From a1726dc45add7525f51617cd399a3fe22b5d474b Mon Sep 17 00:00:00 2001
From: Georg Lauterbach <44545919+georglauterbach@users.noreply.github.com>
Date: Wed, 6 Apr 2022 16:48:41 +0200
Subject: [PATCH] scripts: added `TZ` environment variable to set timezone
 (#2530)

---
 docs/content/config/environment.md    |  4 ++++
 mailserver.env                        |  6 ++++++
 target/scripts/start-mailserver.sh    |  3 +++
 target/scripts/startup/setup-stack.sh | 22 ++++++++++++++++++++
 test/mail_time.bats                   | 29 +++++++++++++++++++++++++++
 5 files changed, 64 insertions(+)
 create mode 100644 test/mail_time.bats

diff --git a/docs/content/config/environment.md b/docs/content/config/environment.md
index 2a645150..600c334c 100644
--- a/docs/content/config/environment.md
+++ b/docs/content/config/environment.md
@@ -52,6 +52,10 @@ Set different options for mynetworks option (can be overwrite in postfix-main.cf
 
 Note: you probably want to [set `POSTFIX_INET_PROTOCOLS=ipv4`](#postfix_inet_protocols) to make it work fine with Docker.
 
+##### TZ
+
+Set the timezone. If this variable is unset, the container runtime will try to detect the time using `/etc/localtime`, which you can alternatively mount into the container. The value of this variable must follow the pattern `AREA/ZONE`, i.e. of you want to use Germany's time zone, use `Europe/Berlin`. You can lookup all available timezones [here](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List).
+
 ##### ENABLE_AMAVIS
 
 Amavis content filter (used for ClamAV & SpamAssassin)
diff --git a/mailserver.env b/mailserver.env
index 158fb9a0..dc577928 100644
--- a/mailserver.env
+++ b/mailserver.env
@@ -62,6 +62,12 @@ UPDATE_CHECK_INTERVAL=1d
 # connected-networks => Add all connected docker networks (ipv4 only)
 PERMIT_DOCKER=none
 
+# Set the timezone. If this variable is unset, the container runtime will try to detect the time using
+# `/etc/localtime`, which you can alternatively mount into the container. The value of this variable
+# must follow the pattern `AREA/ZONE`, i.e. of you want to use Germany's time zone, use `Europe/Berlin`.
+# You can lookup all available timezones here: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List
+TZ=
+
 # In case you network interface differs from 'eth0', e.g. when you are using HostNetworking in Kubernetes,
 # you can set NETWORK_INTERFACE to whatever interface you want. This interface will then be used.
 #  - **empty** => eth0
diff --git a/target/scripts/start-mailserver.sh b/target/scripts/start-mailserver.sh
index b4512a9c..cb5d2be5 100755
--- a/target/scripts/start-mailserver.sh
+++ b/target/scripts/start-mailserver.sh
@@ -107,6 +107,7 @@ VARS[SPOOF_PROTECTION]="${SPOOF_PROTECTION:=0}"
 VARS[SRS_SENDER_CLASSES]="${SRS_SENDER_CLASSES:=envelope_sender}"
 VARS[SSL_TYPE]="${SSL_TYPE:=}"
 VARS[TLS_LEVEL]="${TLS_LEVEL:=modern}"
+VARS[TZ]="${TZ:=}"
 VARS[UPDATE_CHECK_INTERVAL]="${UPDATE_CHECK_INTERVAL:=1d}"
 VARS[VIRUSMAILS_DELETE_DELAY]="${VIRUSMAILS_DELETE_DELAY:=7}"
 
@@ -131,6 +132,8 @@ function register_functions
   _register_setup_function '_setup_default_vars'
   _register_setup_function '_setup_file_permissions'
 
+  [[ -n ${TZ} ]] && _register_setup_function '_setup_timezone'
+
   if [[ ${SMTP_ONLY} -ne 1 ]]
   then
     _register_setup_function '_setup_dovecot'
diff --git a/target/scripts/startup/setup-stack.sh b/target/scripts/startup/setup-stack.sh
index f4eaf0be..b54c410e 100644
--- a/target/scripts/startup/setup-stack.sh
+++ b/target/scripts/startup/setup-stack.sh
@@ -1263,3 +1263,25 @@ EOF
   supervisorctl reread
   supervisorctl update
 }
+
+function _setup_timezone
+{
+  _log 'debug' "Setting timezone to '${TZ}'"
+
+  local ZONEINFO_FILE="/usr/share/zoneinfo/${TZ}"
+
+  if [[ ! -e ${ZONEINFO_FILE} ]]
+  then
+    _log 'warn' "Cannot find timezone '${TZ}'"
+    return 1
+  fi
+
+  if ln -fs "${ZONEINFO_FILE}" /etc/localtime \
+  && dpkg-reconfigure -f noninteractive tzdata &>/dev/null
+  then
+    _log 'trace' "Set time zone to '${TZ}'"
+  else
+    _log 'warn' "Setting timezone to '${TZ}' failed"
+    return 1
+  fi
+}
diff --git a/test/mail_time.bats b/test/mail_time.bats
new file mode 100644
index 00000000..4fb5e9bc
--- /dev/null
+++ b/test/mail_time.bats
@@ -0,0 +1,29 @@
+load 'test_helper/common'
+
+setup_file() {
+  local PRIVATE_CONFIG
+  PRIVATE_CONFIG="$(duplicate_config_for_container .)"
+
+  docker run -d --name mail_time \
+    -v "${PRIVATE_CONFIG}":/tmp/docker-mailserver \
+    -v "$(pwd)/test/test-files":/tmp/docker-mailserver-test:ro \
+    -e TZ='Asia/Jakarta' \
+    -e LOG_LEVEL=debug \
+    -h mail.my-domain.com -t "${NAME}"
+
+  wait_for_smtp_port_in_container mail_time
+}
+
+teardown_file() {
+    docker rm -f mail_time
+}
+
+@test "checking time: setting the time with TZ works correctly" {
+  run docker exec mail_time cat /etc/timezone
+  assert_success
+  assert_output 'Asia/Jakarta'
+
+  run docker exec mail_time date '+%Z'
+  assert_success
+  assert_output 'WIB'
+}