diff --git a/docs/howItWorks.md b/docs/howItWorks.md new file mode 100644 index 00000000000..8ffedcbab73 --- /dev/null +++ b/docs/howItWorks.md @@ -0,0 +1,52 @@ +# How does `kustomize build` work + +Call stack when running `kustomize build`, with link to code. + +## Run build + +* [RunBuild](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/kustomize/internal/commands/build/build.go#L121) + * [MakeKustomizer](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/krusty/kustomizer.go#L32) + * [Run](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/krusty/kustomizer.go#L47): performs a kustomization. It uses its internal filesystem reference to read the file at the given path argument, interpret it as a kustomization.yaml + // file, perform the kustomization it represents, and return the resulting resources. + * Create factories + * [tranformer.NewFactoryImpl](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/k8sdeps/transformer/factory.go#L17) + * [resmap.NewFactory](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/resmap/factory.go#L21) + * [resource.NewFactory](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/resource/factory.go#L23) + * [kustruct.NewKunstructuredFactoryImpl](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/k8sdeps/kunstruct/factory.go#L28) + * [loader.NewLoader](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/loader/loader.go#L19) + * [validator.NewKustValidator](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/k8sdeps/validator/validators.go#L23) + * [NewKustTarget](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L38) + * [Load](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L54) + * [MakeCustomizeResMap](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L109): details in next section + * [emitResources](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/kustomize/internal/commands/build/build.go#L143) + +## Make resource map + +* [makeCustomizeResMap](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L117) + * [AccumulateTarget](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L196): returns a new ResAccumulator, holding customized resources and the data/rules used to do so. The name back references and vars are not yet fixed. + * [accummulateResources](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L302): fills the given resourceAccumulator with resources read from the given list of paths. + * Merge config from builtin and CRDs + * [runGenerators](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L239) + * [configureBuiltinGenerators](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget_configplugin.go#L28) + * ConfigMapGenerator + * SecretGenerator + * [configureExternalGenerators]() + * Iterate all generators + * [runTransfomers](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L274) + * [configureBuiltinTransformers](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget_configplugin.go#L44) + * PatchStrategicMergeTransformer + * PatchTransformer + * NamespaceTransformer + * PrefixSuffixTransformer + * LabelTransformer + * AnnotationsTransformer + * PatchJson6902Transformer + * ReplicaCountTransformer + * ImageTagTransformer + * [configureExternalTransformers](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L291) + * [MergeVars](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/accumulator/resaccumulator.go#L64) + * The following steps must be done last, not as part of the recursion implicit in AccumulateTarget. + * [addHashesToNames](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L153) + * [FixBackReferences](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/accumulator/resaccumulator.go#L160): Given that names have changed (prefixs/suffixes added), fix all the back references to those names. + * [ResolveVars](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/accumulator/resaccumulator.go#L141) + * [computeInventory](https://github.com/kubernetes-sigs/kustomize/blob/c7d78970fb86782dbdded3a93944b774f826071f/api/internal/target/kusttarget.go#L163)