1#!/usr/bin/env bash
2# Use this script to test if a given TCP host/port are available
3
4WAITFORIT_cmdname=${0##*/}
5
6echoerr() { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo "$@" 1>&2; fi }
7
8usage()
9{
10 cat << USAGE >&2
11Usage:
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
21USAGE
22 exit 1
23}
24
25wait_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 > /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)) seconds"
45 break
46 fi
47 sleep 1
48 done
49 return $WAITFORIT_result
50}
51
52wait_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" INT
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
71while [[ $# -gt 0 ]]
72do
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: $1"
129 usage
130 ;;
131 esac
132done
133
134if [[ "$WAITFORIT_HOST" == "" || "$WAITFORIT_PORT" == "" ]]; then
135 echoerr "Error: you need to provide a host and port to test."
136 usage
137fi
138
139WAITFORIT_TIMEOUT=${WAITFORIT_TIMEOUT:-15}
140WAITFORIT_STRICT=${WAITFORIT_STRICT:-0}
141WAITFORIT_CHILD=${WAITFORIT_CHILD:-0}
142WAITFORIT_QUIET=${WAITFORIT_QUIET:-0}
143
144# Check to see if timeout is from busybox?
145WAITFORIT_TIMEOUT_PATH=$(type -p timeout)
146WAITFORIT_TIMEOUT_PATH=$(realpath $WAITFORIT_TIMEOUT_PATH 2>/dev/null || readlink -f $WAITFORIT_TIMEOUT_PATH)
147
148WAITFORIT_BUSYTIMEFLAG=""
149if [[ $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
156else
157 WAITFORIT_ISBUSY=0
158fi
159
160if [[ $WAITFORIT_CHILD -gt 0 ]]; then
161 wait_for
162 WAITFORIT_RESULT=$?
163 exit $WAITFORIT_RESULT
164else
165 if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
166 wait_for_wrapper
167 WAITFORIT_RESULT=$?
168 else
169 wait_for
170 WAITFORIT_RESULT=$?
171 fi
172fi
173
174if [[ $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[@]}"
180else
181 exit $WAITFORIT_RESULT
182fiView as plain text