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[SOLVED] How to force SSL for Kubernetes Ingress on GKE - kubernetes

[SOLVED] A Simple Guide to Forcing SSL for Kubernetes Ingress on GKE

In today’s online world, we need to secure our applications with SSL (Secure Socket Layer). It is not just a good idea but very important. In this chapter, we will look at how to force SSL for Kubernetes Ingress on Google Kubernetes Engine (GKE). We will check out different solutions that can make our applications safer. These solutions also help users by sending HTTP traffic to HTTPS. Whether we are experienced with Kubernetes or just starting, this guide will help us understand how to set up SSL redirection in our GKE space.

Solutions We Will Talk About:

  • Solution 1 - Setting Up Ingress Resource with SSL Redirect
  • Solution 2 - Using Annotations to Force SSL
  • Solution 3 - Configuring Backend Service for HTTPS
  • Solution 4 - Creating a Global SSL Policy
  • Solution 5 - Testing SSL Redirection
  • Solution 6 - Troubleshooting Common Issues

By following this guide, we will learn to set up SSL redirection. We will also see some best ways to manage our Kubernetes Ingress resources. For more information on related topics, we can check these articles: Ingress vs. Load Balancer and Kubernetes Pod Memory Management. Let’s start to secure our Kubernetes applications with SSL!

Solution 1 - Setting Up Ingress Resource with SSL Redirect

We can force SSL for our Kubernetes Ingress on Google Kubernetes Engine (GKE) by setting up an Ingress resource with an SSL redirect. This setup makes sure that all HTTP traffic goes to HTTPS. This way, we get a secure connection for our applications.

Step-by-Step Configuration

  1. Create a TLS Secret: First, we need to create a TLS secret. This secret will hold our SSL certificate and key. We can make a self-signed certificate for testing or use one from a Certificate Authority (CA).

    kubectl create secret tls my-tls-secret --cert=path/to/tls.crt --key=path/to/tls.key

  2. Define the Ingress Resource: Next, we create an Ingress resource. This resource specifies the backend service and has the right annotations to force SSL redirection.

    Here is an example of a simple Ingress resource configuration:

    apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "gce"
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true" # Nginx specific annotation
spec:
  tls:
    - hosts:
        - your-domain.com
      secretName: my-tls-secret
  rules:
    - host: your-domain.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-service
                port:
                  number: 80

  3. Deploy the Ingress Resource: Now we apply the configuration using kubectl.

    kubectl apply -f ingress.yaml

  4. Verify the Ingress: After we deploy the Ingress, we check if it is set up correctly. We also make sure that SSL redirection works. We can do this by opening our application via HTTP and see if it redirects to HTTPS.

Additional Considerations

  • We must ensure our DNS points to the Ingress IP address.
  • If we use a different Ingress controller (not NGINX), we should use the right annotations and setups for that controller.

By following these steps, we can successfully force SSL for our Kubernetes Ingress on GKE. This will keep our application communications secure. For more details on Kubernetes Ingress resources, we can check the difference between Ingress and LoadBalancer.

Solution 2 - Using Annotations to Force SSL

To make SSL work for your Kubernetes Ingress on Google Kubernetes Engine (GKE), we can use annotations in our Ingress resource. Annotations are simple key-value pairs. They give information about our resource and help change how our Ingress controller behaves.

Step-by-Step Implementation

  1. Create or Update Ingress Resource: We need to set up our Ingress resource with the right annotations to make SSL redirection happen. Here is an example of an Ingress resource that forces SSL using annotations:

    apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-app-ingress
  annotations:
    kubernetes.io/ingress.class: "gce"
    ingress.gcp.kubernetes.io/ssl-redirect: "true"
spec:
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-app-service
                port:
                  number: 80

    In this YAML setup, the annotation ingress.gcp.kubernetes.io/ssl-redirect: "true" tells the GKE Ingress controller to send HTTP traffic to HTTPS.

  2. Apply the Ingress Configuration: We can use kubectl to apply our Ingress setup:

    kubectl apply -f my-app-ingress.yaml

  3. Verify the Configuration: After we apply the Ingress setup, we should check if SSL redirection works. We can access our application through HTTP (like http://myapp.example.com). We should be sent automatically to the HTTPS version (like https://myapp.example.com).

Additional Annotations

We can also think about other important annotations to improve our SSL setup:

  • ingress.gcp.kubernetes.io/pre-shared-cert: Use this to specify a pre-shared SSL certificate if we have one.
  • ingress.gcp.kubernetes.io/force-ssl-redirect: This can be used instead of ssl-redirect for some setups.

Important Notes

  • We need to make sure that our Ingress controller is set up correctly to support SSL.
  • For the redirection to work, it is good to have both HTTP and HTTPS services in our Ingress. The above setup mainly redirects HTTP traffic to HTTPS.
  • For more information about Ingress setups, we can check Ingress vs Load Balancer.

