Bug 1932113

Summary:	[Kuryr] Enforce nodes MTU for the Namespaces and Pods
Product:	OpenShift Container Platform	Reporter:	Maysa Macedo <mdemaced>
Component:	Networking	Assignee:	Maysa Macedo <mdemaced>
Networking sub component:	kuryr	QA Contact:	Itzik Brown <itbrown>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	high
Priority:	medium	CC:	gcheresh, juriarte, mdulko
Version:	4.6.z
Target Milestone:	---
Target Release:	4.7.z
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1931674
Clones:	1932114 (view as bug list)		Environment:
Last Closed:	2021-04-26 16:08:25 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1931674
Bug Blocks:	1932114

Comment 1 Michał Dulko 2021-03-24 12:00:00 UTC

Is there a backport involved in this one? If not this should get moved to ON_QA too.

Comment 5 Itzik Brown 2021-04-21 15:39:53 UTC

Checked with 
OSP13 2021-03-24.1/RH7-RHOS-13.0
OCP 4.7.0-0.nightly-2021

Using a tenant:
Create a network with MTU 1400 and a subnet
(shiftstack) [cloud-user@installer-host ~]$ openstack network show net1 |grep mtu
| mtu                       | 1400        

Created a router and added to the router as well as setting the gateway

Checked the MTU of the openshift-kuryr-net
(shiftstack) [cloud-user@installer-host ~]$ openstack network show ns/openshift-kuryr-net | grep mtu
| mtu                       | 1400   

Created pods using the following:
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
  labels:
    app: demo
spec:
  replicas: 3
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: demo
        image: kuryr/demo
        ports:
        - containerPort: 8080

Checked MTU on the pods
(shiftstack) [cloud-user@installer-host ~]$ oc get pods
NAME                   READY   STATUS    RESTARTS   AGE
demo-66cdc7b66-hlhvx   1/1     Running   0          114s
demo-66cdc7b66-l845f   1/1     Running   0          114s
demo-66cdc7b66-rx4vq   1/1     Running   0          114s
(shiftstack) [cloud-user@installer-host ~]$ oc exec -it demo-66cdc7b66-hlhvx -- ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
62: eth0@if2: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1400 qdisc noqueue state UP qlen 1000
    link/ether fa:16:3e:b4:2d:5b brd ff:ff:ff:ff:ff:ff

Comment 7 errata-xmlrpc 2021-04-26 16:08:25 UTC

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 (Moderate: OpenShift Container Platform 4.7.8 security and bug fix update), 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/RHSA-2021:1225