Helm

Helm Charts

• Bundle of YAML Files
• Configuration of database apps, monitoring apps etc. can be saved in Helm charts and reuse these configurations
• Create your own HRML charts with Helm
• Push them to Helm Repository
• Download and use existing ones

It's also used as templating engine. Instead of writing docker files for many microservices we can create a template with variables and use it as templates.

Variables defined like

image: {{ .Values.container.name }} 

and in values.yaml file we set

image: my-app-image

it's used for different environments as well

Directory Structure

• Top level mychart folder is the name of the chart
• Chart.yaml is meta info about chart
• values.yaml is the values for the template files
• charts folder is for chart dependencies
• templates folder is for the template files

mychart/
  Chart.yaml
  values.yaml
  charts/
  templates/
...

heml install <chartname>

Overwriting values

heml install --values=my-values.yaml <chartname>

values.yaml

imageName: myapp
port: 8080
version: 1.0.0

my-values.yaml

version: 2.0.0

Useful Links

• Helm hub: https://hub.helm.sh/
• Helm charts GitHub Project: https://github.com/helm/charts
• Installing Helm: https://helm.sh/docs/intro/install/
• Helm v3 release notes: https://helm.sh/blog/helm-3-released/