:
          - mountPath: /opt/jboss/conf
            name: security-proxy-configuration-volume
          ports:
          - containerPort: 8080
            protocol: TCP
          readinessProbe:
            httpGet:
              path: "/"
              port: 8080

Note that container specifies a volumeMount named security-proxy-configuration-volume: we’ll use it to store the proxy’s configuration file. You should add the volume under the spec/template/spec node for query-deployment, sibling to the dnsPolicy property (it’s probably right under the previous code snippet):

        volumes:
          - configMap:
              name: ${JAEGER_SERVICE_NAME}-configuration
              items:
                - key: proxy
                  path: proxy.json
            name: security-proxy-configuration-volume

Now, we need to specify the ConfigMap, with the proxy’s configuration entry. To do that, we add a new top-level item to the template. As a suggestion, we recommend keeping it close to where it’s consumed. For instance, right before the query-deployment:

- apiVersion: v1
  kind: ConfigMap
  metadata:
    name: ${JAEGER_SERVICE_NAME}-configuration
    labels:
      app: jaeger
      jaeger-infra: security-proxy-configuration
  data:
    proxy: |
      {
          "target-url": "http://localhost:16686",
          "bind-address": "0.0.0.0",
          "http-port": "8080",
          "applications": [
              {
                  "base-path": "/",
                  "adapter-config": {
                    "realm": "jaeger",
                    "auth-server-url": "${REDHAT_SSO_URL}",
                    "ssl-required": "external",
                    "resource": "proxy-jaeger",
                    "credentials": {
                      "secret": "THE-SECRET-FROM-INSTALLATION-FILE"
                    }
                  }
            ,
            "constraints": [
                      {
                          "pattern": "/*",
                          "roles-allowed": [
                              "user"
                          ]
                      }
                  ]
              }
          ]
      }

Note that we are only allowing users with the role user to log into our Jaeger UI. In a real world scenario, you might want to adjust this to fit your setup. For instance, your user data might come from LDAP, and you only want to allow users from specific LDAP groups to access the Jaeger UI.

The secret within the credentials should match the secret we got from Keycloak at the beginning of this exercise. Our most curious readers will note that we mentioned the template parameter REDHAT_SSO_URL under the property auth-server-url. Either change that to your Keycloak server, or let’s specify a template parameter, allowing us to set this at deployment time. Under the parameters section of the template, add the following property:

- description: The URL to the Red Hat SSO / Keycloak server
  displayName: Red Hat SSO URL
  name: REDHAT_SSO_URL
  required: true
  value: http://THE-URL-FROM-THE-INSTALLATION-FILE:8080/auth

This value should be a location that is reacheable by both your browser and by the sidecar, like your host’s LAN IP (192.x, 10.x). Localhost/127.x is not going to work.

As a final step, we need to change the service to direct requests to the port 8080 (proxy) instead of 16686. This is done by changing the property targetPort on the service named query-service, setting it to 8080:

- apiVersion: v1
  kind: Service
  metadata:
    name: ${JAEGER_SERVICE_NAME}-query
    labels:
      app: jaeger
      jaeger-infra: query-service
  spec:
    ports:
    - name: jaeger-query
      port: 80
      protocol: TCP
      targetPort: 8080
    selector:
      jaeger-infra: query-pod
    type: LoadBalancer

As a reference, here’s the complete template file that can be used for this blog post.

Deploying

Now that we have everything ready, let’s deploy Jaeger into our OpenShift cluster. Run the following command from the same directory you stored the YAML file from the previous steps, referenced here by the name jaeger-production-template.yml:

oc process -f jaeger-production-template.yml | oc create -n jaeger -f -

During the first couple of minutes, it’s OK if the pods jaeger-query and jaeger-collector fail, as Cassandra will still be booting. Eventually, the service should be up and running, as shown in the following image.

Once it is ready to serve requests, click on URL for the route (https://jaeger-query-jaeger.127.0.0.1.nip.io). You should be presented with a login screen, served by the Keycloak server. Login with the credentials you set on the previous steps, and you should reach the regular Jaeger UI.

Conclusion

In this exercise, we’ve seen how to add a security proxy to our Jaeger Query pod as a sidecar. All incoming requests go through this sidecar and all features available in Keycloak can be used transparently, such as 2-Factor authentication, service accounts, single sign-on, brute force attack protection, LDAP support and much more.

Published by Juraci Paixão Kröhling on 18 July 2017