[proxy] Handle null HostConfigs gracefully in start

proxy/start_container_interceptor.go

@@ -24,7 +24,7 @@ func (i *startContainerInterceptor) InterceptRequest(r *http.Request) error {
 	}
 
 	hostConfig := &docker.HostConfig{}
-	if err := unmarshalRequestBody(r, &hostConfig); err != nil {
+	if err := unmarshalRequestBody(r, hostConfig); err != nil {
 		return err
 	}
 

test/666_abuse_of_start_test.sh

@@ -18,4 +18,8 @@ proxy docker_on $HOST1 create --name=c3 -v /tmp:/hosttmp $SMALL_IMAGE $CHECK_ETH
 proxy docker_api_on $HOST1 POST /containers/c3/start '{"Binds":[],"Dns":null,"DnsSearch":null,"ExtraHosts":null,"VolumesFrom":null,"Devices":null,"NetworkMode":""}'
 assert "docker_on $HOST1 inspect -f '{{.State.Running}} {{.State.ExitCode}} {{.HostConfig.Dns}}' c3" "false 0 [$docker_bridge_ip]"
 
+# Start c4 with an 'null' HostConfig
+proxy docker_on $HOST1 create --name=c4 $SMALL_IMAGE echo foo
+assert_raises "proxy docker_api_on $HOST1 POST /containers/c4/start 'null'"
+
 end_suite

test/config.sh

@@ -106,7 +106,7 @@ docker_api_on() {
     data=$4
     shift 4
     [ -z "$DEBUG" ] || greyly echo "Docker (API) on $host:$DOCKER_PORT: $method $url" >&2
-    echo -n "$data" | curl -s -X "$method" -H Content-Type:application/json "http://$host:$DOCKER_PORT/v1.15$url" -d @-
+    echo -n "$data" | curl -s -f -X "$method" -H Content-Type:application/json "http://$host:$DOCKER_PORT/v1.15$url" -d @-
 }
 
 proxy() {