I am using the .🔨-create-production-image script to build my application container and generate the docker-compose.prod.yml file. However, it seems to me that the quotes (or double-quotes) surrounding the values are removed and do not appear in the generated docker-compose.prod.yml.
This is especially annoying for the “ports” definition. Here is a quote from the compose file reference page:
When mapping ports in the
HOST:CONTAINERformat, you may experience erroneous results when using a container port lower than 60, because YAML parses numbers in the formatxx:yyas a base-60 value. For this reason, we recommend always explicitly specifying your port mappings as strings.
So here is an example. I have a container which needs the port 21 to be exposed:
ftp_server:
image: zhabba/pure-ftpd-arm64
container_name: ftp_admin
ports:
- "21:21"
- "30000-30009:30000-30009"
Once the .🔨-create-production-image script has been executed, the docker-compose.prod.yml file looks like this:
ftp_server:
image: zhabba/pure-ftpd-arm64
container_name: ftp_admin
ports:
- 21:21
- 30000-30009:30000-30009
Finally, when running this on my board, I cannot access the FTP server. A docker container inspect ftp_admin reveals the following:
[
{
[...]
"HostConfig": {
[...]
"PortBindings": {
"1281/tcp": [
{
"HostIp": "",
"HostPort": ""
}
],
"30000/tcp": [
{
"HostIp": "",
"HostPort": "30000"
}
],
[...]
The port 21 disappeared and was replaced by the port 1281… which exactly corresponds to “21:21” interpreted as a base-60 value.
I temporarily fixed the issue by manually adding the quotes around 21:21 in the docker-compose.prod.yml file, but I know I will someday forget to do it… Is there another way to fix it?
I have been browsing the community for a while, but I still hope this is no duplicate…