Accept the `?`, `:?`, `+` and `:+` interpolation operators in Compose
network names, such as `${CONTAINER_NAME?error}`. The validation added
in v4.4.0 only knew `-` and `:-`, so these valid files stopped deploying.
The text after `?` is an error message and is not used as the default of
the created environment variable. Unsafe operands are still rejected.
Fixes#12126
A Docker Compose application could use ${VAR} as a network name, but
only services created the variable. With ${VAR:-default} the value was
hidden and could not be edited; with ${VAR} Compose got an empty name
and the deployment failed. Applications now get the variable (and its
preview copy) with the default from the compose file, like services.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Andras BacsaiandClaude Opus 5.5