Bug 1572514

Summary:	[CRI-O] /dev/shm can not be automatically shared among all the pod's containers
Product:	OpenShift Container Platform	Reporter:	weiwei jiang <wjiang>
Component:	Containers	Assignee:	Daniel Walsh <dwalsh>
Status:	CLOSED ERRATA	QA Contact:	DeShuai Ma <dma>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	3.10.0	CC:	amurdaca, aos-bugs, dwalsh, jhonce, jokerman, mmccomas, mpatel
Target Milestone:	---
Target Release:	3.10.0
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Clone Of:		Environment:
Last Closed:	2018-07-30 19:14:14 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description weiwei jiang 2018-04-27 08:03:56 UTC

Description of problem:
When try to check /dev/shm shared data on cri-o env, found that /dev/shm is not shared among all the pods containers. /etc/shm is current used for cri-o.

Version-Release number of selected component (if applicable):
# uname -a 
Linux host-172-16-120-61 3.10.0-862.el7.x86_64 #1 SMP Wed Mar 21 18:14:51 EDT 2018 x86_64 x86_64 x86_64 GNU/Linux
# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 7.5 (Maipo)

#oc v3.10.0-0.29.0
kubernetes v1.10.0+b81c8f8
features: Basic-Auth GSSAPI Kerberos SPNEGO

Server https://host-8-249-20.host.centralci.eng.rdu2.redhat.com:8443
openshift v3.10.0-0.29.0
kubernetes v1.10.0+b81c8f8

# oc get nodes -o wide   
NAME                  STATUS    ROLES     AGE       VERSION           EXTERNAL-IP   OS-IMAGE                                      KERNEL-VERSION          CONTAINER-RUNTIME
host-172-16-120-102   Ready     compute   1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-105   Ready     compute   1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-124   Ready     compute   1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-5     Ready     master    1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-61    Ready     master    1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-67    Ready     master    1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1
host-172-16-120-78    Ready     compute   1d        v1.10.0+b81c8f8   <none>        Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.el7.x86_64   cri-o://1.10.0-beta.1



How reproducible:
Always

Steps to Reproduce:
1.
    Given I have a project
    When I run oc create over ERB URL: https://raw.githubusercontent.com/openshift-qe/v3-testfiles/master/pods/pod_with_two_containers.json
    Then the step should succeed
    When the pod named "doublecontainers" becomes ready
    # Enter container 1 and write files
    When I run the :exec client command with:
      | pod              | doublecontainers        |
      | container        | hello-openshift         |
      | oc_opts_end      |                         |
      | exec_command     | sh                      |
      | exec_command_arg | -c                      |
      | exec_command_arg | echo "hi" > /dev/shm/c1 |
    Then the step should succeed
    When I run the :exec client command with:
      | pod              | doublecontainers |
      | container        | hello-openshift  |
      | exec_command     | cat              |
      | exec_command_arg | /dev/shm/c1      |
    Then the step should succeed
    And the output should contain "hi"
    # Enter container 2 and check whether it can share the files under directory /dev/shm
    When I run the :exec client command with:
      | pod              | doublecontainers       |
      | container        | hello-openshift-fedora |
      | exec_command     | cat                    |
      | exec_command_arg | /dev/shm/c1            |
    Then the step should succeed
2.
3.

Actual results:
11:00:48 INFO> Shell Commands: oc exec doublecontainers  --config=/home/jenkins/workspace/Runner-v3/workdir/cucushift-oc310-standard-slave-hxkvq-0/ose_user3.kubeconfig  --container=hello-openshift-fedora cat /dev/shm/c1

STDERR:
cat: /dev/shm/c1: No such file or directory
command terminated with exit code 1


Expected results:
/dev/shm should be shared among all the pod's containers

Additional info:

Comment 1 Daniel Walsh 2018-05-02 16:39:50 UTC

Weird, If containers are sharing the IPC Namespace they should be sharing shm.  I know we put a patch in for podman to handle this, I also thought we had something in CRI-O for this.  (I thought we first did it for CRI-O)

Comment 2 Daniel Walsh 2018-05-03 19:26:48 UTC

https://github.com/kubernetes-incubator/cri-o/pull/1545
Fixes this issue.

Comment 3 Daniel Walsh 2018-05-03 19:29:22 UTC

Fixed in cri-o-1.10.1

Comment 5 weiwei jiang 2018-06-05 08:35:54 UTC

Checked with 
# oc version 
oc v3.10.0-0.58.0
kubernetes v1.10.0+b81c8f8
features: Basic-Auth GSSAPI Kerberos SPNEGO

Server https://ip-172-18-4-200.ec2.internal:8443
openshift v3.10.0-0.58.0
kubernetes v1.10.0+b81c8f8

# oc get nodes -o wide 
NAME                           STATUS    ROLES     AGE       VERSION           EXTERNAL-IP      OS-IMAGE                                      KERNEL-VERSION              CONTAINER-RUNTIME
ip-172-18-4-200.ec2.internal   Ready     master    43m       v1.10.0+b81c8f8   54.152.136.226   Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.3.2.el7.x86_64   cri-o://1.10.2-dev
ip-172-18-8-253.ec2.internal   Ready     compute   38m       v1.10.0+b81c8f8   34.207.142.98    Red Hat Enterprise Linux Server 7.5 (Maipo)   3.10.0-862.3.2.el7.x86_64   cri-o://1.10.2-dev



# oc exec -c hello-openshift doublecontainers -- sh -c "echo hi > /dev/shm/c1"
# oc exec -c hello-openshift doublecontainers -- sh -c "cat /dev/shm/c1"
hi
# oc exec -c hello-openshift-fedora doublecontainers -- sh -c "cat /dev/shm/c1"
hi

Comment 7 errata-xmlrpc 2018-07-30 19:14:14 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, 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/RHBA-2018:1816