6

I have followed this tutorial in order to run kubernetes cluster locally in a Docker container. When I run kubectl get nodes, I get:

The connection to the server localhost:8080 was refused - did you specify the right host or port?

I have noticed that some containers started by kubelet, like apiserver, are exited. This is the output of docker ps -a:

CONTAINER ID        IMAGE                                             COMMAND                  CREATED             STATUS                       PORTS               NAMES
778bc9a9a93c        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube apiserver"   3 seconds ago       Exited (255) 2 seconds ago                       k8s_apiserver.78ec1de_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_de6ff8f9
12dd99c83c34        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/setup-files.sh IP:1"   3 seconds ago       Exited (7) 2 seconds ago                         k8s_setup.e5aa3216_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_3283400b
ef7383fa9203        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/setup-files.sh IP:1"   4 seconds ago       Exited (7) 4 seconds ago                         k8s_setup.e5aa3216_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_87beca1b
b3896f4896b1        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube scheduler"   5 seconds ago       Up 4 seconds                                     k8s_scheduler.fc12fcbe_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_16584c07
e9b1bc5aeeaa        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube apiserver"   5 seconds ago       Exited (255) 4 seconds ago                       k8s_apiserver.78ec1de_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_87e1ad70
c81dbe181afa        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube controlle"   5 seconds ago       Up 4 seconds                                     k8s_controller-manager.70414b65_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_1e30d242
63dfa0fb0881        gcr.io/google_containers/etcd:2.2.1               "/usr/local/bin/etcd "   5 seconds ago       Up 4 seconds                                     k8s_etcd.7e452b0b_k8s-etcd-sw-ansible01_default_1df6a8b4d6e129d5ed8840e370203c11_94a862fa
6bb963ef351d        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube proxy --m"   5 seconds ago       Up 4 seconds                                     k8s_kube-proxy.9a9f4853_k8s-proxy-sw-ansible01_default_5e5303a9d49035e9fad52bfc4c88edc8_6098241c
311e2788de45        gcr.io/google_containers/pause:2.0                "/pause"                 5 seconds ago       Up 4 seconds                                     k8s_POD.6059dfa2_k8s-master-sw-ansible01_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_79e4e3e8
3b3cf3ada645        gcr.io/google_containers/pause:2.0                "/pause"                 5 seconds ago       Up 4 seconds                                     k8s_POD.6059dfa2_k8s-etcd-sw-ansible01_default_1df6a8b4d6e129d5ed8840e370203c11_9eb869b9
aa7efd2154fb        gcr.io/google_containers/pause:2.0                "/pause"                 5 seconds ago       Up 5 seconds                                     k8s_POD.6059dfa2_k8s-proxy-sw-ansible01_default_5e5303a9d49035e9fad52bfc4c88edc8_b66baa5f
c380b4a9004e        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube kubelet -"   12 seconds ago      Up 12 seconds                                    kubelet

Info

  • Docker version: 1.10.3

  • Kubernetes version: 1.2.2

  • OS: Ubuntu 14.04

Docker run command

docker run --volume=/:/rootfs:ro --volume=/sys:/sys:ro --volume=/var/lib/docker/:/var/lib/docker:rw --volume=/var/lib/kubelet/:/var/lib/kubelet:rw --volume=/var/run:/var/run:rw --net=host --pid=host --privileged=true --name=kubelet -d gcr.io/google_containers/hyperkube-amd64:v1.2.2 /hyperkube kubelet --containerized --hostname-override="172.20.34.112" --address="0.0.0.0" --api-servers=http://localhost:8080 --config=/etc/kubernetes/manifests --cluster-dns=10.0.0.10 --cluster-domain=cluster.local --allow-privileged=true --v=2

