feat(helm): Add an ability to set addition env via helm (#399)

* feat: Add local bin dir to helmignore

In case somebody wants to test the chart locally, after generating docs,
tests will fail, because helm will consider bin as a part of the chart,
and the size of the binary is too big to be installed to k8s

* feat: Add an ability to set addition env via helm

Now it should be possible to set addition environment variables that are
going to be used by sql_exporter deployment.

User can either set a value of the variable, so it's taken directly from
Values, or use a value from an already existing Secret or ConfigMap.

helm/.helmignore

@@ -21,3 +21,5 @@
 .idea/
 *.tmproj
 .vscode/
+# Dir with local binaries
+bin

helm/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: sql-exporter
 description: Database agnostic SQL exporter for Prometheus
 type: application
-version: 0.2.3
+version: 0.2.4
 appVersion: 0.13.0
 keywords:
   - exporter

helm/README.md

@@ -1,6 +1,6 @@
 # sql-exporter
 
-![Version: 0.2.2](https://img.shields.io/badge/Version-0.2.2-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 0.13.0](https://img.shields.io/badge/AppVersion-0.13.0-informational?style=flat-square)
+![Version: 0.2.4](https://img.shields.io/badge/Version-0.2.4-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 0.13.0](https://img.shields.io/badge/AppVersion-0.13.0-informational?style=flat-square)
 
 Database agnostic SQL exporter for Prometheus
 
@@ -72,4 +72,4 @@ It's also possible to define collectors (i.e. metrics and queries) in separate f
 
 ## Dev Notes
 
-After updating default `Values`, please execute `make gen_docs` to update the `README.md` file
+After changing default `Values`, please execute `make gen_docs` to update the `README.md` file. Readme file is generated by the `helm-docs` tool, so make sure not to edit it manually.

helm/templates/deployment.yaml

@@ -54,6 +54,26 @@ spec:
             readOnly: true
             mountPath: /etc/sql_exporter/collectors/
           {{- end }}
+          {{- if .Values.env }}
+          env:
+            {{- range $key, $value := .Values.env }}
+            - name: {{ $key }}
+              {{- if $value.value }}
+              value: {{ $value.value }}
+              {{- else }}
+              valueFrom:
+                {{- if eq $value.from.kind "Secret" }}
+                secretKeyRef:
+                {{- else if eq $value.from.kind "ConfigMap" }}
+                configMapKeyRef:
+                {{- else }}
+                {{- fail "Values.env[].from.kind should be either Secret or ConfigMap" }}
+                {{- end }}
+                  name: {{ $value.from.name }}
+                  key: {{ $value.from.key }}
+              {{- end }}
+            {{- end }}
+            {{- end }}
           livenessProbe:
             httpGet:
               path: /healthz

helm/values.yaml

@@ -23,13 +23,15 @@ service:
   # -- Service labels
   labels: {}
   # -- Service annotations
-  annotations: {}
+  annotations:
+    {}
     # example of prometheus usage
     # prometheus.io/scrape: "true"
     # prometheus.io/path: "/metrics"
 
 # -- Resource limits and requests for the application controller pods
-resources: {}
+resources:
+  {}
   # limits:
   #   cpu: 100m
   #   memory: 128Mi
@@ -43,7 +45,8 @@ podLabels: {}
 podAnnotations: {}
 
 # -- Pod security context
-podSecurityContext: {}
+podSecurityContext:
+  {}
   # capabilities:
   #   drop:
   #   - ALL
@@ -64,6 +67,16 @@ serviceMonitor:
   # -- ServiceMonitor scrape timeout
   # scrapeTimeout: 10s
 
+# Additional env variables
+# - kind should be either Secret or ConfigMap
+# - name is the name of the Secret or ConfigMap that should be used
+# - key is the key of the object inside of a Secret or ConfigMap
+# env:
+#   SQLEXPORTER_TARGET_DSN:
+#     from:
+#       kind: Secret
+#       name: sql_exporter_secret
+#       key: CONNECTION_STRING
 config:
   global:
     # -- Scrape timeout
@@ -76,7 +89,6 @@ config:
     max_connections: 3
     # -- Number of idle connections.
     max_idle_connections: 3
-
 # Target and collectors are not set so the chart is more flexible. Please configure it yourself.
 # target:
 #   data_source_name: 'sqlserver://prom_user:[email protected]:1433'