unitc - a curl wrapper for configuring NGINX Unit

README.md

unitc

A curl wrapper for configuring NGINX Unit

Just provide the configuration URI (e.g. /config/routes) and unitc will find the control socket to construct the full address in curl syntax.

USAGE: unitc [HTTP method] [--quiet] URI

Providing a JSON configuration on stdin will use the PUT method unless a specific method is specified. Otherwise a GET is used to read the configuration. HTTP methods can be specified in lower case. jq is used to prettify the output, if available.

When making changes, the error log is monitored and new log entries are shown.

Examples:

unitc /config
unitc /control/applications/my_app/restart
echo '{"*:8080": {"pass": "routes"}}' | unitc /config/listeners
unitc /config < unitconf.json
unitc delete /config/routes

unitc

#!/bin/bash
# unitc - a curl wrapper for configuring NGINX Unit
# [v1.3 30-Jul-2022] Liam Crilly <liam@nginx.com>
#
# CHANGELOG
# v1.3 Bug fixes and improved error handling
# v1.2 Accepts lower-case HTTP methods, simpler/portable cache format
# v1.1 Uses jq(1) if available for prettified output, added --help
# v1.0 Initial version with socket detection and log monitoring
#
# TODO
# - Iteratively scan for new log entries
# - Optionally provide JSON config as filename on command line

# Defaults
#
QUIET=0
METHOD=PUT
SHOW_LOG=1

while [ $# -gt 1 ]; do
	OPTION=`echo $1 | tr '[a-z]' '[A-Z]'`
	case $OPTION in
		"-H" | "--HELP")
			shift
			;;

		"-Q" | "--QUIET")
			QUIET=1
			shift
			;;

		"GET" | "PUT" | "POST" | "DELETE")
			METHOD=$OPTION
			shift
			;;

		"HEAD" | "PATCH" | "PURGE" | "OPTIONS")
			echo "${0##*/}: ERROR: Invalid HTTP method ($OPTION)"
			exit 1
			;;

		*)
			echo "${0##*/}: ERROR: Invalid option ($1)"
			exit 1
			;;
	esac
done

if [ $# -lt 1 ] || [ "${1:0:1}" = "-" ]; then
	echo "USAGE: ${0##*/} [HTTP method] [--quiet] URI"
        echo " - Configuration JSON is read from stdin"
        echo " - Default method is PUT with stdin, else GET"
        echo " - The control socket is automatically detected"
	exit 1
fi

if [ "${1:0:1}" != "/" ]; then
    echo "${0##*/}: ERROR: Invalid configuration URI"
    exit 1
fi

# Check if Unit is running, find the main process
#
PID=(`ps ax | grep unit:\ main | grep -v \ grep | awk '{print $1}'`)
if [ ${#PID[@]} -eq 0 ]; then
	echo "${0##*/}: ERROR: unitd not running"
	exit 1
elif [ ${#PID[@]} -gt 1 ]; then
	echo "${0##*/}: ERROR: multiple unitd processes detected (${PID[@]})"
	exit 1
fi

# Read the significant unitd conifuration from cache file (or create it)
#
if [[ -f /tmp/${0##*/}.$PID ]]; then
	source /tmp/${0##*/}.$PID
else
	PARAMS=`ps -p $PID | grep unitd | cut -f2- -dv | tr '[]' ' ' | cut -f4- -d ' ' | sed -e 's/ --/\n--/g'`

	# Get control address
	#
	CTRL_ADDR=`echo "$PARAMS" | grep '\--control' | cut -f2 -d' '`
	if [ "$CTRL_ADDR" = "" ]; then
		CTRL_ADDR=`unitd --help | grep -A1 '\--control' | tail -1 |  cut -f2 -d\"`
	fi

	# Prepare for network or Unix socket addressing
	#
	if [ `echo $CTRL_ADDR | grep -c ^unix:` -eq 1 ]; then
		CURL_ADDR="--unix-socket `echo $CTRL_ADDR | cut -f2- -d:` _"
	else
		CURL_ADDR="http://$CTRL_ADDR"
	fi

	# Get error log filename
	#
	ERROR_LOG=`echo "$PARAMS" | grep '\--log' | cut -f2 -d' '`
	if [ "$ERROR_LOG" = "" ]; then
		ERROR_LOG=`unitd --help | grep -A1 '\--log' | tail -1 | cut -f2 -d\"`
	fi

	# Cache the discovery for this unit PID (and cleanup any old files)
	#
	rm /tmp/${0##*/}.* 2> /dev/null
	echo CURL_ADDR=\"${CURL_ADDR}\" > /tmp/${0##*/}.$PID
	echo ERROR_LOG=${ERROR_LOG} >> /tmp/${0##*/}.$PID
fi

# Test for jq
#
if hash jq 2> /dev/null; then
	PRETTY="jq"
else
	PRETTY="cat"
fi

# Get current length of error log before we make any changes
#
if [ -f $ERROR_LOG ]; then
	LOG_LEN=`wc -l < $ERROR_LOG`
else
	QUIET=1
fi

# Adjust HTTP method and curl params based on presence of stdin payload
#
if [ -t 0 ]; then
	if [ "$METHOD" = "DELETE" ]; then
		curl -s -X $METHOD $CURL_ADDR$1 | $PRETTY
	else
		SHOW_LOG=0
		curl -s $CURL_ADDR$1 | $PRETTY
	fi
else
	echo "$(cat)" | curl -s -X $METHOD --data-binary @- $CURL_ADDR$1 | $PRETTY
fi
if [ ${PIPESTATUS[0]} -ne 0 ]; then
	echo "${0##*/}: ERROR: curl exited with an error"
fi

if [[ $SHOW_LOG -gt 0 && $QUIET -eq 0 ]]; then
	echo -n "${0##*/}: Waiting for log..."
	sleep $SHOW_LOG
	echo ""
	sed -n $((LOG_LEN+1)),\$p $ERROR_LOG
fi

# vim: syntax=bash