kustomize-krm-envsubst

This is an Exec KRM function for Kustomize. It applies envsubst as per this package: https://github.com/drone/envsubst on the configuration files

Installation

Build from source:

go install github.com/logandavies181/kustomize-krm-envsubst@latest

Or check out releases

Usage

As an Exec KRM function

Install this binary as above.

Add a transformer to your kustomize configuration

# kustomization.yaml
resources:
- secret.yaml
transformers:
- transformer.yaml

# transformer.yaml
apiVersion: kustomize-krm-envsubst/v1alpha
kind: Envsubst
metadata:
  name: envsubst
  annotations:
    config.kubernetes.io/function: |
      exec:
        # ~ is not expanded by kustomize :(
        path: /path/to/kustomize-krm-envsubst
#excludedVariableNames: [] # used to denylist certain env var names from being injected    
#includedVariableNames: [] # used to enumerate the list of env var names to inject
#ignoredKeys: [] # used to exclude parts of the input from processing 
                 # for example if you're passing a script in a configmap
#values: # explicit keys and values to inject
#  FOO: baz
#  BAR: zar

Inject environment variables into your manifests!

# secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: super-secret-value
# always use stringData for using this plugin with secrets
stringData:
  password: ${PASSWORD}

Render your configuration

# Can only be run in this mode with `kustomize build` and not `kubectl kustomize`
# see https://github.com/kubernetes-sigs/kustomize/issues/4556#issuecomment-1092095023

kustomize build --enable-alpha-plugins --enable-exec .

As a legacy exec plugin

Use this method to use this plugin with kubectl kustomize

Install the binary to ${XDG_CONFIG_HOME:-~/.config}/kustomize/plugin/kustomize-krm-envsubst/v1alpha/kustomize-krm-envsubst/kustomize-krm-envsubst

Set up your kustomization.yaml and other files as above but use this config for transformer.yaml:

# transformer.yaml
apiVersion: kustomize-krm-envsubst/v1alpha
kind: Envsubst
metadata:
  name: envsubst
#excludedVariableNames: [] # used to denylist certain env var names from being injected    
#includedVariableNames: [] # used to enumerate the list of env var names to inject
#ignoredKeys: [] # used to exclude parts of the input from processing 
                 # for example if you're passing a script in a configmap
#values: # explicit keys and values to inject
#  FOO: baz
#  BAR: zar