325 lines
14 KiB
Markdown
325 lines
14 KiB
Markdown
---
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title: "Argocd Dynamic Environment Per Branch: Part 1"
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date: 2023-02-25T14:00:00+01:00
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draft: true
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ShowToc: true
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cover:
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image: "cover.png"
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caption: "Argocd Dynamic Environment Per Branch Part 1"
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relative: false
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responsiveImages: false
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---
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[Do you remember?]({{< ref "dont-use-argocd-for-infrastructure" >}})
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> And using `helmfile`, I will install `ArgoCD` to my clusters, of course, because it's an awesome tool, without any doubts. But don't manage your infrastructure with it, because it's a part of your infrastructure, and it's a service that you provide to other teams. And I'll talk about in one of the next posts.
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Yes, I have written 4 posts where I was almost absuletely negative about `ArgoCD`. But I was talking about infrastructure then. I've got some ideas about how to describe it in a better way, but I think I will write another post about it.
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Here, I want to talk about dynamic *(preview)* environments, and I'm going to describe how to create them using my blog as an example. My blog is a pretty easy application. From `Kubernetes` perspective, it's just a container with some static content. And here, you already can notice that static is an opposite of dynamic, so it's the first problem that I'll have to tackle. Turning static content into dynamic. So my blog consists of `markdown` files that are used by `hugo` for a web page generation.
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>Initially I was using `hugo` server to serve the static, but it needs way more resources than `nginx`, so I've decided in favor of `nginx`.
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I think that I'll write 2 of 3 posts about it, because it's too much to cover in only one. So here, I'd share how I was preparing my blog to be ready for dynamic environments.
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So this is how my workflow looked like before I decided to use dynamic environments.
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- I'm editing `hugo` content while using `hugo server` locally
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- Pushing changes to a `non-main` branch
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- When everything is ready, I'm uploading pictures to the `minio` storage
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- And merging a non-main branch to the main
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- Drone-CI is downloading images from `minio` and builds a docker image with the `latest` tag
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- First step is to generate a static content by `hugo`
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- Second step is to put that static content in `nginx` container
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- Drone-CI is pushing a new image to my registry
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- `Keel` spots that images was updated and pulls it.
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- Pod with a static is being recreated, and I have my blog with a new content
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What I don't like about it? I can't test something unless it's in `production`. And when I stated to work on adding comments (that is still WIP) I've understood that I'd like to have a real environemnt where I can test everything before firing the main pipeline. Even though having a static development environment would be fine for me, because I'm the only one who do the development here, I don't like the concept of static envs, and I want to be able to work on different posts in the same time. Also, adding a new static environemnt for development purposes it kind of the same amount of work as implementing a solution for deploying them dynamically.
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Before I can start deploying them, I have to prepare the application for that. At the first glance changes looks like that:
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1. Container must not contain any static content
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2. I can't use only latest tags anymore
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3. Helm chart has a lot of stuff that's hardcoded
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4. CI pipelines must be adjusted
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5. Deployment process should be rethought
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### Static Container
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Static content doesn't play well with dynamic environments. I'd even say, doesn't play at all. So at least I must stop defining hostname for my blog on the build stage. One container should be able to run anywhere with the same result. So I've decided that instedd of putting the generated static content in the container with `nginx` on the build stage, I need to ship a container with source code to `Kubernetes`, generate static there and put it to a container with `nginx`. So before my deployment looked like that:
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```YAML
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spec:
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containers:
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- image: git.badhouseplants.net/allanger/badhouseplants-net:latest
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imagePullPolicy: Always
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name: badhouseplants-net
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```
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And it was enough. Now it looks like that:
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```YAML
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containers:
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- image: nginx:latest
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imagePullPolicy: Always
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name: nginx
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ports:
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- containerPort: 80
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name: http
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protocol: TCP
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resources: {}
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volumeMounts:
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- mountPath: /var/www
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name: public-content
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readOnly: true
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- mountPath: /etc/nginx/conf.d
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name: nginx-config
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readOnly: true
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initContainers:
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- args:
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- --baseURL
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- https://dynamic-charts-dev.badhouseplants.net/
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image: git.badhouseplants.net/allanger/badhouseplants-net:d727a51c0443eb4194bdaebf8ab0e94c0f228b06
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imagePullPolicy: Always
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name: badhouseplants-net
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resources: {}
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terminationMessagePath: /dev/termination-log
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terminationMessagePolicy: File
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volumeMounts:
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- mountPath: /src/static
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name: s3-data
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readOnly: true
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- mountPath: /src/public
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name: public-content
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restartPolicy: Always
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- emptyDir:
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sizeLimit: 1Gi
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name: public-content
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- configMap:
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defaultMode: 420
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name: nginx-config
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name: nginx-config
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```
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So in the `init` container I'm generating a static content (`--baseUrL` flag is templated with `Helm`). Putting the result to the directory that is mounted as en `emptyDir` volume. And then later I'm mounting this folder to a container with `nginx`. Now I can use my docker image wherever I'd like with the same result It doesn't depend on the hostmame that was fixed during the build.
