Set vm.max_map_count on cluster nodes

Question

I try to install ElasticSearch (latest) on a cluster nodes on Google Container Engine but ElasticSearch needs the variable : vm.max_map_count to be >= 262144.

Answer 1

I found another solution while looking at this repository.

It relies on the use of an init container, the plus side is that only the init container is running with privileges:

annotations:
    pod.beta.kubernetes.io/init-containers: '[
      {
      "name": "sysctl",
        "image": "busybox",
        "imagePullPolicy": "IfNotPresent",
        "command": ["sysctl", "-w", "vm.max_map_count=262144"],
        "securityContext": {
          "privileged": true
        }
      }
    ]'

There is a new syntax available since Kubernetes 1.6 which still works for 1.7. Starting with 1.8 this new syntax is required. The declaration of init containers is moved to spec:

  - name: init-sysctl
    image: busybox
    command:
    - sysctl
    - -w
    - vm.max_map_count=262144
    imagePullPolicy: IfNotPresent
    securityContext:
      privileged: true