CA Bundle Injection in Kubernetes
Introduction
This guide offers a systematic approach to troubleshoot and resolve issues with QPoint Operator Certificate Authority (CA) bundle injection in Docker containers running in Kubernetes. This is crucial when automatic CA bundle injection is not natively supported by QPoint for specific container images.
Natively Supported CA Bundle Paths
/etc/ssl/certs/ca-certificates.crt
Commonly Associated With: Debian-based distributions like Ubuntu. A standard path for CA certificates bundle./etc/pki/tls/certs/ca-bundle.crt
Commonly Associated With: Red Hat-based distributions including CentOS and Fedora. Part of the system's default setup for storing trusted CA certificates./etc/ssl/ca-bundle.pem
Commonly Associated With: Less common but found in certain Linux distributions or customized environments. Used in manually configured CA bundles./etc/pki/tls/cacert.pem
Commonly Associated With: Also found in Red Hat-based distributions, similar in use toca-bundle.crt
./etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
Commonly Associated With: Newer versions of Red Hat-based distributions. Part of the dynamic CA configuration system./etc/ssl/cert.pem
Commonly Associated With: Some Unix-like operating systems like FreeBSD and various Linux distributions. A more generic CA certificate path.
Symptoms of CA Bundle Injection Issues
SSL/TLS Communication Errors: Including certificate verification failures or "unable to get local issuer certificate" messages.
Application-Specific Errors: Failure to connect to external services using SSL/TLS.
Log Messages: Indicating SSL/TLS certificate issues in containers or Kubernetes pods.
Identifying CA Bundle Injection Issues
Review Application Logs: Check for SSL/TLS-related error messages using
kubectl logs <pod-name>
.Inspect Container Configuration: Examine the container's configuration and
Dockerfile
, looking for CA bundle path specifications.Verify CA Bundle Path in the Container: Access the container's shell with
kubectl exec -it <pod-name> -- /bin/bash
and check the CA bundle paths.Test SSL/TLS Connections from Within the Container: Use tools like
curl
oropenssl
to test external SSL/TLS connections.Check QPoint Configuration and Logs: Look for indications of CA bundle handling issues in QPoint logs.
Fixing CA Bundle Injection Issues
Identify the Container Base Image: Understand the default paths and mechanisms for CA bundle storage in your base image.
Research Base Image Documentation: Look for information on SSL/TLS configurations and default CA bundle paths.
Inspect the Container's Dockerfile: Note any
ENV
instructions indicating the use of environment variables for CA certificates.Examine the Application's Documentation: Some applications might allow specifying the CA bundle path through an environment variable.
Configuring Kubernetes Deployment
Modify the container specification in your Kubernetes deployment YAML using env
to set the appropriate environment variable for your application's language.
Python Applications:
Node.js Applications:
Ruby Applications:
Go Applications:
.NET Core Applications:
Validating the Configuration
After deploying the updated configuration, check the container logs for SSL/TLS related errors and perform connectivity tests to services requiring SSL/TLS.
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