kubelet container logs

I0422 11:04:45.158370     541 plugins.go:56] Registering credential provider: .dockercfg
I0422 11:05:25.199632     541 plugins.go:291] Loaded volume plugin "kubernetes.io/aws-ebs"
I0422 11:05:25.199788     541 plugins.go:291] Loaded volume plugin "kubernetes.io/empty-dir"
I0422 11:05:25.199863     541 plugins.go:291] Loaded volume plugin "kubernetes.io/gce-pd"
I0422 11:05:25.199903     541 plugins.go:291] Loaded volume plugin "kubernetes.io/git-repo"
I0422 11:05:25.199948     541 plugins.go:291] Loaded volume plugin "kubernetes.io/host-path"
I0422 11:05:25.199982     541 plugins.go:291] Loaded volume plugin "kubernetes.io/nfs"
I0422 11:05:25.200023     541 plugins.go:291] Loaded volume plugin "kubernetes.io/secret"
I0422 11:05:25.200059     541 plugins.go:291] Loaded volume plugin "kubernetes.io/iscsi"
I0422 11:05:25.200115     541 plugins.go:291] Loaded volume plugin "kubernetes.io/glusterfs"
I0422 11:05:25.200170     541 plugins.go:291] Loaded volume plugin "kubernetes.io/persistent-claim"
I0422 11:05:25.200205     541 plugins.go:291] Loaded volume plugin "kubernetes.io/rbd"
I0422 11:05:25.200249     541 plugins.go:291] Loaded volume plugin "kubernetes.io/cinder"
I0422 11:05:25.200289     541 plugins.go:291] Loaded volume plugin "kubernetes.io/cephfs"
I0422 11:05:25.200340     541 plugins.go:291] Loaded volume plugin "kubernetes.io/downward-api"
I0422 11:05:25.200382     541 plugins.go:291] Loaded volume plugin "kubernetes.io/fc"
I0422 11:05:25.200430     541 plugins.go:291] Loaded volume plugin "kubernetes.io/flocker"
I0422 11:05:25.200471     541 plugins.go:291] Loaded volume plugin "kubernetes.io/azure-file"
I0422 11:05:25.200519     541 plugins.go:291] Loaded volume plugin "kubernetes.io/configmap"
I0422 11:05:25.200601     541 server.go:645] Started kubelet
E0422 11:05:25.200796     541 kubelet.go:956] Image garbage collection failed: unable to find data for container /
I0422 11:05:25.200843     541 server.go:126] Starting to listen read-only on 0.0.0.0:10255
I0422 11:05:25.201531     541 server.go:109] Starting to listen on 0.0.0.0:10250
E0422 11:05:25.201684     541 event.go:202] Unable to write event: 'Post http://localhost:8080/api/v1/namespaces/default/events: dial tcp 127.0.0.1:8080: connection refused' (may retry after sleeping)
I0422 11:05:25.206656     541 fs_resource_analyzer.go:66] Starting FS ResourceAnalyzer
I0422 11:05:25.206714     541 manager.go:123] Starting to sync pod status with apiserver
I0422 11:05:25.206888     541 kubelet.go:2356] Starting kubelet main sync loop.
I0422 11:05:25.207036     541 kubelet.go:2365] skipping pod synchronization - [container runtime is down]
I0422 11:05:25.333829     541 factory.go:233] Registering Docker factory
I0422 11:05:25.336920     541 factory.go:97] Registering Raw factory
I0422 11:05:25.392065     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:25.392148     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:25.398401     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:25.492441     541 manager.go:1003] Started watching for new ooms in manager
I0422 11:05:25.493365     541 oomparser.go:182] oomparser using systemd
I0422 11:05:25.495129     541 manager.go:256] Starting recovery of all containers
I0422 11:05:25.583462     541 manager.go:261] Recovery completed
I0422 11:05:25.622022     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:25.622065     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:25.622485     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:26.038631     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:26.038753     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:26.039300     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:26.852863     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:26.852892     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:26.853320     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:28.468911     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:28.468937     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:28.469355     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:30.207357     541 kubelet.go:2388] SyncLoop (ADD, "file"): "k8s-etcd-172.20.34.112_default(1df6a8b4d6e129d5ed8840e370203c11), k8s-proxy-172.20.34.112_default(5e5303a9d49035e9fad52bfc4c88edc8), k8s-master-172.20.34.112_default(4c6ab43ac4ee970e1f563d76ab3d3ec9)"
E0422 11:05:30.207416     541 kubelet.go:2307] error getting node: node '172.20.34.112' is not in cache
E0422 11:05:30.207465     541 kubelet.go:2307] error getting node: node '172.20.34.112' is not in cache
E0422 11:05:30.207505     541 kubelet.go:2307] error getting node: node '172.20.34.112' is not in cache
E0422 11:05:30.209316     541 kubelet.go:1764] Failed creating a mirror pod for "k8s-proxy-172.20.34.112_default(5e5303a9d49035e9fad52bfc4c88edc8)": Post http://localhost:8080/api/v1/namespaces/default/pods: dial tcp 127.0.0.1:8080: connection refused
E0422 11:05:30.209332     541 kubelet.go:1764] Failed creating a mirror pod for "k8s-etcd-172.20.34.112_default(1df6a8b4d6e129d5ed8840e370203c11)": Post http://localhost:8080/api/v1/namespaces/default/pods: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:30.209396     541 manager.go:1688] Need to restart pod infra container for "k8s-proxy-172.20.34.112_default(5e5303a9d49035e9fad52bfc4c88edc8)" because it is not found
W0422 11:05:30.209828     541 manager.go:408] Failed to update status for pod "_()": Get http://localhost:8080/api/v1/namespaces/default/pods/k8s-etcd-172.20.34.112: dial tcp 127.0.0.1:8080: connection refused
E0422 11:05:30.209899     541 kubelet.go:1764] Failed creating a mirror pod for "k8s-master-172.20.34.112_default(4c6ab43ac4ee970e1f563d76ab3d3ec9)": Post http://localhost:8080/api/v1/namespaces/default/pods: dial tcp 127.0.0.1:8080: connection refused
W0422 11:05:30.212690     541 manager.go:408] Failed to update status for pod "_()": Get http://localhost:8080/api/v1/namespaces/default/pods/k8s-proxy-172.20.34.112: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:30.214297     541 manager.go:1688] Need to restart pod infra container for "k8s-master-172.20.34.112_default(4c6ab43ac4ee970e1f563d76ab3d3ec9)" because it is not found
W0422 11:05:30.214935     541 manager.go:408] Failed to update status for pod "_()": Get http://localhost:8080/api/v1/namespaces/default/pods/k8s-master-172.20.34.112: dial tcp 127.0.0.1:8080: connection refused
I0422 11:05:30.220596     541 manager.go:1688] Need to restart pod infra container for "k8s-etcd-172.20.34.112_default(1df6a8b4d6e129d5ed8840e370203c11)" because it is not found
I0422 11:05:31.693419     541 kubelet.go:2754] Recording NodeHasSufficientDisk event message for node 172.20.34.112
I0422 11:05:31.693456     541 kubelet.go:1134] Attempting to register node 172.20.34.112
I0422 11:05:31.694191     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused

