pyt0xic · March 28, 2025 11:40
diff --git a/psql-proxy.sh b/psql-proxy.sh
 #!/usr/bin/env bash
 # This script creates a tunnel to a PostgreSQL database using socat from within a kube pod.
 # Will download socat binary if not found in the system.

 # Configuration variables
 REMOTE_HOST="$DB_HOSTNAME"
 LOCAL_PORT=5432
 REMOTE_PORT=5432
 SOCAT_PATH="$(command -v socat || echo '/tmp/socat')"
 SOCAT_URL="https://github.com/3ndG4me/socat/releases/download/v1.7.3.3/socatx64.bin"

 LONGOPTS="host:,local:,remote:,socat-path:,socat-url:,help"
 OPTIONS="H:l:r:p:u:h"

 set -o errexit -o pipefail -o noclobber -o nounset

 # Function to display usage
 print_usage() {
 	echo "Usage: $0 [OPTIONS]"
 	echo "Create a tunnel to a PostgreSQL database using socat."
 	echo
 	echo "Options:"
 	echo "  -H, --host HOST       Database hostname (required if DB_HOSTNAME not set)"
 	echo "  -l, --local PORT      Local port to listen on (default: 5432)"
 	echo "  -r, --remote PORT     Remote port to connect to (default: 5432)"
 	echo "  -p, --socat-path PATH Path to socat binary (default: \$(command -v socat || echo '/tmp/socat'))"
 	echo "  -u, --socat-url URL   Download URL for socat (default: https://github.com/3ndG4me/socat/releases/download/v1.7.3.3/socatx64.bin)"
 	echo "  -h, --help            Display this help and exit"
 	echo
 	echo "Environment variables:"
 	echo "  DB_HOSTNAME           Database hostname (used if --host not specified)"
 }

 # Function for logging
 log_message() {
 	echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
 }

 cleanup() {
 	log_message "Cleaning up"
 	# Remove $SOCAT_PATH if it is a temporary file and exists
 	[ -f "$SOCAT_PATH" ] && [ "$SOCAT_PATH" = "/tmp/socat" ] && rm -f "$SOCAT_PATH"
 }

 # Error handling function
 handle_error() {
 	log_message "ERROR: $1"
 	# Clean up if needed
 	cleanup
 	# print_usage
 	exit 1
 }

 # Parse args using new getopt from util-linux.
 parse_args() {
 	# ignore errexit with `&& true`
 	getopt --test >/dev/null && true
 	if [[ $? -ne 4 ]]; then
 		die 'Cannot parse args, "getopt --test" failed in this environment.'
 	fi
 	# -temporarily store output to be able to check for errors
 	# -activate quoting/enhanced mode (e.g. by writing out “--options”)
 	# -pass arguments only via   -- "$@"   to separate them correctly
 	# -if getopt fails, it complains itself to stdout
 	PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@") || exit 2
 	# read getopt’s output this way to handle the quoting right:
 	eval set -- "$PARSED"
 	# Extract options and their arguments into variables.
 	while true; do
 		case "$1" in
 		-H | --host)
 			REMOTE_HOST="$2"
 			shift 2
 			;;
 		-l | --local)
 			LOCAL_PORT="$2"
 			shift 2
 			;;
 		-r | --remote)
 			REMOTE_PORT="$2"
 			shift 2
 			;;
 		-p | --socat-path)
 			SOCAT_PATH="$2"
 			shift 2
 			;;
 		-u | --socat-url)
 			SOCAT_URL="$2"
 			shift 2
 			;;
 		-h | --help)
 			print_usage
 			exit 0
 			;;
 		--)
 			shift
 			break
 			;;
 		*)
 			handle_error "Unknown option: $1"
 			;;
 		esac
 	done
 }

 download_socat() {
 	log_message "Downloading socat binary from $SOCAT_URL"
 	curl -L "$SOCAT_URL" -o "$SOCAT_PATH" || handle_error "Failed to download socat"
 	log_message "Making socat binary executable"
 	chmod +x "$SOCAT_PATH" || handle_error "Failed to make socat executable"
 	log_message "Using socat binary at $SOCAT_PATH"
 }

 ensure_socat_installed() {
 	if [ -x "$SOCAT_PATH" ]; then
 		log_message "Using socat binary at $SOCAT_PATH"
 	else
 		download_socat
 	fi
 }

 print_kubectl_port_forward_command() {
 	log_message "To forward the local port to a Kubernetes pod, run the following command:"
 	echo -e "\t\tkubectl port-forward $(hostname) 54320:$LOCAL_PORT\n"
 }

 print_psql_command() {
 	log_message "To connect to the database, run the following command:"
    echo -e "\t\tPGPASSWORD=$DB_PASSWORD psql -h localhost -p 54320 -U $DB_USERNAME $DB_DATABASE\n"
 }

 create_tunnel() {
 	if [ -z "$REMOTE_HOST" ]; then
 		handle_error "Database hostname not specified"
 	fi
 	log_message "Creating tunnel from localhost:$LOCAL_PORT to $REMOTE_HOST:$REMOTE_PORT"
 	print_kubectl_port_forward_command
 	print_psql_command
 	trap 'echo "Tunnel closed"; [ "$SOCAT_PATH" = "/tmp/socat" ] && rm -f "$SOCAT_PATH"; exit 0' INT TERM
 	"$SOCAT_PATH" tcp-listen:"$LOCAL_PORT",fork,reuseaddr tcp-connect:"$REMOTE_HOST":"$REMOTE_PORT" || handle_error "Tunnel failed"
 }

 parse_args "$@"
 ensure_socat_installed && create_tunnel
	#!/usr/bin/env bash
	# This script creates a tunnel to a PostgreSQL database using socat from within a kube pod.
	# Will download socat binary if not found in the system.

