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Flannel and docker don't start

I'm trying to set up a kubernetes cluster on 2 nodes , centos 7.1 using this guide. However when I attempt to start the services on the minion like so:

for SERVICES in kube-proxy kubelet docker flanneld; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES 
done

I get the following error:

-- Logs begin at Wed 2015-12-23 13:00:41 UTC, end at Wed 2015-12-23 16:03:54 UTC. --
Dec 23 16:03:47 sc-test2 systemd[1]: docker-storage-setup.service: main process exited, code=exited, status=1/FAILURE
Dec 23 16:03:47 sc-test2 systemd[1]: Failed to start Docker Storage Setup.
-- Subject: Unit docker-storage-setup.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker-storage-setup.service has failed.
-- 
-- The result is failed.
Dec 23 16:03:47 sc-test2 systemd[1]: Unit docker-storage-setup.service entered failed state.
Dec 23 16:03:48 sc-test2 flanneld[36477]: E1223 16:03:48.187350 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:49 sc-test2 flanneld[36477]: E1223 16:03:49.189860 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:50 sc-test2 flanneld[36477]: E1223 16:03:50.192894 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:51 sc-test2 flanneld[36477]: E1223 16:03:51.194940 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:52 sc-test2 flanneld[36477]: E1223 16:03:52.197222 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:53 sc-test2 flanneld[36477]: E1223 16:03:53.199248 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)
Dec 23 16:03:54 sc-test2 flanneld[36477]: E1223 16:03:54.201160 36477 network.go:53] Failed to retrieve network config: 100: Key not found (/atomic.io)

I'm sure I set the key on the master with : etcdctl mk /coreos.com/network/config '{"Network":"172.17.0.0/16"}'

By far installation seems to be the hardest bit on using kubernetes :(

like image 949
Jonathan Avatar asked Dec 23 '15 16:12

Jonathan


1 Answers

Today's christmas but I spent the whole day trying to get this to work :) This is what I did:

#1 FLANNEL

As mentioned I'd set the flannel etcd key on the master with:

etcdctl mk /coreos.com/network/config '{"Network":"172.17.0.0/16"}'

but I got this error when trying to start flannel on the minion:

Failed to retrieve network config: 100: Key not found (/atomic.io)

So I edited the /etc/sysconfig/flanneld file on the minion from:

# Flanneld configuration options  

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD="http://master:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_KEY="/coreos.com/network"

# Any additional options that you want to pass
#FLANNEL_OPTIONS=""

to:

# Flanneld configuration options  

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD="http://master:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_KEY="/atomic.io/network"

# Any additional options that you want to pass
#FLANNEL_OPTIONS=""

i.e. changed the FLANNEL_ETCD key.

After this systemctl start flanneld worked.

#2 DOCKER

I didn't find a way to make the version installed as a dependency by kubernetes work so I uninstalled it and following the docker docs for Centos installed docker-engine and manually created a docker.service file for systemctl.

cd /usr/lib/systemd/system

and the contents of the docker.service:

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network.target docker.socket
Requires=docker.socket
Requires=flanneld.service
After=flanneld.service

[Service]
EnvironmentFile=/etc/sysconfig/flanneld
ExecStart=/usr/bin/docker daemon -H fd:// --bip=${FLANNEL_SUBNET}
Restart=on-failure
RestartSec=5


[Install]
WantedBy=multi-user.target

then start and enable the daemon with systemctl as well as query the status.

systemctl restart docker
systemctl enable docker
systemctl status docker
like image 94
Jonathan Avatar answered Oct 19 '22 18:10

Jonathan