api server container (exited) logs

I0425 13:18:55.516154       1 genericapiserver.go:82] Adding storage destination for group batch 
W0425 13:18:55.516177       1 server.go:383] No RSA key provided, service account token authentication disabled 
F0425 13:18:55.516185       1 server.go:410] Invalid Authentication Config: open /srv/kubernetes/basic_auth.csv: no such file or directory
6
+50

I've reproduced your issue before, and I've also successfully run the kubelet container a couple times.

Here is the exact command I am running when it succeeds: export K8S_VERSION=v1.2.2 docker run \ --volume=/:/rootfs:ro \ --volume=/sys:/sys:ro \ --volume=/var/lib/docker/:/var/lib/docker:rw \ --volume=/var/lib/kubelet/:/var/lib/kubelet:rw \ --volume=/var/run:/var/run:rw \ --net=host \ --pid=host \ --privileged=true \ --name=kubelet \ -d \ gcr.io/google_containers/hyperkube-amd64:${K8S_VERSION} \ /hyperkube kubelet \ --containerized \ --hostname-override="127.0.0.1" \ --address="0.0.0.0" \ --api-servers=http://localhost:8080 \ --config=/etc/kubernetes/manifests \ --allow-privileged=true --v=2

I removed these 2 settings from the tutorial's suggested command because DNS wasn't needed in my case: --cluster-dns=10.0.0.10 --cluster-domain=cluster.local

Also, I started the docker SSH portal in the background before starting the kubelet container, using this command:

docker-machine ssh `docker-machine active` -f -N -L "8080:localhost:8080"

I also did not make any changes to SSL certificates.

I am able to run the kubelet container with K8S_VERSION=v1.2.2 and K8S_VERSION=1.2.3.

