First pass at HA statefulset

Author: malcolmholmes

prometheus-ksonnet/lib/prometheus-ha-mixin.libsonnet

@@ -0,0 +1,42 @@
+{
+  prometheus_config_0: $.prometheus_config,
+  prometheus_config_1: $.prometheus_config,
+
+  prometheusAlerts_0: $.prometheusAlerts,
+  prometheusAlerts_1: $.prometheusAlerts,
+
+  prometheusRules_0: $.prometheusRules,
+  prometheusRules_1: $.prometheusRules,
+
+  prometheus+:: {
+    local configMap = $.core.v1.configMap,
+
+    prometheus_config_map:: {},
+
+    prometheus_config_maps: [{
+      configMap.new('%s-config-0' % self.name) +
+      configMap.withData({
+        'prometheus.yml': $.util.manifestYaml($.prometheus_config_0),
+        'alerts.rules': $.util.manifestYaml($.prometheusAlerts_0),
+        'recording.rules': $.util.manifestYaml($.prometheusRules_0),
+      }),
+      configMap.new('%s-config-1' % self.name) +
+      configMap.withData({
+        'prometheus.yml': $.util.manifestYaml($.prometheus_config_1),
+        'alerts.rules': $.util.manifestYaml($.prometheusAlerts_1),
+        'recording.rules': $.util.manifestYaml($.prometheusRules_1),
+      }),
+    ]},
+
+  prometheus_config_mount:: {},
+
+  prometheus_init_container::
+    container.new('prometheus-init', 'busybox') +
+    container.withCommand(["ln", "-s", "/etc/$HOSTNAME", "/etc/prometheus"]),
+
+  prometheus_statefulset:
+    $.util.configVolumeMount('%s-config-0' % self.name, '/etc/prometheus-0') +
+    $.util.configVolumeMount('%s-config-1' % self.name, '/etc/prometheus-1') +
+    statefulset.mixin.spec.template.spec.withInitContainers(self.prometheus_init_container) +
+    statefulset.mixin.spec.withReplicas(2),
+}

prometheus-ksonnet/lib/prometheus.libsonnet

@@ -77,6 +77,9 @@
     local statefulset = $.apps.v1.statefulSet,
     local volumeMount = $.core.v1.volumeMount,
 
+    prometheus_config_mount::
+      $.util.configVolumeMount('%s-config' % self.name, '/etc/prometheus'),
+
     prometheus_statefulset:
       local _config = self._config;
 
@@ -86,7 +89,7 @@
         ),
         self.prometheus_watch_container,
       ], self.prometheus_pvc) +
-      $.util.configVolumeMount('%s-config' % self.name, '/etc/prometheus') +
+      self.prometheus_config_mount +
       statefulset.mixin.spec.withServiceName('prometheus') +
       statefulset.mixin.spec.template.metadata.withAnnotations({
         'prometheus.io.path': '%smetrics' % _config.prometheus_web_route_prefix,