nginxinc/nginx-unprivileged:stable-alpine errors when starting

[millerick]

Bug Overview

After the latest update was pushed, trying to start nginx inside of the image errors.

/ $ nginx
2025/04/25 23:10:00 [notice] 14#14: using the "epoll" event method
2025/04/25 23:10:00 [notice] 14#14: nginx/1.28.0
2025/04/25 23:10:00 [notice] 14#14: built by gcc 14.2.0 (Alpine 14.2.0)
2025/04/25 23:10:00 [notice] 14#14: OS: Linux 6.13.7-orbstack-00283-g9d1400e7e9c6
2025/04/25 23:10:00 [notice] 14#14: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2025/04/25 23:10:00 [emerg] 15#15: open() "/run/nginx.pid" failed (13: Permission denied)
nginx: [emerg] open() "/run/nginx.pid" failed (13: Permission denied)

Expected Behavior

Running nginx is able to start like it did previously in nginxinc/nginx-unprivileged:stable-alpine3.20

/ $ nginx
2025/04/25 23:13:39 [notice] 13#13: using the "epoll" event method
2025/04/25 23:13:39 [notice] 13#13: nginx/1.26.3
2025/04/25 23:13:39 [notice] 13#13: built by gcc 13.2.1 20240309 (Alpine 13.2.1_git20240309)
2025/04/25 23:13:39 [notice] 13#13: OS: Linux 6.13.7-orbstack-00283-g9d1400e7e9c6
2025/04/25 23:13:39 [notice] 13#13: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2025/04/25 23:13:39 [notice] 14#14: start worker processes
2025/04/25 23:13:39 [notice] 14#14: start worker process 15
/ $ 2025/04/25 23:13:39 [notice] 14#14: start worker process 16
2025/04/25 23:13:39 [notice] 14#14: start worker process 17
2025/04/25 23:13:39 [notice] 14#14: start worker process 18
2025/04/25 23:13:39 [notice] 14#14: start worker process 19
2025/04/25 23:13:39 [notice] 14#14: start worker process 20
2025/04/25 23:13:39 [notice] 14#14: start worker process 21
2025/04/25 23:13:39 [notice] 14#14: start worker process 22
2025/04/25 23:13:39 [notice] 14#14: start worker process 23
2025/04/25 23:13:39 [notice] 14#14: start worker process 24
2025/04/25 23:13:39 [notice] 14#14: start worker process 25
2025/04/25 23:13:39 [notice] 14#14: start worker process 26
2025/04/25 23:13:39 [notice] 14#14: start worker process 27
2025/04/25 23:13:39 [notice] 14#14: start worker process 28

Steps to Reproduce the Bug

Dockfile contents

FROM nginxinc/nginx-unprivileged:stable-alpine

ENTRYPOINT ["nginx"]

Build and run it with docker run -it $(docker build -q .). Observe that the same does not happen if nginxinc/nginx-unprivileged:stable-alpine3.20 is used, but does happen in nginxinc/nginx-unprivileged:stable-alpine3.21 and nginxinc/nginx-unprivileged:stable-alpine.

Environment Details

Docker version 27.5.1, build 9f9e405
This is happening on my Mac laptop, as well as in the build system in all of our environments.

Additional Context

No response

[millerick]

Between nginxinc/nginx-unprivileged:stable-alpine3.20 and nginxinc/nginx-unprivileged:stable-alpine3.21 it looks like /etc/nginx/nginx.conf was changed from

pid        /tmp/nginx.pid;

to

pid        /run/nginx.pid;

[millerick]

The problem comes from here:

docker-nginx-unprivileged/Dockerfile-alpine-slim.template

Line 98 in 8655fa1

&& sed -i 's,/var/run/nginx.pid,/tmp/nginx.pid,' /etc/nginx/nginx.conf \

It looks like the underlying location changed from /var/run/nginx.pid to /run/nginx.pid and now the replacement no longer works.

I will leave it to the maintainers to decide if this is a regression in this repository or if it is a regression in nginx itself and fix the issue in the appropriate location.

[millerick]

PR that moved the default location: nginx/pkg-oss#26

[rhee876527]

For what it's worth, I was able to rollback to version: nginxinc/nginx-unprivileged:1.27.4-alpine3.21-slim which was released 5 days ago so this error appears to be more recent and may not be related to alpine 3.21 versions.

[jngrb]

In can confirm that the issue is in:

• docker.io/nginxinc/nginx-unprivileged:1.27.5
• docker.io/nginxinc/nginx-unprivileged:1.27.5-alpine

(both from yesterday)

while

• docker.io/nginxinc/nginx-unprivileged:1.27.4
• docker.io/nginxinc/nginx-unprivileged:1.27.4-alpine
• docker.io/nginxinc/nginx-unprivileged:1.26.3
• docker.io/nginxinc/nginx-unprivileged:1.26.3-alpine

all still work (from 5 and 4 days ago, respectively)

So it seems to be related to the 1.27.4 -> 1.27.5 switch matching with millerick's suggestion that PR nginx/pkg-oss#26 is to blame

[jngrb]

Created a PR #303 with a proposal for a fix

May I please ask why such a critical problem (containers don't even start under any condition) is not noticed in a CI/CD prior to the release to docker.io and other public image hubs?

There some mentioning about pipeline problems in #301 though...

[maxweisspoker]

May I please ask why such a critical problem (containers don't even start under any condition) is not noticed in a CI/CD prior to the release to docker.io and other public image hubs?

I'm curious about this as well. Hit my cluster an hour ago. Extremely frustrating that this is getting released under a "stable" tag.

[boxexchanger]

+1

[ewancoder]

Yes same here, was trying to debug a build pipeline for hours and finally figured it's a bug. Clean docker run nginxinc/nginx-unprivileged:stable-alpine crashes on two different machines with /run/nginx.pid' Permission denied.

[hamzanajeebkhaan]

+1