From dcef9b53a3fc90da4fa716699bd4691d59a043ab Mon Sep 17 00:00:00 2001
From: Volodymyr Burenin <vburenin@gmail.com>
Date: Sun, 18 Feb 2018 19:21:10 -0600
Subject: [PATCH 1/2] Add ability to cache generated dependency, so not much
 time wasted during the build process.

---
 Makefile                 |  6 +++++-
 infra/scripts/go-deps.sh | 23 ++++++++++++++++++-----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 8bf756d6e7..c95dc29b22 100644
--- a/Makefile
+++ b/Makefile
@@ -488,7 +488,7 @@ distro: all
 mrrobot:
 	@rm -rf *.xml *.html *.log *.zip VCH-0-*
 
-clean:
+clean: cleandeps
 	@echo removing binaries
 	@rm -rf $(BIN)/*
 	@echo removing Go object files
@@ -520,3 +520,7 @@ clean:
 distclean: clean
 	@echo removing binaries
 	@rm -rf $(BIN)
+
+cleandeps:
+	@echo removing dependency cache
+	@rm -rf .godeps_cache
diff --git a/infra/scripts/go-deps.sh b/infra/scripts/go-deps.sh
index fa06f799cf..e49525d07b 100755
--- a/infra/scripts/go-deps.sh
+++ b/infra/scripts/go-deps.sh
@@ -21,19 +21,32 @@
 #     pkg       This is github.com/vmware/vic/cmd/imagec for example
 #
 
+cache_dir=.godeps_cache
+
 pkg=$1
 flags=$2
+cachedname=`echo .$1.godeps_cache | sed 's/\//_/g'`
 
 if [ -d "$pkg" ]; then
-    if [[ "$flags" == *d* ]]
-    then
+
+    if [[ "$flags" == *d* ]]; then
         # Only output if make is given the '-d' flag
         echo "Generating deps for $pkg" >&2
     fi
 
-    go list -f '{{join .Deps "\n"}}' github.com/vmware/vic/"$pkg" 2>/dev/null | \
-        xargs go list -f '{{if not .Standard}}{{.ImportPath}}{{end}}' 2>/dev/null | \
-        sed -e 's:github.com/vmware/vic/\(.*\)$:\1/*:'
+    if [ -n "$VIC_CACHE_DEPS" ]; then
+        mkdir -p $cache_dir
+        if [ ! -f $cache_dir/$cachedname ]; then
+            go list -f '{{join .Deps "\n"}}' github.com/vmware/vic/"$pkg" 2>/dev/null | \
+                xargs go list -f '{{if not .Standard}}{{.ImportPath}}{{end}}' 2>/dev/null | \
+                sed -e 's:github.com/vmware/vic/\(.*\)$:\1/*:' > "$cache_dir/$cachedname"
+        fi
+        cat "$cache_dir/$cachedname"
+    else
+        go list -f '{{join .Deps "\n"}}' github.com/vmware/vic/"$pkg" 2>/dev/null | \
+            xargs go list -f '{{if not .Standard}}{{.ImportPath}}{{end}}' 2>/dev/null | \
+            sed -e 's:github.com/vmware/vic/\(.*\)$:\1/*:'
+    fi
 else
     if [[ "$flags" == *d* ]]
     then

From d3aaddadcfa343aa39d562cb57145224dc9caf3a Mon Sep 17 00:00:00 2001
From: Volodymyr Burenin <vburenin@gmail.com>
Date: Tue, 20 Feb 2018 11:57:45 -0600
Subject: [PATCH 2/2] Added docs.

---
 README.md                | 16 ++++++++++++++++
 infra/scripts/go-deps.sh |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/README.md b/README.md
index 9878c4fd9d..d761874801 100644
--- a/README.md
+++ b/README.md
@@ -86,6 +86,22 @@ To run unit tests after a successful build, issue the following:
 make test
 ```
 
+Running "make" every time causes Go dependency regeneration for each component, so that "make" can rebuild only those components that are changed.  However, such regeneration may take significant amount of time when it is not really needed. To fight that developers can use cached dependencies that can be enabled by defining the environment variable VIC_CACHE_DEPS. As soon as it is set, infra/scripts/go-deps.sh will read cached version of dependencies if those exist.
+
+```shell
+export VIC_CACHE_DEPS=1
+```
+
+This is important to note that as soon as you add a new package or an internal project dependency that didn't exist before, those dependencies
+should be regenerated to reflect latest changes. It can be done just by running:
+
+```shell
+make cleandeps
+```
+
+After that next "make" run will regenerate dependencies from scratch.
+
+
 ## Managing vendor/ directory
 
 To build the VIC Engine dependencies, ensure `GOPATH` is set, then issue the following.
diff --git a/infra/scripts/go-deps.sh b/infra/scripts/go-deps.sh
index e49525d07b..0f48b97266 100755
--- a/infra/scripts/go-deps.sh
+++ b/infra/scripts/go-deps.sh
@@ -20,6 +20,9 @@
 #
 #     pkg       This is github.com/vmware/vic/cmd/imagec for example
 #
+# If VIC_CACHE_DEPS environment variable is defined, this script will attempt to read
+# cached dependencies from disk if those exist. If they are not cached, dependencies will be
+# regenerated and cached.
 
 cache_dir=.godeps_cache