Expose a Docker-based Postgres database to localhost

dbproxy.sh

#!/usr/bin/env bash
#
# Start a reverse proxy for the Postgres DB,
# exposing port 5432 locally.
#
# To use this, on your local machine, run:
#
# ssh -t -L 5432:localhost:5432 username@hostname 'cd $HOME/path/to/folder/ && ./dbproxy.sh'

set -e

SERVICE="database"
CONTAINER=$(docker compose ps -q "$SERVICE")
NET_NAME=$(docker inspect --format '{{.HostConfig.NetworkMode}}' "$CONTAINER")
ALIAS=$(docker inspect --format '{{index .NetworkSettings.Networks "'$NET_NAME'" "Aliases" 0}}' "$CONTAINER")
LOCALPORT="5432"
PROXY_NAME=dbproxy

echo "Exposing $SERVICE on localhost:$LOCALPORT"

docker ps -q --filter "name=$PROXY_NAME" | grep -q . && docker stop "$PROXY_NAME"

docker run \
    --rm \
    --name "$PROXY_NAME" \
    --net "$NET_NAME" \
    --publish "$LOCALPORT:1234" \
    alpine/socat TCP-LISTEN:1234,fork "TCP-CONNECT:$ALIAS:$LOCALPORT" &

pid=$!

echo "Ready! Press Ctrl-C to close."

trap "kill $pid" INT HUP
wait $pid