[prometheus-mysql-exporter] Support multiple target (#3751)

* [prometheus-mysql-exporter]: multi-target probe support

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* [prometheus-mysql-exporter]: updating value comments for targets structure

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* [prometheus-mysql-exporter]: add default relabeling for multiple target

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* feat(prometheus-mysql-exporter): modify values structure and now support shared credentials pattern

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* [prometheus-mysql-exporter]: modify values comment

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* chore: bump chart version to 2.2.0

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* docs: indent targets doc string

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>

* Update charts/prometheus-mysql-exporter/values.yaml

Signed-off-by: André Bauer <monotek@users.noreply.github.com>

* Update charts/prometheus-mysql-exporter/values.yaml

Signed-off-by: André Bauer <monotek@users.noreply.github.com>

---------

Signed-off-by: Remy Mollandin <remy.mollandin@skale-5.com>
Signed-off-by: André Bauer <monotek@users.noreply.github.com>
Co-authored-by: André Bauer <monotek@users.noreply.github.com>

charts/prometheus-mysql-exporter/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 description: A Helm chart for prometheus mysql exporter with cloudsqlproxy
 name: prometheus-mysql-exporter
-version: 2.1.1
+version: 2.2.0
 home: https://github.com/prometheus/mysqld_exporter
 appVersion: v0.15.0
 sources:

charts/prometheus-mysql-exporter/README.md

@@ -41,6 +41,41 @@ _See [helm upgrade](https://helm.sh/docs/helm/helm_upgrade/) for command documen
 helm upgrade [RELEASE_NAME] [CHART] --install
 ```
 
+### Multiple-target probes
+
+mysql_exporter now support multi-target probes using the `/probe` route. To enable this feature, set `serviecMonitor.multipleTarget.enabled` to `true` and define your targets in `serviceMonitor.multipleTarget.targets`.
+Credentials for each target should be referenced in the associate config file. Target name should match the entry in the config file.
+As an example, for a config file with two targets:
+
+```yaml
+serviceMonitor:
+  multipleTarget:
+    enabled: true
+    targets:
+      - name: localhost
+        endpoint: 127.0.0.1
+      - name: remote
+        endpoint: 8.8.8.8
+        port: 3307
+```
+
+Config file should have the following entries:
+
+```cnf
+[client]
+user=NOT_USED
+password=NOT_USED
+[client.localhost]
+user=localhost_user
+password=localhost_password
+[client.remote]
+user=remote_user
+password=remote_password
+```
+
+The configuration file can be referenced using `mysql.existingConfigSecret`.
+If all your target use the same credentials, you can set `serviceMonitor.sharedSecret.enabled` to `true` and define the key name in `serviceMonitor.sharedSecret.name`.
+
 ### From 1.x to 2.x
 
 mysqld_exporter has been updated to [v0.15.0](https://github.com/prometheus/mysqld_exporter/releases/tag/v0.15.0), removing support for `DATA_SOURCE_NAME`. Configuration for exporter use `--config.my-cnf` with a custom cnf file (secret).

charts/prometheus-mysql-exporter/templates/servicemonitor.yaml

@@ -30,6 +30,43 @@ spec:
 {{ toYaml . | trim | indent 4 -}}
   {{- end }}
   endpoints:
+  {{- if .Values.serviceMonitor.multipleTarget.enabled }}
+  {{- range  .Values.serviceMonitor.multipleTarget.targets }}
+    - path: /probe
+      port: {{ $.Values.service.name }}
+  {{- if $.Values.serviceMonitor.interval }}
+      interval: {{ $.Values.serviceMonitor.interval }}
+  {{- end }}
+  {{- if $.Values.serviceMonitor.scrapeTimeout }}
+      scrapeTimeout: {{ $.Values.serviceMonitor.scrapeTimeout }}
+  {{- end }}
+      metricRelabelings:
+        - action: replace
+          replacement: {{ .endpoint }}
+          sourceLabels: [instance]
+          targetLabel: instance
+        - action: replace
+          replacement: {{ .name }}
+          sourceLabels: [target]
+          targetLabel: target
+      {{- if $.Values.serviceMonitor.metricRelabelings -}}
+        {{ toYaml $.Values.serviceMonitor.metricRelabelings | nindent 8 }}
+      {{- end }}
+  {{- if $.Values.serviceMonitor.relabelings }}
+      relabelings: {{ toYaml $.Values.serviceMonitor.relabelings | nindent 8 }}
+  {{- end }}
+      params:
+        target:
+          - {{ .endpoint }}:{{ .port | default 3306 }}
+        {{- if $.Values.serviceMonitor.multipleTarget.sharedSecret.enabled }}
+        auth_module:
+          - client.{{ $.Values.serviceMonitor.multipleTarget.sharedSecret.name }}
+        {{- else }}
+        auth_module:
+          - client.{{ .name }}
+        {{- end }}
+  {{- end }}
+  {{- else }}
     - path: /metrics
       port: {{ .Values.service.name }}
   {{- if .Values.serviceMonitor.interval }}
@@ -44,4 +81,5 @@ spec:
   {{- if .Values.serviceMonitor.relabelings }}
       relabelings: {{ toYaml .Values.serviceMonitor.relabelings | nindent 8 }}
   {{- end }}
+  {{- end }}
 {{- end }}

charts/prometheus-mysql-exporter/values.yaml

@@ -45,6 +45,21 @@ serviceMonitor:
   metricRelabelings: []
   # Set relabel_configs as per https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
   relabelings: []
+  # Enable multi target scraping.
+  multipleTarget:
+    enabled: false
+    targets: []
+      # target connection information with name (required), endpoint (required) and port (optionnal)
+      # if sharedSecret is not enabled the name must match an entry client.{{ name }} existing in the secret
+      # - endpoint: mysql1.dns.local
+      #   name: mysql1
+      #   port: 3307
+      # - endpoint: mysql2.dns.local
+      #   name: mysql2
+    # Enable shared credentials for all targets
+    sharedSecret:
+      enabled: false
+      name: ""
 
 serviceAccount:
   # Specifies whether a ServiceAccount should be created