Add options for build container rsync optimization

KUBE_RSYNC_COMPRESS env var sets rsync compression level.
KUBE_RSYNC_GENERATED_TO_BUILD_CONTAINER env var disables rsyncing
generated files to build containers.

build-tools/common.sh

@@ -643,6 +643,22 @@ function kube::build::stop_rsyncd_container() {
   kube::build::destroy_container "${KUBE_RSYNC_CONTAINER_NAME}"
 }
 
+function kube::build::rsync {
+  local -a rsync_opts=(
+    --archive
+    --prune-empty-dirs
+    --password-file="${LOCAL_OUTPUT_BUILD_CONTEXT}/rsyncd.password"
+  )
+  if (( ${KUBE_VERBOSE} >= 6 )); then
+    rsync_opts+=("-iv")
+  fi
+  if (( ${KUBE_RSYNC_COMPRESS} > 0 )); then
+     rsync_opts+=("--compress-level=${KUBE_RSYNC_COMPRESS}")
+  fi
+  V=3 kube::log::status "Running rsync"
+  rsync "${rsync_opts[@]}" "$@"
+}
+
 # This will launch rsyncd in a container and then sync the source tree to the
 # container over the local network.
 function kube::build::sync_to_container() {
@@ -650,26 +666,22 @@ function kube::build::sync_to_container() {
 
   kube::build::start_rsyncd_container
 
-  local rsync_extra=""
-  if (( ${KUBE_VERBOSE} >= 6 )); then
-    rsync_extra="-iv"
-  fi
-
   # rsync filters are a bit confusing.  Here we are syncing everything except
   # output only directories and things that are not necessary like the git
-  # directory. The '- /' filter prevents rsync from trying to set the
+  # directory and generated files. The '- /' filter prevents rsync
-  # uid/gid/perms on the root of the sync tree.
+  # from trying to set the uid/gid/perms on the root of the sync tree.
-  V=3 kube::log::status "Running rsync"
+  # As an exception, we need to sync generated files in staging/, because
-  rsync ${rsync_extra} \
+  # they will not be re-generated by 'make'.
-    --archive \
+  kube::build::rsync \
     --delete \
-    --prune-empty-dirs \
+    --filter='+ /staging/**' \
-    --password-file="${LOCAL_OUTPUT_BUILD_CONTEXT}/rsyncd.password" \
     --filter='- /.git/' \
     --filter='- /.make/' \
     --filter='- /_tmp/' \
     --filter='- /_output/' \
     --filter='- /' \
+    --filter='- zz_generated.*' \
+    --filter='- generated.proto' \
     "${KUBE_ROOT}/" "rsync://k8s@${KUBE_RSYNC_ADDR}/k8s/"
 
   kube::build::stop_rsyncd_container
@@ -694,11 +706,7 @@ function kube::build::copy_output() {
   #
   # We are looking to copy out all of the built binaries along with various
   # generated files.
-  V=3 kube::log::status "Running rsync"
+  kube::build::rsync \
-  rsync ${rsync_extra} \
-    --archive \
-    --prune-empty-dirs \
-    --password-file="${LOCAL_OUTPUT_BUILD_CONTEXT}/rsyncd.password" \
     --filter='- /vendor/' \
     --filter='- /_temp/' \
     --filter='+ /_output/dockerized/bin/**' \

hack/lib/init.sh

@@ -25,6 +25,10 @@ KUBE_OUTPUT_SUBPATH="${KUBE_OUTPUT_SUBPATH:-_output/local}"
 KUBE_OUTPUT="${KUBE_ROOT}/${KUBE_OUTPUT_SUBPATH}"
 KUBE_OUTPUT_BINPATH="${KUBE_OUTPUT}/bin"
 
+# This controls rsync compression. Set to a value > 0 to enable rsync
+# compression for build container
+KUBE_RSYNC_COMPRESS="${KUBE_RSYNC_COMPRESS:-0}"
+
 # Set no_proxy for localhost if behind a proxy, otherwise, 
 # the connections to localhost in scripts will time out
 export no_proxy=127.0.0.1,localhost