Why is nginx not starting in Windows Server 2019 docker container? - docker

Question

UPDATE 3 (Solution):
I installed the latest Windows updates on my host and specified the exact servercore image to match my updated Windows Server version:
mcr.microsoft.com/windows/servercore:10.0.17763.973
When running the container everything worked as expected.
Original question:
I cannot figure out why nginx doesn't start in my container running on Windows Server 2019.
Nothing is written to the nginx error.log and inspecting the System Event using this answer doesn't provide any information regarding nginx.
When I run nginx directly on the server (i.e. without the container) it starts up fine.
Here are the contents of the dockerfile:
FROM mcr.microsoft.com/windows/servercore:ltsc2019
WORKDIR C:/nginx
COPY /. ./
CMD ["nginx"]
I run the container using the following command:
docker run -d --rm -p 80:80 --name nginx `
-v C:/Data/_config/nginx/conf:C:/nginx/conf `
-v C:/Data/_config/nginx/temp:C:/nginx/temp `
-v C:/Data/_config/nginx/logs:C:/nginx/logs `
nginx-2019
If I exec into the running container I can see that the directory structure is as expected:
Microsoft Windows [Version 10.0.17763.1040]
(c) 2018 Microsoft Corporation. All rights reserved.
C:\nginx>dir
Volume in drive C has no label.
Volume Serial Number is 72BD-907D
Directory of C:\nginx
02/27/2020 06:05 AM <DIR> .
02/27/2020 06:05 AM <DIR> ..
02/27/2020 06:05 AM <DIR> conf
02/27/2020 05:11 AM <DIR> contrib
02/27/2020 05:11 AM <DIR> docs
02/27/2020 05:11 AM <DIR> html
02/27/2020 05:55 AM <DIR> logs
02/27/2020 05:14 AM <DIR> conf
01/21/2020 03:30 PM 3,712,512 nginx.exe
01/21/2020 04:41 PM <DIR> temp
1 File(s) 3,716,608 bytes
9 Dir(s) 21,206,409,216 bytes free
UPDATE 1:
As part of my troubleshooting process I started up a clean VM on Azure and after installing Docker and recreating the Docker image using the exact same files, it starts up as expected.
This means that the issue is specific to my server and not a general issue.
UPDATE 2:
By removing the --rm from the run command I find the following info by running docker ps -a after the container exits:
Exited (3221225785) 4 seconds ago
I can't find any info on what the exit code means.

Answer 1

I was having the same issue, but for me it wasn't docker or nginx, it was the image.
image mcr.microsoft.com/windows/servercore:ltsc2019 was updated on 2/11/2020 and both container and host must have the same update (KB4532691 I think) or some processes may fail silently.
I updated my host, and all is well.
See microsoft-windows-servercore
and you-might-encounter-issues-when-using-windows-server-containers-with-t for more info