From dd79c5f4f67a366325b2ddb4c060fd49651c6118 Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@clickhouse.com>
Date: Tue, 14 Feb 2023 09:49:05 +0100
Subject: [PATCH] Easy debugging of clickhouse-server in Docker

---
 docker/server/entrypoint.sh | 14 +++++++++++++-
 src/Server/TCPHandler.cpp   |  4 ----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/docker/server/entrypoint.sh b/docker/server/entrypoint.sh
index dfd8f2e3e54..538934f07fa 100755
--- a/docker/server/entrypoint.sh
+++ b/docker/server/entrypoint.sh
@@ -172,7 +172,19 @@ if [[ $# -lt 1 ]] || [[ "$1" == "--"* ]]; then
     # so the container can't be finished by ctrl+c
     CLICKHOUSE_WATCHDOG_ENABLE=${CLICKHOUSE_WATCHDOG_ENABLE:-0}
     export CLICKHOUSE_WATCHDOG_ENABLE
-    exec /usr/bin/clickhouse su "${USER}:${GROUP}" /usr/bin/clickhouse-server --config-file="$CLICKHOUSE_CONFIG" "$@"
+
+    # An option for easy restarting and replacing clickhouse-server in a container, especially in Kubernetes.
+    # For example, you can replace the clickhouse-server binary to another and restart it while keeping the container running.
+    if [[ "${CLICKHOUSE_DOCKER_RESTART_ON_EXIT:-0}" -eq "1" ]]; then
+        while true; do
+            # This runs the server as a child process of the shell script:
+            /usr/bin/clickhouse su "${USER}:${GROUP}" /usr/bin/clickhouse-server --config-file="$CLICKHOUSE_CONFIG" "$@"
+            echo >&2 'ClickHouse Server exited, and the environment variable CLICKHOUSE_DOCKER_RESTART_ON_EXIT is set to 1. Restarting the server.'
+        done
+    else
+        # This replaces the shell script with the server:
+        exec /usr/bin/clickhouse su "${USER}:${GROUP}" /usr/bin/clickhouse-server --config-file="$CLICKHOUSE_CONFIG" "$@"
+    fi
 fi
 
 # Otherwise, we assume the user want to run his own process, for example a `bash` shell to explore this image
diff --git a/src/Server/TCPHandler.cpp b/src/Server/TCPHandler.cpp
index 69096a110a9..84587af47bb 100644
--- a/src/Server/TCPHandler.cpp
+++ b/src/Server/TCPHandler.cpp
@@ -1,5 +1,4 @@
 #include <algorithm>
-#include <iomanip>
 #include <iterator>
 #include <memory>
 #include <mutex>
@@ -24,7 +23,6 @@
 #include <IO/LimitReadBuffer.h>
 #include <IO/ReadHelpers.h>
 #include <IO/WriteHelpers.h>
-#include <IO/copyData.h>
 #include <Formats/NativeReader.h>
 #include <Formats/NativeWriter.h>
 #include <Interpreters/executeQuery.h>
@@ -39,9 +37,7 @@
 #include <Core/ExternalTable.h>
 #include <Access/AccessControl.h>
 #include <Access/Credentials.h>
-#include <Storages/ColumnDefault.h>
 #include <DataTypes/DataTypeLowCardinality.h>
-#include <DataTypes/DataTypeEnum.h>
 #include <Compression/CompressionFactory.h>
 #include <Common/logger_useful.h>
 #include <Common/CurrentMetrics.h>