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### No more `latest`
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Since I want to have my envs updated on each commit, I can't push only `latest` anymore. So I've decided to use `commit sha` as tags for my images. But it means that I'll have a lot of them now and having `300Mb` of images and other media is becoming very painful. That means that I need to stop putting images directly to container during the build. So instead of using `rclone` to get data from `minio` in a `drone` pipeline, I'm adding another `init` container to my deployment.
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```YAML
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initContainers:
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- args:
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- -c
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- rclone copy -P badhouseplants-public:/badhouseplants-static /static
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command:
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- sh
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env:
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- name: RCLONE_CONFIG
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value: /tmp/rclone.conf
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image: rclone/rclone:latest
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imagePullPolicy: Always
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name: rclone
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resources: {}
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terminationMessagePath: /dev/termination-log
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terminationMessagePolicy: File
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volumeMounts:
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- mountPath: /tmp
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name: rclone-config
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readOnly: true
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- mountPath: /static
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name: s3-data
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volumes:
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- name: rclone-config
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secret:
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defaultMode: 420
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secretName: rclone-config
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- emptyDir:
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sizeLimit: 1Gi
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name: s3-data
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```
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And also, I'm mounting the `s3-data` volume to the `hugo` container, so it can generate my blog with all images.
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### Helm chart should be more flexible
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I had to find all the values, that should be different between different environments. And turned out, it's not a lot.
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1. Istio `VirtualServices` hostnames (Or Ingress hostname, if you don't use Istio)
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2. Image tag for the container with the source code
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3. And a hostname that should be passed to hugo as a base URL
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4. Preview environments should display pages that are still `drafts`
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So all of that I've put to `values.yaml`
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```YAML
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istio:
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hosts:
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- badhouseplants.net
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hugo:
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image:
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tag: $COMMIT_SHA
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baseURL: https://badhouseplants.net/
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buildDrafts: false
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```
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### CI pipelines
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Now I need to push a new image on each commit instead of pushing only once the code made it to the main branch, But I also don't want to have something that doesn't work completely in my registry, because I'm self-hosting and ergo I care about storage. So before building and pushing an image, I need to to test it,
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```YAML
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# ---------------------------------------------------------------
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# -- My Dockerfile is very small and easy, so it's not a problem
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# -- to duplicate its logic in a job. But I think that
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# -- a better way to implement this, would be to build an image
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# -- with Dockerfile, run it, and push, if everything is fine
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# ---------------------------------------------------------------
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- name: Test a build
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image: klakegg/hugo
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commands:
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- hugo
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- name: Build and push the docker image
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image: plugins/docker
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settings:
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registry: git.badhouseplants.net
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username: allanger
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password:
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from_secret: GITEA_TOKEN
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repo: git.badhouseplants.net/allanger/badhouseplants-net
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tags: ${DRONE_COMMIT_SHA}
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```
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Now if my code is not really broken, I'll have an image for each commit. And when I merge my branch to `main` I can use a tag from the latest preview build on for the production instance. So I'm almost sure that what I've tested before is what a visitor will see.
