We will stage 1 file for a Secret that will hold the HTTP basic auth credentials - htpasswd. We will stage 2 files for a ConfigMap that will hold the website configuration - nf and nf. Let's consider an nginx container that defines 2 hosts - a frontend website that is unrestricted, and an admin website that is protected by HTTP basic auth. Our sample will stage configuration files and secret files, and use a deployment script to translate these to Kubernetes ConfigMaps and Secrets.Īll of the sample code in this guide can be found at the GitHub repository boxboat/kube-configmap-secret-update. When dealing with Configuration as Code, it is nice to be able to stage the configuration for deployment just as it will appear inside of the container. Essentially, Git becomes the source of truth for your deployment, which ensures that your currently deployed system is documented in source control and makes disaster recovery easier. GitOps is a method for storing Configuration as Code in a source control repository, and automatically updating deployed state when the repository changes. This blog post describes a solution that creates ConfigMaps and Secrets alongside a Deployment, and uses a hash of these resources to automatically trigger a rolling update if they have changed. This can lead to complicated logic since objects using the old configuration will need to be detected and recreated.Īnother approach is to trigger a rolling update of the Deployment when it's dependent ConfigMaps and Secrets are updated. One approach for dealing with this is to add application logic to watch ConfigMap and Secret files for changes, and reconfigure the application on the fly. If an application reads a ConfigMap or Secret value on startup, it may have a stale configuration after a ConfigMap or Secret is updated. Both of these resources are commonly used when deploying a GitOps Configuration as Code workflow.ĬonfigMap and Secret files inside of containers are updated automatically when the underlying ConfigMap or Secret is updated. The Kubernetes Secret resource is used to mount secret files into pods. The Kubernetes ConfigMap resource is used to mount configuration files into pods. GitOps Kubernetes Rolling Update when ConfigMaps and Secrets Change

What is kubernetes configmap