153 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
			
		
		
	
	
			153 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
# Shared Configuration Across Teams
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Assume you have a two or more teams, each works for a different internal or external service, like:
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- Product 1
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- Product 2
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- Observability
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The simplest `helmfile.yaml` that declares the whole cluster that is composed of the three services would look like the below:
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```yaml
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releases:
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- name: product1-api
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  chart: product1-charts/api
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  # snip
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- name: product1-web
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  chart: product1-charts/web
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  # snip
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- name: product2-api
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  chart: saas-charts/api
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  # snip
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- name: product2-web
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  chart: product2-charts/web
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  # snip
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- name: observability-prometheus-operator
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  chart: stable/prometheus-operator
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  # snip
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- name: observability-process-exporter
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  chart: stable/prometheus-operator
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  # snip
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```
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This works, but what if you wanted to a separate cluster per service to achieve smaller blast radius?
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Let's start by creating a `helmfile.yaml` for each service.
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`product1/helmfile.yaml`:
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```yaml
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releases:
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- name: product1-api
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  chart: product1-charts/api
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  # snip
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- name: product1-web
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  chart: product1-charts/web
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  # snip
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- name: observability-prometheus-operator
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  chart: stable/prometheus-operator
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  # snip
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- name: observability-process-exporter
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  chart: stable/prometheus-operator
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  # snip
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```
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`product2/helmfile.yaml`:
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```yaml
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releases:
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- name: product2-api
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  chart: product2-charts/api
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  # snip
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- name: product2-web
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  chart: product2-charts/web
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  # snip
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- name: observability-prometheus-operator
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  chart: stable/prometheus-operator
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  # snip
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- name: observability-process-exporter
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  chart: stable/prometheus-operator
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  # snip
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```
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You will (of course!) notice this isn't DRY.
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To remove the duplication of observability stack between the two helmfiles, create a "sub-helmfile" for the observability stack.
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`observability/helmfile.yaml`:
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```yaml
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- name: observability-prometheus-operator
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  chart: stable/prometheus-operator
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  # snip
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- name: observability-process-exporter
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  chart: stable/prometheus-operator
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  # snip
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```
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As you might have imagined, the observability helmfile can be reused from the two product helmfiles by declaring `helmfiles`.
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`product1/helmfile.yaml`:
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```yaml
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helmfiles:
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- ../observability/helmfile.yaml
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releases:
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- name: product1-api
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  chart: product1-charts/api
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  # snip
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- name: product1-web
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  chart: product1-charts/web
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  # snip
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```
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`product2/helmfile.yaml`:
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```yaml
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helmfiles:
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- ../observability/helmfile.yaml
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releases:
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- name: product2-api
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  chart: product2-charts/api
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  # snip
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- name: product2-web
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  chart: product2-charts/web
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  # snip
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```
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## Using sub-helmfile as a template
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You can go even further by generalizing the product related releases as a pair of `api` and `web`:
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`shared/helmfile.yaml`:
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```yaml
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releases:
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- name: product{{ env "PRODUCT_ID" }}-api
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  chart: product{{ env "PRODUCT_ID" }}-charts/api
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  # snip
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- name: product{{ env "PRODUCT_ID" }}-web
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  chart: product{{ env "PRODUCT_ID" }}-charts/web
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  # snip
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```
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Then you only need one single product helmfile
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`product/helmfile.yaml`:
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```yaml
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helmfiles:
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- ../observability/helmfile.yaml
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- ../shared/helmfile.yaml
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```
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Now that we use the environment variable `PRODUCT_ID` to as the parameters of release names, you need to set it before running `helmfile`, so that it produces the differently named releases per product:
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```console
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$ PRODUCT_ID=1 helmfile -f product/helmfile.yaml apply
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$ PRODUCT_ID=2 helmfile -f product/helmfile.yaml apply
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```
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