I’m new to K8s and just installed by kubespray with this one
https://kubernetes.io/docs/setup/production-environment/tools/kubespray/.
k8s – v1.20.2.
calico – 3.16.6.
pod-cidr = 10.214.0.0/16.
service-cidr = 10.215.0.1/16.
kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
web-79d88c97d6-lk2sq 1/1 Running 0 31h 10.214.39.1 dev1 <none> <none>
web2-5b669f8984-gwfx2 1/1 Running 0 8h 10.214.40.130 dev2 <none> <none>
I can curl to web-79d88c97d6-lk2sq pod in dev2 but can’t in dev1.
Is it normal? If not so how can i fix it?
curl -v 10.214.39.1:8080
* About to connect() to 10.214.39.1 port 8080 (#0)
* Trying 10.214.39.1...
* Connection timed out
* Failed connect to 10.214.39.1:8080; Connection timed out
* Closing connection 0
traceroute 10.214.39.1
traceroute to 10.214.39.1 (10.214.39.1), 30 hops max, 60 byte packets
1 gateway (10.61.8.1) 7.790 ms 8.173 ms 8.394 ms
2 10.6.41.10 (10.6.41.10) 0.613 ms 10.6.41.6 (10.6.41.6) 0.505 ms 10.6.41.8 (10.6.41.8) 0.612 ms
3 10.6.32.150 (10.6.32.150) 0.740 ms 10.6.9.169 (10.6.9.169) 0.962 ms 10.6.32.158 (10.6.32.158) 1.233 ms
4 10.6.32.178 (10.6.32.178) 0.350 ms 10.6.32.232 (10.6.32.232) 8.849 ms 10.6.32.236 (10.6.32.236) 8.850 ms
5 172.24.0.172 (172.24.0.172)
6 * * *
7 * * *
8 * * *
9 * * *
from web-79d88c97d6-lk2sq pod to web2-5b669f8984-gwfx2 pod curl worked
Kube-system Pod status
kube-system calico-kube-controllers-847f479bc5-k52fm 1/1 Running 0 31h
kube-system calico-node-8x5h8 1/1 Running 0 31h
kube-system calico-node-9lhbn 1/1 Running 0 31h
kube-system calico-node-bh9f8 1/1 Running 0 31h
kube-system calico-node-dpxjk 1/1 Running 0 31h
kube-system calico-node-fl5gj 1/1 Running 0 31h
kube-system calico-node-g2qzl 1/1 Running 0 31h
kube-system calico-node-g9x82 1/1 Running 0 31h
kube-system calico-node-pl292 1/1 Running 0 31h
kube-system calico-node-t7kwd 1/1 Running 0 31h
kube-system calico-node-v5s8r 1/1 Running 0 31h
kube-system coredns-847f564ccf-l4qk9 0/1 CrashLoopBackOff 441 31h
kube-system dns-autoscaler-b5c786945-pxbwh 0/1 Running 0 31h
kube-system kube-apiserver-dev10 1/1 Running 0 31h
kube-system kube-apiserver-dev8 1/1 Running 0 31h
kube-system kube-apiserver-dev9 1/1 Running 0 31h
kube-system kube-controller-manager-dev10 1/1 Running 0 168m
kube-system kube-controller-manager-dev8 1/1 Running 0 167m
kube-system kube-controller-manager-dev9 1/1 Running 0 166m
kube-system kube-proxy-89cbl 1/1 Running 0 31h
kube-system kube-proxy-8d6tm 1/1 Running 0 31h
kube-system kube-proxy-8qnm9 1/1 Running 0 31h
kube-system kube-proxy-bblxx 1/1 Running 0 31h
kube-system kube-proxy-fshgk 1/1 Running 0 31h
kube-system kube-proxy-j5s6f 1/1 Running 0 31h
kube-system kube-proxy-m8jts 1/1 Running 0 31h
kube-system kube-proxy-r9wqh 1/1 Running 0 31h
kube-system kube-proxy-t4r7g 1/1 Running 0 31h
kube-system kube-proxy-wxs4m 1/1 Running 0 31h
kube-system kube-scheduler-dev10 1/1 Running 0 168m
kube-system kube-scheduler-dev8 1/1 Running 0 167m
kube-system kube-scheduler-dev9 1/1 Running 0 166m
kube-system kubernetes-dashboard-5f87bdc77d-4j8rp 1/1 Running 408 31h
kube-system kubernetes-metrics-scraper-64db6db887-k48b6 0/1 CrashLoopBackOff 417 31h
kube-system nginx-proxy-dev1 1/1 Running 0 31h
kube-system nginx-proxy-dev2 1/1 Running 0 31h
kube-system nginx-proxy-dev3 1/1 Running 0 31h
kube-system nginx-proxy-dev4 1/1 Running 0 31h
kube-system nginx-proxy-dev5 1/1 Running 0 31h
kube-system nginx-proxy-dev6 1/1 Running 0 31h
kube-system nginx-proxy-dev7 1/1 Running 0 31h
kube-system nodelocaldns-5plj9 1/1 Running 0 31h
kube-system nodelocaldns-hb6lm 1/1 Running 0 31h
kube-system nodelocaldns-j4wtf 1/1 Running 0 31h
kube-system nodelocaldns-lkj2g 1/1 Running 0 31h
kube-system nodelocaldns-pp4xd 1/1 Running 0 31h
kube-system nodelocaldns-ttvwq 1/1 Running 0 31h
kube-system nodelocaldns-vgnwv 1/1 Running 0 31h
kube-system nodelocaldns-vpfjm 1/1 Running 0 31h
kube-system nodelocaldns-xfzw4 1/1 Running 0 31h
kube-system nodelocaldns-zrnfl 1/1 Running 0 31h
kubectl get componentstatuses
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-1 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
test-curl-deployment-5cdddb7854-24n82 1/1 Running 0 17s 10.214.223.135 dev4 <none> <none>
test-curl-deployment-5cdddb7854-jpzwp 1/1 Running 0 17s 10.214.102.6 dev3 <none> <none>
test-curl-deployment-5cdddb7854-qtr8k 1/1 Running 0 17s 10.214.229.6 dev2 <none> <none>
web-79d88c97d6-lk2sq 1/1 Running 0 2d 10.214.39.1 dev5 <none> <none>
web2-5b669f8984-gwfx2 1/1 Running 0 25h 10.214.40.130 dev7 <none> <none>
