Support configurable log level in weave-npc

[awh]

From @awh on October 14, 2016 8:43

Via a configmap or an environment variable.

Copied from original issue: weaveworks-experiments/weave-npc#20

[bboreham]

I believe the crux of this issue is that while the weave-npc program supports our usual command-line flag --log-level, it is nontrivial to edit this into the yaml for the DaemonSet.

Our config generator at cloud.weave.works allows you to add environment variables, so perhaps that is the way to go.

[hairyhenderson]

For anyone else who came to this from a google search, this can be accomplished by patching the PodSpec in the DaemonSet to add --log-level=error to the args list.

I did something like this:

weave-patch.yml:

kind: DaemonSet
metadata:
  name: weave-net
  namespace: kube-system
spec:
  template:
    spec:
      containers:
        - name: weave-npc
          args:
            - --log-level=error

$ kubectl patch -n kube-system daemonset weave-net --patch "$(< weave-patch.yml)"