Archives September 2022

kind: local Kubernetes cluster (minikube alternative)

4 min read

kind is a tool for runnint local Kubernetes clusters on Docker, just in the same way minikube can work (if configuring it to use docker). It was primarily designed for testing Kubernetes itself, but we can use it for local development or CI as well.

29/09/2021
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Kubernetes: List objects from a specific api group (name collision)

1 min read

When we have different apiGroups providing objects with the same name (same kind), kubectl needs a way of telling them apart:

$ kubectl api-resources | grep '\bconfigs\b'
configs                                                   config.gatekeeper.sh/v1alpha1                   true         Config
configs                                                   operator.openshift.io/v1                        false        Config

28/09/2022

go get: Add a module from a private GitHub repository

2 min read

If you try to add a golang module that is on a private repository you'll get an error similar to this:

$ go get github.com/pet2cattle/golang-demo
go: downloading github.com/pet2cattle/golang-demo v0.0.0-20220925191817-0b4b7026fa7f
go: github.com/pet2cattle/golang-demo@v0.0.0-20220925191817-0b4b7026fa7f: verifying module: github.com/pet2cattle/golang-demo@v0.0.0-20220925191817-0b4b7026fa7f: reading https://sum.golang.org/lookup/github.com/pet2cattle/golang-demo@v0.0.0-20220925191817-0b4b7026fa7f: 404 Not Found
        server response:
        not found: github.com/pet2cattle/golang-demo@v0.0.0-20220925191817-0b4b7026fa7f: invalid version: git ls-remote -q origin in /tmp/gopath/pkg/mod/cache/vcs/75d68059a7355b978972dea177e930262ce90abe410680b8db8a45a587e02c26: exit status 128:
                fatal: could not read Username for 'https://github.com': terminal prompts disabled
        Confirm the import path was entered correctly.
        If this is a private repository, see https://golang.org/doc/faq#git_https for additional information.

26/09/2022

ComponentStatus is going to be deprecated in v1.19+

2 min read

If you are using kubectl get componentstatuses you might have noticed that have been deprecated:

$ kubectl get componentstatuses
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE   ERROR
controller-manager   Healthy   ok        
scheduler            Healthy   ok

23/09/2022

Install a development Vault on Kubernetes

2 min read

If you are using Vault for storing secrets, it is desirable to have a different Vault for testing, CI and development. Having to setup an alternate production-grade Vault can be just not worth it (specially for volatile environments)

For local environments it comes handy to use the dev server mode, for Kubernetes we can use the pet2cattle/helm-testvault to deploy it as an in-cluster service

22/09/2022
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AWS Controllers for Kubernetes - S3

3 min read

Amazon has recently released a set of controllers (actually they are operators because they are using CRDs) to create resources on AWS using Kubernetes objects. It works in the same way it crossplane works

Let's install an test the ACK S3

21/09/2022
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Install awstools on a Mac

4 min read

awstools is a CLI tool that provides a small set of commands to manage the most commonly EC2 resources. It's installation it's not hard since it is a python script that has a list of dependencies on the requirements.txt file, but now it's even easier on Mac since there is a tap available

20/09/2022
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Patching a kubernetes object with kubectl patch and a patch file

2 min read

We can use the kubectl patch command with the -p option to update an existing kubernetes object:
```
$ kubectl patch sc gp2 -p '{"allowVolumeExpansion": true}'
storageclass.storage.k8s.io/gp2 patched
```
When the patch is small is a very convenient way of patching it but as the patch grows it becomes less convenient

19/09/2022
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Kubernetes: Apply parts of a manifest by labels

2 min read

Sometimes we might have a manifest file with a lot of objects in it but we don't really need them all. We can use it's labels to install just the objects that have a specific label.

15/09/2022
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Install minikube on an Apple Sillicon without Docker Desktop

4 min read

minikube docker colima apple M1 arm64 apple sillicon

If you try to install minikube on an Apple Sillicon (such as Apple M1, M2...) you will face that some hypervisors doesn't support arm64 yet. Using Docker Destop, on the other hand, has recently changed it's license so it might not be suitable to you

$ minikube start
😄  minikube v1.26.1 on Darwin 12.5.1 (arm64)
✨  Automatically selected the parallels driver. Other choices: ssh, qemu2 (experimental)

❌  Exiting due to DRV_UNSUPPORTED_OS: The driver 'parallels' is not supported on darwin/arm64

$ minikube start --driver docker
😄  minikube v1.26.1 on Darwin 12.5.1 (arm64)
✨  Using the docker driver based on user configuration

💣  Exiting due to PROVIDER_DOCKER_NOT_RUNNING: "docker version --format -" exit status 1: Cannot connect to the Docker daemon at unix:///Users/jordiprats/.rd/docker.sock. Is the docker daemon running?
💡  Suggestion: Start the Docker service
📘  Documentation: https://minikube.sigs.k8s.io/docs/drivers/docker/

There are several alternatives to Docker Desktop but the one that I found more convenient and easier to install is Colima

14/09/2022

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From pet to cattle

Treat your kubernetes clusters like cattle, not pets