Deploy InfluxDB in cluster mode

This change adds the ability to deploy a cluster of InfluxDB servers
with HAProxy in front. HAProxy will forward requests only to the first
node unless it gets unavailable. In that case, it will fail over to the
second node (and possibly the third node).
diff --git a/haproxy/proxy/listen/stacklight/influxdb.yml b/haproxy/proxy/listen/stacklight/influxdb.yml
new file mode 100644
index 0000000..8ab700f
--- /dev/null
+++ b/haproxy/proxy/listen/stacklight/influxdb.yml
@@ -0,0 +1,26 @@
+parameters:
+  haproxy:
+    proxy:
+      listen:
+        influxdb:
+          mode: http
+          options:
+            - "httpchk GET /ping"
+            - httplog
+            - dontlog-normal
+          binds:
+            - address: ${_param:cluster_vip_address}
+              port: ${_param:cluster_influxdb_port}
+          servers:
+            - name: ${_param:cluster_node01_hostname}
+              host: ${_param:cluster_node01_address}
+              port: 8086
+              params: 'check'
+            - name: ${_param:cluster_node02_hostname}
+              host: ${_param:cluster_node02_address}
+              port: 8086
+              params: 'backup check'
+            - name: ${_param:cluster_node03_hostname}
+              host: ${_param:cluster_node03_address}
+              port: 8086
+              params: 'backup check'
diff --git a/reclass/storage/system/stacklight_server_cluster.yml b/reclass/storage/system/stacklight_server_cluster.yml
index 9d40ea9..edb7a94 100644
--- a/reclass/storage/system/stacklight_server_cluster.yml
+++ b/reclass/storage/system/stacklight_server_cluster.yml
@@ -11,8 +11,6 @@
           domain: ${_param:cluster_domain}
           classes:
           - cluster.${_param:cluster_name}.stacklight.server
-          - system.influxdb.server.single
-          - system.influxdb.database.stacklight
           - system.elasticsearch.client.single
           - system.grafana.client.single
           - system.kibana.client.single
diff --git a/reclass/storage/system/stacklight_server_single.yml b/reclass/storage/system/stacklight_server_single.yml
index 6ef1050..2b397f6 100644
--- a/reclass/storage/system/stacklight_server_single.yml
+++ b/reclass/storage/system/stacklight_server_single.yml
@@ -11,8 +11,6 @@
           - cluster.${_param:cluster_name}.stacklight.server
           - system.elasticsearch.client.single
           - system.grafana.client.single
-          - system.influxdb.server.single
-          - system.influxdb.database.stacklight
           - system.kibana.client.single
           params:
             salt_master_host: ${_param:reclass_config_master}