I refactored my k8s objects to use Kustomization, Components, replacements, patches and got to a good DRY state so that I don't repeat much between 2 apps and between those across dev and test environments. While doing so I am referring to objects outside of the folder (but same repository)
components:
- ../../common-nonprod
- ../../common-nonprod-ui
My question is will ArgoCD be able to detect a change in the app if any of the files inside the common folders change that this application refers to as components.
In other words does ArgoCD performs kustomize build to detect what changed ?
Yes. ArgoCD runs kustomize build to realize your manifests before trying to apply them to the cluster. ArgoCD doesn't care which files have changed; it simply cares that the manifests produced by kustomize build differ (or not) from what is currently deployed in the cluster.
Related
I have a lot of cronjobs I need to set on Kubernetes.
I want a file to manage them all and set them to Kubernetes on deployment. I wish that if I remove a cron from that file it will be removed from Kubernetes too.
Basically, I want to handle the corns like I'm handling them today on the machine (from a cron file that I would deploy). Add, remove and change crons.
I couldn't find a way of doing so. Does someone have an idea?
Library or framework I can use like helm? Or any other solution.
I highly recommend using gitops with argocd as a solution for Kubernetes configure management. Run crontab in deployment is a bad ideal because it hard to monitor your job result (cronjob job result can be get by kube-state-metrics exporter).
The ideal is packaging your manifest (it may be kubernetes manifest, kustomize, helm...etc...) -> put them to git -> argocd makes sure your configure deployed correctly
The advantages of gitops are include:
centralize your configuration
versioning your configuration
git authentication & authorization
traceable
multi-cluster deployment with argocd
automation deployment & sync
...
Gitops is not a difficult and is the mordern way for kubernetes configure management. Let's try
I used Helm to do so. I built a template to go over all crons, which I inserted as values to the helm template (Very similar to crontab but more structured) - see in the example.
Then, all I need to do is run a helm upgrade with a new corn (values) file and it updates everything accordingly. If I updated, removed, or added a new corn everything is happening automatically and with versioning. You can also add a namespace to your cronjobs to make it more encapsulated.
Here is a very good and easy-to-understand example I used. And its git repo
Using Kubernetes we make use of Helm and Kustomize to bundle our application. This helps consistently updating something like an application, but gets kind of bloated for a hole “environment” or cluster.
ArgoCD seems like a good solution for updating a hole cluster, as you can “mirror” your git state to the cluster. This works even when dropping resources or updating an existing complex deployment.
Now I want to build branch based ephemeral environments and think ArgoCD seems a bit bloated for this feature as for every branch environment I would have to commit to the git repository and add something.
The idea is, every branch based environment lives in its own namespace. I search for a tool managing this namespace and being able to do updates, and drops of the hole thing.
What is a good solution for this problem?
I've been using terraform for a while and I really like it. I also set up Atlantis so that my team could have a "GitOps" flow. This is my current process:
Add or remove resources from Terraform files
Push changes to GitHub and create a pull request
Atlantis picks up changes and creates a terraform plan
When the PR is approved, Atlantis applies the changes
I recently found myself needing to set up a few managed Kubernetes clusters using Amazon EKS. While Terraform is capable of creating most of the basic infrastructure, it falls short when setting up some of the k8s resources (no support for gateways or ingress, no support for alpha/beta features, etc). So instead I've been relying on a manual approach using kubectl:
Add the resource to an existing file or create a new file
Add a line to a makefile that runs the appropriate command (kubectl apply or create) on the new file
If I'm using a helm chart, add a line with helm template and then kubectl apply (I didn't really like using tiller, and helm3 is getting rid of it anyway)
If I want to delete a resource, I do it manually with kubectl delete
This process feels nowhere near as clean as what we're doing in Terraform. There are several key problems:
There's no real dry-run. Using kubectl --dry-run or kubectl diff doesn't really work, it's only a client-side diff. Server-side diff functions are currently in alpha
There's no state file. If I delete stuff from the manifests, I have to remember to also delete it from the cluster manually.
No clear way to achieve gitops. I've looked at Weaveworks Flux but that seems to be geared more towards deploying applications.
The makefile is getting more and more complicated. It doesn't feel like this is scaleable.
I should acknowledge that I'm fairly new to Kubernetes, so might be overlooking something obvious.
