I may have a stupid question but could someone explain what "Available" correctly represent in DaemonSets? I checked What is the difference between current and available pod replicas in kubernetes deployment? answer but there are no readiness errors.
In cluster i see below status:
$ kubectl get ds -n kube-system
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR
kube-proxy 6 6 5 6 5 beta.kubernetes.io/os=linux
Why it is showing as 5 instead of 6?
all pods are running perfectly fine without any "readiness" errors or restarts?
$ kubectl get pods -n kube-system | grep kube-proxy
kube-proxy-cv7vv 1/1 Running 0 20d
kube-proxy-kcd67 1/1 Running 0 20d
kube-proxy-l4nfk 1/1 Running 0 20d
kube-proxy-mkvjd 1/1 Running 0 87d
kube-proxy-qb7nz 1/1 Running 0 36d
kube-proxy-x8l87 1/1 Running 0 87d
Could someone tell what can be checked further?
The Available field shows the number of replicas or pods that are ready to accept traffic and passed all the criterion such as readiness or liveness probe or any other condition that verifies that your application is ready to serve the requests coming from user.
Related
I have successfully installed istio and deployed some sample app and application is up and running.
root#master:~# kubectl get pod
NAME READY STATUS RESTARTS AGE
mydata-v1-847cd777c4-kc495 2/2 Running 0 39m
mydata-v2-65bbf55977-j67xp 2/2 Running 0 39m
myweb-66dc56ccd6-5g64b 2/2 Running 0 40m
NAME READY STATUS RESTARTS AGE
grafana-784c89f4cf-cxpcz 1/1 Running 0 15d
istio-egressgateway-bd477794-qv7n8 1/1 Running 0 15d
istio-ingressgateway-79df7c789f-qlqcf 1/1 Running 0 15d
istiod-6dc55bbdd-t5klg 1/1 Running 0 15d
jaeger-7f78b6fb65-xhz8j 1/1 Running 0 15d
kiali-dc84967d9-99lwv 1/1 Running 1 13d
prometheus-7bfddb8dbf-nd4gn 2/2 Running 35 15d
Next i changed kiali dashboard cluster IP to Nodeport to access the dash brad from the browser
kubectl patch svc kiali -n istio-system --type='json' -p '[{"op":"replace","path":"/spec/type","value":"NodePort"},{"op":"replace","path":"/spec/ports/0/nodePort","value":30010}]'
Finally i can able to access the dashboard using node port with my host Ip http://machineip_port/ and could see my k8 namespaces without any apps please find the attached screen shot
could you please help me someone last one week i am running into this issue.
The problem is that
"Namespaces that do not exist at the time of install but are created
later in the future will not be accessible by Kiali". Resource.
So, first, keep in mind you should not edit kiali's ConfigMap, but only Kiali's Custom Resource Definition(CRD), which is used by Kiali Operator.
Run kubectl edit kiali kiali in the namespace you have the CRD available.
Then add the following under spec:
spec:
deployment:
accessible_namespaces:
- ["**"]
This will give Kiali access to all current namespaces and to any you'll create in the future.
I'm trying to understand how kubernetes works, so I tried to do this operation for my minikube:
~ kubectl delete pod --all -n kube-system
pod "coredns-f9fd979d6-5n4b6" deleted
pod "etcd-minikube" deleted
pod "kube-apiserver-minikube" deleted
pod "kube-controller-manager-minikube" deleted
pod "kube-proxy-879lg" deleted
pod "kube-scheduler-minikube" deleted
It's okay. Pods deleted as wish. But if I do kubectl get pods -n kube-system I will see:
NAME READY STATUS RESTARTS AGE
coredns-f9fd979d6-5d25r 1/1 Running 0 50s
etcd-minikube 1/1 Running 0 50s
kube-apiserver-minikube 1/1 Running 0 50s
kube-controller-manager-minikube 1/1 Running 0 50s
kube-proxy-nlw69 1/1 Running 0 43s
kube-scheduler-minikube 1/1 Running 0 49s
Okay. I thought it's ReplicaSet or DaemonSet:
➜ ~ kubectl get ds -n kube-system
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
kube-proxy 1 1 1 1 1 kubernetes.io/os=linux 18m
➜ ~ kubectl get rs -n kube-system
NAME DESIRED CURRENT READY AGE
coredns-f9fd979d6 1 1 1 18m
It is true for coredns and kube-proxy. But what about others (apiserver, etcd, controller and scheduler)? Why are they still alive?
The control plane pods are run as static Pods - static Pods are not managed by the control plane controllers like e.g. DaemonSet and ReplicaSet. Static pods are instead managed by the Kubelet daemon on the local node directly.
