kustomize-go-exec-plugin

README

Kustomize Go Exec Plugin

Sample Kustomize exec plugins written in Go.

Kustomize supports two types of plugins (Go / Exec), but the Go plugin is "very annoying" because it is realized using the Go plugin system. This repository is trying to write some Kustomize exec plugins in Go.

This repository contains the following simple plugins:

• Secret Generator:
  • Generates a manifest of Kubernetes secret. You can specify the secret name, namespace, and literals(key-value pairs) of the data field.
• Line Insertion Transformer:
  • Inserts lines into base manifests. This plugin inserts specified strings above lines that include the anchor text.

Usage

Build and Run

First, you have to build Go binaries that will be used as Kustomize exec plugin. You can do it only by executing the make job at the repository root dir.

$ git clone git@github.com:hhiroshell/kustomize-go-exec-plugin.git && cd kustomize-go-exec-plugin

$ make

Then, set the environment variable KUSTOMIZE_PLUGIN_HOME to the path of the plugin directory.

$ export KUSTOMIZE_PLUGIN_HOME=$(pwd)/plugin

Now, you can use the sample plugins by executing the kustomize command as follows.

$ kustomize build --enable-alpha-plugins example/secret-generator

How to write the kustomization.yaml

Sample plugin binaries can run as Go CLI commands. So you can see all flags of plugins by executing with the --help flag.

$ plugin/hhiroshell.github.com/v1/secretgenerator/SecretGenerator --help
Kustomize exec plugin that generates a manifest of kubernetes secret written in yaml format.
You can specify the secret name, namespace and literals(key-value pairs) of the data field, via CLI flags.

Usage:
  SecretGenerator [flags]

Flags:
  -h, --help                  help for SecretGenerator
      --literal stringArray   Literal key-value pairs used as data of the Secret. (e.g. --literal key=value)
      --name string           Name of the generated Secret
      --namespace string      Namespace of the generated Secret (default "default")

All options are available by writing them in the argsOneLiner field of the plugin’s configuration file referenced from kustomization.yaml.

• plugin's configuration file (e.g. secret-generator.yaml)

apiVersion: hhiroshell.github.com/v1
kind: SecretGenerator
metadata:
  name: secret-generator
argsOneLiner: |
  --name exmaple-name
  --namespace example-namespace
  --literal hoge=fuga
  --literal foo=bar

• kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

generators:
- secret-generator.yaml

For more detail about plugin configurations, see the official Kustomize plugins guide.