	# Configuration variables
	REMOTE_HOST="$DB_HOSTNAME"
	LOCAL_PORT=5432
	REMOTE_PORT=5432
	SOCAT_PATH="$(command -v socat \|\| echo '/tmp/socat')"
	SOCAT_URL="https://github.com/3ndG4me/socat/releases/download/v1.7.3.3/socatx64.bin"

	LONGOPTS="host:,local:,remote:,socat-path:,socat-url:,help"
	OPTIONS="H:l:r:p:u:h"

	set -o errexit -o pipefail -o noclobber -o nounset

	# Function to display usage
	print_usage() {
	echo "Usage: $0 [OPTIONS]"
	echo "Create a tunnel to a PostgreSQL database using socat."
	echo
	echo "Options:"
	echo " -H, --host HOST Database hostname (required if DB_HOSTNAME not set)"
	echo " -l, --local PORT Local port to listen on (default: 5432)"
	echo " -r, --remote PORT Remote port to connect to (default: 5432)"
	echo " -p, --socat-path PATH Path to socat binary (default: \$(command -v socat \|\| echo '/tmp/socat'))"
	echo " -u, --socat-url URL Download URL for socat (default: https://github.com/3ndG4me/socat/releases/download/v1.7.3.3/socatx64.bin)"
	echo " -h, --help Display this help and exit"
	echo
	echo "Environment variables:"
	echo " DB_HOSTNAME Database hostname (used if --host not specified)"
	}

	# Function for logging
	log_message() {
	echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
	}

	cleanup() {
	log_message "Cleaning up"
	# Remove $SOCAT_PATH if it is a temporary file and exists
	[ -f "$SOCAT_PATH" ] && [ "$SOCAT_PATH" = "/tmp/socat" ] && rm -f "$SOCAT_PATH"
	}

	# Error handling function
	handle_error() {
	log_message "ERROR: $1"
	# Clean up if needed
	cleanup
	# print_usage
	exit 1
	}

	# Parse args using new getopt from util-linux.
	parse_args() {
	# ignore errexit with `&& true`
	getopt --test >/dev/null && true
	if [[ $? -ne 4 ]]; then
	die 'Cannot parse args, "getopt --test" failed in this environment.'
	fi
	# -temporarily store output to be able to check for errors
	# -activate quoting/enhanced mode (e.g. by writing out “--options”)
	# -pass arguments only via -- "$@" to separate them correctly
	# -if getopt fails, it complains itself to stdout
	PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@") \|\| exit 2
	# read getopt’s output this way to handle the quoting right:
	eval set -- "$PARSED"
	# Extract options and their arguments into variables.
	while true; do
	case "$1" in
	-H \| --host)
	REMOTE_HOST="$2"
	shift 2
	;;
	-l \| --local)
	LOCAL_PORT="$2"
	shift 2
	;;
	-r \| --remote)
	REMOTE_PORT="$2"
	shift 2
	;;
	-p \| --socat-path)
	SOCAT_PATH="$2"
	shift 2
	;;
	-u \| --socat-url)
	SOCAT_URL="$2"
	shift 2
	;;
	-h \| --help)
	print_usage
	exit 0
	;;
	--)
	shift
	break
	;;
	*)
	handle_error "Unknown option: $1"
	;;
	esac
	done
	}

	download_socat() {
	log_message "Downloading socat binary from $SOCAT_URL"
	curl -L "$SOCAT_URL" -o "$SOCAT_PATH" \|\| handle_error "Failed to download socat"
	log_message "Making socat binary executable"
	chmod +x "$SOCAT_PATH" \|\| handle_error "Failed to make socat executable"
	log_message "Using socat binary at $SOCAT_PATH"
	}

	ensure_socat_installed() {
	if [ -x "$SOCAT_PATH" ]; then
	log_message "Using socat binary at $SOCAT_PATH"
	else
	download_socat
	fi
	}

	print_kubectl_port_forward_command() {
	log_message "To forward the local port to a Kubernetes pod, run the following command:"
	echo -e "\t\tkubectl port-forward $(hostname) 54320:$LOCAL_PORT\n"
	}

	print_psql_command() {
	log_message "To connect to the database, run the following command:"
	echo -e "\t\tPGPASSWORD=$DB_PASSWORD psql -h localhost -p 54320 -U $DB_USERNAME $DB_DATABASE\n"
	}

	create_tunnel() {
	if [ -z "$REMOTE_HOST" ]; then
	handle_error "Database hostname not specified"
	fi
	log_message "Creating tunnel from localhost:$LOCAL_PORT to $REMOTE_HOST:$REMOTE_PORT"
	print_kubectl_port_forward_command
	print_psql_command
	trap 'echo "Tunnel closed"; [ "$SOCAT_PATH" = "/tmp/socat" ] && rm -f "$SOCAT_PATH"; exit 0' INT TERM
	"$SOCAT_PATH" tcp-listen:"$LOCAL_PORT",fork,reuseaddr tcp-connect:"$REMOTE_HOST":"$REMOTE_PORT" \|\| handle_error "Tunnel failed"
	}

	parse_args "$@"
	ensure_socat_installed && create_tunnel