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| 1 | +#!/usr/bin/env bash |
| 2 | +# Use this script to test if a given TCP host/port are available |
| 3 | + |
| 4 | +cmdname=$(basename $0) |
| 5 | + |
| 6 | +echoerr() { if [[ $QUIET -ne 1 ]]; then echo "$@" 1>&2; fi } |
| 7 | + |
| 8 | +usage() |
| 9 | +{ |
| 10 | + cat << USAGE >&2 |
| 11 | +Usage: |
| 12 | + $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 [[ $TIMEOUT -gt 0 ]]; then |
| 28 | + echoerr "$cmdname: waiting $TIMEOUT seconds for $HOST:$PORT" |
| 29 | + else |
| 30 | + echoerr "$cmdname: waiting for $HOST:$PORT without a timeout" |
| 31 | + fi |
| 32 | + start_ts=$(date +%s) |
| 33 | + while : |
| 34 | + do |
| 35 | + if [[ $ISBUSY -eq 1 ]]; then |
| 36 | + nc -z $HOST $PORT |
| 37 | + result=$? |
| 38 | + else |
| 39 | + (echo > /dev/tcp/$HOST/$PORT) >/dev/null 2>&1 |
| 40 | + result=$? |
| 41 | + fi |
| 42 | + if [[ $result -eq 0 ]]; then |
| 43 | + end_ts=$(date +%s) |
| 44 | + echoerr "$cmdname: $HOST:$PORT is available after $((end_ts - start_ts)) seconds" |
| 45 | + break |
| 46 | + fi |
| 47 | + sleep 1 |
| 48 | + done |
| 49 | + return $result |
| 50 | +} |
| 51 | + |
| 52 | +wait_for_wrapper() |
| 53 | +{ |
| 54 | + # In order to support SIGINT during timeout: http://unix.stackexchange.com/a/57692 |
| 55 | + if [[ $QUIET -eq 1 ]]; then |
| 56 | + timeout $BUSYTIMEFLAG $TIMEOUT $0 --quiet --child --host=$HOST --port=$PORT --timeout=$TIMEOUT & |
| 57 | + else |
| 58 | + timeout $BUSYTIMEFLAG $TIMEOUT $0 --child --host=$HOST --port=$PORT --timeout=$TIMEOUT & |
| 59 | + fi |
| 60 | + PID=$! |
| 61 | + trap "kill -INT -$PID" INT |
| 62 | + wait $PID |
| 63 | + RESULT=$? |
| 64 | + if [[ $RESULT -ne 0 ]]; then |
| 65 | + echoerr "$cmdname: timeout occurred after waiting $TIMEOUT seconds for $HOST:$PORT" |
| 66 | + fi |
| 67 | + return $RESULT |
| 68 | +} |
| 69 | + |
| 70 | +# process arguments |
| 71 | +while [[ $# -gt 0 ]] |
| 72 | +do |
| 73 | + case "$1" in |
| 74 | + *:* ) |
| 75 | + hostport=(${1//:/ }) |
| 76 | + HOST=${hostport[0]} |
| 77 | + PORT=${hostport[1]} |
| 78 | + shift 1 |
| 79 | + ;; |
| 80 | + --child) |
| 81 | + CHILD=1 |
| 82 | + shift 1 |
| 83 | + ;; |
| 84 | + -q | --quiet) |
| 85 | + QUIET=1 |
| 86 | + shift 1 |
| 87 | + ;; |
| 88 | + -s | --strict) |
| 89 | + STRICT=1 |
| 90 | + shift 1 |
| 91 | + ;; |
| 92 | + -h) |
| 93 | + HOST="$2" |
| 94 | + if [[ $HOST == "" ]]; then break; fi |
| 95 | + shift 2 |
| 96 | + ;; |
| 97 | + --host=*) |
| 98 | + HOST="${1#*=}" |
| 99 | + shift 1 |
| 100 | + ;; |
| 101 | + -p) |
| 102 | + PORT="$2" |
| 103 | + if [[ $PORT == "" ]]; then break; fi |
| 104 | + shift 2 |
| 105 | + ;; |
| 106 | + --port=*) |
| 107 | + PORT="${1#*=}" |
| 108 | + shift 1 |
| 109 | + ;; |
| 110 | + -t) |
| 111 | + TIMEOUT="$2" |
| 112 | + if [[ $TIMEOUT == "" ]]; then break; fi |
| 113 | + shift 2 |
| 114 | + ;; |
| 115 | + --timeout=*) |
| 116 | + TIMEOUT="${1#*=}" |
| 117 | + shift 1 |
| 118 | + ;; |
| 119 | + --) |
| 120 | + shift |
| 121 | + CLI=("$@") |
| 122 | + break |
| 123 | + ;; |
| 124 | + --help) |
| 125 | + usage |
| 126 | + ;; |
| 127 | + *) |
| 128 | + echoerr "Unknown argument: $1" |
| 129 | + usage |
| 130 | + ;; |
| 131 | + esac |
| 132 | +done |
| 133 | + |
| 134 | +if [[ "$HOST" == "" || "$PORT" == "" ]]; then |
| 135 | + echoerr "Error: you need to provide a host and port to test." |
| 136 | + usage |
| 137 | +fi |
| 138 | + |
| 139 | +TIMEOUT=${TIMEOUT:-15} |
| 140 | +STRICT=${STRICT:-0} |
| 141 | +CHILD=${CHILD:-0} |
| 142 | +QUIET=${QUIET:-0} |
| 143 | + |
| 144 | +# check to see if timeout is from busybox? |
| 145 | +# check to see if timeout is from busybox? |
| 146 | +TIMEOUT_PATH=$(realpath $(which timeout)) |
| 147 | +if [[ $TIMEOUT_PATH =~ "busybox" ]]; then |
| 148 | + ISBUSY=1 |
| 149 | + BUSYTIMEFLAG="-t" |
| 150 | +else |
| 151 | + ISBUSY=0 |
| 152 | + BUSYTIMEFLAG="" |
| 153 | +fi |
| 154 | + |
| 155 | +if [[ $CHILD -gt 0 ]]; then |
| 156 | + wait_for |
| 157 | + RESULT=$? |
| 158 | + exit $RESULT |
| 159 | +else |
| 160 | + if [[ $TIMEOUT -gt 0 ]]; then |
| 161 | + wait_for_wrapper |
| 162 | + RESULT=$? |
| 163 | + else |
| 164 | + wait_for |
| 165 | + RESULT=$? |
| 166 | + fi |
| 167 | +fi |
| 168 | + |
| 169 | +if [[ $CLI != "" ]]; then |
| 170 | + if [[ $RESULT -ne 0 && $STRICT -eq 1 ]]; then |
| 171 | + echoerr "$cmdname: strict mode, refusing to execute subprocess" |
| 172 | + exit $RESULT |
| 173 | + fi |
| 174 | + exec "${CLI[@]}" |
| 175 | +else |
| 176 | + exit $RESULT |
| 177 | +fi |
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