API key and OPA
Learn how to combine the API key and OPA extauth modules to perform multi-step authentication for incoming requests.
When a client sends an API key to authenticate with another service in the cluster, the gateway proxy can extract and validate the API key by using the API key extauth module. In addition, if the API key contains additional metadata, such as the user ID or email address, you can specify these fields in the headersFromMetadataEntry section of your extauth policy. This way, Gloo Gateway can extract these metadata fields from the API key and add them as headers to the request. The headers and the API key are then forwarded to the OPA module where additional validation checks can be performed.
In this guide, you can try out different API key and OPA configurations, such as:
- Successfully validate requests with additional API key metadata by using the OPA extauth module.
- Deny requests that do not provide additional metadata in the API key.
- Create an OPA rule to allow only certain API keys.
If you import or export resources across workspaces, your policies might not apply. For more information, see Import and export policies.
Before you begin
This guide assumes that you use the same names for components like clusters, workspaces, and namespaces as in the getting started. If you have different names, make sure to update the sample configuration files in this guide.
- Set up Gloo Mesh Gateway in a single cluster.
- Install Bookinfo and other sample apps.
Configure an HTTP listener on your gateway and set up basic routing for the sample apps.
Make sure that the external auth service is installed and running. If not, install the external auth service.
kubectl get pods -A -l app=ext-auth-serviceMake sure that you have the following CLI tools, or something comparable:
base64to encode strings.
Configure API key and OPA external auth
Create an extauth server that you use to enforce the extauth policies in this guide.
kubectl apply -f - <<EOF apiVersion: admin.gloo.solo.io/v2 kind: ExtAuthServer metadata: name: ext-auth-server namespace: bookinfo spec: destinationServer: port: number: 8083 ref: cluster: $CLUSTER_NAME name: ext-auth-service namespace: gloo-mesh EOFCreate a Kubernetes secret that stores your API key and additional metadata, such as the user ID and email address.
kubectl -n bookinfo create secret generic user-glooy \ --type extauth.solo.io/apikey \ --from-literal=user-id=user-id-glooy \ --from-literal=user-email=glooy@solo.io \ --from-literal=user-name=glooy \ --from-literal=api-key=N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcyLabel the secret so that you can reference this secret in your extauth policy more easily.
kubectl -n bookinfo label secret user-glooy extauth=apikeyCreate a configmap for an OPA rule that validates the user’s email address that you added earlier. The following examples verifies that the email address in the
x-user-emailheader ends withsolo.io. Note that the OPA rules refers to thex-user-emailheader and not the actualuser-emailfield in the Kubernetes secret. The mapping of theuser-emailfield to thex-user-emailrequest header is done when you create the extauth policy in the next step.kubectl apply -f - <<EOF apiVersion: v1 kind: ConfigMap metadata: name: allow-api-key-from-trusted-email-domain namespace: bookinfo labels: team: infrastructure data: policy.rego: | package test default allow = false allow { endswith(input.state["x-user-email"], "@solo.io") } EOFCreate an extauth policy that references both the secret that contains the API key and the configmap with your OPA rule. In this example, you configure Gloo Mesh Gateway to extract the
user-emailfield from the API key and add it as thex-user-emailheader to the request so that it can be passed on to the OPA module for further validation.kubectl apply -f - <<EOF apiVersion: security.policy.gloo.solo.io/v2 kind: ExtAuthPolicy metadata: name: ratings-apikey namespace: bookinfo spec: applyToRoutes: - route: labels: route: ratings config: server: name: ext-auth-server namespace: bookinfo cluster: $CLUSTER_NAME glooAuth: configs: - name: APIKey apiKeyAuth: headerName: api-key headersFromMetadataEntry: x-user-email: name: user-email required: true k8sSecretApikeyStorage: labelSelector: extauth: apikey - name: opa opaAuth: modules: - name: allow-api-key-from-trusted-email-domain namespace: bookinfo query: "data.test.allow == true" EOFSend a request to the ratings app and pass the API key that you added to the Kubernetes secret.
- HTTP:
curl -vik --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy" - HTTPS:
curl -vik --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy"
Example output:
< HTTP/2 200 HTTP/2 200 < content-type: application/json content-type: application/json < date: Tue, 28 Mar 2023 20:16:40 GMT date: Tue, 28 Mar 2023 20:16:40 GMT < x-envoy-upstream-service-time: 5 x-envoy-upstream-service-time: 5 < server: istio-envoy server: istio-envoy * Connection #0 to host www.example.com left intact {"id":1,"ratings":{"Reviewer1":5,"Reviewer2":4}}%- HTTP:
Create another configmap and add an OPA rule that references metadata that does not exist in the API key.
kubectl apply -f - <<EOF apiVersion: v1 kind: ConfigMap metadata: name: allow-api-key-from-certain-cost-centers namespace: bookinfo labels: team: infrastructure data: policy.rego: | package test default allow = false allow { startswith(input.state["x-user-cost-center"], "733") } EOFUpdate the extauth policy to reference the new configmap.
