1+ #! /usr/bin/env bash
2+ # Use this script to test if a given TCP host/port are available
3+
4+ WAITFORIT_cmdname=${0##*/ }
5+
6+ echoerr () { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo " $@ " 1>&2 ; fi }
7+
8+ usage ()
9+ {
10+ cat << USAGE >&2
11+ Usage:
12+ $WAITFORIT_cmdname host:port [-s] [-t timeout] [-- command args]
13+ -h HOST | --host=HOST Host or IP under test
14+ -p PORT | --port=PORT TCP port under test
15+ Alternatively, you specify the host and port as host:port
16+ -s | --strict Only execute subcommand if the test succeeds
17+ -q | --quiet Don't output any status messages
18+ -t TIMEOUT | --timeout=TIMEOUT
19+ Timeout in seconds, zero for no timeout
20+ -- COMMAND ARGS Execute command with args after the test finishes
21+ USAGE
22+ exit 1
23+ }
24+
25+ wait_for ()
26+ {
27+ if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
28+ echoerr " $WAITFORIT_cmdname : waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST :$WAITFORIT_PORT "
29+ else
30+ echoerr " $WAITFORIT_cmdname : waiting for $WAITFORIT_HOST :$WAITFORIT_PORT without a timeout"
31+ fi
32+ WAITFORIT_start_ts=$( date +%s)
33+ while :
34+ do
35+ if [[ $WAITFORIT_ISBUSY -eq 1 ]]; then
36+ nc -z $WAITFORIT_HOST $WAITFORIT_PORT
37+ WAITFORIT_result=$?
38+ else
39+ (echo -n > /dev/tcp/$WAITFORIT_HOST /$WAITFORIT_PORT ) > /dev/null 2>&1
40+ WAITFORIT_result=$?
41+ fi
42+ if [[ $WAITFORIT_result -eq 0 ]]; then
43+ WAITFORIT_end_ts=$( date +%s)
44+ echoerr " $WAITFORIT_cmdname : $WAITFORIT_HOST :$WAITFORIT_PORT is available after $(( WAITFORIT_end_ts - WAITFORIT_start_ts)) "
45+ break
46+ fi
47+ sleep 1
48+ done
49+ return $WAITFORIT_result
50+ }
51+
52+ wait_for_wrapper ()
53+ {
54+ # In order to support SIGINT during timeout: http://unix.stackexchange.com/a/57692
55+ if [[ $WAITFORIT_QUIET -eq 1 ]]; then
56+ timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --quiet --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
57+ else
58+ timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
59+ fi
60+ WAITFORIT_PID=$!
61+ trap " kill -INT -$WAITFORIT_PID "
62+ wait $WAITFORIT_PID
63+ WAITFORIT_RESULT=$?
64+ if [[ $WAITFORIT_RESULT -ne 0 ]]; then
65+ echoerr " $WAITFORIT_cmdname : timeout occurred after waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST :$WAITFORIT_PORT "
66+ fi
67+ return $WAITFORIT_RESULT
68+ }
69+
70+ # process arguments
71+ while [[ $# -gt 0 ]]
72+ do
73+ case " $1 " in
74+ * :* )
75+ WAITFORIT_hostport=(${1//:/ } )
76+ WAITFORIT_HOST=${WAITFORIT_hostport[0]}
77+ WAITFORIT_PORT=${WAITFORIT_hostport[1]}
78+ shift 1
79+ ;;
80+ --child)
81+ WAITFORIT_CHILD=1
82+ shift 1
83+ ;;
84+ -q | --quiet)
85+ WAITFORIT_QUIET=1
86+ shift 1
87+ ;;
88+ -s | --strict)
89+ WAITFORIT_STRICT=1
90+ shift 1
91+ ;;
92+ -h)
93+ WAITFORIT_HOST=" $2 "
94+ if [[ $WAITFORIT_HOST == " " ; then break ; fi
95+ shift 2
96+ ;;
97+ --host=* )
98+ WAITFORIT_HOST=" ${1#* =} "
99+ shift 1
100+ ;;
101+ -p)
102+ WAITFORIT_PORT=" $2 "
103+ if [[ $WAITFORIT_PORT == " " ; then break ; fi
104+ shift 2
105+ ;;
106+ --port=* )
107+ WAITFORIT_PORT=" ${1#* =} "
108+ shift 1
109+ ;;
110+ -t)
111+ WAITFORIT_TIMEOUT=" $2 "
112+ if [[ $WAITFORIT_TIMEOUT == " " ; then break ; fi
113+ shift 2
114+ ;;
115+ --timeout=* )
116+ WAITFORIT_TIMEOUT=" ${1#* =} "
117+ shift 1
118+ ;;
119+ --)
120+ shift
121+ WAITFORIT_CLI=(" $@ "
122+ break
123+ ;;
124+ --help)
125+ usage
126+ ;;
127+ * )
128+ echoerr " Unknown argument: $1 "
129+ usage
130+ ;;
131+ esac
132+ done
133+
134+ if [[ " $WAITFORIT_HOST " == " " || " $WAITFORIT_PORT " == " " ; then
135+ echoerr " Error: you need to provide a host and port to test."
136+ usage
137+ fi
138+
139+ WAITFORIT_TIMEOUT=${WAITFORIT_TIMEOUT:- 15}
140+ WAITFORIT_STRICT=${WAITFORIT_STRICT:- 0}
141+ WAITFORIT_CHILD=${WAITFORIT_CHILD:- 0}
142+ WAITFORIT_QUIET=${WAITFORIT_QUIET:- 0}
143+
144+ # Check to see if timeout is from busybox?
145+ WAITFORIT_TIMEOUT_PATH=$( type -p timeout)
146+ WAITFORIT_TIMEOUT_PATH=$( realpath $WAITFORIT_TIMEOUT_PATH 2> /dev/null || readlink -f $WAITFORIT_TIMEOUT_PATH )
147+
148+ WAITFORIT_BUSYTIMEFLAG=" "
149+ if [[ $WAITFORIT_TIMEOUT_PATH =~ " busybox" ; then
150+ WAITFORIT_ISBUSY=1
151+ # Check if busybox timeout uses -t flag
152+ # (recent Alpine versions don't support -t anymore)
153+ if timeout & > /dev/stdout | grep -q -e ' -t ' ; then
154+ WAITFORIT_BUSYTIMEFLAG=" -t"
155+ fi
156+ else
157+ WAITFORIT_ISBUSY=0
158+ fi
159+
160+ if [[ $WAITFORIT_CHILD -gt 0 ]]; then
161+ wait_for
162+ WAITFORIT_RESULT=$?
163+ exit $WAITFORIT_RESULT
164+ else
165+ if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
166+ wait_for_wrapper
167+ WAITFORIT_RESULT=$?
168+ else
169+ wait_for
170+ WAITFORIT_RESULT=$?
171+ fi
172+ fi
173+
174+ if [[ $WAITFORIT_CLI != " " ; then
175+ if [[ $WAITFORIT_RESULT -ne 0 && $WAITFORIT_STRICT -eq 1 ]]; then
176+ echoerr " $WAITFORIT_cmdname : strict mode, refusing to execute subprocess"
177+ exit $WAITFORIT_RESULT
178+ fi
179+ exec " ${WAITFORIT_CLI[@]} "
180+ else
181+ exit $WAITFORIT_RESULT
182+ fi
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