kubeadm init preflight check error - cannot unmarshal number into Go value of type bool

[githubvick]

Is this a BUG REPORT or FEATURE REQUEST?

BUG REPORT

Versions

kubeadm version (use kubeadm version): kubeadm version: version.Info{Major:"1", Minor:"6", GitVersion:"v1.6.1", GitCommit:"b0b7a323cc5a4a2019b2e9520c21c7830b7f708e", GitTreeState:"clean", BuildDate:"2017-04-03T20:33:27Z", GoVersion:"go1.7.5", Compiler:"gc", Platform:"linux/amd64"}

Environment:

• Kubernetes version (use kubectl version):Client Version: version.Info{Major:"1", Minor:"6", GitVersion:"v1.6.1", GitCommit:"b0b7a323cc5a4a2019b2e9520c21c7830b7f708e", GitTreeState:"clean", BuildDate:"2017-04-03T20:44:38Z", GoVersion:"go1.7.5", Compiler:"gc", Platform:"linux/amd64"}
• Cloud provider or hardware configuration:VMWare virtual machine in Vcloud director
• OS (e.g. from /etc/os-release): Red Hat Enterprise Linux Server release 7.3 (Maipo)
• Kernel (e.g. uname -a): Linux jcia9362 4.1.12-61.1.24.el7uek.x86_64 kubeadm init starts paused containers on ubuntu 16.04 #2 SMP Wed Jan 4 14:05:13 PST 2017 x86_64 x86_64 x86_64 GNU/Linux
• Others:

What happened?

Error encountered during kubeadm init and stops

Error message is

[preflight] The system verification failed. Printing the output from the verification:
OS: Linux
KERNEL_VERSION: 4.1.12-61.1.24.el7uek.x86_64
CONFIG_NAMESPACES: enabled
CONFIG_NET_NS: enabled
CONFIG_PID_NS: enabled
CONFIG_IPC_NS: enabled
CONFIG_UTS_NS: enabled
CONFIG_CGROUPS: enabled
CONFIG_CGROUP_CPUACCT: enabled
CONFIG_CGROUP_DEVICE: enabled
CONFIG_CGROUP_FREEZER: enabled
CONFIG_CGROUP_SCHED: enabled
CONFIG_CPUSETS: enabled
CONFIG_MEMCG: enabled
CONFIG_INET: enabled
CONFIG_EXT4_FS: enabled (as module)
CONFIG_PROC_FS: enabled
CONFIG_NETFILTER_XT_TARGET_REDIRECT: enabled (as module)
CONFIG_NETFILTER_XT_MATCH_COMMENT: enabled (as module)
CONFIG_OVERLAY_FS: enabled (as module)
CONFIG_AUFS_FS: not set - Required for aufs.
CONFIG_BLK_DEV_DM: enabled (as module)
CGROUPS_CPU: enabled
CGROUPS_CPUACCT: enabled
CGROUPS_CPUSET: enabled
CGROUPS_DEVICES: enabled
CGROUPS_FREEZER: enabled
CGROUPS_MEMORY: enabled
[preflight] Some fatal errors occurred:
        failed to get docker info: Error reading remote info: json: cannot unmarshal number into Go value of type bool
[preflight] If you know what you are doing, you can skip pre-flight checks with `--skip-preflight-checks`

What you expected to happen?

kubeadm init should proceed without issues

How to reproduce it (as minimally and precisely as possible)?

Followed these steps to install and configure kubeadm

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://yum.kubernetes.io/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
EOF

setenforce 0

yum install docker kubelet kubeadm kubectl kubernetes-cni

systemctl enable docker

systemctl start docker
systemctl enable kubelet

systemctl start kubelet
kubeadm init

Anything else we need to know?

added --cgroup-driver=systemd and commented network args and tried after systemctl daemon-reload

I'm able to initialize and setup kubeadm on another VMWare virtual machine with this OS specs

CentOS Linux release 7.3.1611 (Core)

Linux kubeadmmaster 3.10.0-514.10.2.el7.x86_64 #1 SMP Fri Mar 3 00:04:05 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

[chey]

If it helps. I can confirm this is happening. I have also confirmed your fix of adding --cgroup-driver=systemd to:
/etc/systemd/system/kubelet.service.d/10-kubeadm.conf

Update:
As a side note, I cannot register new nodes. Probably because I'm not able to do a full kubeadm init.

