Update wait-for-it.sh

wait-for-it.sh

@@ -1,15 +1,19 @@
 #!/usr/bin/env bash
+
 # Use this script to test if a given TCP host/port are available
 
-WAITFORIT_cmdname=${0##*/}
+cmdname=${0##*/}
 
-echoerr() { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo "$@" 1>&2; fi }
+echoerr() {
+    if [[ $QUIET -ne 1 ]]; then
+        echo "$@" 1>&2
+    fi
+}
 
-usage()
-{
+usage() {
     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
@@ -22,161 +26,106 @@ USAGE
     exit 1
 }
 
-wait_for()
-{
-    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
-        echoerr "$WAITFORIT_cmdname: waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
-    else
-        echoerr "$WAITFORIT_cmdname: waiting for $WAITFORIT_HOST:$WAITFORIT_PORT without a timeout"
-    fi
-    WAITFORIT_start_ts=$(date +%s)
-    while :
-    do
-        if [[ $WAITFORIT_ISBUSY -eq 1 ]]; then
-            nc -z $WAITFORIT_HOST $WAITFORIT_PORT
-            WAITFORIT_result=$?
-        else
-            (echo -n > /dev/tcp/$WAITFORIT_HOST/$WAITFORIT_PORT) >/dev/null 2>&1
-            WAITFORIT_result=$?
+wait_for() {
+    local start_ts=$(date +%s)
+
+    while :; do
+        if nc -z $HOST $PORT >/dev/null 2>&1; then
+            local end_ts=$(date +%s)
+            echoerr "$cmdname: $HOST:$PORT is available after $((end_ts - start_ts)) seconds"
+            return 0
         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"
-            break
+
+        if [[ $TIMEOUT -gt 0 && $(( $(date +%s) - start_ts )) -ge $TIMEOUT ]]; then
+            echoerr "$cmdname: timeout occurred after waiting $TIMEOUT seconds for $HOST:$PORT"
+            return 1
         fi
+
         sleep 1
     done
-    return $WAITFORIT_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 &
-    else
-        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_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"
-    fi
-    return $WAITFORIT_RESULT
+wait_for_wrapper() {
+    trap "kill -INT $!" INT
+    wait_for &
+    wait $!
+    return $?
 }
 
-# process arguments
-while [[ $# -gt 0 ]]
-do
+# Process arguments
+while [[ $# -gt 0 ]]; do
     case "$1" in
-        *:* )
-        WAITFORIT_hostport=(${1//:/ })
-        WAITFORIT_HOST=${WAITFORIT_hostport[0]}
-        WAITFORIT_PORT=${WAITFORIT_hostport[1]}
-        shift 1
-        ;;
+        *:*)
+            IFS=':' read -r HOST PORT <<< "$1"
+            shift
+            ;;
         --child)
-        WAITFORIT_CHILD=1
-        shift 1
-        ;;
+            CHILD=1
+            shift
+            ;;
         -q | --quiet)
-        WAITFORIT_QUIET=1
-        shift 1
-        ;;
+            QUIET=1
+            shift
+            ;;
         -s | --strict)
-        WAITFORIT_STRICT=1
-        shift 1
-        ;;
-        -h)
-        WAITFORIT_HOST="$2"
-        if [[ $WAITFORIT_HOST == "" ]]; then break; fi
-        shift 2
-        ;;
-        --host=*)
-        WAITFORIT_HOST="${1#*=}"
-        shift 1
-        ;;
-        -p)
-        WAITFORIT_PORT="$2"
-        if [[ $WAITFORIT_PORT == "" ]]; then break; fi
-        shift 2
-        ;;
-        --port=*)
-        WAITFORIT_PORT="${1#*=}"
-        shift 1
-        ;;
-        -t)
-        WAITFORIT_TIMEOUT="$2"
-        if [[ $WAITFORIT_TIMEOUT == "" ]]; then break; fi
-        shift 2
-        ;;
-        --timeout=*)
-        WAITFORIT_TIMEOUT="${1#*=}"
-        shift 1
-        ;;
+            STRICT=1
+            shift
+            ;;
+        -h | --host=*)
+            HOST="${1#*=}"
+            shift
+            ;;
+        -p | --port=*)
+            PORT="${1#*=}"
+            shift
+            ;;
+        -t | --timeout=*)
+            TIMEOUT="${1#*=}"
+            shift
+            ;;
         --)
-        shift
-        WAITFORIT_CLI=("$@")
-        break
-        ;;
+            shift
+            CLI=("$@")
+            break
+            ;;
         --help)
-        usage
-        ;;
+            usage
+            ;;
         *)
-        echoerr "Unknown argument: $1"
-        usage
-        ;;
+            echoerr "Unknown argument: $1"
+            usage
+            ;;
     esac
 done
 
-if [[ "$WAITFORIT_HOST" == "" || "$WAITFORIT_PORT" == "" ]]; then
+if [[ -z "$HOST" || -z "$PORT" ]]; then
     echoerr "Error: you need to provide a host and port to test."
     usage
 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 $WAITFORIT_TIMEOUT_PATH)
+TIMEOUT=${TIMEOUT:-15}
+STRICT=${STRICT:-0}
+CHILD=${CHILD:-0}
+QUIET=${QUIET:-0}
 
-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
+    exit $?
 else
-    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
+    if [[ $TIMEOUT -gt 0 ]]; then
         wait_for_wrapper
-        WAITFORIT_RESULT=$?
     else
         wait_for
-        WAITFORIT_RESULT=$?
     fi
-fi
+    RESULT=$?
 
-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 [[ $CLI ]]; then
+        if [[ $RESULT -ne 0 && $STRICT -eq 1 ]]; then
+            echoerr "$cmdname: strict mode, refusing to execute subprocess"
+            exit $RESULT
+        fi
+        exec "${CLI[@]}"
+    else
+        exit $RESULT
     fi
-    exec "${WAITFORIT_CLI[@]}"
-else
-    exit $WAITFORIT_RESULT
 fi