NULL response found at Query Inspector in Grafana

[kmaiti]

Hello,

I'm trying to test this plugin app. I'm unable to see the graphs in all panels. Following is my setup.

k8s version : 1.8.1
snap-k8s : Installed manually in kube-system namespace with latest version. Manifest is below.
graphite-statsd : latest , running as pod in monitoring ns, controlled by helm.
grafana : latest version running as pod in monitoring ns, controlled by helm.

• I can see all metrics data in graphite UI.
• Configured graphite datasource. Grafana can successfully connect to it.
• Installed "kubernetes-app" plugin and configured "k8s cluster". [Have doubt if app gets data from graphite then why I need to connect to k8s cluster. Additionally there is datasource section in this cluster configuration section that should be graphite as per README.].
• While I click on cluster, I can see it has data but if I click on any dashboard out of four, nothing shows any graphs.
• error message pops up "Failed to connect. Could not connect to the specified cluster." at the right top corner.
• While I look at any panel's metrics with "Query Analyser ", I can see query gets NULL response.
• Nothing suspicious found in grafana log file that is setup in debug mode.

Is there anything I'm missing or it's a bug?

snap-k8s manifest

`apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: snap
namespace: kube-system
spec:
template:
metadata:
name: snap
labels:
daemon: snapd
spec:
containers:
- name: snap
image: raintank/snap_k8s:v5
volumeMounts:
- mountPath: /sys/fs/cgroup
name: cgroup
- mountPath: /var/run/docker.sock
name: docker-sock
- mountPath: /var/lib/docker
name: fs-stats
- mountPath: /usr/local/bin/docker
name: docker
- mountPath: /proc_host
name: proc
- mountPath: /opt/snap/tasks
name: snap-tasks
ports:
- containerPort: 8181
hostPort: 8181
name: snap-api
imagePullPolicy: IfNotPresent
securityContext:
privileged: true
env:
- name: PROCFS_MOUNT
value: /proc_host
volumes:
- name: dev
hostPath:
path: /dev
- name: cgroup
hostPath:
path: /sys/fs/cgroup
- name: docker-sock
hostPath:
path: /var/run/docker.sock
- name: fs-stats
hostPath:
path: /var/lib/docker
- name: docker
hostPath:
path: /usr/bin/docker
- name: proc
hostPath:
path: /proc
- name: snap-tasks
configMap:
name: snap-tasks
dnsPolicy: ClusterFirstWithHostNet
hostPID: true
hostNetwork: true
restartPolicy: Always
schedulerName: default-scheduler
serviceAccount: snap
serviceAccountName: snap

apiVersion: v1
kind: ConfigMap
metadata:
name: snap-tasks
namespace: kube-system
data:
core.json: |-
{
"version": 1,
"schedule": {
"type": "simple",
"interval": "10s"
},
"workflow": {
"collect": {
"metrics": {
"/intel/docker/":{},
"/intel/procfs/cpu/": {},
"/intel/procfs/meminfo/": {},
"/intel/procfs/iface/": {},
"/intel/linux/iostat/": {},
"/intel/procfs/load/": {}
},
"config": {
"/intel/procfs": {
"proc_path": "/proc_host"
}
},
"process": null,
"publish": [
{
"plugin_name": "graphite",
"config": {
"prefix": "snap.dev.<%NODE%>",
"server": "graphite-statsd-graphite-statsd.monitoring.svc.cluster.local",
"port": 2003
}
}
]
}
}
}`
graphite-statsd:

`replicaCount: 1
image:
repository: graphiteapp/graphite-statsd
tag: latest
pullPolicy: IfNotPresent
service:
name: graphite
type: ClusterIP
tcpProtocol: TCP
udpProtocol: UDP
nginxInternalPort: 80
carbonReceiverPlainInternalPort: 2003
carbonReceiverPickleInternalPort: 2004
carbonAggregatorPlainInternalPort: 2023
carbonAggregatorPickleInternalPort: 2024
statsdInternalPort: 8125
statsdAdminInternalPort: 8126
ingress:
enabled: true

Used to create an Ingress record.

hosts:
graphite.example.com
annotations:
kubernetes.io/ingress.class: nginx
kubernetes.io/tls-acme: "true"
tls:
# Secrets must be manually created in the namespace.
secretName: chart-graphite-tls
hosts: graphite.example.com`

From Query Analyser
{
"xhrStatus": "complete",
"request": {
"method": "POST",
"url": "api/datasources/proxy/2/render",
"data": "target=alias(sumSeries(snap.dev.%7B%7D.intel.procfs.meminfo.mem_available)%2C%20'available')&target=alias(sumSeries(snap.dev.%7B%7D.intel.procfs.meminfo.mem_free)%2C%20'free')&target=alias(sumSeries(snap.dev.%7B%7D.intel.procfs.meminfo.mem_used)%2C%20'used')&from=-15min&until=now&format=json&maxDataPoints=630"
},
"response": []
}