[githubvick]

I was able to workaround this by installing the below docker version and running yum install kubelet kubeadm kubectl kubernetes-cni

Client:
 Version:      1.12.2
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   a8c3fe4
 Built:
 OS/Arch:      linux/amd64

Server:
 Version:      1.12.2
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   a8c3fe4
 Built:
 OS/Arch:      linux/amd64

[jazemzer]

I'm facing the exact same issue

[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[init] Using Kubernetes version: v1.6.4
[init] Using Authorization mode: RBAC
[preflight] Running pre-flight checks
[preflight] The system verification failed. Printing the output from the verification:
OS: Linux
KERNEL_VERSION: 3.10.0-514.6.1.el7.x86_64
CONFIG_NAMESPACES: enabled
CONFIG_NET_NS: enabled
CONFIG_PID_NS: enabled
CONFIG_IPC_NS: enabled
CONFIG_UTS_NS: enabled
CONFIG_CGROUPS: enabled
CONFIG_CGROUP_CPUACCT: enabled
CONFIG_CGROUP_DEVICE: enabled
CONFIG_CGROUP_FREEZER: enabled
CONFIG_CGROUP_SCHED: enabled
CONFIG_CPUSETS: enabled
CONFIG_MEMCG: enabled
CONFIG_INET: enabled
CONFIG_EXT4_FS: enabled (as module)
CONFIG_PROC_FS: enabled
CONFIG_NETFILTER_XT_TARGET_REDIRECT: enabled (as module)
CONFIG_NETFILTER_XT_MATCH_COMMENT: enabled (as module)
CONFIG_OVERLAY_FS: enabled (as module)
CONFIG_AUFS_FS: not set - Required for aufs.
CONFIG_BLK_DEV_DM: enabled (as module)
CGROUPS_CPU: enabled
CGROUPS_CPUACCT: enabled
CGROUPS_CPUSET: enabled
CGROUPS_DEVICES: enabled
CGROUPS_FREEZER: enabled
CGROUPS_MEMORY: enabled
[preflight] Some fatal errors occurred:
failed to get docker info: Error reading remote info: json: cannot unmarshal number into Go value of type bool
/proc/sys/net/bridge/bridge-nf-call-iptables does not exist
[preflight] If you know what you are doing, you can skip pre-flight checks with --skip-preflight-checks

[timothysc]

I do not see this running 1.6.4 on CentOS 7.3 with Docker 1.12.6

Can you repro on this stack ^ ?

[jazemzer]

I switched to Docker 1.12.6 as mentioned and got rid of preflight check

Client:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.6.4
 Git commit:   78d1802
 Built:        Tue Jan 10 20:20:01 2017
 OS/Arch:      linux/amd64

Server:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.6.4
 Git commit:   78d1802
 Built:        Tue Jan 10 20:20:01 2017
 OS/Arch:      linux/amd64

and I'm running the following kubelet and Linux version

# kubelet --version
Kubernetes v1.6.4

# uname -r
3.10.0-514.16.1.el7.x86_64

But now its stuck at 'control plane to become ready.

# kubeadm init
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[init] Using Kubernetes version: v1.6.4
[init] Using Authorization mode: RBAC
[preflight] Running pre-flight checks
[preflight] WARNING: Connection to "https://10.189.12.47:6443" uses proxy "http://webproxy:3128/". If that is not intended, adjust your proxy settings
[preflight] Starting the kubelet service
[certificates] Generated CA certificate and key.
[certificates] Generated API server certificate and key.
[certificates] API Server serving cert is signed for DNS names [xxxkubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.189.12.47]
[certificates] Generated API server kubelet client certificate and key.
[certificates] Generated service account token signing key and public key.
[certificates] Generated front-proxy CA certificate and key.
[certificates] Generated front-proxy client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[apiclient] Created API client, waiting for the control plane to become ready

and I'm certain that I've disabled selinux

[luxas]

@jazemzer That seems like a (separate) proxy issue. Please open a new issue and give more details.
I think your proxy is somehow mis-configured so that kubelet can't pull the right images or something.

I think this is a docker issue, maybe specific to v1.12.2?

[githubvick]

Yes, this issue is specific to Docker version < v1.12.2. It actually works on 1.12.2. I can close the issue if you want.