improve script for updating clickhouse-docs

docs/get-clickhouse-docs.sh

@@ -27,5 +27,27 @@ else
     exit 1
     ;;
   esac
+
+  if [ -n "$2" ]; then
+    set_git_hook="$2"
+  elif [ ! -n "$1" ]; then
+    read -rp "Would you like to setup git hook for automatic update? (y|n): " set_git_hook
+  fi
+
+  if [ "$set_git_hook" = "y" ]; then
+    hook_command="$(pwd)/pull-clickhouse-docs-hook.sh 24"
+    hook_file=$(realpath "$(pwd)/../.git/hooks/post-checkout")
+    already_have=$(grep -Faq "pull-clickhouse-docs-hook.sh" "$hook_file" 2>/dev/null && echo 1 || echo 0)
+    if [ $already_have -eq 0 ]; then
+      echo "Appending '$hook_command' to $hook_file"
+      echo "$hook_command" >> "$hook_file"
+      chmod u+x "$hook_file"  # Just in case it did not exist before append
+    else
+      echo "Looks like the update hook already exists, will not add another one"
+    fi
+  elif [ ! "$set_git_hook" = "n" ]; then
+    echo "Expected 'y' or 'n', got '$set_git_hook', will not setup git hook"
+  fi
+
   git clone "$git_url" "clickhouse-docs"
 fi

docs/pull-clickhouse-docs-hook.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -e
+# The script to update user-guides documentation repo
+# https://github.com/ClickHouse/clickhouse-docs
+
+WORKDIR=$(dirname "$0")
+WORKDIR=$(readlink -f "${WORKDIR}")
+cd "$WORKDIR"
+
+UPDATE_PERIOD_HOURS="${1:-24}"  # By default update once per 24 hours; 0 means "always update"
+
+if [ ! -d "clickhouse-docs" ]; then
+    echo "There's no clickhouse-docs/ dir, run get-clickhouse-docs.sh first to clone the repo"
+    exit 1
+fi
+
+# Do not update it too often
+LAST_FETCH_TS=$(stat -c %Y clickhouse-docs/.git/FETCH_HEAD 2>/dev/null || echo 0)
+CURRENT_TS=$(date +%s)
+HOURS_SINCE_LAST_FETCH=$(( (CURRENT_TS - LAST_FETCH_TS) / 60 / 60 ))
+
+if [ "$HOURS_SINCE_LAST_FETCH" -lt "$UPDATE_PERIOD_HOURS" ]; then
+    exit 0;
+fi
+
+echo "Updating clickhouse-docs..."
+git -C clickhouse-docs pull