If you are creating a standalone go library for your operator and have types that are used in your operator CRD spec/status, you will see that you need code-generation to generate DeepCopy and DeepCopyInto methods for your types. For API types in your operator, make generate will do that for you automatically using controller-tools. But for your library project that is not using controller-tools, you can do the same code generation using github.com/kubernetes/code-generator.
An example is here: https://github.com/jeesmon/operator-utils/blob/main/Makefile#L14-L20
Steps:
- Add deepcopy-gen markers for your types
ex:
https://github.com/jeesmon/operator-utils/blob/main/status/doc.go#L1-L3
https://github.com/jeesmon/operator-utils/blob/main/status/status.go#L25
- Install deepcopy-gen from code-generator project
go install k8s.io/code-generator/cmd/deepcopy-gen@v0.24.0-alpha.3
- Generate deepcoy file
ex:
deepcopy-gen -i github.com/jeesmon/operator-utils/status -h hack/boilerplate.go.txt --trim-path-prefix github.com/jeesmon/operator-utils --output-base . --output-package github.com/jeesmon/operator-utils/status -O zz_deepcopy
Above command will create a zz_deepcopy.go file with DeepCopy* methods
ex: https://github.com/jeesmon/operator-utils/blob/main/status/zz_deepcopy.go
- Makefile example
https://github.com/jeesmon/operator-utils/blob/main/Makefile#L14-L20
More on code generation:
https://cloud.redhat.com/blog/kubernetes-deep-dive-code-generation-customresources