Detect and use the DOCKER_HOST environment variable

For working with docker-machine, for example.

diff --git a/launcher b/launcher
index 2776e686a7624e6b148ae84a8411c5631cf41505..02ed96bf58dc4f74c999775fb62b59ca1405f090 100755 (executable)
--- a/launcher
+++ b/launcher
@@ -33,7 +33,9 @@ else
   attach_on_run="-d"
 fi
 
-if [ -x "$(which ip 2>/dev/null)" ]; then
+if [ -n "$DOCKER_HOST" ]; then
+  docker_ip=`sed -e 's/^tcp:\/\/\(.*\):.*$/\1/' <<< "$DOCKER_HOST"`
+elif [ -x "$(which ip 2>/dev/null)" ]; then
   docker_ip=`ip addr show docker0 | \
                   grep 'inet ' | \
                   awk '{ split($2,a,"/"); print a[1] }';`