fix wait-for-it.sh

docker/wait-for-it.sh

@@ -1,15 +1,22 @@
-#!/usr/bin/env bash
-# Use this script to test if a given TCP host/port are available
+#!/usr/bin/env sh
+#   Use this script to test if a given TCP host/port are available
 
-WAITFORIT_cmdname=${0##*/}
+set -e
 
-echoerr() { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo "$@" 1>&2; fi }
+cmdname=$(basename "$0")
+
+echoerr() {
+    if [ "$QUIET" -ne 1 ]; then
+        printf "%s\n" "$*" 1>&2;
+    fi
+}
 
 usage()
 {
+    exitcode="$1"
     cat << USAGE >&2
 Usage:
-    $WAITFORIT_cmdname host:port [-s] [-t timeout] [-- command args]
+    $cmdname host:port [-s] [-t timeout] [-- command args]
     -h HOST | --host=HOST       Host or IP under test
     -p PORT | --port=PORT       TCP port under test
                                 Alternatively, you specify the host and port as host:port
@@ -19,164 +26,140 @@ Usage:
                                 Timeout in seconds, zero for no timeout
     -- COMMAND ARGS             Execute command with args after the test finishes
 USAGE
-    exit 1
+    exit "$exitcode"
 }
 
 wait_for()
 {
-    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
-        echoerr "$WAITFORIT_cmdname: waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
+    if [ "$TIMEOUT" -gt 0 ]; then
+        echoerr "$cmdname: waiting $TIMEOUT seconds for $HOST:$PORT"
     else
-        echoerr "$WAITFORIT_cmdname: waiting for $WAITFORIT_HOST:$WAITFORIT_PORT without a timeout"
+        echoerr "$cmdname: waiting for $HOST:$PORT without a timeout"
     fi
-    WAITFORIT_start_ts=$(date +%s)
-    while :
+    start_ts=$(date +%s)
+    while true
     do
-        if [[ $WAITFORIT_ISBUSY -eq 1 ]]; then
-            nc -z $WAITFORIT_HOST $WAITFORIT_PORT
-            WAITFORIT_result=$?
-        else
-            (echo > /dev/tcp/$WAITFORIT_HOST/$WAITFORIT_PORT) >/dev/null 2>&1
-            WAITFORIT_result=$?
-        fi
-        if [[ $WAITFORIT_result -eq 0 ]]; then
-            WAITFORIT_end_ts=$(date +%s)
-            echoerr "$WAITFORIT_cmdname: $WAITFORIT_HOST:$WAITFORIT_PORT is available after $((WAITFORIT_end_ts - WAITFORIT_start_ts)) seconds"
+        nc -z "$HOST" "$PORT" >/dev/null 2>&1
+        result=$?
+        if [ $result -eq 0 ]; then
+            end_ts=$(date +%s)
+            echoerr "$cmdname: $HOST:$PORT is available after $((end_ts - start_ts)) seconds"
             break
         fi
         sleep 1
     done
-    return $WAITFORIT_result
+    return $result
 }
 
 wait_for_wrapper()
 {
     # In order to support SIGINT during timeout: http://unix.stackexchange.com/a/57692
-    if [[ $WAITFORIT_QUIET -eq 1 ]]; then
-        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --quiet --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
+    if [ "$QUIET" -eq 1 ]; then
+        timeout -t "$TIMEOUT" "$0" -q -child "$HOST":"$PORT" -t "$TIMEOUT" &
     else
-        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
+        timeout -t "$TIMEOUT" "$0" --child "$HOST":"$PORT" -t "$TIMEOUT" &
     fi
-    WAITFORIT_PID=$!
-    trap "kill -INT -$WAITFORIT_PID" INT
-    wait $WAITFORIT_PID
-    WAITFORIT_RESULT=$?
-    if [[ $WAITFORIT_RESULT -ne 0 ]]; then
-        echoerr "$WAITFORIT_cmdname: timeout occurred after waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
+    PID=$!
+    trap 'kill -INT -$PID' INT
+    wait $PID
+    RESULT=$?
+    if [ $RESULT -ne 0 ]; then
+        echoerr "$cmdname: timeout occurred after waiting $TIMEOUT seconds for $HOST:$PORT"
     fi
-    return $WAITFORIT_RESULT
+    return $RESULT
 }
 