By using annotations in a smart way, we can control SSL settings for our Kubernetes Ingress on GKE. This will help keep our applications secure.

Solution 3 - Configuring Backend Service for HTTPS

We need to force SSL for our Kubernetes Ingress on Google Kubernetes Engine (GKE). It is important to set up the backend service for HTTPS. This makes sure that traffic from the Ingress to our services is safe. Here are the steps to set up the backend service for HTTPS.

Step 1: Create a Backend Service

First, we create a backend service to handle our HTTPS traffic. We can do this with a YAML file. Here is an example:

apiVersion: cloud.google.com/v1
kind: BackendService
metadata:
  name: my-backend-service
  namespace: default
spec:
  healthChecks:
    - healthCheck:
        name: my-health-check
  backendType: "GCE"
  portName: "https"
  protocol: "HTTPS"
  timeoutSec: 10
  sessionAffinity: "NONE"

In this example:

  • Change my-backend-service to the name we want for our service.
  • The healthChecks part should point to a health check that is already set for HTTPS.

Step 2: Configure TLS Certificates

Next, we need TLS certificates for our backend service. We can use Google-managed certificates or upload our own. To create a Google-managed certificate, we can run this command:

kubectl create -f - <<EOF
apiVersion: networking.gke.io/v1
kind: ManagedCertificate
metadata:
  name: my-managed-cert
spec:
  domains:
  - "your-domain.com"
EOF

We should replace your-domain.com with our real domain name.

Step 3: Update Ingress Resource

Now, we update our Ingress resource to use the backend service we set up for HTTPS. Here is how we can configure the Ingress:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "gce"
    networking.gke.io/managed-certificates: "my-managed-cert"
spec:
  tls:
    - hosts:
        - "your-domain.com"
      secretName: my-tls-secret
  rules:
    - host: "your-domain.com"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-backend-service
                port:
                  name: https

In this Ingress setup:

  • The tls part shows the host and the secret that has the TLS certificates.
  • The rules part tells where to send our HTTPS traffic to the backend service.

Step 4: Deploy the Configuration

After we create the YAML files for our backend service and Ingress, we apply them with these commands:

kubectl apply -f backend-service.yaml
kubectl apply -f ingress.yaml

Step 5: Verify HTTPS Configuration

Once we deploy the resources, we need to check if our Ingress is set up right for HTTPS. We can use this command to see the status of our Ingress:

kubectl describe ingress my-ingress

This command will give us information about the Ingress. It will show if it has an IP address and if the TLS setup is correct.

By making sure our backend service is set up right for HTTPS, we can force SSL for our Kubernetes Ingress on GKE. For more information about Kubernetes Ingress resources, we can read this Ingress vs Load Balancer article.

Solution 4 - Creating a Global SSL Policy

We can enforce SSL for all our services in Google Kubernetes Engine (GKE) using Ingress by creating a Global SSL Policy. This policy helps us make sure that all traffic is encrypted. It also allows only secure connections. Let us see how to set it up.

Step 1: Define the SSL Policy

We need to create a custom SSL policy. This policy says what security features we want. For example, we can set the minimum TLS version and cipher suites. Here is an example of how to create an SSL policy with strict security settings:

apiVersion: compute.googleapis.com/v1
kind: sslPolicies
metadata:
  name: my-global-ssl-policy
spec:
  profile: CUSTOM
  minTlsVersion: TLS_1_2
  customFeatures:
    - MODERN

Step 2: Apply the SSL Policy

After we create the SSL policy, we need to apply it to our Ingress resources. We can add the SSL policy in our Ingress YAML configuration like this:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "gce"
spec:
  tls:
    - hosts:
        - example.com
      secretName: tls-secret
  rules:
    - host: example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-service
                port:
                  number: 80
  # Link the SSL policy here
  gceBackendService:
    sslPolicy: my-global-ssl-policy

Step 3: Deploy the Configuration

Now we apply the above configuration using kubectl:

kubectl apply -f ingress.yaml

Step 4: Verify SSL Policy Application

After we apply the Ingress configuration, we need to verify that the SSL policy is linked with our Ingress resource. We can check this by running:

kubectl describe ingress my-ingress

We should look for a line that shows the SSL policy is applied.

Additional Notes

  • We need to make sure that our backend services can handle HTTPS traffic.
  • Let us test our setup. We will go to our domain using HTTPS to make sure SSL is working.
  • For more information on Kubernetes Ingress and SSL policies, please check the official GKE documentation.

By following these steps, we can create a Global SSL Policy. This helps us enforce SSL for our Kubernetes Ingress resources on GKE. It makes sure that communication across our applications is secure.