I am building a Kubernetes cluster following this tutorial, and I have troubles to access the Kubernetes dashboard. I already created another question about it that you can see here, but while digging up into my cluster, I think that the problem might be somewhere else and that's why I create a new question.
I start my master, by running the following commands:
> kubeadm reset
> kubeadm init --apiserver-advertise-address=[MASTER_IP] > file.txt
> tail -2 file.txt > join.sh # I keep this file for later
> kubectl apply -f https://git.io/weave-kube/
> kubectl -n kube-system get pod
NAME READY STATUS RESTARTS AGE
coredns-fb8b8dccf-kb2zq 0/1 Pending 0 2m46s
coredns-fb8b8dccf-nnc5n 0/1 Pending 0 2m46s
etcd-kubemaster 1/1 Running 0 93s
kube-apiserver-kubemaster 1/1 Running 0 93s
kube-controller-manager-kubemaster 1/1 Running 0 113s
kube-proxy-lxhvs 1/1 Running 0 2m46s
kube-scheduler-kubemaster 1/1 Running 0 93s
Here we can see that I have two coredns pods stuck in Pending state forever, and when I run the command :
> kubectl -n kube-system describe pod coredns-fb8b8dccf-kb2zq
I can see in the Events part the following Warning :
Failed Scheduling : 0/1 nodes are available 1 node(s) had taints that the pod didn't tolerate.
Since it is a Warning and not and Error, and that as a Kubernetes newbie, taints does not mean much to me, I tried to connect a node to the master (using the previously saved command) :
> cat join.sh
kubeadm join [MASTER_IP]:6443 --token [TOKEN] \
--discovery-token-ca-cert-hash sha256:[ANOTHER_TOKEN]
> ssh [USER]#[WORKER_IP] 'bash' < join.sh
This node has joined the cluster.
On the master, I check that the node is connected:
> kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubemaster NotReady master 13m v1.14.1
kubeslave1 NotReady <none> 31s v1.14.1
And I check my pods :
> kubectl -n kube-system get pod
NAME READY STATUS RESTARTS AGE
coredns-fb8b8dccf-kb2zq 0/1 Pending 0 14m
coredns-fb8b8dccf-nnc5n 0/1 Pending 0 14m
etcd-kubemaster 1/1 Running 0 13m
kube-apiserver-kubemaster 1/1 Running 0 13m
kube-controller-manager-kubemaster 1/1 Running 0 13m
kube-proxy-lxhvs 1/1 Running 0 14m
kube-proxy-xllx4 0/1 ContainerCreating 0 2m16s
kube-scheduler-kubemaster 1/1 Running 0 13m
We can see that another kube-proxy pod have been created and is stuck in ContainerCreating status.
And when I am doing a describe again :
kubectl -n kube-system describe pod kube-proxy-xllx4
I can see in the Events part multiple identical Warnings :
Failed create pod sandbox : rpx error: code = Unknown desc = failed pulling image "k8s.gcr.io/pause:3.1": Get https://k8s.gcr.io/v1/_ping: dial tcp: lookup k8s.gcr.io on [::1]:53 read up [::1]43133->[::1]:53: read: connection refused
Here are my repositories :
docker image ls
REPOSITORY TAG
k8s.gcr.io/kube-proxy v1.14.1
k8s.gcr.io/kube-apiserver v1.14.1
k8s.gcr.io/kube-controller-manager v1.14.1
k8s.gcr.io/kube-scheduler v1.14.1
k8s.gcr.io/coredns 1.3.1
k8s.gcr.io/etcd 3.3.10
k8s.gcr.io/pause 3.1
And so, for the dashboard part, I tried to start it with the command
> kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml
But the dashboard pod is stuck in Pending state.
kubectl -n kube-system get pod
NAME READY STATUS RESTARTS AGE
coredns-fb8b8dccf-kb2zq 0/1 Pending 0 40m
coredns-fb8b8dccf-nnc5n 0/1 Pending 0 40m
etcd-kubemaster 1/1 Running 0 38m
kube-apiserver-kubemaster 1/1 Running 0 38m
kube-controller-manager-kubemaster 1/1 Running 0 39m
kube-proxy-lxhvs 1/1 Running 0 40m
kube-proxy-xllx4 0/1 ContainerCreating 0 27m
kube-scheduler-kubemaster 1/1 Running 0 38m
kubernetes-dashboard-5f7b999d65-qn8qn 1/1 Pending 0 8s
So, event though my problem originaly was that I cannot access to my dashboard, I guess that the real problem is deeper thant that.
I know that I just put a lot of information here, but I am a k8s beginner and I am completely lost on this.
There is an issue I experienced with coredns pods stuck in a pending mode when setting up your own cluster; which I resolve by adding pod network.