+TIMEOUT=15
+STRICT=0
+CHILD=0
+QUIET=0
 # process arguments
-while [[ $# -gt 0 ]]
+while [ $# -gt 0 ]
 do
     case "$1" in
         *:* )
-        WAITFORIT_hostport=(${1//:/ })
-        WAITFORIT_HOST=${WAITFORIT_hostport[0]}
-        WAITFORIT_PORT=${WAITFORIT_hostport[1]}
+        HOST=$(printf "%s\n" "$1"| cut -d : -f 1)
+        PORT=$(printf "%s\n" "$1"| cut -d : -f 2)
         shift 1
         ;;
         --child)
-        WAITFORIT_CHILD=1
+        CHILD=1
         shift 1
         ;;
         -q | --quiet)
-        WAITFORIT_QUIET=1
+        QUIET=1
         shift 1
         ;;
         -s | --strict)
-        WAITFORIT_STRICT=1
+        STRICT=1
         shift 1
         ;;
         -h)
-        WAITFORIT_HOST="$2"
-        if [[ $WAITFORIT_HOST == "" ]]; then break; fi
+        HOST="$2"
+        if [ "$HOST" = "" ]; then break; fi
         shift 2
         ;;
         --host=*)
-        WAITFORIT_HOST="${1#*=}"
+        HOST=$(printf "%s" "$1" | cut -d = -f 2)
         shift 1
         ;;
         -p)
-        WAITFORIT_PORT="$2"
-        if [[ $WAITFORIT_PORT == "" ]]; then break; fi
+        PORT="$2"
+        if [ "$PORT" = "" ]; then break; fi
         shift 2
         ;;
         --port=*)
-        WAITFORIT_PORT="${1#*=}"
+        PORT="${1#*=}"
         shift 1
         ;;
         -t)
-        WAITFORIT_TIMEOUT="$2"
-        if [[ $WAITFORIT_TIMEOUT == "" ]]; then break; fi
+        TIMEOUT="$2"
+        if [ "$TIMEOUT" = "" ]; then break; fi
         shift 2
         ;;
         --timeout=*)
-        WAITFORIT_TIMEOUT="${1#*=}"
+        TIMEOUT="${1#*=}"
         shift 1
         ;;
         --)
         shift
-        WAITFORIT_CLI=("$@")
         break
         ;;
         --help)
-        usage
+        usage 0
         ;;
         *)
         echoerr "Unknown argument: $1"
-        usage
+        usage 1
         ;;
     esac
 done
 
-if [[ "$WAITFORIT_HOST" == "" || "$WAITFORIT_PORT" == "" ]]; then
+if [ "$HOST" = "" -o "$PORT" = "" ]; then
     echoerr "Error: you need to provide a host and port to test."
-    usage
+    usage 2
 fi
 
-WAITFORIT_TIMEOUT=${WAITFORIT_TIMEOUT:-15}
-WAITFORIT_STRICT=${WAITFORIT_STRICT:-0}
-WAITFORIT_CHILD=${WAITFORIT_CHILD:-0}
-WAITFORIT_QUIET=${WAITFORIT_QUIET:-0}
-
-# Check to see if timeout is from busybox?
-WAITFORIT_TIMEOUT_PATH=$(type -p timeout)
-WAITFORIT_TIMEOUT_PATH=$(realpath $WAITFORIT_TIMEOUT_PATH 2>/dev/null || readlink -f $WAITFORIT_TIMEOUT_PATH)
-
-WAITFORIT_BUSYTIMEFLAG=""
-if [[ $WAITFORIT_TIMEOUT_PATH =~ "busybox" ]]; then
-    WAITFORIT_ISBUSY=1
-    # Check if busybox timeout uses -t flag
-    # (recent Alpine versions don't support -t anymore)
-    if timeout &>/dev/stdout | grep -q -e '-t '; then
-        WAITFORIT_BUSYTIMEFLAG="-t"
-    fi
-else
-    WAITFORIT_ISBUSY=0
-fi
-
-if [[ $WAITFORIT_CHILD -gt 0 ]]; then
+if [ $CHILD -gt 0 ]; then
     wait_for
-    WAITFORIT_RESULT=$?
-    exit $WAITFORIT_RESULT
+    RESULT=$?
+    exit $RESULT
 else
-    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
+    if [ "$TIMEOUT" -gt 0 ]; then
         wait_for_wrapper
-        WAITFORIT_RESULT=$?
+        RESULT=$?
     else
         wait_for
-        WAITFORIT_RESULT=$?
+        RESULT=$?
     fi
 fi
 
-if [[ $WAITFORIT_CLI != "" ]]; then
-    if [[ $WAITFORIT_RESULT -ne 0 && $WAITFORIT_STRICT -eq 1 ]]; then
-        echoerr "$WAITFORIT_cmdname: strict mode, refusing to execute subprocess"
-        exit $WAITFORIT_RESULT
+if [ "$*" != "" ]; then
+    if [ $RESULT -ne 0 -a $STRICT -eq 1 ]; then
+        echoerr "$cmdname: strict mode, refusing to execute subprocess"
+        exit $RESULT
     fi
-    exec "${WAITFORIT_CLI[@]}"
+    exec "$@"
 else
-    exit $WAITFORIT_RESULT
-fi
+    exit $RESULT
+fi