$ kubectl exec test-curl-deployment-5cdddb7854-24n82 -- curl -m 3 test-curl-deployment-5cdddb7854-jpzwp
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- 0:00:05 --:--:-- 0
curl: (28) Resolving timed out after 3000 milliseconds
command terminated with exit code 28
coredns pod log and description
Name: coredns-847f564ccf-l4qk9
Namespace: kube-system
Priority: 2000000000
Priority Class Name: system-cluster-critical
Node: dev10/xxx.xxx.xxx.xxx
Start Time: Wed, 05 Jan 2022 15:29:19 +0900
Labels: k8s-app=kube-dns
pod-template-hash=847f564ccf
Annotations: cni.projectcalico.org/podIP: 10.214.122.1/32
cni.projectcalico.org/podIPs: 10.214.122.1/32
seccomp.security.alpha.kubernetes.io/pod: runtime/default
Status: Running
IP: 10.214.122.1
IPs:
IP: 10.214.122.1
Controlled By: ReplicaSet/coredns-847f564ccf
Containers:
coredns:
Container ID: docker://91492fa6c6a42b2606fc8ae5edc5c5f188bb4a8175e3a6c5185f8a9dbe30cc5d
Image: k8s.gcr.io/coredns:1.7.0
Image ID: docker-pullable://k8s.gcr.io/coredns@sha256:73ca82b4ce829766d4f1f10947c3a338888f876fbed0540dc849c89ff256e90c
Ports: 53/UDP, 53/TCP, 9153/TCP
Host Ports: 0/UDP, 0/TCP, 0/TCP
Args:
-conf
/etc/coredns/Corefile
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Fri, 07 Jan 2022 16:58:24 +0900
Finished: Fri, 07 Jan 2022 17:00:13 +0900
Ready: False
Restart Count: 687
Limits:
memory: 170Mi
Requests:
cpu: 100m
memory: 70Mi
Liveness: http-get http://:8080/health delay=0s timeout=5s period=10s #success=1 #failure=10
Readiness: http-get http://:8181/ready delay=0s timeout=5s period=10s #success=1 #failure=10
Environment: <none>
Mounts:
/etc/coredns from config-volume (rw)
/var/run/secrets/kubernetes.io/serviceaccount from coredns-token-hr9ht (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
config-volume:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: coredns
Optional: false
coredns-token-hr9ht:
Type: Secret (a volume populated by a Secret)
SecretName: coredns-token-hr9ht
Optional: false
QoS Class: Burstable
Node-Selectors: kubernetes.io/os=linux
Tolerations: node-role.kubernetes.io/control-plane:NoSchedule
node-role.kubernetes.io/master:NoSchedule
node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning BackOff 8m4s (x3447 over 20h) kubelet Back-off restarting failed container
Warning Unhealthy 3m19s (x2865 over 20h) kubelet Liveness probe failed: Get "http://10.214.122.1:8080/health": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
0107 07:59:56.981861 1 trace.go:116] Trace[817455089]: "Reflector ListAndWatch" name:pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125 (started: 2022-01-07 07:59:26.981164884 +0000 UTC m=+62.651400285) (total time: 30.000649425s):
Trace[817455089]: [30.000649425s] [30.000649425s] END
E0107 07:59:56.981887 1 reflector.go:178] pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125: Failed to list *v1.Endpoints: Get "https://10.215.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0": dial tcp 10.215.0.1:443: i/o timeout
I0107 07:59:57.665238 1 trace.go:116] Trace[1006933274]: "Reflector ListAndWatch" name:pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125 (started: 2022-01-07 07:59:27.66473076 +0000 UTC m=+63.334966123) (total time: 30.0004649s):
Trace[1006933274]: [30.0004649s] [30.0004649s] END
E0107 07:59:57.665261 1 reflector.go:178] pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125: Failed to list *v1.Namespace: Get "https://10.215.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0": dial tcp 10.215.0.1:443: i/o timeout
I0107 07:59:57.935685 1 trace.go:116] Trace[629431445]: "Reflector ListAndWatch" name:pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125 (started: 2022-01-07 07:59:27.935177307 +0000 UTC m=+63.605412681) (total time: 30.000464179s):
Trace[629431445]: [30.000464179s] [30.000464179s] END
E0107 07:59:57.935704 1 reflector.go:178] pkg/mod/k8s.io/[email protected]/tools/cache/reflector.go:125: Failed to list *v1.Service: Get "https://10.215.0.1:443/api/v1/services?limit=500&resourceVersion=0": dial tcp 10.215.0.1:443: i/o timeout
2
Answers
Hi it is not normal to curl one node and not curling another, even if you think there ip’s are different its just the node difference. You can curl via kubectl exec and check whether are you able to curl the service or not
and you can share the result probably.
As the curl error message is showing you have a dns issue, not network! curl failed to resolve the pod name, and if you check pods status in kube-system namespace, coredns failed to run and it’s in CrashLoopBackOff status.
Check your core dns logs.