integrate changes from rawmind0, use optional sysctl container to set max_map_count on hosts

templates/es-cluster/0/README.md

@@ -2,8 +2,4 @@
 
 A scalable Elasticsearch cluster
 
-## Notes
-
-You have to set vm.max_map_count to atleast 262144 on each of the hosts that will run Elasticsearch!
-
-To do so run `sudo sysctl -w vm.max_map_count=262144`
+WARN: To avoid vm.max_map_count errors you could set "Update host sysctl" to true. Then param vm.max_map_count will be update to 262144 if it's less in your hosts.

templates/es-cluster/0/docker-compose.yml.tpl

@@ -5,6 +5,9 @@ services:
             io.rancher.scheduler.affinity:container_label_soft_ne: io.rancher.stack_service.name=$${stack_name}/$${service_name}
             io.rancher.container.hostname_override: container_name
             io.rancher.sidekicks: es-storage
+            {{- if eq .Values.UPDATE_SYSCTL "true" -}}
+                ,es-sysctl
+            {{- end}}
         image: docker.elastic.co/elasticsearch/elasticsearch:5.4.0
         environment: 
             - "cluster.name=${cluster_name}"
@@ -35,6 +38,9 @@ services:
             io.rancher.scheduler.affinity:container_label_soft_ne: io.rancher.stack_service.name=$${stack_name}/$${service_name}
             io.rancher.container.hostname_override: container_name
             io.rancher.sidekicks: es-storage
+            {{- if eq .Values.UPDATE_SYSCTL "true" -}}
+                ,es-sysctl
+            {{- end}}
         image: docker.elastic.co/elasticsearch/elasticsearch:5.4.0
         environment: 
             - "cluster.name=${cluster_name}"
@@ -66,6 +72,9 @@ services:
             io.rancher.scheduler.affinity:container_label_soft_ne: io.rancher.stack_service.name=$${stack_name}/$${service_name}
             io.rancher.container.hostname_override: container_name
             io.rancher.sidekicks: es-storage
+            {{- if eq .Values.UPDATE_SYSCTL "true" -}}
+                ,es-sysctl
+            {{- end}}
         image: docker.elastic.co/elasticsearch/elasticsearch:5.4.0
         environment: 
             - "cluster.name=${cluster_name}"
@@ -91,7 +100,7 @@ services:
             - es-storage
         depends_on: 
             - es-master
-    
+
     es-storage:
         labels:
             io.rancher.container.start_once: true
@@ -100,6 +109,17 @@ services:
         volumes: 
             - es-storage-volume:/usr/share/elasticsearch/data
 
+    {{- if eq .Values.UPDATE_SYSCTL "true" }}
+    es-sysctl:
+        labels:
+            io.rancher.container.start_once: true
+        image: rawmind/alpine-sysctl:0.1
+        privileged: true
+        environment: 
+            - "SYSCTL_KEY=vm.max_map_count" 
+            - "SYSCTL_VALUE=262144"
+    {{- end}}
+
 volumes:
   es-storage-volume:
     driver: local

templates/es-cluster/0/rancher-compose.yml

@@ -11,6 +11,18 @@
           description: "Name of the Elasticsearch Cluster"
           default: "es-cluster"
         
+        - variable: "UPDATE_SYSCTL"
+          label: "Update host sysctl:"
+          description: |
+            Set true to avoid vm.max_map_count errors.
+            WARN: If set true, host param vm.max_map_count will be update to 262144.
+          default: false
+          required: true
+          type: enum
+          options:
+            - false
+            - true
+
         - variable: "master_heap_size"
           type: "string"
           required: true