Simplifies the work needed to create a new deb

- automates much of the workflow for building a deb package
- adds a version.txt file that is used configure the version on the deb package
  * updates the Dockerfile to make use of this

tools/dockerfile/grpc_build_deb/Dockerfile

@@ -30,6 +30,9 @@
 # Dockerfile to build Debian packages for gRPC C core.
 FROM grpc/base
 
+# Add the file containing the gRPC version
+ADD version.txt version.txt
+
 # Install dependencies
 RUN apt-get update && apt-get install -y lintian
 

tools/dockerfile/grpc_build_deb/version.txt

@@ -0,0 +1 @@
+0.5.1

tools/gce_setup/grpc_docker.sh

@@ -673,7 +673,7 @@ _grpc_build_proto_bins_args() {
 }
 
 # grpc_build_proto_bins
-# 
+#
 # - rebuilds the dist_proto docker image
 #   * doing this builds the protoc and the ruby, python and cpp bins statically
 #
@@ -693,11 +693,11 @@ grpc_build_proto_bins() {
   gce_has_instance $grpc_project $host || return 1;
   local project_opt="--project $grpc_project"
   local zone_opt="--zone $grpc_zone"
-  
+
   # rebuild the dist_proto image
   local label='dist_proto'
   grpc_update_image -- -h $host $label || return 1
- 
+
   # run a command to copy the generated archive to the docker host
   local docker_prefix='sudo docker run -v /tmp:/tmp/proto_bins_out'
   local tar_name='proto-bins*.tar.gz'
@@ -715,6 +715,58 @@ grpc_build_proto_bins() {
   gcloud compute copy-files $rmt_tar $local_copy $project_opt $zone_opt || return 1
 }
 
+_grpc_build_debs_args() {
+  [[ -n $1 ]] && {  # host
+    host=$1
+    shift
+  } || {
+    host='grpc-docker-builder'
+  }
+}
+
+# grpc_build_debs
+#
+# - rebuilds the build_debs
+#   * doing this builds a deb package for release debs
+#
+# - runs a docker command that copies the debs from the docker instance to its
+#   host
+# - copies the debs from the host to the local machine
+grpc_build_debs() {
+  _grpc_ensure_gcloud_ssh || return 1;
+
+  # declare vars local so that they don't pollute the shell environment
+  # where this func is used.
+  local grpc_zone grpc_project dry_run  # set by _grpc_set_project_and_zone
+  # set by _grpc_build_debs_args
+  local host
+
+  # set the project zone and check that all necessary args are provided
+  _grpc_set_project_and_zone -f _grpc_build_debs_args "$@" || return 1
+  gce_has_instance $grpc_project $host || return 1;
+  local project_opt="--project $grpc_project"
+  local zone_opt="--zone $grpc_zone"
+
+  # rebuild the build_deb image
+  local label='build_deb'
+  grpc_update_image -- -h $host $label || return 1
+
+  # run a command to copy the debs from the docker instance to the host.
+  local docker_prefix='sudo docker run -v /tmp:/tmp/host_deb_out'
+  local cp_cmd="/bin/bash -c 'cp -v /tmp/deb_out/*.deb /tmp/host_deb_out'"
+  local cmd="$docker_prefix grpc/$label $cp_cmd"
+  local ssh_cmd="bash -l -c \"$cmd\""
+  echo "will run:"
+  echo "  $ssh_cmd"
+  echo "on $host"
+  gcloud compute $project_opt ssh $zone_opt $host --command "$cmd" || return 1
+
+  # copy the debs from host machine to the local one.
+  local rmt_debs="$host:/tmp/*.deb"
+  local local_copy="$(pwd)"
+  gcloud compute copy-files $rmt_debs $local_copy $project_opt $zone_opt || return 1
+}
+
 _grpc_launch_servers_args() {
   [[ -n $1 ]] && {  # host
     host=$1
@@ -1310,5 +1362,3 @@ _grpc_default_creds_test_flags() {
 _grpc_gce_test_flags() {
   echo " --default_service_account=155450119199-r5aaqa2vqoa9g5mv2m6s3m1l293rlmel@developer.gserviceaccount.com --oauth_scope=https://www.googleapis.com/auth/xapi.zoo"
 }
-
-# TODO(grpc-team): add grpc_interop_gen_xxx_cmd for python