diff --git a/.env_web b/.env_web
index 4732507a9..e93a2e5a0 100644
--- a/.env_web
+++ b/.env_web
@@ -19,3 +19,6 @@ ZBX_SERVER_NAME=Composed installation
 # ZBX_SESSION_NAME=zbx_sessionid
 # Timezone one of: http://php.net/manual/en/timezones.php
 # PHP_TZ=Europe/Riga
+# ZBX_DENY_GUI_ACCESS=false
+# ZBX_GUI_ACCESS_IP_RANGE=['127.0.0.1']
+# ZBX_GUI_WARNING_MSG=Zabbix is under maintenance.
diff --git a/web-apache-mysql/alpine/Dockerfile b/web-apache-mysql/alpine/Dockerfile
index d77f9ae6b..45b6b3a04 100644
--- a/web-apache-mysql/alpine/Dockerfile
+++ b/web-apache-mysql/alpine/Dockerfile
@@ -79,9 +79,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     chown --quiet -R zabbix:root /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chgrp -R 0 /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chmod -R g=u /etc/zabbix/ /usr/share/zabbix/modules/ && \
diff --git a/web-apache-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-mysql/alpine/docker-entrypoint.sh b/web-apache-mysql/alpine/docker-entrypoint.sh
index 69c292e41..284b01832 100755
--- a/web-apache-mysql/alpine/docker-entrypoint.sh
+++ b/web-apache-mysql/alpine/docker-entrypoint.sh
@@ -170,6 +170,10 @@ prepare_web_server() {
 prepare_zbx_web_config() {
     echo "** Preparing Zabbix frontend configuration file"
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-apache-mysql/centos/Dockerfile b/web-apache-mysql/centos/Dockerfile
index 8bd88b80b..fe4fc3ba2 100644
--- a/web-apache-mysql/centos/Dockerfile
+++ b/web-apache-mysql/centos/Dockerfile
@@ -74,9 +74,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/web-apache-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-mysql/centos/docker-entrypoint.sh b/web-apache-mysql/centos/docker-entrypoint.sh
index 8332b1eda..07a46e372 100755
--- a/web-apache-mysql/centos/docker-entrypoint.sh
+++ b/web-apache-mysql/centos/docker-entrypoint.sh
@@ -179,6 +179,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-apache-mysql/ubuntu/Dockerfile b/web-apache-mysql/ubuntu/Dockerfile
index 4d3e70991..84548e226 100644
--- a/web-apache-mysql/ubuntu/Dockerfile
+++ b/web-apache-mysql/ubuntu/Dockerfile
@@ -79,9 +79,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     ./locale/make_mo.sh && \
     mkdir -p /var/lib/locales/supported.d/ && \
     rm -f /var/lib/locales/supported.d/local && \
diff --git a/web-apache-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-mysql/ubuntu/docker-entrypoint.sh b/web-apache-mysql/ubuntu/docker-entrypoint.sh
index 698a5c258..0c05947f1 100755
--- a/web-apache-mysql/ubuntu/docker-entrypoint.sh
+++ b/web-apache-mysql/ubuntu/docker-entrypoint.sh
@@ -170,6 +170,10 @@ prepare_web_server() {
 prepare_zbx_web_config() {
     echo "** Preparing Zabbix frontend configuration file"
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-apache-pgsql/alpine/Dockerfile b/web-apache-pgsql/alpine/Dockerfile
index 450cb5d6e..c4411089b 100644
--- a/web-apache-pgsql/alpine/Dockerfile
+++ b/web-apache-pgsql/alpine/Dockerfile
@@ -78,9 +78,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     chown --quiet -R zabbix:root /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chgrp -R 0 /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chmod -R g=u /etc/zabbix/ /usr/share/zabbix/modules/ && \
diff --git a/web-apache-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-pgsql/alpine/docker-entrypoint.sh b/web-apache-pgsql/alpine/docker-entrypoint.sh
index c52ee4145..276658c5c 100755
--- a/web-apache-pgsql/alpine/docker-entrypoint.sh