Looks like because there is no Network Addon installed, the nodes are taint as not-ready. Installing the Addon would remove the taints and the Pods will be able to schedule. In my case adding flannel fixed the issue.
EDIT: There is a note about this in the official k8s documentation - Create cluster with kubeadm:
The network must be deployed before any applications. Also, CoreDNS
will not start up before a network is installed. kubeadm only
supports Container Network Interface (CNI) based networks (and does
not support kubenet).
Actually it is the opposite of a deep or serious issue. This is a trivial issue. Always you see a pod stuck on Pending state, it means the scheduler is having a hard time to schedule the pod; mostly because there are no enough resources on the node.
In your case it is a taint that has the node, and your pod doesn't have the toleration. What you have to do is to describe the node and get the taint:
kubectl describe node | grep -i taints
Note: you might have more then one taint. So you might want to do kubectl describe no NODE since with grep you will only see one taint.
Once you get the taint, that will be something like hello=world:NoSchedule; which means key=value:effect, you will have to add a toleration section in your Deployment. This is an example Deployment so you can see how it should look like:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx
labels:
app: nginx
spec:
replicas: 10
strategy:
type: Recreate
template:
metadata:
labels:
app: nginx
spec:
containers:
- image: nginx
name: nginx
ports:
- containerPort: 80
name: http
tolerations:
- effect: NoExecute #NoSchedule, PreferNoSchedule
key: node
operator: Equal
value: not-ready
tolerationSeconds: 3600
As you can see there is the toleration section in the yaml. So, if I would have a node with node=not-ready:NoExecute taint, no pod would be able to be scheduled on that node, unless would have this toleration.
Also you can remove the taint, if you don need it. To remove a taint you would describe the node, get the key of the taint and do:
kubectl taint node NODE key-
Hope it makes sense. Just add this section to your deployment, and it will work.
Set up the flannel network tool.
Running commands:
$ sysctl net.bridge.bridge-nf-call-iptables=1
$ kubectl apply -f
https://raw.githubusercontent.com/coreos/flannel/62e44c867a2846fefb68bd5f178daf4da3095ccb/Documentation/kube-flannel.yml
I'm starting a Kubernetes cluster of 3 nodes (1 master, 2 worker)
Trying to go by steps described in Ansible playbook - https://gitlab.com/LinarNadyrov/gcp/tree/master
Applying playbook steps 1,2,3 consequentially
After than, I connect to master to check status:
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
NAME STATUS ROLES AGE VERSION
master NotReady master 17m v1.13.0
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
enter link description here
kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-86c58d9df4-7jc4b 0/1 Pending 0 3h45m
coredns-86c58d9df4-929xf 0/1 Pending 0 3h45m
etcd-officemasterkub 1/1 Running 2 7h26m
kube-apiserver-officemasterkub 1/1 Running 2 7h26m
kube-controller-manager-officemasterkub 1/1 Running 2 7h26m
kube-flannel-ds-5jhbx 0/1 Pending 0 7h20m
kube-flannel-ds-wqfvs 0/1 Pending 0 7h20m
kube-proxy-gmngj 1/1 Running 2 7h27m
kube-proxy-ppbqp 1/1 Running 1 7h20m
kube-proxy-r2rn6 1/1 Running 1 7h20m
kube-scheduler-officemasterkub 1/1 Running 2 7h26m
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Status is NotReady
Could anyone help me with it?
What's the problem? What should be done to fix it? Maybe I missed something?
Thanx in advance!
Линар Надыров the problem here is with your flannel yaml file. You did not specify any resources in the DaemonSet so there are no flannel pods spawning.
I did not check any further as it was enough reason why is this issue occurring. You can use this yaml if this is for testing purposes. Or edit your accordingly to the provided example.
In your file change the line 43 to:
shell: kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml >> pod_network_setup.txt
You can find more about DaemonSets here.
I'm setting up a Kubernetes cluster on a customer.
I've done this process before multiple times, including dealing with vagrant specifics and I've been able to constantly get a K8s cluster up and running without too much fuss.
Now, on this customer I'm doing the same but I've been finding a lot of issues when setting things up, which is completely unexpected.
Comparing to other places where I've setup Kubernetes, the only obvious difference that I see is that I have a proxy server which I constantly have to battle with. Nothing that a NO_PROXY env hasn't been able to handle.
The main issue I'm facing is setting up Canal (Calico + Flannel).
For some reason, on Masters 2 and 3 it just won't start.
