How to get logs of deployment from Kubernetes? - kubernetes

Question

I am creating an InfluxDB deployment in a Kubernetes cluster (v1.15.2), this is my yaml file:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: monitoring-influxdb
namespace: kube-system
spec:
replicas: 1
template:
metadata:
labels:
task: monitoring
k8s-app: influxdb
spec:
containers:
- name: influxdb
image: registry.cn-hangzhou.aliyuncs.com/google_containers/heapster-influxdb-amd64:v1.5.2
volumeMounts:
- mountPath: /data
name: influxdb-storage
volumes:
- name: influxdb-storage
emptyDir: {}
---
apiVersion: v1
kind: Service
metadata:
labels:
task: monitoring
# For use as a Cluster add-on (https://github.com/kubernetes/kubernetes/tree/master/cluster/addons)
# If you are NOT using this as an addon, you should comment out this line.
kubernetes.io/cluster-service: 'true'
kubernetes.io/name: monitoring-influxdb
name: monitoring-influxdb
namespace: kube-system
spec:
ports:
- port: 8086
targetPort: 8086
selector:
k8s-app: influxdb
And this is the pod status:
$ kubectl get deployment -n kube-system
NAME READY UP-TO-DATE AVAILABLE AGE
coredns 1/1 1 1 163d
kubernetes-dashboard 1/1 1 1 164d
monitoring-grafana 0/1 0 0 12m
monitoring-influxdb 0/1 0 0 11m
Now, I've been waiting 30 minutes and there is still no pod available, how do I check the deployment log from command line? I could not access the Kubernetes dashboard now. I am searching a command to get the pod log, but now there is no pod available. I already tried to add label in node:
kubectl label nodes azshara-k8s03 k8s-app=influxdb
This is my deployment describe content:
$ kubectl describe deployments monitoring-influxdb -n kube-system
Name: monitoring-influxdb
Namespace: kube-system
CreationTimestamp: Wed, 04 Mar 2020 11:15:52 +0800
Labels: k8s-app=influxdb
task=monitoring
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"extensions/v1beta1","kind":"Deployment","metadata":{"annotations":{},"name":"monitoring-influxdb","namespace":"kube-system"...
Selector: k8s-app=influxdb,task=monitoring
Replicas: 1 desired | 0 updated | 0 total | 0 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: k8s-app=influxdb
task=monitoring
Containers:
influxdb:
Image: registry.cn-hangzhou.aliyuncs.com/google_containers/heapster-influxdb-amd64:v1.5.2
Port: <none>
Host Port: <none>
Environment: <none>
Mounts:
/data from influxdb-storage (rw)
Volumes:
influxdb-storage:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
OldReplicaSets: <none>
NewReplicaSet: <none>
Events: <none>
This is another way to get logs:
$ kubectl -n kube-system logs -f deployment/monitoring-influxdb
error: timed out waiting for the condition
There is no output for this command:
kubectl logs --selector k8s-app=influxdb
There is all my pod in kube-system namespace:
~/Library/Mobile Documents/com~apple~CloudDocs/Document/k8s/work/heapster/heapster-deployment ⌚ 11:57:40
$ kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-569fd64d84-5q5pj 1/1 Running 0 46h
kubernetes-dashboard-6466b68b-z6z78 1/1 Running 0 11h
traefik-ingress-controller-hx4xd 1/1 Running 0 11h

Answer 1

kubectl logs deployment/<name-of-deployment> # logs of deployment
kubectl logs -f deployment/<name-of-deployment> # follow logs

Answer 2

You can try kubectl describe deploy monitoring-influxdb to get some high-level view of the deployment, maybe some information here.
For more detailed logs, first get the pods: kubectl get po
Then, request the pod logs: kubectl logs <pod-name>

Answer 3

Adding references of two great tools that might help you view cluster logs:
If you wish to view logs from your terminal without using a "heavy" 3rd party logging solution I would consider using K9S which is a great CLI tool that help you get control over your cluster.
If you are not bound only to the CLI and still want run locally I would recommend on Lens.