*: added pre-commit hook. (#3112)

hooks/pre-commit

@@ -0,0 +1,73 @@
+#!/bin/bash
+# This file modified from k8s
+# https://github.com/kubernetes/kubernetes/blob/master/hooks/pre-commit
+
+# How to use this hook?
+# ln -s hooks/pre-commit .git/hooks/
+# In case hook is not executable
+# chmod +x .git/hooks/pre-commit
+
+readonly reset=$(tput sgr0)
+readonly red=$(tput bold; tput setaf 1)
+readonly green=$(tput bold; tput setaf 2)
+
+exit_code=0
+
+echo -ne "Checking that it builds..."
+if ! OUT=$(make 2>&1); then
+    echo
+    echo "${red}${OUT}"
+    exit_code=1
+else
+    echo "${green}OK"
+fi
+echo "${reset}"
+
+echo -ne "Checking for files that need gofmt... "
+files_need_gofmt=()
+files=($(git diff --cached --name-only --diff-filter ACM | grep "\.go" | grep -v -e "^_vendor"))
+for file in "${files[@]}"; do
+    # Check for files that fail gofmt.
+    diff="$(git show ":${file}" | gofmt -s -d 2>&1)"
+    if [[ -n "$diff" ]]; then
+        files_need_gofmt+=("${file}")
+    fi
+done
+
+if [[ "${#files_need_gofmt[@]}" -ne 0 ]]; then
+    echo "${red}ERROR!"
+    echo "Some files have not been gofmt'd. To fix these errors, "
+    echo "copy and paste the following:"
+    echo "  gofmt -s -w ${files_need_gofmt[@]}"
+    exit_code=1
+else
+    echo "${green}OK"
+fi
+echo "${reset}"
+
+echo -ne "Checking for files that need goword... "
+files_need_goword=()
+files=($(git diff --cached --name-only --diff-filter ACM | grep "\.go" | grep -v -e "^_vendor"))
+for file in "${files[@]}"; do
+    # Check for files that fail goword.
+    diff=$(goword ${file})
+    if [[ -n "$diff" ]]; then
+        files_need_goword+=("${file}")
+    fi
+done
+
+if [[ "${#files_need_goword[@]}" -ne 0 ]]; then
+    echo "${red}ERROR!"
+    echo "Some files may have spelling errors."
+    # echo ${files_need_goword[@]}
+    echo "make goword for more details"
+    exit_code=1
+else
+    echo "${green}OK"
+fi
+echo "${reset}"
+
+if [[ "${exit_code}" != 0 ]]; then
+    echo "${red}Aborting commit${reset}"
+fi
+exit ${exit_code}