Red Hat Bugzilla – Bug 1457062
Docker MTU is wrong when SDN is adjusted to smaller MTU
Last modified: 2017-08-16 15:51 EDT
Description of problem: When the OpenShift SDN is smaller than "default", the docker MTU also needs to be adjusted. Version-Release number of selected component (if applicable): Found doing a build with the latest OpenShift 3.5 How reproducible: 100% Steps to Reproduce: 1. Install OpenShift in env where the MTU of the SDN will be adjusted down, e.g.: in an OpenStack environment 2. Observe how some builds are failing, e.g.: a DockerStrategy build with the following source: https://github.com/oybed/test-network 3. Change the docker mtu (add '--mtu=1400' to the /etc/sysconfig/docker-network file) and observe the builds are passing. Actual results: Failed builds due to incorrect MTU setting for docker Expected results: The installation should have set the docker MTU (just like it does for the SDN) Additional info:
Proposed fix https://github.com/openshift/openshift-ansible/pull/4336
Merged into 3.6, I'll backport to 3.3 - 3.5 once QE verifies this bug.
Or 3.4 and 3.5. This change isn't necessary in 3.3 as we reconfigured docker back in the dark ages.
Verified this bug with openshift-ansible-3.6.98-1.git.0.e651d65.el7.noarch, and PASS. # cat /etc/sysconfig/docker-network # /etc/sysconfig/docker-network DOCKER_NETWORK_OPTIONS=' --mtu=1350' # grep -i mtu /etc/origin/node/node-config.yaml mtu: 1350 # oc new-app https://github.com/oybed/test-network -n install-test # oc get build -n install-test NAME TYPE FROM STATUS STARTED DURATION test-network-1 Docker Git@71c648f Complete 51 seconds ago 20s
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2017:1716