adds waiting for multiple hosts based on eficode/pull/11

Author: Okeanos

README.md

@@ -9,7 +9,7 @@ When using this tool, you only need to pick the `wait-for` file as part of your
 ## Usage
 
 ```
-wait-for host:port [-t timeout] [-- command args]
+wait-for [host:port...] [-t timeout] [-- command args]
   -q | --quiet                        Do not output any status messages
   -l | --loose                        Execute subcommand even if the test times out
   -t TIMEOUT | --timeout=timeout      Timeout in seconds, zero for no timeout
@@ -52,13 +52,32 @@ services:
       - db
 ```
 
+To wait for several containers to become available:
+
+ ```
+version: '2'
+ services:
+  db:
+    image: postgres:9.4
+
+   elk:
+    image: sebp/elk
+
+   backend:
+    build: backend
+    command: sh -c './wait-for db:5432 elk:9563 -- npm start'
+    depends_on:
+      - db
+      - elk
+```
+
 ## Testing
 
 Ironically testing is done using [bats](https://github.com/sstephenson/bats), which on the other hand is depending on [bash](https://en.wikipedia.org/wiki/Bash_(Unix_shell)).
 
     docker build -t wait-for .
     docker run -t wait-for
-    
+
 ## Note
 
 Make sure netcat is installed in your Dockerfile before running the command.

wait-for

@@ -31,7 +31,7 @@ usage() {
   exitcode="$1"
   cat << USAGE >&2
 Usage:
-  $(basename $0) host:port [-t timeout] [-- command args]
+  $(basename $0) [host:port...] [-t timeout] [-- command args]
   -q | --quiet                        Do not output any status messages
   -l | --loose                        Execute subcommand even if the test times out
   -t TIMEOUT | --timeout=timeout      Timeout in seconds, zero for no timeout
@@ -56,24 +56,25 @@ wait_for() {
   local result
   for i in `seq $TIMEOUT` ; do
     # use a 1-second timeout, but still sleep 0.1 seconds after just to be safe
-    test_connection "$HOST" "$PORT"
+    test_connection "$1" "$2"
     result=$?
     if [ $result -eq 0 ] ; then break ; fi
     sleep 1
   done
-  [ $result -ne 0 ] && echoerr "Operation timed out"
+  [ $result -ne 0 ] && echoerr "Operation timed out waiting for $1:$2"
   if [ $result -eq 0 -o $LOOSE -eq 1 -a $# -gt 0 ] ; then
     TIMEOUT=$OLD_TIMEOUT QUIET=$OLD_QUIET PORT=$OLD_PORT HOST=$OLD_HOST LOOSE=$OLD_LOOSE exec "$@"
   fi
   exit $result
 }
 
+SERVICES=""
+
 while [ $# -gt 0 ]
 do
   case "$1" in
     *:* )
-    HOST=$(printf "%s\n" "$1"| cut -d : -f 1)
-    PORT=$(printf "%s\n" "$1"| cut -d : -f 2)
+    SERVICES="${SERVICES} $1"
     shift 1
     ;;
     -q | --quiet)
@@ -107,9 +108,23 @@ do
   esac
 done
 
-if [ "$HOST" = "" -o "$PORT" = "" ]; then
-  echoerr "Error: you need to provide a host and port to test."
-  usage 2
+if [ "$SERVICES" = "" ] ; then
+	echoerr "Error: you need to provide at least one service to test."
+	usage 2
 fi
 
-wait_for "$@"
+for SERVICE in ${SERVICES} ; do
+	HOST=$(printf "%s\n" "$SERVICE"| cut -d : -f 1)
+	PORT=$(printf "%s\n" "$SERVICE"| cut -d : -f 2)
+
+	if [ "$HOST" = "" -o "$PORT" = "" ]; then
+  	echoerr "Error: you need to provide a host and port to test."
+  	usage 2
+	fi
+
+	wait_for "$HOST" "$PORT"
+done
+
+if [ $# -gt 0 ] ; then
+	exec "$@"
+fi

wait-for.bats

@@ -13,6 +13,12 @@
   [ "$output" != "success" ]
 }
 
+@test "google and bing should be immediately found" {
+  run ./wait-for google.com:80 bing.com:80 -- echo 'success'
+
+   [ "$output" = "success" ]
+}
+
 @test "nonexistent server should start command if loose option is specified" {
   run ./wait-for -q -t 1 -l noserver:9999 -- echo 'passable' 2>&1