https://github.com/slok/imagepull-controller-workshop
A Kubernetes controller workshop where we are creating a imagepullsecret-patcher controller
https://github.com/slok/imagepull-controller-workshop
Last synced: about 2 months ago
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A Kubernetes controller workshop where we are creating a imagepullsecret-patcher controller
- Host: GitHub
- URL: https://github.com/slok/imagepull-controller-workshop
- Owner: slok
- License: apache-2.0
- Created: 2021-03-03T08:21:34.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2021-03-04T09:57:20.000Z (over 4 years ago)
- Last Synced: 2024-06-19T13:47:00.253Z (over 1 year ago)
- Language: Go
- Size: 47.9 KB
- Stars: 4
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Codeowners: .github/CODEOWNERS
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README
# imagepull-controller-workshop
## Versions
- [workshop]: First working version without some code for the workshop.
- [v0.1.0]: First working versions.
- [v0.2.0]: Optimized version for secret retrieval.
## Agenda
### Introduction
#### Problem
- Explain the problem to solve.
- https://github.com/titansoft-pte-ltd/imagepullsecret-patcher
- https://github.com/titansoft-pte-ltd/imagepullsecret-patcher/blob/master/main.go#L110
- https://medium.com/titansoft-engineering/kubernetes-cluster-wide-access-to-private-container-registry-with-imagepullsecret-patcher-b8b8fb79f7e5
#### Concepts
- Controller Concepts
- Edge and level trigger ([1][a], [2][b])
- [Reconciliation]
- Explain controller components ([1][c], [2][d]).
- ListerWatcher
- Handler
- Queue (ID and cache) and workers.
- [Optimizations made on the Listers][loops-or-events].
### Implementation
#### Explanation
- What is [Kooper] and alternatives.
- [client-go].
- [Kubebuilder].
- [Operator framework][operator-framework].
- Explain project structure.
#### Implement
```bash
git clone git@github.com:slok/imagepull-controller-workshop.git && cd ./imagepull-controller-workshop
git checkout workshop
```
- [Implement Retriever][workshop-retriever].
- [Implement Handler][workshop-handler].
- Test with local cluster using [kind].
```bash
kind create cluster
kubectl apply -f ./tests/manual/secret.yaml
go run ./cmd/imagepull-controller-workshop/ -r default --secret-name test-imagepull-credentials --development
```
### Optional homework
- Metrics.
- Unit testing.
- Secret.
- Caching (Check [v0.2.0]).
- Update on change (Secret controller).
- Service account.
- Update on change instead of ensuring.
### Further information
- [Explain garbage collection][k8s-gc].
- Owner reference.
- Finalizers.
- Creating an Operator.
- [kube-code-generator].
- Create CRDs with clients.
- Generate CRD ([1][e], [2][f], [3][g])
- Generate Client ([1][h], [2][i])
- Production ready operator example ([Bilrost]).
[a]: https://speakerdeck.com/thockin/edge-vs-level-triggered-logic
[b]: https://hackernoon.com/level-triggering-and-reconciliation-in-kubernetes-1f17fe30333d
[c]: https://github.com/spotahome/gontroller
[d]: https://product.spotahome.com/gontroller-a-go-library-to-create-reliable-feedback-loop-controllers-832d4a9522ea
[e]: https://github.com/slok/kube-code-generator/blob/master/example/Makefile#L32
[f]: https://github.com/slok/kube-code-generator/blob/master/example/apis/comic/v1/types.go
[g]: https://github.com/slok/kube-code-generator/blob/master/example/manifests/comic.kube-code-generator.slok.dev_heroes.yaml
[h]: https://github.com/slok/kube-code-generator/blob/master/example/Makefile#L13
[i]: https://github.com/slok/kube-code-generator/blob/master/example/client/clientset/versioned/clientset.go#L32
[reconciliation]: https://speakerdeck.com/thockin/kubernetes-what-is-reconciliation
[kooper]: https://github.com/spotahome/kooper
[client-go]: https://github.com/kubernetes/client-go
[kubebuilder]: https://github.com/kubernetes-sigs/kubebuilder
[operator-framework]: https://github.com/operator-framework
[kind]: https://github.com/kubernetes-sigs/kind
[bilrost]: https://github.com/slok/bilrost
[loops-or-events]: https://speakerdeck.com/thockin/kubernetes-controllers-are-they-loops-or-events
[workshop]: https://github.com/slok/imagepull-controller-workshop/tree/workshop
[v0.1.0]: https://github.com/slok/imagepull-controller-workshop/tree/v0.1.0
[v0.2.0]: https://github.com/slok/imagepull-controller-workshop/tree/v0.2.0
[workshop-retriever]: https://github.com/slok/imagepull-controller-workshop/blob/workshop/internal/controller/retrieve.go#L21
[workshop-handler]: https://github.com/slok/imagepull-controller-workshop/blob/workshop/internal/controller/handle.go#L95-L101
[k8s-gc]: https://kubernetes.io/docs/concepts/workloads/controllers/garbage-collection/
[kube-code-generator]: https://github.com/slok/kube-code-generator