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> But with this kind of setup I've reached docker pull limit pretty fast, so I've decided that I need to have a builder image in my registry too. Of course, it must be an automated action, but right off the bat, I've just pushed the `hugo` image to my registry with the `latest` tag and created an issue to fix it later
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```BASH
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docker pull klakegg/hugo
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docker tag klakegg/hugo git.badhouseplants.net/badhouseplants/hugo-builder
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docker push
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```
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And update my Dockerfile to look like this:
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```DOCKERFILE
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FROM git.badhouseplants.net/badhouseplants/hugo-builder
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WORKDIR /src
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COPY . /src
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ENTRYPOINT ["hugo"]
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```
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### How to deploy
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Previously I was using the same helmfile that I use for everything else in my k8s cluster. It was fine for static envs, but when I need to deploy them dynamically, it's not an option anymore. And here `ArgoCD` enters the room. I'm creating an `ApplicationSet` that looks like that:
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```YAML
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apiVersion: argoproj.io/v1alpha1
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kind: ApplicationSet
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metadata:
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name: badhouseplants-net
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namespace: argo-system
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spec:
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generators:
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- list:
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elements:
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- name: application # just not to lose a backward compability with the prevouos setup
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app: badhouseplants
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branch: main
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chart_version: 0.3.6
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# Image that is lates now, we'll get there later
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value: |
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hugo:
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image:
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tag: latest
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# And this is an example of environemnt that I want to be created.
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- name: dynamic-charts
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app: badhouseplants
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branch: dynamic-charts
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chart_version: 0.3.6
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value: |
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istio:
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hosts:
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- dynamic-charts-dev.badhouseplants.net
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hugo:
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image:
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tag: 5d742a71731320883db698432303c92aee4d68a1
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baseURL: https://dynamic-charts-dev.badhouseplants.net/
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buildDrafts: true
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template:
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metadata:
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name: "{{ app }}-{{ name }}"
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namespace: argo-system
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spec:
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project: "default"
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source:
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helm:
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valueFiles:
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- values.yaml
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values: "{{ value }}"
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repoURL: https://git.badhouseplants.net/api/packages/allanger/helm
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targetRevision: "{{ chart_version }}"
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chart: badhouseplants-net
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destination:
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server: "https://kubernetes.default.svc"
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namespace: "{{ app }}-{{ name }}"
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syncPolicy:
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syncOptions:
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- CreateNamespace=true
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```
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But storing I don't like an idea of storing something like that in the repository. So in the git I'm putting something like that.
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```YAML
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apiVersion: argoproj.io/v1alpha1
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kind: ApplicationSet
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metadata:
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name: badhouseplants-net
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namespace: argo-system
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spec:
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generators:
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- list:
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elements:
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- name: application
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app: badhouseplants
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branch: main
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chart_version: 0.3.6
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value: |
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hugo:
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image:
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tag: $ARGO_IMAGE_TAG
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...
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```
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Since I'm not using latest anymore, I need to add use a new tag every time a new image is pushed. But let's test with the preview env first:
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```YAML
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# ./kube/template.yaml
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...
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- name: $ARGO_APP_BRANCH
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app: badhouseplants
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branch: $ARGO_APP_BRANCH
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chart_version: $ARGO_APP_CHART_VERSION
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value: |
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istio:
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hosts:
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- $ARGO_APP_HOSTNAME
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hugo:
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image:
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tag: $ARGO_APP_IMAGE_TAG
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baseURL: https://$ARGO_APP_HOSTNAME/
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buildDrafts: true
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...
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```
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And the logic that I would like to have in my setup would be
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- In the git repo there is only application set with the main instance only (production)
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- After a new image is pushed to registry, I'm getting this application set as `yaml` and appending new generator to it.
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- Applying a new `ApplicationSet` and syncing application using the `argo` cli tool
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First, let's set environment variables:
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```
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- $ARGO_APP_BRANCH = $DRONE_BRANCH | I don't want to use it directly, in case if I want to stop using Drone
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- $ARGO_APP_CHART_VERSION should be taken from the `./chart/Chart.yaml` file. `cat chart/Chart.yaml | yq '.version'`
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- $ARGO_APP_HOSTNAME, I want it to look like that: "$DRONE_BRANCH-dev.badhouseplants.net"
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- $ARGO_APP_IMAGE_TAG = $DRONE_COMMIT_SHA
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```
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So after setting all these variables, I can use `envsubst < ./kube/template.yaml` to create a correct generator. After that I only need to append it to one that is already in k8s. *And not to append if it's already there*.
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So let's design out pipeline:
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1. Get an application set is currently deployed to k8s
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```BASH
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kubectl get application-set
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```
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