Is there a way for me to achieve a process similar to what I have in Terraform, within the Kubernetes universe?
This is more of an opinion question so I'll answer with an opinion. If you like to manage configuration you can try some of these tools:
If you want to use existing YAML files (configurations) and use something at a higher level you can try kustomize.
If you want to manage Kubernetes configurations using Jsonnet you should take a look at Ksonnet. Keep in mind that Ksonnet will not be supported in the future.
If you want to just automatically do a helm update in an automated way, there is not a tool there yet. You will have to build something at this point to orchestrate everything. For example, we ended up creating an in house tool that does this.
Say that I have 5 apis that i want to deploy in a Kubernetes cluster, my question is simply what is the best practice to store the yaml files related to Kubernetes.
In projects I've seen online, Kubernetes yaml files are just added to the the api project itself. I wonder if it makes sense to decouple all files related to Kubernetes in an entirely separate "project", and which is managed by VCS as a completely separated entity from the api projects themselves.
This question arises since I'm currently reading a book about Kubernetes, on the topic namespaces, and considered it might be a good idea to have separate namespaces per environment (DEV / UAT / PROD), and it may make sense to have these files in a centralized "Kubernetes" project (unless it might be better to have a separate cluster per environment (?)).
Whether to put the yaml in the same repo as the app is a question that projects answer in different ways. You might want to put them together if you find that you often change both at the same time or you just find it clearer to see everything in one place. You might separate if you mostly work on the yaml separately or if you find it less clutttered or want different visibility for it (e.g. different teams to look at it). If things get more sophisticated then you'll actually want to generate the yaml from templates and inject environment-specific configuration into it at deploy time (whether those environments are namespaces or clusters) - see Best practices for storing kubernetes configuration in source control for more discussion on this.
From Production k8s experience for CI/CD:
One cluster per environment such as dev , stage , prod ( optionally per data centre )
One namespace per project
One git deployment repo per project
One branch in git deployment repo per environment
Use configmaps for configuration aspects
Use secret management solution to store and use secrets
I've checked out helm.sh of course, but at first glance the entire setup seems a little complicated (helm-client & tiller-server). It seems to me like I can get away by just having a helm-client in most cases.
This is what I currently do
Let's say I have a project composed of 3 services viz. postgres, express, nginx.
I create a directory called product-release that is as follows:
product-release/
.git/
k8s/
postgres/
Deployment.yaml
Service.yaml
Secret.mustache.yaml # Needs to be rendered by the dev before use
express/
Deployment.yaml
Service.yaml
nginx/
Deployment.yaml
Service.yaml
updates/
0.1__0.2/
Job.yaml # postgres schema migration
update.sh # k8s API server scritps to patch/replace existing k8s objects, and runs the state change job
The usual git stuff can apply now. Everytime I make a change, I make changes to the spec files, test them, write the update scripts to help move from the last version to this current version and then commit it and tag it.
Questions:
This works for me so far, but is this "the right way"?
Why does helm have the tiller server? Isn't it simpler to do the templating on the client-side? Of course, if you want to separate the activity of the deployment from the knowledge of the application (like secrets) the templating would have to happen on the server, but otherwise why?
Seems that https://redspread.com/ (open source) addresses this particular issue, but needs more development before it'll be production ready - at least from my team quick glance at it.
We'll stick with keeping yaml files in git together with the deployed application for now I guess.
We are using kubernetes/helm (the latest/incubated version) and a central repository for Helm charts (with references container images built for our component releases).
In other words, the Helm package definitions and its dependencies are separate from the source code and image definitions that make up the several components of our web applications.
Notice: Tiller has been removed in Helm v3. Checkout this answer to see details on why it needs tiller in Helm v2 and why it's removed in Helm v3: https://v3.helm.sh/docs/faq/#removal-of-tiller
According to the idea of GitOps, what you did is a right way (to perform release from a git repo). However, if you want to push it further to make it more common, you can plan more goals including:
Choose a configuration management system beyond k8s app declarative definition only. E.g., Helm (like above answer https://stackoverflow.com/a/42053983/914967), Kustomize. They're pure client-side only.
avoid custom release process by altering update.sh with popular tools like kubectl apply or helm install.
drive change delivery from git tags/branches by using a CI/CD engine like argocd, Travis CI or GitHub Actions.
Uses branching strategy so that you can try changes on test/staging/production/ environment before delivering it directly.