Error mounting volumes on Openshift (Next gen) - mongodb

Question

I'm testing the new Openshift platform based on Docker and Kubernetes.
I've created a new project from scratch, then when I try to deploy a simple MongoDB service (as well with a python app), I got the following errors in the Monitoring section in Web console:
Unable to mount volumes for pod "mongodb-1-sfg8t_rob1(e9e53040-ab59-11e6-a64c-0e3d364e19a5)": timeout expired waiting for volumes to attach/mount for pod "mongodb-1-sfg8t"/"rob1". list of unattached/unmounted volumes=[mongodb-data]
Error syncing pod, skipping: timeout expired waiting for volumes to attach/mount for pod "mongodb-1-sfg8t"/"rob1". list of unattached/unmounted volumes=[mongodb-data]
It seems a problem mounting the PVC in the container, however the PVC is correctly created and bounded:
oc get pvc
Returns:
NAME STATUS VOLUME CAPACITY ACCESSMODES AGE
mongodb-data Bound pv-aws-9dged 1Gi RWO 29m
I've deployed it with the following commands:
oc process -f openshift/templates/mongodb.json | oc create -f -
oc deploy mongodb --latest
The complete log from Web console:
The content of the template that I used is:
{
"kind": "Template",
"apiVersion": "v1",
"metadata": {
"name": "mongo-example",
"annotations": {
"openshift.io/display-name": "Mongo example",
"tags": "quickstart,mongo"
}
},
"labels": {
"template": "mongo-example"
},
"message": "The following service(s) have been created in your project: ${NAME}.",
"objects": [
{
"kind": "PersistentVolumeClaim",
"apiVersion": "v1",
"metadata": {
"name": "${DATABASE_DATA_VOLUME}"
},
"spec": {
"accessModes": [
"ReadWriteOnce"
],
"resources": {
"requests": {
"storage": "${DB_VOLUME_CAPACITY}"
}
}
}
},
{
"kind": "Service",
"apiVersion": "v1",
"metadata": {
"name": "${DATABASE_SERVICE_NAME}",
"annotations": {
"description": "Exposes the database server"
}
},
"spec": {
"ports": [
{
"name": "mongodb",
"port": 27017,
"targetPort": 27017
}
],
"selector": {
"name": "${DATABASE_SERVICE_NAME}"
}
}
},
{
"kind": "DeploymentConfig",
"apiVersion": "v1",
"metadata": {
"name": "${DATABASE_SERVICE_NAME}",
"annotations": {
"description": "Defines how to deploy the database"
}
},
"spec": {
"strategy": {
"type": "Recreate"
},
"triggers": [
{
"type": "ImageChange",
"imageChangeParams": {
"automatic": true,
"containerNames": [
"mymongodb"
],
"from": {
"kind": "ImageStreamTag",
"namespace": "",
"name": "mongo:latest"
}
}
},
{
"type": "ConfigChange"
}
],
"replicas": 1,
"selector": {
"name": "${DATABASE_SERVICE_NAME}"
},
"template": {
"metadata": {
"name": "${DATABASE_SERVICE_NAME}",
"labels": {
"name": "${DATABASE_SERVICE_NAME}"
}
},
"spec": {
"volumes": [
{
"name": "${DATABASE_DATA_VOLUME}",
"persistentVolumeClaim": {
"claimName": "${DATABASE_DATA_VOLUME}"
}
}
],
"containers": [
{
"name": "mymongodb",
"image": "mongo:latest",
"ports": [
{
"containerPort": 27017
}
],
"env": [
{
"name": "MONGODB_USER",
"value": "${DATABASE_USER}"
},
{
"name": "MONGODB_PASSWORD",
"value": "${DATABASE_PASSWORD}"
},
{
"name": "MONGODB_DATABASE",
"value": "${DATABASE_NAME}"
}
],
"volumeMounts": [
{
"name": "${DATABASE_DATA_VOLUME}",
"mountPath": "/data/db"
}
],
"readinessProbe": {
"timeoutSeconds": 1,
"initialDelaySeconds": 5,
"exec": {
"command": [ "/bin/bash", "-c", "mongo --eval 'db.getName()'"]
}
},
"livenessProbe": {
"timeoutSeconds": 1,
"initialDelaySeconds": 30,
"tcpSocket": {
"port": 27017
}
},
"resources": {
"limits": {
"memory": "${MEMORY_MONGODB_LIMIT}"
}
}
}
]
}
}
}
}
],
"parameters": [
{
"name": "NAME",
"displayName": "Name",
"description": "The name",
"required": true,
"value": "mongo-example"
},
{
"name": "MEMORY_MONGODB_LIMIT",
"displayName": "Memory Limit (MONGODB)",
"required": true,
"description": "Maximum amount of memory the MONGODB container can use.",
"value": "512Mi"
},
{
"name": "DB_VOLUME_CAPACITY",
"displayName": "Volume Capacity",
"description": "Volume space available for data, e.g. 512Mi, 2Gi",
"value": "512Mi",
"required": true
},
{
"name": "DATABASE_DATA_VOLUME",
"displayName": "Volumne name for DB data",
"required": true,
"value": "mongodb-data"
},
{
"name": "DATABASE_SERVICE_NAME",
"displayName": "Database Service Name",
"required": true,
"value": "mongodb"
},
{
"name": "DATABASE_NAME",
"displayName": "Database Name",
"required": true,
"value": "test1"
},
{
"name": "DATABASE_USER",
"displayName": "Database Username",
"required": false
},
{
"name": "DATABASE_PASSWORD",
"displayName": "Database User Password",
"required": false
}
]
}
Is there any issue with my template ? Is it a OpenShift issue ? Where and how can I get further details about the mount problem in OpenShift logs ?

Answer 1

So, I think you're coming up against 2 different issues.
You're template is setup to pull from the Mongo image on Dockerhub (specified by the blank "namespace" value. When trying to pull the mongo:latest image from Dockerhub in the Web UI, you are greeted by a friendly message notifying you that the docker image is not usable because it runs as root:
OpenShift Online Dev preview has been having some issues related to PVC recently (http://status.preview.openshift.com/). Specifically this reported bug at the moment, https://bugzilla.redhat.com/show_bug.cgi?id=1392650. This may be a cause for some issues, as the "official" Mongo image on OpenShift is also failing to build.
I would like to direct you to an OpenShift MongoDB template, not the exact one used in the Developer Preview, but should hopefully provide some good direction going forward! https://github.com/openshift/openshift-ansible/blob/master/roles/openshift_examples/files/examples/v1.4/db-templates/mongodb-persistent-template.json