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE
kube-system canal-2pvpr 2/3 CrashLoopBackOff 7 14m 10.136.3.37 devmn2.cpdprd.pt
kube-system canal-rdmnl 2/3 CrashLoopBackOff 7 14m 10.136.3.38 devmn3.cpdprd.pt
kube-system canal-swxrw 3/3 Running 0 14m 10.136.3.36 devmn1.cpdprd.pt
kube-system kube-apiserver-devmn1.cpdprd.pt 1/1 Running 1 1h 10.136.3.36 devmn1.cpdprd.pt
kube-system kube-apiserver-devmn2.cpdprd.pt 1/1 Running 1 4h 10.136.3.37 devmn2.cpdprd.pt
kube-system kube-apiserver-devmn3.cpdprd.pt 1/1 Running 1 1h 10.136.3.38 devmn3.cpdprd.pt
kube-system kube-controller-manager-devmn1.cpdprd.pt 1/1 Running 0 15m 10.136.3.36 devmn1.cpdprd.pt
kube-system kube-controller-manager-devmn2.cpdprd.pt 1/1 Running 0 15m 10.136.3.37 devmn2.cpdprd.pt
kube-system kube-controller-manager-devmn3.cpdprd.pt 1/1 Running 0 15m 10.136.3.38 devmn3.cpdprd.pt
kube-system kube-dns-86f4d74b45-vqdb4 0/3 ContainerCreating 0 1h <none> devmn2.cpdprd.pt
kube-system kube-proxy-4j7dp 1/1 Running 1 2h 10.136.3.38 devmn3.cpdprd.pt
kube-system kube-proxy-l2wpm 1/1 Running 1 2h 10.136.3.36 devmn1.cpdprd.pt
kube-system kube-proxy-scm9g 1/1 Running 1 2h 10.136.3.37 devmn2.cpdprd.pt
kube-system kube-scheduler-devmn1.cpdprd.pt 1/1 Running 1 1h 10.136.3.36 devmn1.cpdprd.pt
kube-system kube-scheduler-devmn2.cpdprd.pt 1/1 Running 1 4h 10.136.3.37 devmn2.cpdprd.pt
kube-system kube-scheduler-devmn3.cpdprd.pt 1/1 Running 1 1h 10.136.3.38 devmn3.cpdprd.pt
Looking for the specific error, I've come to find out that the issue is with the kube-flannel container, which is throwing an error:
[exXXXXX#devmn1 ~]$ kubectl logs canal-rdmnl -n kube-system -c kube-flannel
I0518 16:01:22.555513 1 main.go:487] Using interface with name ens192 and address 10.136.3.38
I0518 16:01:22.556080 1 main.go:504] Defaulting external address to interface address (10.136.3.38)
I0518 16:01:22.565141 1 kube.go:130] Waiting 10m0s for node controller to sync
I0518 16:01:22.565167 1 kube.go:283] Starting kube subnet manager
I0518 16:01:23.565280 1 kube.go:137] Node controller sync successful
I0518 16:01:23.565311 1 main.go:234] Created subnet manager: Kubernetes Subnet Manager - devmn3.cpdprd.pt
I0518 16:01:23.565331 1 main.go:237] Installing signal handlers
I0518 16:01:23.565388 1 main.go:352] Found network config - Backend type: vxlan
I0518 16:01:23.565440 1 vxlan.go:119] VXLAN config: VNI=1 Port=0 GBP=false DirectRouting=false
E0518 16:01:23.565619 1 main.go:279] Error registering network: failed to acquire lease: node "devmn3.cpdprd.pt" pod cidr not assigned
I0518 16:01:23.565671 1 main.go:332] Stopping shutdownHandler...
I just can't understand why.
Some relevant info:
My clusterCIDR and podCIDR are: 192.168.151.0/25 (I know, it's weird, don't ask unless it's a huge issue)
I've setup etcd on systemd
I've modified the kube-controller-manager.yaml to change the mask size to 25 (otherwise the IP mentioned before wouldn't work).
I'm installing everything with Kubeadm. One weird thing I did notice was that, when viewing the config (kubeadm config view) much of the information that I had setup on the kubeadm config.yaml (for kubeadm init) was not present in the config view, including the paths to etcd certs.
I'm also not sure why that happened, but I've fixed it (hopefully) by editing the kubeadm config map (kubectl edit cm kubeadm-config -n kube-system) and saving it.
Still no luck with canal.
Can anyone help me figure out what's wrong?
I have documented pretty much every step of the configuration I've done, so if required I may be able to provide it.
EDIT:
I figured how meanwhile that indeed my master2 and 3 do not have a podCIDR associated. Why would this happen? And how can I add it?
Try to edit:
/etc/kubernetes/manifests/kube-controller-manager.yaml
and add
--allocate-node-cidrs=true
--cluster-cidr=192.168.151.0/25
then, reload kubelet.
I found this information here and it was useful for me.