Categories: kubernetes

Running tcpdump on an OpenShift cluster

3 min read

If we want to take a look at the network traffic that we get out of an OpenShift node we can use the oc debug command to spin up a privileged pod with tcpdump installed. This way we don't need to ssh into the worker node.

22/05/2023
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Automatically stablish a SSH tunnel to connect to k8s with kubectl

4 min read

Kubernetes is a powerful container orchestration platform used by many organizations to deploy and manage their applications. Interacting with a Kubernetes cluster requires configuring the kubeconfig file with the necessary credentials. However, managing these credentials can be challenging, especially in scenarios where a bastion host or SSH tunnel is required.

With kubectl-tokensshtunnel we can automate the process of creating an SSH tunnel to a remote server and retrieving the Kubernetes credentials from there. This tool simplifies access to remote Kubernetes clusters by securely caching the credentials for a specified duration.

18/05/2023
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Operator-SDK: Set custom fields for kubectl get

2 min read

When writing a custom Kubernetes operator using operator-sdk we might want to change the fields are show when running kubectl get:
```
$ kubectl get example
NAME   AGE
demo   4h20m
```
To do so, we'll need to add the additionalPrinterColumns field the the CustomResourceDefinition, but since we are using operator-sdk to take care of this, we'll need to use some annotations in the resource definition file.

15/05/2023
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Velero: Backup and restore

4 min read

Just in the same way we backup physical servers, we need to backup Kubernetes workloads to be able to restore it to its previous state: We'll need make sure we are going to be able to restore the objects of any namespace and it's data (PersistentVolumes)

08/05/2023
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Prometheus: Using Namespace Labels to Narrow Down Prometheus Query Results

1 min read

We can use the labels of a namespace to narrow down the results of a query. For example. we are going to write a query to identify Kubernetes namespaces that have external secrets in a non-ready state and belong to a specific team (we are going to use team-a in this example).

19/04/2023
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