On a successful run, I observe all the processes are "Up"; none are "Exited":

$ docker ps -a
CONTAINER ID        IMAGE                                             COMMAND                  CREATED             STATUS              PORTS               NAMES
42e6d973f624        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube apiserver"   About an hour ago   Up About an hour                        k8s_apiserver.78ec1de_k8s-master-127.0.0.1_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_5d260d3c
135c020f14b4        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube controlle"   About an hour ago   Up About an hour                        k8s_controller-manager.70414b65_k8s-master-127.0.0.1_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_9b338f27
873656c913fd        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/setup-files.sh IP:1"   About an hour ago   Up About an hour                        k8s_setup.e5aa3216_k8s-master-127.0.0.1_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_ff89fc7c
8b12f5f20e8f        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube scheduler"   About an hour ago   Up About an hour                        k8s_scheduler.fc12fcbe_k8s-master-127.0.0.1_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_ea90af75
93d9b2387b2e        gcr.io/google_containers/etcd:2.2.1               "/usr/local/bin/etcd "   About an hour ago   Up About an hour                        k8s_etcd.7e452b0b_k8s-etcd-127.0.0.1_default_1df6a8b4d6e129d5ed8840e370203c11_d66f84f0
f6e45af93ee9        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube proxy --m"   About an hour ago   Up About an hour                        k8s_kube-proxy.9a9f4853_k8s-proxy-127.0.0.1_default_5e5303a9d49035e9fad52bfc4c88edc8_b0084efc
f6748442f2d1        gcr.io/google_containers/pause:2.0                "/pause"                 About an hour ago   Up About an hour                        k8s_POD.6059dfa2_k8s-master-127.0.0.1_default_4c6ab43ac4ee970e1f563d76ab3d3ec9_f4758f9b
d515c10910c4        gcr.io/google_containers/pause:2.0                "/pause"                 About an hour ago   Up About an hour                        k8s_POD.6059dfa2_k8s-etcd-127.0.0.1_default_1df6a8b4d6e129d5ed8840e370203c11_3248c1d6
958f4865df9f        gcr.io/google_containers/pause:2.0                "/pause"                 About an hour ago   Up About an hour                        k8s_POD.6059dfa2_k8s-proxy-127.0.0.1_default_5e5303a9d49035e9fad52bfc4c88edc8_3850b11e
2611ee951476        gcr.io/google_containers/hyperkube-amd64:v1.2.2   "/hyperkube kubelet -"   About an hour ago   Up About an hour                        kubelet

On a successful run, I also see similar log output as you when I run docker logs kubelet. In particular, I see: Unable to register 127.0.0.1 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused

But, eventually, it works: $ kubectl -s http://localhost:8080 cluster-info Kubernetes master is running at http://localhost:8080 $ kubectl get nodes NAME STATUS AGE 127.0.0.1 Ready 1h 192.168.99.100 NotReady 1h localhost NotReady 1h

Other tips:

  • You might need to wait a little bit for the API server to start up. For example, this guy uses a while loop: until $(kubectl -s http://localhost:8080 cluster-info &> /dev/null); do sleep 1 done

  • On Mac OS X, I've noticed the Docker VM can get unstable whenever my wireless changes, or when I suspend/resume my laptop. I can usually resolve such issues with a docker-machine restart.

  • When experimenting with kubelet, I'll often want to stop the kubelet container and stop/remove all containers in my docker. I do that by running docker stop kubelet && docker rm -f $(docker ps -aq)

Info about my setup, OS X El Capitan 10.11.2:

$ docker --version
Docker version 1.10.3, build 20f81dd
$ kubectl version
Client Version: version.Info{Major:"1", Minor:"2", GitVersion:"v1.2.0", GitCommit:"5cb86ee022267586db386f62781338b0483733b3", GitTreeState:"clean"}
Server Version: version.Info{Major:"1", Minor:"2", GitVersion:"v1.2.2", GitCommit:"528f879e7d3790ea4287687ef0ab3f2a01cc2718", GitTreeState:"clean"}
2

[I'm not a kubernetes expert - just following my nose here].

kubelet's failure is apparently a consequent symptom of port 8080 being closed, which you noted at the beginning of your question. It's not where you should be focused.

Note the following line in the logs you showed us:

I0422 11:05:28.469355     541 kubelet.go:1137] Unable to register 172.20.34.112 with the apiserver: Post http://localhost:8080/api/v1/nodes: dial tcp 127.0.0.1:8080: connection refused

So, kubelet is trying to contact the apiserver, and getting connection refused. That's not surprising given that as you note, it has exited.

The log lines you show us for the apiserver show it complaining about not having a certificate. The certificates are normally in /var/run/kubernetes (noted here). That falls within the /var/run volume that's set up in the docker command for running kubernetes in your tutorial. I'd be looking closely at that volume specification to see if you've made any mistakes, and to see if the certificates are in there as expected.

There's a few bits at https://github.com/kubernetes/kubernetes/issues/11000 which might be useful for figuring out what's going wrong with your certs, including devurandom providing a script for creating the certs if that's what's needed.

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