Fix issue #26776: missing /zmq_swss directory causes orchagent crash

[Allen-John-ML]

Issue: missing /zmq_swss directory causes orchagent crash

Why I did it

After sonic-net/sonic-swss#4243 was merged (around 2026-04-01), orchagent uses ZMQ with IPC sockets for P4 orchestration. These sockets are bound to paths like ipc:///zmq_swss/p4orch_zmq_swss_ep.
On real SONiC systems: The /zmq_swss directory is bind-mounted into the swss container from the host filesystem via the docker run configuration in rules/docker-orchagent.mk.
On docker-sonic-vs: The container runs standalone (e.g., via containerlab) without a host bind mount, so the /zmq_swss directory doesn't exist. When orchagent tries to bind to the ZMQ IPC endpoint, zmq_bind() fails with errno 2 (No such file or directory), causing orchagent to abort.

How I did it

I've added a directory creation step in the docker-sonic-vs Dockerfile:
File: platform/vs/docker-sonic-vs/Dockerfile.j2
Change: Added lines 171-173 to create the /zmq_swss directory:

How to verify it

The workaround mentioned in the issue (manually creating the directory and restarting) confirms this fix will work:
docker exec mkdir -p /zmq_swss
docker exec supervisorctl
restart start.sh

Which release branch to backport (provide reason below if selected)

• 202305
• 202311
• 202405
• 202411
• 202505
• 202511
  Reason for backporting: docker-sonic-vs crashes on startup due to missing /zmq_swss directory. This bug affects
  stable releases as well, so backporting ensures docker-sonic-vs runs correctly on those branches.

Tested branch (Please provide the tested image version)

• 20200712

Description for the changelog

PR#26776 under sonic-net repo. Added lines 171-173 to create the /zmq_swss directory to ensure that the directory exists inside the container filesystem, allowing orchagent to successfully bind to its ZMQ IPC endpoints and start properly.

Link to config_db schema for YANG module changes

N/A

A picture of a cute animal (not mandatory but encouraged)

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[mssonicbld]

/azp run Azure.sonic-buildimage

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Allen-John-ML / name: Allen John (763fe95)

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Allen-John-ML]

/azpw run

[mssonicbld]

⚠️ Notice: /azpw run only runs failed jobs now. If you want to trigger a whole pipline run, please rebase your branch or close and reopen the PR.
💡 Tip: You can also use /azpw retry to retry failed jobs directly.

Retrying failed(or canceled) jobs...

[mssonicbld]

Retrying failed(or canceled) stages in build 1090818:

✅Stage Test:

• Job impacted-area-kvmtest-multi-asic-t1 by Elastictest: retried.
• Job impacted-area-kvmtest-t2 by Elastictest: retried.
• Job impacted-area-kvmtest-t1-lag by Elastictest: retried.

[Allen-John-ML]

/azpw retry

[mssonicbld]

Retrying failed(or canceled) jobs...

[mssonicbld]

Retrying failed(or canceled) stages in build 1090818:

✅Stage Test:

• Job impacted-area-kvmtest-t2 by Elastictest: retried.
• Job impacted-area-kvmtest-multi-asic-t1 by Elastictest: retried.

[sreeiyer-1]

@Allen-John-ML - for DCO, please use "--signoff" with git commit

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Allen-John-ML]

/azpw retry

[mssonicbld]

Retrying failed(or canceled) jobs...

[mssonicbld]

Retrying failed(or canceled) stages in build 1096283:

✅Stage Test:

• Job impacted-area-kvmtest-t0 by Elastictest: retried.

[sreeiyer-1]

@arlakshm - for review and approval.

[sreeiyer-1]

@arlakshm - can you please review or suggest someone can review.

[Allen-John-ML]

@lguohan Hi. Could you please review this PR?

[mssonicbld]

This PR has backport request for branches: 202305,202311,202405,202411,202505,202511.
Adding label(s) for branch(es) 202305,202311,202405,202411,202505,202511.

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[mssonicbld]

The change is not in 202305 yet. @Allen-John-ML, please manually create the cherry pick PR for branch 202305.
You can ping the release branch owner(github account: ) to approve your cherry pick PR.
If this change is already in 202305, please comment "already in 202305". Thanks!

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[mssonicbld]

The change is not in 202311 yet. @Allen-John-ML, please manually create the cherry pick PR for branch 202311.
You can ping the release branch owner(github account: ) to approve your cherry pick PR.
If this change is already in 202311, please comment "already in 202311". Thanks!

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[mssonicbld]

The change is not in 202405 yet. @Allen-John-ML, please manually create the cherry pick PR for branch 202405.
You can ping the release branch owner(github account: bingwang-ms) to approve your cherry pick PR.
If this change is already in 202405, please comment "already in 202405". Thanks!

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[mssonicbld]

The change is not in 202411 yet. @Allen-John-ML, please manually create the cherry pick PR for branch 202411.
You can ping the release branch owner(github account: kperumalbfn) to approve your cherry pick PR.
If this change is already in 202411, please comment "already in 202411". Thanks!

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[mssonicbld]

The change is not in 202505 yet. @Allen-John-ML, please manually create the cherry pick PR for branch 202505.
You can ping the release branch owner(github account: yejianquan) to approve your cherry pick PR.
If this change is already in 202505, please comment "already in 202505". Thanks!

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[mssonicbld]

Cherry-pick PR to 202511: #27900

[mssonicbld]

Cherry-pick PR to msft-202512: Azure/sonic-buildimage-msft#2804

[mssonicbld]

This PR has backport request label(s) for branch(es): 202305,202311,202405,202411,202505,202511,msft-202512, but is missing required test information. Please make sure you tick the tested branch(es) in the Tested branch section and provide test evidence (e.g., 202305: <test result>) in the Test result section as well in your PR description.

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[mssonicbld]

@Allen-John-ML cherry pick PR didn't pass PR checker after retry. Please help check! Thanks.
Azure/sonic-buildimage-msft#2804

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