fix: add hash calculation

[icco]

This sets the existingPath to go with existingName so that hash calculation happens.

See the following code for reference:

• https://github.com/open-telemetry/opentelemetry-helm-charts/blob/a3074b4a0c9839054488ff08d5daabeb5d89d522/charts/opentelemetry-collector/values.yaml#L87-L89
• https://github.com/open-telemetry/opentelemetry-helm-charts/blob/a3074b4a0c9839054488ff08d5daabeb5d89d522/charts/opentelemetry-collector/templates/_helpers.tpl#L234-L249

[orca-security-us]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

[obs-gh-mattcotter]

@icco thanks for your pull request! Were you able to get this to work locally? When I try it, the subchart is unable to find the template since it looks for a relative path. Here's the error I see:

Error: INSTALLATION FAILED: template: agent/charts/prometheus-scraper/templates/deployment.yaml:35:12: executing "agent/charts/prometheus-scraper/templates/deployment.yaml" at <include "opentelemetry-collector.configTemplateChecksumAnnotation" .>: error calling include: template: agent/charts/cluster-events/templates/_helpers.tpl:239:22: executing "opentelemetry-collector.configTemplateChecksumAnnotation" at <include (print $.Template.BasePath "/" .Values.configMap.existingPath) .>: error calling include: template: no template "agent/charts/prometheus-scraper/templates/prometheus-scraper-configmap.yaml" associated with template "gotpl"

Seems like someone else has had this same issue when using the collector chart as a subchart:
open-telemetry/opentelemetry-helm-charts#1302 (comment)
If you have this working, let's figure out what is missing in my setup and we can get this feature enabled.

[icco]

@icco thanks for your pull request! Were you able to get this to work locally? When I try it, the subchart is unable to find the template since it looks for a relative path. Here's the error I see:

Error: INSTALLATION FAILED: template: agent/charts/prometheus-scraper/templates/deployment.yaml:35:12: executing "agent/charts/prometheus-scraper/templates/deployment.yaml" at <include "opentelemetry-collector.configTemplateChecksumAnnotation" .>: error calling include: template: agent/charts/cluster-events/templates/_helpers.tpl:239:22: executing "opentelemetry-collector.configTemplateChecksumAnnotation" at <include (print $.Template.BasePath "/" .Values.configMap.existingPath) .>: error calling include: template: no template "agent/charts/prometheus-scraper/templates/prometheus-scraper-configmap.yaml" associated with template "gotpl"

Seems like someone else has had this same issue when using the collector chart as a subchart: open-telemetry/opentelemetry-helm-charts#1302 (comment) If you have this working, let's figure out what is missing in my setup and we can get this feature enabled.

I didn't have a local test environment for this so I didn't test it, but you're right, running helm template, I also see this error.

open-telemetry/opentelemetry-helm-charts#1737 also highlights this issue. I tried reading through https://helm.sh/docs/chart_template_guide/subcharts_and_globals/#sharing-templates-with-subcharts and I'm not enough of a helm expert to understand how to take advantage of this. I wonder if we could make a fix to the otel helm chart to make this work.

Do you have a test env setup to test changes to the otel chart with your observe chart?

Or should we try the hash option that the issue I linked suggests as a work around?

[obs-gh-mattcotter]

I didn't have a local test environment for this so I didn't test it, but you're right, running helm template, I also see this error.

open-telemetry/opentelemetry-helm-charts#1737 also highlights this issue. I tried reading through https://helm.sh/docs/chart_template_guide/subcharts_and_globals/#sharing-templates-with-subcharts and I'm not enough of a helm expert to understand how to take advantage of this. I wonder if we could make a fix to the otel helm chart to make this work.

Do you have a test env setup to test changes to the otel chart with your observe chart?

Or should we try the hash option that the issue I linked suggests as a work around?

@icco I looked into the possibility of sharing templates, and my most promising lead was that we could re-define opentelemetry-collector.configName and change the name of the template referenced in the pod volumes. However, I hit a similar problem of not being able to pass variables into a template definition. For example, something like this would be great:

{{ $forwarderConfig := include "observe.daemonset.applyForwarderConfig" . }}

{{- define "opentelemetry-collector.configName" -}}
    {{- if eq .Chart.Name "forwarder" -}}
        forwarder-{{ print $forwarderConfig | sha256sum }}
    {{- else -}}
        {{ .Chart.Name }}
    {{- end -}}
{{- end }}

but the result is Error: parse error at (agent/templates/_config.tpl:47): undefined variable "$forwarderConfig".

The workaround of always restarting by adding a random annotation seems solid to me if that's the behavior that you want. You can do that with our current helm chart by adding this to your values.yaml file (or using it as a separate file):

cluster-events:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

prometheus-scraper:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

cluster-metrics:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

node-logs-metrics:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

monitor:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

forwarder:
  podAnnotations:
    randAlphaNum/autoRestartEverytime: "{{ randAlphaNum 5 }}"

I also was able to find a workaround using config map hashing when deploying with Kustomize, but that's a completely separate tool and wouldn't help unless you happen to be using it.