Solution 5 - Testing SSL Redirection

After we put SSL redirection in our Kubernetes Ingress on GKE, we must check that the redirection works well. Testing SSL redirection helps us make sure all HTTP requests go to HTTPS. This makes our application more secure.

Steps to Test SSL Redirection

  1. Use Curl Command: The easy way to test SSL redirection is to use the curl command with the -I (big i) option. This command gets the HTTP headers. We can see how the redirection works without downloading the whole page.

    Run this command in your terminal:

    curl -I http://your-domain.com

    Change your-domain.com to your real domain. We should see a response with a 301 Moved Permanently status and a Location header that shows the HTTPS version of the site, like this:

    HTTP/1.1 301 Moved Permanently
Location: https://your-domain.com/

  2. Browser Testing: Open a web browser. Go to the HTTP version of your site (for example, http://your-domain.com). Look at the address bar to see if it automatically goes to the HTTPS version (like https://your-domain.com). Make sure the padlock icon shows up. This means the connection is secure.

  3. Use Online Tools: We can use different online tools to test redirection and SSL setups. Tools like Redirect Check show the full redirect path and the HTTP status codes for each step.

  4. Check SSL Certificate: After we confirm the redirection works, we need to check that our SSL certificate is working right. We can use this command to see the certificate details:

    openssl s_client -connect your-domain.com:443

    Find the Certificate chain and Server certificate parts in the output. This helps us make sure our SSL certificate is installed correctly.

  5. Automated Testing: For automated testing, we can use tools like Selenium or Postman. These help us script the testing process. This is good for bigger applications with many endpoints that need checking.

Example of Curl Command Output

When the redirection is set up correctly, the output of the curl command should look like this:

HTTP/1.1 301 Moved Permanently
Location: https://your-domain.com/
Content-Type: text/html; charset=UTF-8
Content-Length: 0
Date: Mon, 01 Jan 2023 00:00:00 GMT

This output shows that the request to the HTTP endpoint was redirected to the HTTPS endpoint.

By doing these steps, we can test SSL redirection in our Kubernetes Ingress on GKE. This makes sure all traffic goes over HTTPS safely. For more information about fixing common Kubernetes issues, we can read this article on checking Kubernetes pod CPU and memory.

Solution 6 - Troubleshooting Common Issues

When we set up SSL for Kubernetes Ingress on Google Kubernetes Engine (GKE), we might face some common problems. These problems can stop SSL redirection or create other issues. Here are steps to help us fix these problems.

  1. Verify Ingress Resource Configuration
    We need to check that our Ingress resource is set up right. It should redirect HTTP traffic to HTTPS. Look for these important parts in our Ingress manifest:

    apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "gce"
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true" # Check if this is right for our ingress controller
spec:
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-service
                port:
                  number: 80

  2. Check Firewall Rules
    We should make sure that the firewall rules for our GKE cluster allow HTTPS (port 443) traffic. We can check the firewall rules in the Google Cloud Console under the “VPC network” section.

  3. Inspect SSL Certificate
    We need to verify that the SSL certificate is set up correctly and linked to our load balancer. We can use this command to see our managed certificates:

    gcloud compute ssl-certificates list

    Make sure the certificate is active and connected to our Ingress resource.

  4. Review Ingress Controller Logs
    We should check the logs of our Ingress controller for any errors or warnings. For example, if we use the NGINX Ingress controller, we can get logs with:

    kubectl logs -n kube-system -l app.kubernetes.io/name=ingress-nginx

    Look for messages about SSL settings or redirects.

  5. Testing with cURL
    We can use a cURL command to test the HTTP to HTTPS redirection:

    curl -I http://myapp.example.com

    We should see a 301 Moved Permanently response with a Location header that shows the HTTPS URL.

  6. Check Backend Service Configuration
    We need to ensure that our backend service can handle HTTPS traffic if we are ending SSL at the backend. We might have to set up health checks and make sure they are correct.

  7. Debugging Annotations
    If we use special annotations to enforce SSL, we need to check that they are right in our Ingress resource. For NGINX, the important annotation is:

    nginx.ingress.kubernetes.io/force-ssl-redirect: "true"

    For GCE ingress, we should use the right annotation settings from the Kubernetes Ingress documentation.

  8. Consult the Kubernetes Documentation
    If we still have problems, we can look at the Kubernetes documentation for more tips and best practices about SSL setup in GKE.

By following these steps, we can find and fix common issues with forcing SSL for our Kubernetes Ingress on GKE.

Conclusion

In this article, we looked at different ways to force SSL for Kubernetes Ingress on GKE. We talked about setting up an Ingress resource with SSL redirect. We also used annotations and configured backend services.

These methods make our applications safer. They help to ensure that traffic is encrypted. This is very important for keeping sensitive data safe.

If we want to learn more about managing Kubernetes resources, we can check out Kubernetes pod memory management or checking Kubernetes pod CPU usage.

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