gitlab-ci-pipelines-exporter: Allow specifying name of existing Secret containing tokens

[shivjm]

I have a Secret containing my GitLab API token and webhook token. I’d like to be able to use that instead of specifying them in plaintext when installing the chart, so I added them as env variables:

          - name: "GCPE_WEBHOOK_SECRET_TOKEN"
            valueFrom:
              secretKeyRef:
                name: gitlab-ci-pipelines-exporter-secret
                value: webhook-token
          - name: "GCPE_GITLAB_TOKEN"
            valueFrom:
              secretKeyRef:
                name: gitlab-ci-pipelines-exporter-secret
                value: gitlab-api-token

Unfortunately, the chart unconditionally expects them to be provided as plaintext parameters:

helm-charts/charts/gitlab-ci-pipelines-exporter/templates/secret.yaml

Lines 14 to 18 in 095facc

	{{- if .Values.config.gitlab }}
	GCPE_GITLAB_TOKEN: {{ required "gitlab token must be set" .Values.config.gitlab.token | b64enc }}
	{{- else }}
	{{- fail "gitlab token must be set" }}
	{{- end }}

helm-charts/charts/gitlab-ci-pipelines-exporter/templates/secret.yaml

Lines 24 to 30 in 095facc

	{{- if .Values.config.server }}
	{{- if .Values.config.server.webhook }}
	{{- if .Values.config.server.webhook.enabled }}
	GCPE_WEBHOOK_SECRET_TOKEN: {{ required "webhook secret token must be set" .Values.config.server.webhook.secret_token | b64enc }}
	{{- end }}
	{{- end }}
	{{- end }}

I’d like to be able to point at my Secret instead.

(Incidentally, I’m trying to get to the point where I can test whether mvisonneau/gitlab-ci-pipelines-exporter#280 is resolved… it’s been a really long road, for many reasons, and I apologize for the silence.)