• Testing a TCP connection using bash

  2 min read

  
  

  To be able to debug issues we can test a TCP connection using netcat (nc) or even telnet. But when we are on a containerized environment such as Kubernetes it can be a challenge when the container doesn't have the right tools for the job

  $ nc
  bash: nc: command not found
  $ netcat
  bash: netcat: command not found
  $ telnet
  bash: telnet: command not found
  

  05/07/2021

  Read more...

• Using terraform try function to retrieve optional values on maps

  2 min read

  
  

  It's common practice to use a map in terraform to configure resources. If we want to use a map with optional values we can make use of the try() function

  Let's us the following map as an example:

    config = {
      namespaces = ["namespace1", "namespace2"]
  
      (...)
    }
  

  02/07/2021

  Read more...

• Using an HPA object to autoscale a deployment based on it's Pods CPU metrics

  3 min read

  
  

  On Kubernetes, scaling an application is just a matter of defining how many replicas we want:

  $ kubectl scale deployment/demo --replicas=5
  deployment.apps/demo scaled
  

  Having to manually adjust the number of replicas is not really practical. Here's where the HorizontalPodAutoscaler (HPA) comes into play

  01/07/2021

  Read more...

• Kubernetes Pod: Share a temporal Volume across containers

  2 min read

  
  

  If we need to be able to share some data across containers (one generates the data and the other one consumes it) we can use an emptyDir to create a Volume to mount on both containers.

  30/06/2021

  Read more...

• What's the meaning of the sections of a kubeconfig file?

  2 min read

  
  

  The configuration file kubeconfig (~/.kube/config) is used to get access to a Kubernetes cluster. It looks like a Kubernetes object that defines the cluster, the user and the context to use:

  apiVersion: v1
  kind: Config
  preferences: {}
  
  clusters:
  (...)
  
  users:
  (...)
  
  contexts:
  (...)
  

  Let's take a minikube kubeconfig as an example

  29/06/2021

  Read more...

More recent...

Older content...