Chapter 5. Tutorial: Using AWS WAF and Amazon CloudFront to protect Red Hat OpenShift Service on AWS workloads

Procedure

1. In your terminal, configure the following environment variables:

   $ export DOMAIN=apps.example.com
   $ export AWS_PAGER=""
   $ export CLUSTER_NAME=$(oc get infrastructure cluster -o=jsonpath="{.status.infrastructureName}"  | sed 's/-[a-z0-9]\{5\}$//')
   $ export REGION=$(oc get infrastructure cluster -o=jsonpath="{.status.platformStatus.aws.region}")
   $ export AWS_ACCOUNT_ID=$(aws sts get-caller-identity --query Account --output text)
   $ export SCRATCH="/tmp/${CLUSTER}/cloudfront-waf"
   $ mkdir -p ${SCRATCH}
   $ echo "Cluster: ${CLUSTER}, Region: ${REGION}, AWS Account ID: ${AWS_ACCOUNT_ID}"

2. Replace the DOMAIN value apps.example.com with the custom domain you want to use for the IngressController.

   Note

   The "Cluster" output from the previous command might be the name of your cluster, the internal ID of your cluster, or the cluster’s domain prefix. If you prefer to use another identifier, you can manually set this value by running the following command:

   $ export CLUSTER=my-custom-value

Procedure

1. Create a new TLS secret from a private key and a public certificate, where fullchain.pem is your full wildcard certificate chain (including any intermediaries) and privkey.pem is your wildcard certificate’s private key.

   Example

   $ oc -n openshift-ingress create secret tls waf-tls --cert=fullchain.pem --key=privkey.pem

2. Create a new IngressController resource:

   For example waf-ingress-controller.yaml:

   apiVersion: operator.openshift.io/v1
   kind: IngressController
   metadata:
     name: cloudfront-waf
     namespace: openshift-ingress-operator
   spec:
     domain: apps.example.com
     defaultCertificate:
       name: waf-tls
     endpointPublishingStrategy:
       loadBalancer:
         dnsManagementPolicy: Unmanaged
         providerParameters:
           aws:
             type: NLB
           type: AWS
         scope: External
       type: LoadBalancerService
     routeSelector:
       matchLabels:
        route: waf

   where:

   • domain: apps.example.com:: Replace with the custom domain you want to use for the IngressController.
   • routeSelector:: Filters the set of routes serviced by the Ingress Controller. In this tutorial, we will use the waf route selector, but if no value was to be provided, no filtering would occur.

3. Apply the IngressController:

   Example

   $ oc apply -f waf-ingress-controller.yaml

4. Verify that your IngressController has successfully created an external load balancer:

   $ oc -n openshift-ingress get service/router-cloudfront-waf

   Example output

   NAME                    TYPE           CLUSTER-IP      EXTERNAL-IP                                                                     PORT(S)                      AGE
   router-cloudfront-waf   LoadBalancer   172.30.16.141   a68a838a7f26440bf8647809b61c4bc8-4225395f488830bd.elb.us-east-1.amazonaws.com   80:30606/TCP,443:31065/TCP   2m19s

Procedure

1. Retrieve the newly created custom ingress controller’s NLB hostname:

   $ NLB=$(oc -n openshift-ingress get service router-cloudfront-waf \
     -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')

2. Import your certificate into Amazon Certificate Manager, where cert.pem is your wildcard certificate, fullchain.pem is your wildcard certificate’s chain and privkey.pem is your wildcard certificate’s private key.

   Note

   Regardless of what region your cluster is deployed, you must import this certificate to us-east-1 as Amazon CloudFront is a global AWS service.

   Example

   $ aws acm import-certificate --certificate file://cert.pem \
     --certificate-chain file://fullchain.pem \
     --private-key file://privkey.pem \
     --region us-east-1

3. Log into the AWS console to create a CloudFront distribution.

4. Configure the CloudFront distribution by using the following information:

   Note

   If an option is not specified in the table below, leave them the default (which may be blank).

   Expand

   Option	Value
   Origin domain	Output from the previous command [a]
   Name	rosa-waf-ingress [b]
   Viewer protocol policy	Redirect HTTP to HTTPS
   Allowed HTTP methods	GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE
   Cache policy	CachingDisabled
   Origin request policy	AllViewer
   Web Application Firewall (WAF)	Enable security protections
   Use existing WAF configuration	true
   Choose a web ACL	cloudfront-waf
   Alternate domain name (CNAME)	*.apps.example.com [c]
   Custom SSL certificate	Select the certificate you imported from the step above [d]

   Show more
   1. Run echo ${NLB} to get the origin domain.
   2. If you have multiple clusters, ensure the origin name is unique.
   3. This should match the wildcard domain you used to create the custom ingress controller.
   4. This should match the alternate domain name entered above.

5. Retrieve the Amazon CloudFront Distribution endpoint:

   $ aws cloudfront list-distributions --query "DistributionList.Items[?Origins.Items[?DomainName=='${NLB}']].DomainName" --output text

6. Update the DNS of your custom wildcard domain with a CNAME to the Amazon CloudFront Distribution endpoint from the step above.

   Example

   *.apps.example.com CNAME d1b2c3d4e5f6g7.cloudfront.net

Procedure

1. Create a new project for your sample application by running the following command:

   $ oc new-project hello-world

2. Deploy a hello world application:

   $ oc -n hello-world new-app --image=docker.io/openshift/hello-openshift

3. Create a route for the application specifying your custom domain name:

   Example

   $ oc -n hello-world create route edge --service=hello-openshift hello-openshift-tls \
   --hostname hello-openshift.${DOMAIN}

4. Label the route to admit it to your custom ingress controller:

   $ oc -n hello-world label route.route.openshift.io/hello-openshift-tls route=waf

Procedure

1. Test that the app is accessible behind Amazon CloudFront:

   Example

   $ curl "https://hello-openshift.${DOMAIN}"

   Example output

   Hello OpenShift!

2. Test that the WAF denies a bad request:

   Example

   $ curl -X POST "https://hello-openshift.${DOMAIN}" \
     -F "user='<script><alert>Hello></alert></script>'"

   Example output

   <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
   <HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
   <TITLE>ERROR: The request could not be satisfied</TITLE>
   </HEAD><BODY>
   <H1>403 ERROR</H1>
   <H2>The request could not be satisfied.</H2>
   <HR noshade size="1px">
   Request blocked.
   We can't connect to the server for this app or website at this time. There might be too much traffic or a configuration error. Try again later, or contact the app or website owner.
   <BR clear="all">
   If you provide content to customers through CloudFront, you can find steps to troubleshoot and help prevent this error by reviewing the CloudFront documentation.
   <BR clear="all">
   <HR noshade size="1px">
   <PRE>
   Generated by cloudfront (CloudFront)
   Request ID: nFk9q2yB8jddI6FZOTjdliexzx-FwZtr8xUQUNT75HThPlrALDxbag==
   </PRE>
   <ADDRESS>
   </ADDRESS>
   </BODY></HTML>

   The expected result is a 403 ERROR, which means the AWS WAF is protecting your application.