I've defined a mount point like so:
- name: dir-graphite
configMap:
name: hub-logstash-grafana
items:
- key: logstash.conf.file
path: configwith a later volume declaration:
volumes:
volumeMounts:
- mountPath: "/opt/blackduck/hub/logs"
name: dir-webapp
- mountPath: "/var/lib/logstash/data"
name: dir-logstash
- mountPath: "/tmp/x"
name: dir-graphiteIn kubernetes 1.6.6, I see
Aug 05 02:02:59 ip-10-0-26-84 kubelet[30344]: I0805 02:02:59.912640 30344 operation_generator.go:597]
MountVolume.SetUp succeeded for volume "kubernetes.io/configmap/a47ebff8-7976-11e7-8369-12207729cdd2-dir-graphite" (spec.Name: "dir-graphite") pod "a47ebff8-7976-11e7-8369-12207729cdd2" (UID: "a47ebff8-7976-11e7-8369-12207729cdd2").That is, I can see the mount set up operation succeeding for my config map, however, when i inspect the actual created container, I see no associated mount:
"Mounts": [
{
"Source": "/var/lib/kubelet/pods/a47ebff8-7976-11e7-8369-12207729cdd2/etc-hosts",
"Destination": "/etc/hosts",
"Mode": "",
"RW": true,
"Propagation": "rprivate"
},
{
"Source": "/var/lib/kubelet/pods/a47ebff8-7976-11e7-8369-12207729cdd2/containers/logstash/86b079de",
"Destination": "/dev/termination-log",
"Mode": "",
"RW": true,
"Propagation": "rprivate"
},
{
"Source": "/var/lib/kubelet/pods/a47ebff8-7976-11e7-8369-12207729cdd2/volumes/kubernetes.io~secret/default-token-2t0cl",
"Destination": "/var/run/secrets/kubernetes.io/serviceaccount",
"Mode": "ro",
"RW": false,
"Propagation": "rprivate"
}
The following snippet is indeed correct:
31 containers:
32 - image: blackducksoftware/hub-logstash:4.0.0
33 name: logstash
34 volumeMounts:
35 - name: dir-graphite
36 mountPath: /tmp/xI beleive there is a situation where if you have a minor indentation off, in 1.6, validation isnt very strict, so you get a no-op where a volume is loaded but the mount paths don't necessarily get read into anything.
For the record , if the volume is truly attached, you should see this in your mount points when running docker inspect:
"Mounts": [
{
"Source": "/var/lib/kubelet/pods/bf655bb7-7985-11e7-8369-12207729cdd2/volumes/kubernetes.io~configmap/dir-graphite",
"Destination": "/tmp/x",
"Mode": "",
"RW": true,
"Propagation": "rprivate"
},
Moral of the story: In the case of ConfigMaps (and likely any other volume that is lazily mounted by a kubelet), A successful MountVolume.SetUp log at the kubelet level doesn't gaurantee that your files were mounted into a container, rather, it only means that the kubelet was able to create a volume corresponding to one of your defined ConfigMap volumes.