toelt / helmify

Creates Helm chart from Kubernetes yaml

Helmify

CLI that creates Helm charts from kubernetes yamls.

Helmify reads a list of supported k8s objects from stdin and converts it to a helm chart. Designed to generate charts for k8s operators but not limited to. See examples of charts generated by helmify.

Submit issue if some features missing for your use-case.

Usage

1. From file: cat my-app.yaml | helmify mychart

   Will create 'mychart' directory with Helm chart from yaml file with k8s objects.

2. From directory with yamls:

   awk 'FNR==1 && NR!=1  {print "---"}{print}' /<my_directory>/*.yaml | helmify mychart

   Will create 'mychart' directory with Helm chart from all yaml files in <my_directory> directory.

3. From kustomize output:

   kustomize build <kustomize_dir> | helmify mychart

   Will create 'mychart' directory with Helm chart from kustomize output.

Integrate to your Operator-SDK/Kubebuilder project

Tested with operator-sdk version: "v1.8.0".

1. Open Makefile in your operator project generated by Operator-SDK or Kubebuilder.
2. Add these lines to Makefile:

   HELMIFY = $(shell pwd)/bin/helmify
   helmify:
       $(call go-get-tool,$(HELMIFY),github.com/arttor/helmify/cmd/[email protected])
   
   helm: manifests kustomize helmify
       $(KUSTOMIZE) build config/default | $(HELMIFY)

3. Run make helm in project root. It will generate helm chart with name 'chart' in 'chart' directory.

Install

With Homebrew (for MacOS or Linux): brew install arttor/tap/helmify

Or download suitable for your system binary from the Releases page. Unpack the helmify binary and add it to your PATH and you are good to go!

Available options

Helmify takes a chart name for an argument. Usage:

helmify [flags] CHART_NAME - CHART_NAME is optional. Default is 'chart'. Can be a directory, e.g. 'deploy/charts/mychart'.

flag	description	sample
-h -help	Prints help	helmify -h
-v	Enable verbose output. Prints WARN and INFO.	helmify -v
-vv	Enable very verbose output. Also prints DEBUG.	helmify -vv
-version	Print helmify version.	helmify -version

Status

Supported default operator resources:

• deployment
• service
• RBAC (serviceaccount, (cluster-)role, (cluster-)rolebinding)
• configs (configmap, secret)
• webhooks (cert, issuer, ValidatingWebhookConfiguration)

Known issues

• Helmify will not overwrite Chart.yaml file if presented. Done on purpose.
• Helmify will not delete existing template files, only overwrite.
• Helmify overwrites templates and values files on every run. This meas that all your manual changes in helm template files will be lost on the next run.

Develop

To support a new type of k8s object template:

1. Implement helmify.Processor interface. Place implementation in pkg/processor. The package contains examples for most k8s objects.
2. Register your processor in the pkg/app/app.go
3. Add relevant input sample to test_data/kustomize.output.

Run

Clone repo and execute command:

cat test_data/k8s-operator-kustomize.output | go run ./cmd/helmify mychart

Will generate mychart Helm chart form file test_data/k8s-operator-kustomize.output representing typical operator kustomize output.

Test

For manual testing, run program with debug output:

cat test_data/k8s-operator-kustomize.output | go run ./cmd/helmify -vv mychart

Then inspect logs and generated chart in ./mychart directory.

To execute tests, run:

go test ./...

Beside unit-tests, project contains e2e test pkg/app/app_e2e_test.go. It's a go test, which uses test_data/* to generate a chart in temporary directory. Then runs helm lint --strict to check if generated chart is valid.