Hi,
I am following a lab on Kubernetes and Mongodb but all the Pods are always in 0/1 state
what does it mean?
how do i make them READY 1/1
[root@master-node ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
mongo-express-78fcf796b8-wzgvx 0/1 Pending 0 3m41s
mongodb-deployment-8f6675bc5-qxj4g 0/1 Pending 0 160m
nginx-deployment-64bd7b69c-wp79g 0/1 Pending 0 4h44m
Check pod events and logs.
Events are available from describe.
kubectl describe pod mongo-express-78fcf796b8-wzgvx
Logs provide the stdout from the containers in the pod. -c container_name is only necessary for pods with more than 1 container.
kubectl logs mongo-express-78fcf796b8-wzgvx -c container_name
Thank you but what should I see in the logs?
Error messages that should be able to help you diagnose why the containers are stuck in the pending state. If the logs at that level, it’s time to start debugging at other levels.
here is the log but I don’t understand now which error I should see, thanks anyway to all of the help
[root@master-node ~]# kubectl describe pod mongo-express-78fcf796b8-wzgvx
Name: mongo-express-78fcf796b8-wzgvx
Namespace: default
Priority: 0
Node: <none>
Labels: app=mongo-express
pod-template-hash=78fcf796b8
Annotations: <none>
Status: Pending ^W Cerca ^K Taglia ^J Giustifica ^C Posizione M-U Annulla M-A Marca testo
IP: R Inserisci ^\ Sostituisci ^U Incolla ^T Ortografia ^_ Vai a riga M-E Ripeti M-6 Copia
IPs: <none>
Controlled By: ReplicaSet/mongo-express-78fcf796b8
Containers:
mongo-express:
Image: mongo-express
Port: 8081/TCP
Host Port: 0/TCP
Environment:
ME_CONFIG_MONGODB_ADMINUSERNAME: <set to the key 'mongo-root-username' in secret 'mongodb-secret'> Optional: false
ME_CONFIG_MONGODB_ADMINPASSWORD: <set to the key 'mongo-root-password' in secret 'mongodb-secret'> Optional: false
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-2mcpd (ro)
Conditions:
Type Status
PodScheduled False
Volumes:
kube-api-access-2mcpd:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: 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 FailedScheduling 2m40s (x112 over 113m) default-scheduler 0/1 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
[root@master-node ~]# kubectl logs mongo-express-78fcf796b8-wzgvx -c container_name
error: container container_name is not valid for pod mongo-express-78fcf796b8-wzgvx
Guessing you only have a single master node. Something to know about kubeadm is prevents scheduling on the control plane by default. That document provides a command to untaint all your nodes.
If you run kubectl describe node NODE_NAME you will probably see a label or annotation with node-role.kubernetes.io/master as the indicator preventing scheduling.
Yes i am following a lab for a 3 node cluster and i am working on the first node, I understand what you said so what should i do to have READY 1/1 Thanks in advance
[root@master-node ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
master-node Ready control-plane,master 26h v1.21.3
[root@master-node ~]# kubectl describe node master-node
Name: master-node
Roles: control-plane,master
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/arch=amd64
kubernetes.io/hostname=master-node
kubernetes.io/os=linux
node-role.kubernetes.io/control-plane=
node-role.kubernetes.io/master=
node.kubernetes.io/exclude-from-external-load-balancers=
Annotations: flannel.alpha.coreos.com/backend-data: {"VNI":1,"VtepMAC":"da:25:dc:0c:af:35"}
flannel.alpha.coreos.com/backend-type: vxlan
flannel.alpha.coreos.com/kube-subnet-manager: true
flannel.alpha.coreos.com/public-ip: 192.168.30.100
kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
node.alpha.kubernetes.io/ttl: 0
volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp: Mon, 26 Jul 2021 20:34:36 -0400
Taints: node-role.kubernetes.io/master:NoSchedule
Unschedulable: false
Lease:
HolderIdentity: master-node
AcquireTime: <unset>
RenewTime: Tue, 27 Jul 2021 22:43:49 -0400
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason
Message
---- ------ ----------------- ------------------ ------
-------
NetworkUnavailable False Tue, 27 Jul 2021 13:59:48 -0400 Tue, 27 Jul 2021 13:59:48 -0400 FlannelIsUp
Flannel is running on this node
MemoryPressure False Tue, 27 Jul 2021 22:41:01 -0400 Mon, 26 Jul 2021 20:34:36 -0400 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Tue, 27 Jul 2021 22:41:01 -0400 Mon, 26 Jul 2021 20:34:36 -0400 KubeletHasNoDiskPressure kubelet has no disk pressure
PIDPressure False Tue, 27 Jul 2021 22:41:01 -0400 Mon, 26 Jul 2021 20:34:36 -0400 KubeletHasSufficientPID kubelet has sufficient PID available
Ready True Tue, 27 Jul 2021 22:41:01 -0400 Mon, 26 Jul 2021 20:44:55 -0400 KubeletReady
kubelet is posting ready status
Addresses:
InternalIP: 192.168.30.100
Hostname: master-node
Capacity:
cpu: 2
ephemeral-storage: 6334Mi
hugepages-2Mi: 0
memory: 3728016Ki
pods: 110
Allocatable:
cpu: 2
ephemeral-storage: 5977512336
hugepages-2Mi: 0
memory: 3625616Ki
pods: 110
System Info:
Machine ID: 7eb80ce971604dc588326782f26f95f0
System UUID: c122c5ae-fb8e-c043-b7c6-8c3eed40c427
Boot ID: 2f44c701-4441-4916-83f6-b52ab569f262
Kernel Version: 4.18.0-315.el8.x86_64
OS Image: CentOS Stream 8
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://20.10.7
Kubelet Version: v1.21.3
Kube-Proxy Version: v1.21.3
PodCIDR: 10.244.0.0/24
PodCIDRs: 10.244.0.0/24
Non-terminated Pods: (8 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits Age
--------- ---- ------------ ---------- --------------- ------------- ---
kube-system coredns-558bd4d5db-c7gb9 100m (5%) 0 (0%) 70Mi (1%) 170Mi (4%) 26h
kube-system coredns-558bd4d5db-gb9ct 100m (5%) 0 (0%) 70Mi (1%) 170Mi (4%) 26h
kube-system etcd-master-node 100m (5%) 0 (0%) 100Mi (2%) 0 (0%) 26h
kube-system kube-apiserver-master-node 250m (12%) 0 (0%) 0 (0%) 0 (0%) 26h
kube-system kube-controller-manager-master-node 200m (10%) 0 (0%) 0 (0%) 0 (0%) 26h
kube-system kube-flannel-ds-wjgb7 100m (5%) 100m (5%) 50Mi (1%) 50Mi (1%) 25h
kube-system kube-proxy-ccl8k 0 (0%) 0 (0%) 0 (0%) 0 (0%) 26h
kube-system kube-scheduler-master-node 100m (5%) 0 (0%) 0 (0%) 0 (0%) 26h
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
Resource Requests Limits
-------- -------- ------
cpu 950m (47%) 100m (5%)
memory 290Mi (8%) 390Mi (11%)
ephemeral-storage 0 (0%) 0 (0%)
hugepages-2Mi 0 (0%) 0 (0%)
Events: <none>