A `docker-compose` wrapper for multiple configuration files with relative paths

docker-compose.sh

#!/usr/bin/env bash

# A `docker-compose` wrapper for multiple configuration files with relative paths.
# Specifically, build contexts are relative to each compose file's location.
#
# > The way multiple compose file get merged together is now defined by the Compose Specification:
# > https://github.com/compose-spec/compose-spec/blob/master/spec.md#compose-file
# >> Relative paths MUST be resolved based on the first Compose file's parent folder,
# >> whenever complimentary files being merged are hosted in other folders.
# See issue https://github.com/docker/compose/issues/3874#issuecomment-1012923100

PROJECT_NAME=$(basename `pwd`)

# Create temp file securely
TMP_FILE=`mktemp /tmp/docker-compose.XXXXXX` || exit 1
mv ${TMP_FILE} ${TMP_FILE}.yml
TMP_FILE=${TMP_FILE}.yml

# Clean up
finish() {
    rm ${TMP_FILE} ${TMP_FILE}.tmp 2>/dev/null
}

trap finish EXIT


# Prepend given file to config in order to keep the file's relative context
compose-config() {
    mv -f ${TMP_FILE} ${TMP_FILE}.tmp
    # Add the file twice: 1st for the context, 2nd for config overrides
    docker compose -p ${PROJECT_NAME} -f ${1} -f ${TMP_FILE}.tmp -f ${1} config > ${TMP_FILE}
    rm -f ${TMP_FILE}.tmp 2>/dev/null
}

# Separate -f/--file arguments from the rest
args=()
files=()

while [ -n "$1" ]; do
    case "$1" in
        -f | --file)
            shift; files+=($1)
            ;;
        *)
            args+=($1)
            ;;
    esac
    shift
done

# Generate config
for f in ${files[@]}; do
    compose-config ${f}
done

# Prepend version
mv -f ${TMP_FILE} ${TMP_FILE}.tmp
echo 'version: "3"' > ${TMP_FILE}
cat ${TMP_FILE}.tmp >> ${TMP_FILE}
rm -f ${TMP_FILE}.tmp 2>/dev/null

echo -e "
FINAL CONFIG
------------
"
docker compose -f ${TMP_FILE} config
docker compose -f ${TMP_FILE} ${args[@]}
exit $?