Hello,
I am using docker and docker-compose now quite for some time. Recently I had a strange behavior and I cannot understand what it is all about.
I had a minimalistic docker-compose.yml file with a single container configured. This container was built from a subdirectory and running, sharing some ports and some mounts. All right so far.
I have then changed something within the build environment and thus triggered the build. A few seconds later, the new image was finished. Normally, I am used to just do a docker-compose up -d in order to recreate the container with the shiny new image.
In my case the following error
Recreating nginx-live-stream_nginx_1 ... error
ERROR: for nginx-live-stream_nginx_1 Cannot start service nginx: driver failed programming external connectivity on endpoint nginx-live-stream_nginx_1 (1218f72816a19b9ab1ee4656f9845d6f2d60106c1176238515066cebf19cbde7): Bind for 127.0.0.1:1935 failed: port is already allocated
ERROR: for nginx Cannot start service nginx: driver failed programming external connectivity on endpoint nginx-live-stream_nginx_1 (1218f72816a19b9ab1ee4656f9845d6f2d60106c1176238515066cebf19cbde7): Bind for 127.0.0.1:1935 failed: port is already allocated
ERROR: Encountered errors while bringing up the project.
The named port 1935 is in fact intended to be used by the container. When looking at the list of the containers, I am stunned:
# docker-compose ps
Name Command State Ports
---------------------------------------------------------------------------------------------------------------------------------------------------------
afb1a1c2e6f3_nginx-live-stream_nginx_1 nginx -g daemon off; Up 127.0.0.1:1935->1935/tcp, 0.0.0.0:445->443/tcp, 127.0.0.1:81->80/tcp
nginx-live-stream_nginx_1 nginx -g daemon off; Exit 128
Looking at the corresponding output of docker ps reveals that the container afb1a1c2e6f3_nginx-live-stream_nginx_1 seems to be a clone of the original container. I suspect the original container had the id afb1a1c2e6f3 but I no longer can check this.
I tried to get rid of the container using docker stop, docker rm and docker kill. Nothing happens here. The container just sits there, immutable, and takes up the port I need. My last resort was to restart the complete docker service using systemctl restart docker.service. This finally allowed me to remove the container.
Can anyone explain to me what is going on here?
# docker --version
Docker version 19.03.15, build 99e3ed8919
# docker-compose --version
docker-compose version 1.21.0, build unknown