Tag / Kubernetes

by Maik

OpenShift 3.9 missing Webconsole

Getting started with OpenShift 3.9 differs from the prior versions. The OpenShift webconsole, which was provided by default in the past, seems to be no longer shipped and enabled by default. Trying to access via https://oc.example.com:8443 reveals the following (unhelpful) message:

missing service (service “webconsole” not found)
missing route (service “webconsole” not found)

Digging through GitHub issues reveals, that this behavior is intentional and the users have to deploy the Webconsole manually from now (at least if not relying on the official Ansible automation). The required deployment / route / service configurations are provided in the official OpenShift Origin repository. Running the following commands gets you up and running with a fresh webconsole under OpenShift Origin 3.9:

$ git clone https://github.com/openshift/origin
$ echo "Optionally checkout the specific version you are trying to get running"
$ oc login -u system:admin
$ oc create namespace openshift-web-console
$ # Customize install/origin-web-console/console-config.yaml before running the following command
$ # Replace 127.0.0.1 with you own IP / domain if you are not running locally
$ oc process -f install/origin-web-console/console-template.yaml -p "API_SERVER_CONFIG=$(cat install/origin-web-console/console-config.yaml)" | oc apply -n openshift-web-console -f -

Fortunately the uggly error message will most probably disappear in subsequent releases. There is an open PR dealing with it: Bug 1538006 – Improve error page when console not installed

Further references

by Maik

OpenShift: “systemd” is different from docker cgroup driver: “cgroupfs”

Messing around with OpenShift Origin 3.6.0 and their Docker Quickstart guide I stumbled upon some configuration incompatibilities with Kubernetes:

F0819 08:47:34.208186    9065 node.go:282] failed to run Kubelet: failed to create kubelet: misconfiguration: kubelet cgroup driver: "systemd" is different from docker cgroup driver: "cgroupfs"

The issue is caused due to using cgrougfs as Cgroup Driver for Docker. You can verify your Docker config by running docker info | grep Cgroup. You can change your Cgroup Driver to systemd using the native.cgroupdriver parameter for the Docker Daemon. Add the following arg to your /etc/systemd/system/docker.service.d/docker-thinpool.conf (ExecStart) file and /etc/default/docker (DOCKER_OPTS):

--exec-opt native.cgroupdriver=systemd

Relaunch the dockerd afterwards and verify your changes:

systemctl daemon-reload
systemctl restart docker.service
docker info | grep Cgroup

Further references

docker change cgroup driver to systemd

I want to docker to start with systemd cgroup driver. for some reason it using only cgroupfs on my centos 7 server. here is startup config file. # systemctl cat docker # /usr/lib/systemd/system/d…

openshift/origin docker container fails to start: failed to create kubelet: misconfiguration: kubelet cgroup driver: “systemd” is different from docker cgroup driver: “cgroupfs” · Issue #14766 · openshift/origin

Affected System configuration

$ docker version

Client:
 Version:      17.06.1-ce
 API version:  1.30
 Go version:   go1.8.3
 Git commit:   874a737
 Built:        Thu Aug 17 22:51:12 2017
 OS/Arch:      linux/amd64

Server:
 Version:      17.06.1-ce
 API version:  1.30 (minimum version 1.12)
 Go version:   go1.8.3
 Git commit:   874a737
 Built:        Thu Aug 17 22:50:04 2017
 OS/Arch:      linux/amd64
 Experimental: false

$ lsb_release -a
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.3 LTS
Release:    16.04
Codename:   xenial