feat: Send commands to weed shell from the docker image.

Add the ability to send commands to weed shell from the docker image.

Allows an operator to perform maintenance commands like so:
```
docker run \
  --rm \
  -e SHELL_FILER=localhost:8888 \
  -e SHELL_MASTER=localhost:9333 \
  chrislusf/seaweedfs:local \
  "shell" \
  "fs.configure -locationPrefix=/buckets/foo -volumeGrowthCount=3 -replication=002 -apply"
```

1 files changed, 6 insertions, 0 deletions

diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index 6818d9581..80a7fe586 100755
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -57,6 +57,12 @@ case "$1" in
   	exec /usr/bin/weed -logtostderr=true s3 $ARGS $@
 	;;
 
+  'shell')
+  	ARGS="-cluster=$SHELL_CLUSTER -filer=$SHELL_FILER -filerGroup=$SHELL_FILER_GROUP -master=$SHELL_MASTER -options=$SHELL_OPTIONS"
+  	shift
+  	exec echo "$@" | /usr/bin/weed -logtostderr=true shell $ARGS
+  ;;
+
   *)
   	exec /usr/bin/weed $@
 	;;