Overview: running crc on a remote server

This document shows how to deploy an OpenShift instance on a server using CodeReady Containers (crc) that can be accessed remotely from one or more client machines (sometimes called a "headless" instance). This provides a low-cost test and development platform that can be shared by developers. Deploying this way also allows a user to create an instance that uses more cpu and memory resources than may be available on his or her laptop.

While there are benefits to this type of deployment, please note that the primary use case for crc is to deploy a local OpenShift instance on a workstation or laptop and access it directly from the same machine. The headless setup is configured completely outside of crc itself, and supporting a headless setup is beyond the mission of the crc development team. Please do not ask for changes to crc to support this type of deployment, it will only cost the team time as they politely decline :)

The instructions here were tested with Fedora on both the server (F30) and a laptop (F29).

Thanks to

Thanks to Marcel Wysocki from Red Hat for the haproxy solution and the entire CodeReady Containers team for crc!

Useful links

Red Hat blog article on CodeReady Containers

Download page on cloud.redhat.com

CRC documentation on github.io

Project sources on github

Download and setup CRC on a server

Go to the download page and get crc for Linux. You’ll also need the pull secret listed there during the installation process. Make sure to copy the crc binary to /usr/local/bin or somewhere on your path.

The initial setup command only needs to be run once, and it creates a ~/.crc directory. Your user must have sudo privileges since crc will install dependencies for libvirt and modify the NetworkManager config:

$ crc setup

Note: occasionally on some systems this may fail with “Failed to restart NetworkManager”. Just rerun crc setup a few times until it works

Create an OpenShift Instance with CRC

$ crc start

You will be asked for the pull secret from the download page, paste it at the prompt.

Optionally, use the -m and -c flags to increase the VM size, for example a 32GiB with 8 cpus:

$ crc start -m 32768 -c 8

See the documentation or crc -h for other things you can do

If you want to just use crc locally on this machine, you can stop here, you’re all set!

Make sure you have haproxy and a few other things

sudo dnf -y install haproxy policycoreutils-python-utils jq

Modify the firewall on the server

$ sudo systemctl start firewalld
$ sudo firewall-cmd --add-port=80/tcp --permanent
$ sudo firewall-cmd --add-port=6443/tcp --permanent
$ sudo firewall-cmd --add-port=443/tcp --permanent
$ sudo systemctl restart firewalld
$ sudo semanage port -a -t http_port_t -p tcp 6443

Configure haproxy on the server

The steps below will create an haproxy config file with placeholders, update the SERVER_IP and CRC_IP using sed, and copy the new file to the correct location. If you would like to edit the file manually, feel free :)

$ sudo cp /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.bak
$ tee haproxy.cfg &>/dev/null <<EOF
global
        debug

defaults
        log global
        mode    http
        timeout connect 5000
        timeout client 5000
        timeout server 5000

frontend apps
    bind SERVER_IP:80
    bind SERVER_IP:443
    option tcplog
    mode tcp
    default_backend apps

backend apps
    mode tcp
    balance roundrobin
    option ssl-hello-chk
    server webserver1 CRC_IP check

frontend api
    bind SERVER_IP:6443
    option tcplog
    mode tcp
    default_backend api

backend api
    mode tcp
    balance roundrobin
    option ssl-hello-chk
    server webserver1 CRC_IP:6443 check
EOF

$ export SERVER_IP=$(hostname --ip-address)
$ export CRC_IP=$(crc ip)
$ sed -i "s/SERVER_IP/$SERVER_IP/g" haproxy.cfg
$ sed -i "s/CRC_IP/$CRC_IP/g" haproxy.cfg
$ sudo cp haproxy.cfg /etc/haproxy/haproxy.cfg
$ sudo systemctl start haproxy

Setup NetworkManager on the client machine

NetworkManager needs to be configured to use dnsmasq for DNS. Make sure you have dnsmasq installed:

$ sudo dnf install dnsmasq

Add a file to /etc/NetworkManager/conf.d to enable use of dnsmasq. (Some systems may already have this setting in an existing file, depending on what's been done in the past. If that's the case, continue on without creating a new file)

$ sudo tee /etc/NetworkManager/conf.d/use-dnsmasq.conf &>/dev/null <<EOF
[main]
dns=dnsmasq
EOF

Add dns entries for crc:

$ tee external-crc.conf &>/dev/null <<EOF
address=/apps-crc.testing/SERVER_IP
address=/api.crc.testing/SERVER_IP
EOF

$ export SERVER_IP=”your server’s external IP address”
$ sed -i "s/SERVER_IP/$SERVER_IP/g" external-crc.conf
$ sudo cp external-crc.conf /etc/NetworkManager/dnsmasq.d/external-crc.conf
$ sudo systemctl reload NetworkManager

Note: if you've previously run crc locally on the client machine, you likely have a /etc/NetworkManager/dnsmasq.d/crc.conf file that sets up dns for a local VM. Comment out those entries.

Get the oc binary on the client machine

If you don't already have it, you can get the oc client here:

https://mirror.openshift.com/pub/openshift-v4/clients/ocp/latest/

Login to the OpenShift instance from the client machine

The password for the kubeadmin account is printed when crc starts, but if you don't have it handy you can do this as the user running crc on the server:

$ crc console --credentials

Now just login to OpenShift from your client machine using the standard crc url

$ oc login -u kubeadmin -p <kubeadmin password>  https://api.crc.testing:6443

The OpenShift console will be available at https://console-openshift-console.apps-crc.testing

Renewal of expired certificates

Beginning in version 1.2.0, CodeReady Containers will renew embedded certificates when they expire (prior to 1.2.0 it was necessary to download and install a new version). When the certificates need to be renewed, this will be noted in the CRC log output and may take up to 5 minutes.

mbodo/remote_crc.md