kubectl apply -f - <<EOF apiVersion: security.policy.gloo.solo.io/v2 kind: ExtAuthPolicy metadata: name: ratings-apikey namespace: bookinfo spec: applyToRoutes: - route: labels: route: ratings config: server: name: ext-auth-server namespace: bookinfo cluster: $CLUSTER_NAME glooAuth: configs: - name: APIKey apiKeyAuth: headerName: api-key headersFromMetadataEntry: x-user-email: name: user-email required: true k8sSecretApikeyStorage: labelSelector: extauth: apikey - name: opa opaAuth: modules: - name: allow-api-key-from-certain-cost-centers namespace: bookinfo query: "data.test.allow == true" EOFSend another request to the ratings service. This time, the request is denied, because the new
user-cost-centermetadata field could not be extracted from the API key to be processed by the OPA module.- HTTP:
curl -vik --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy" - HTTPS:
curl -vik --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy"
Example output:
* Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)! < HTTP/2 403 HTTP/2 403 < date: Tue, 28 Mar 2023 20:51:24 GMT date: Tue, 28 Mar 2023 20:51:24 GMT < server: istio-envoy server: istio-envoy- HTTP:
Add the
user-cost-centerfield to the API key.kubectl -n bookinfo get secret user-glooy -o json | jq --arg cost_center "$(echo -n 73355 | base64)" '.data["user-cost-center"]=$cost_center' | kubectl apply -f -Update the extauth policy to add the `x-user-cost-center` to the `headersFromMetadataEntry` section so that the field can be extracted from the API key and passed to the OPA extauth module as a header.
12. Send another request to the ratings service. This time, the request succeeds as the```yaml kubectl apply -f - <<EOF apiVersion: security.policy.gloo.solo.io/v2 kind: ExtAuthPolicy metadata: name: ratings-apikey namespace: bookinfo spec: applyToRoutes: - route: labels: route: ratings config: server: name: ext-auth-server namespace: bookinfo cluster: $CLUSTER_NAME glooAuth: configs: - name: APIKey apiKeyAuth: headerName: api-key headersFromMetadataEntry: x-user-email: name: user-email required: true x-user-cost-center: name: user-cost-center required: true k8sSecretApikeyStorage: labelSelector: extauth: apikey - name: opa opaAuth: modules: - name: allow-api-key-from-certain-cost-centers namespace: bookinfo query: "data.test.allow == true" EOF ```user-cost-centercan be extracted and forwarded to the OPA extauth module for further validation.- HTTP:
curl -vik --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy" - HTTPS:
curl -vik --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy"
Example output:
* Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)! < HTTP/2 200 HTTP/2 200 < content-type: application/json content-type: application/json < date: Tue, 28 Mar 2023 20:54:17 GMT date: Tue, 28 Mar 2023 20:54:17 GMT < x-envoy-upstream-service-time: 3 x-envoy-upstream-service-time: 3 < server: istio-envoy server: istio-envoy- HTTP:
Create another configmap and add another OPA rule to verify the API key itself and deny requests that use a specific API key.
kubectl apply -f - <<EOF apiVersion: v1 kind: ConfigMap metadata: name: allow-api-key-from-allowlist namespace: bookinfo labels: team: infrastructure data: policy.rego: | package test default allow = false is_key_allowed = true { allowed_keys := { "N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy", "974b3a3f-0aa9-4a94-bfe7-3fd42942d5e3" } input.state["api_key_value"] == allowed_keys[_] } allow { # deny any keys listed in the allowed_keys array. not is_key_allowed } EOFUpdate the extauth policy to use the new OPA rule.
kubectl apply -f - <<EOF apiVersion: security.policy.gloo.solo.io/v2 kind: ExtAuthPolicy metadata: name: ratings-apikey namespace: bookinfo spec: applyToRoutes: - route: labels: route: ratings config: server: name: ext-auth-server namespace: bookinfo cluster: $CLUSTER_NAME glooAuth: configs: - name: APIKey apiKeyAuth: k8sSecretApikeyStorage: labelSelector: extauth: apikey - name: opa opaAuth: modules: - name: allow-api-key-from-allowlist namespace: bookinfo query: "data.test.allow == true" EOFSend another request to the ratings app. This time, the request is denied, because the API key that is used in the curl request is part of the API keys that are not allowed to be forwarded to the ratings app.
- HTTP:
curl -vik --resolve www.example.com:80:${INGRESS_GW_IP} http://www.example.com:80/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy" - HTTPS:
curl -vik --resolve www.example.com:443:${INGRESS_GW_IP} https://www.example.com:443/ratings/1 -i -H "api-key: N2YwMDIxZTEtNGUzNS1jNzgzLTRkYjAtYjE2YzRkZGVmNjcy"
Example output:
* Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)! < HTTP/2 403 HTTP/2 403 < date: Tue, 28 Mar 2023 20:54:45 GMT date: Tue, 28 Mar 2023 20:54:45 GMT < server: istio-envoy server: istio-envoy- HTTP:
Cleanup
You can optionally remove the resources that you set up as part of this guide.
kubectl delete extauthpolicy ratings-apikey -n bookinfo
kubectl delete configmap allow-api-key-from-allowlist -n bookinfo
kubectl delete configmap allow-api-key-from-certain-cost-centers -n bookinfo
kubectl delete configmap allow-api-key-from-trusted-email-domain -n bookinfo
kubectl delete secret user-glooy -n bookinfo
Known limitations
When you have multiple Kubernetes secrets that share the same label, and you use labels to reference the Kubernetes secret, the extauth policy passes the API key and metadata information from the first Kubernetes secret that is found to the OPA module.