A shell script to wrap `podman-compose config` command to make paths in output absolute

podma-compose-devcontainer-wrapper

#!/bin/sh 
#
# podman-compose wrapper to make relative paths in output of `config` command absolute.
# Currently only paths in build.context and volumes are converted.
#

# path to the podman-compose executable to wrap
PODMAN_COMPOSE="/usr/bin/podman-compose"

COMMAND=""
COMPOSE_FILES=""

# parse command line arguments to determine which command is specified
parse_args () {
  while [ $# -gt 0 ]
  do
    case "$1" in
      -h|--help) COMMAND="help";;
      -f)
        COMPOSE_FILES="${COMPOSE_FILES}$2;"
        shift
        ;;
      help|version|wait|systemd|pull|push|build|up|down|ps|run|exec|start|stop|restart|logs|config|port|pause|unpause|kill)
        COMMAND="$1";;
    esac
    if [ "$COMMAND" ]; then
      break
    fi
    shift
  done
}

# function to test "$1" starts with "$2" or not
starts_with () {
  string="$1"
  char="$2"
  test "${string#"$char"}" != "${string}"
}

parse_args "$@"

if [ "$COMMAND" != config ]; then
  exec "$PODMAN_COMPOSE" "$@"
fi

if [ "$COMPOSE_FILES" ]; then
  # Use the location of the first file as the base directory, because docker-compose behaves this way.
  BASE_FILE="${COMPOSE_FILES%%;*}"
  if ! starts_with "$BASE_FILE" /; then
    BASE_FILE="$PWD/$BASE_FILE"
    BASE_FILE="$(realpath "$BASE_FILE")"
  fi
  BASE_DIR="$(dirname "$BASE_FILE")"
else
  BASE_DIR="$PWD"
fi

# echo '"." is '"$BASE_DIR" >&2

OUTPUT="$("$PODMAN_COMPOSE" "$@")"
RC=$?

if [ $RC -ne 0 ] && [ "$OUTPUT" ]; then
  echo "$OUTPUT"
  exit $RC
fi

IFS="
"

echo "$OUTPUT" | while read -r line
  do
    case $line in
      *" context:"*)
        path="$BASE_DIR/$(echo "$line" | sed 's/^.*: *//')"
        echo "context directory is $path" >&2
        line="${line%%:*}: $(realpath "$path")"
        ;;
      *" volumes:") in_volumes=1;;
      *" - "*)
        if [ "$in_volumes" -eq 1 ]; then
          volume="${line#*- }"
          local_path="${volume%%:*}"
          other="${volume#*:}"
          if [ "${local_path#.}" != "$local_path" ]; then
            local_path=$(realpath "$BASE_DIR/$local_path")
            line="${line%% - *} - $local_path:$other"
          fi
        fi
        ;;
      *) in_volumes=0;;
    esac
    echo "$line"  
  done