The ConfigMap object provides mechanisms to inject containers with configuration data while keeping containers agnostic of OpenShift Container Platform. ConfigMap is similar to secrets, but designed to more conveniently support working with strings that do not contain sensitive information.

Simply so, what is the use of ConfigMap in Kubernetes?

A ConfigMap is an API object used to store non-confidential data in key-value pairs. Pods can consume ConfigMaps as environment variables, command-line arguments, or as configuration files in a volume.

Additionally, how do you define a ConfigMap in Kubernetes?

1. Create the ConfigMap. Create the ConfigMap using the example from the previous section.
2. Add the `envFrom` property to your Pod's YAML. Set the `envFrom` key in each container to an object containing the list of ConfigMaps you want to include. kind: Pod.

Besides, what is ConfigMap and secret in Kubernetes?

The big difference between Secrets and ConfigMaps are that Secrets are obfuscated with a Base64 encoding. There may be more differences in the future, but it is good practice to use Secrets for confidential data (like API keys) and ConfigMaps for non-confidential data (like port numbers).

How do I create a ConfigMap in OpenShift?

Creating a ConfigMap from a file

1. Create the ConfigMap specifying a specific file: $ oc create configmap game-config-2 --from-file=example-files/game.properties --from-file=example-files/ui.properties.
2. Verify the results: $ oc get configmaps game-config-2 -o yaml.

Related Question Answers

What is the difference between Kubernetes engine ConfigMaps and secrets?

The major difference is, Secrets store data in base64 format meanwhile ConfigMaps store data in a plain text. If you have some critical data like, keys, passwords, service accounts credentials, db connection string, etc then you should always go for Secrets rather than Configs.

What is Kubernetes secret?

A Secret is an object that contains a small amount of sensitive data such as a password, a token, or a key. Secrets are similar to ConfigMaps but are specifically intended to hold confidential data. Caution: Kubernetes Secrets are, by default, stored unencrypted in the API server's underlying data store (etcd).

How do I get Configmap?

Create a ConfigMap Using kubectl create configmap

When you are creating a ConfigMap based on a file, the key in the <data-source> defaults to the basename of the file, and the value defaults to the file content. You can use kubectl describe or kubectl get to retrieve information about a ConfigMap.

What is POD in Kubernetes?

A pod is the smallest execution unit in Kubernetes. A pod encapsulates one or more applications. Pods are ephemeral by nature, if a pod (or the node it executes on) fails, Kubernetes can automatically create a new replica of that pod to continue operations.

Where is Configmap stored in Kubernetes?

1 Answer. You view the content of the configmap with 'kubectl get cm -oyaml' i.e. through the k8s API directly as illustrated in You don't need to look inside etcd to see the content of a configmap.

Why do we need volumes in Kubernetes?

Volumes provide a plug-in mechanism to connect ephemeral containers with persistent data stores elsewhere. Kubernetes volumes persist until the Pod -- Kubernetes's atomic unit of container deployment -- is deleted. The Kubernetes user must specify volume mounting for each container in a Pod.

What is Kubernetes vs Docker?

A fundamental difference between Kubernetes and Docker is that Kubernetes is meant to run across a cluster while Docker runs on a single node. Kubernetes is more extensive than Docker Swarm and is meant to coordinate clusters of nodes at scale in production in an efficient manner.

How do I check my Kubernetes secret?

You can use kubectl get secrets/db-user-pass -o yaml or -o json where you'll see the base64-encoded username and password . You can then copy the value and decode it with something like echo <ENCODED_VALUE> | base64 -D (Mac OS X).

Are k8s secrets secure?

To this end, Kubernetes provides an object called Secret, which you can use to store sensitive data. Placing sensitive info into a secret object does not automatically make it secure. By default, data in Kubernetes secrets is stored in Base64 encoding, which is practically the same as plaintext.

Why are Kubernetes secrets base64 encoded?

Kubernetes stores secrets as base64 encoded strings and encrypts the data on disk. In order to save a secret in Kubernetes it must be converted to a base64 string.

How do I deploy a ConfigMap?

Once you define environment variables ConfigMap , you can utilize them in the command section in Pod spec i.e. spec. containers. command using the $(VARIABLE_NAME) format. You need to ensure that the ConfigMap being referenced in a Pod is already created — otherwise, the Pod will not start.

What does kubectl create do?

You can create a Deployment using the kubectl apply , or kubectl create commands. Once created, the Deployment ensures that the desired number of Pods are running and available at all times. The Deployment automatically replaces Pods that fail or are evicted from their nodes.

Do pods provide container volumes?

The main purpose of a pod is to support co-located programs that are running in separate containers. To share data between such containers in a pod, a Kubernetes user can define a shared volume for the pod and mount that volume to the specific path inside each container.

How do I change my kubectl config?

By default, kubectl looks for a file named config in the $HOME/. kube directory. You can specify other kubeconfig files by setting the KUBECONFIG environment variable or by setting the --kubeconfig flag.

Which Kubernetes objects are used to run applications?

We've successfully explored most of the basic Kubernetes objects that you would use when deploying your application. We looked at Pods, ReplicationSets, ReplicationControllers, Deployments, DaemonSets, Namespaces, and Configmaps. We also looked at the different options available when creating these objects.

How do you pass an environment variable in kubectl deployment?

This will export your environment variables inside the container. You cannot pass variables to "kubectl create -f". YAML files should be complete manifests without variables.

How do you make a secret in OpenShift?

When creating secrets:

1. Create a secret object with secret data.
2. Update the pod's service account to allow the reference to the secret.
3. Create a pod, which consumes the secret as an environment variable or as a file (using a secret volume).

How do you run Kubectl?

Install the kubectl Command Line

1. Check that kubectl is correctly installed and configured by running the kubectl cluster-info command: kubectl cluster-info.
2. You can also verify the cluster by checking the nodes.
3. To get complete information on each node, run the following: kubectl describe node.

What is the open source upstream version of OpenShift called?

When we released OpenShift Origin as the open source upstream project for Red Hat OpenShift back in April 2012, we had little inkling of the phenomenal trajectory of cloud-native technology that was to come.

What is OpenShift deployment?

A deployment in OpenShift is a replication controller based on a user defined template called a deployment configuration. Deployments are created manually or in response to triggered events. The deployment system provides: User-customizable strategies to transition from the previous deployment to the new deployment.

How do you make opaque secret in OpenShift?

Go to the Resources->Secrets section in the specified project. There, you will see the newly created opaque type secret with the name provided. Get the detailed view of the created secret, by clicking on the secret name. By selecting Reveal Secret option, you can get the actual values stored in this secret.

How do I edit a ConfigMap file?

Just throw: kubectl edit configmap <name of the configmap> on your command line. Then you can edit your configuration. This opens up a vim editor with the configmap in yaml format. Now simply edit it and save it.

How do I start Minikube?

From a terminal with administrator access (but not logged in as root), run:

1. minikube start.
2. kubectl get po -A.
3. minikube kubectl -- get po -A.
4. minikube dashboard.
5. kubectl create deployment hello-minikube --image= kubectl expose deployment hello-minikube --type=NodePort --port=8080.

Which of the following are Red Hat OpenShift build strategies?

Using build strategies

• Performing Source-to-Image (S2I) incremental builds.
• Overriding Source-to-Image (S2I) builder image scripts.
• Source-to-Image (S2I) environment variables.
• Ignoring Source-to-Image (S2I) source files.
• Creating images from source code with s2i.

Which of the following are Red Hat OpenShift build triggers?

The following build triggers are available:

• Webhook.
• Image change.
• Configuration change.