test image from azure container registry - azure

Question

I created a simple Docker image from a "Hello World" java application.
This is my Dockerfile
FROM java:8
COPY . /var/www/java
WORKDIR /var/www/java
RUN javac HelloWorld.java
CMD ["java", "HelloWorld"]
I pushed the image (java-app) to Azure Container Registry.
$ az acr repository list --name AContainerRegistry --output tableResult
----------------
java-app
I want to deploy it
amhg$ kubectl run dockerproject --image=acontainerregistry.azurecr.io/java-app:v1
deployment.apps "dockerproject" created
amhg$ kubectl expose deployments dockerproject --port=80 --type=LoadBalancer
service "dockerproject" exposed
and see the pods, the pod is crashed
amhg$ kubectl get pods
NAME READY STATUS RESTARTS AGE
dockerproject-b6799d879-pt5rx 0/1 CrashLoopBackOff 8 19m
Is there a way to "test"/run the image from the central registry, how come it crashes?
HERE DESCRIBE POD
amhg$ kubectl describe pod dockerproject-64fbf7649-spc7h
Name: dockerproject-64fbf7649-spc7h
Namespace: default
Node: aks-nodepool1-39744669-0/10.240.0.4
Start Time: Thu, 19 Apr 2018 11:53:58 +0200
Labels: pod-template-hash=209693205
run=dockerproject
Annotations: kubernetes.io/created-by={"kind":"SerializedReference","apiVersion":"v1","reference":{"kind":"ReplicaSet","namespace":"default","name":"dockerproject-64fbf7649","uid":"946610e4-43b7-11e8-9537-0a58ac1...
Status: Running
IP: 10.244.0.38
Controlled By: ReplicaSet/dockerproject-64fbf7649
Containers:
dockerproject:
Container ID: docker://1f2a7a6870a37e4d6b53fc834b0d4d3b681e9faaacc3772177a918e66357404e
Image: acontainerregistry.azurecr.io/java-app:v1
Image ID: docker-pullable://acontainerregistry.azurecr.io/java-app#sha256:eaf6fe53a59de287ad76a18de2c7f05580b1f25153624161aadcc7b8ef47b0c4
Port: <none>
Host Port: <none>
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Thu, 19 Apr 2018 12:35:22 +0200
Finished: Thu, 19 Apr 2018 12:35:23 +0200
Ready: False
Restart Count: 13
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-vkpjm (ro)
Conditions:
Type Status
Initialized True
Ready False
PodScheduled True
Volumes:
default-token-vkpjm:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-vkpjm
Optional: false
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.alpha.kubernetes.io/notReady:NoExecute for 300s
node.alpha.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 43m default-scheduler Successfully assigned dockerproject2-64fbf7649-spc7h to aks-nodepool1-39744669-0
Normal SuccessfulMountVolume 43m kubelet, aks-nodepool1-39744669-0 MountVolume.SetUp succeeded for volume "default-token-vkpjm"
Normal Pulled 43m (x4 over 43m) kubelet, aks-nodepool1-39744669-0 Container image "acontainerregistry.azurecr.io/java-app:v1" already present on machine
Normal Created 43m (x4 over 43m) kubelet, aks-nodepool1-39744669-0 Created container
Normal Started 43m (x4 over 43m) kubelet, aks-nodepool1-39744669-0 Started container
Warning FailedSync 8m (x161 over 43m) kubelet, aks-nodepool1-39744669-0 Error syncing pod
Warning BackOff 3m (x184 over 43m) kubelet, aks-nodepool1-39744669-0 Back-off restarting failed container

Answer 1

When you run an application in the Pod, Kubernetes expects that it will work all the time as a daemon until you will stop it somehow.
In your details about the pod I see this:
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Thu, 19 Apr 2018 12:35:22 +0200
Finished: Thu, 19 Apr 2018 12:35:23 +0200
It means that your application exited with code 0 (which means "all is ok") right after start. So, the image was successfully downloaded (registry is OK) and run, but the application exited.
That's why Kubernetes tries to restart the pod all the time.
The only thing I can suggest - find a reason why the application stops and fix it.