+++ b/web-apache-pgsql/alpine/docker-entrypoint.sh
@@ -154,6 +154,10 @@ prepare_web_server() {
 prepare_zbx_web_config() {
     echo "** Preparing Zabbix frontend configuration file"
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-apache-pgsql/centos/Dockerfile b/web-apache-pgsql/centos/Dockerfile
index 4200a9a03..1ef4dab6a 100644
--- a/web-apache-pgsql/centos/Dockerfile
+++ b/web-apache-pgsql/centos/Dockerfile
@@ -74,9 +74,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/web-apache-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-pgsql/centos/docker-entrypoint.sh b/web-apache-pgsql/centos/docker-entrypoint.sh
index 74611f8fa..39a59c850 100755
--- a/web-apache-pgsql/centos/docker-entrypoint.sh
+++ b/web-apache-pgsql/centos/docker-entrypoint.sh
@@ -166,6 +166,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-apache-pgsql/ubuntu/Dockerfile b/web-apache-pgsql/ubuntu/Dockerfile
index fffc5a7b1..2162cb022 100644
--- a/web-apache-pgsql/ubuntu/Dockerfile
+++ b/web-apache-pgsql/ubuntu/Dockerfile
@@ -79,9 +79,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     ./locale/make_mo.sh && \
     mkdir -p /var/lib/locales/supported.d/ && \
     rm -f /var/lib/locales/supported.d/local && \
diff --git a/web-apache-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php b/web-apache-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-apache-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-apache-pgsql/ubuntu/docker-entrypoint.sh b/web-apache-pgsql/ubuntu/docker-entrypoint.sh
index 3cdef0052..1e21015f6 100755
--- a/web-apache-pgsql/ubuntu/docker-entrypoint.sh
+++ b/web-apache-pgsql/ubuntu/docker-entrypoint.sh
@@ -161,6 +161,10 @@ clear_deploy() {
 prepare_zbx_web_config() {
     echo "** Preparing Zabbix frontend configuration file"
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-mysql/alpine/Dockerfile b/web-nginx-mysql/alpine/Dockerfile
index d9a293caa..e088d9350 100644
--- a/web-nginx-mysql/alpine/Dockerfile
+++ b/web-nginx-mysql/alpine/Dockerfile
@@ -73,9 +73,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     chown --quiet -R zabbix:root /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chgrp -R 0 /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chmod -R g=u /etc/zabbix/ /usr/share/zabbix/modules/ && \
diff --git a/web-nginx-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-mysql/alpine/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-mysql/alpine/docker-entrypoint.sh b/web-nginx-mysql/alpine/docker-entrypoint.sh
index 49f0d2714..ef18bec08 100755
--- a/web-nginx-mysql/alpine/docker-entrypoint.sh
+++ b/web-nginx-mysql/alpine/docker-entrypoint.sh
@@ -183,6 +183,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-mysql/centos/Dockerfile b/web-nginx-mysql/centos/Dockerfile
index 13a391974..b5193069b 100644
--- a/web-nginx-mysql/centos/Dockerfile
+++ b/web-nginx-mysql/centos/Dockerfile
@@ -66,9 +66,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/web-nginx-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-mysql/centos/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-mysql/centos/docker-entrypoint.sh b/web-nginx-mysql/centos/docker-entrypoint.sh
index 22cc9ddb7..c47826b35 100755
--- a/web-nginx-mysql/centos/docker-entrypoint.sh
+++ b/web-nginx-mysql/centos/docker-entrypoint.sh
@@ -183,6 +183,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-mysql/rhel/Dockerfile b/web-nginx-mysql/rhel/Dockerfile
index fc6b074ae..9979e030b 100644
--- a/web-nginx-mysql/rhel/Dockerfile
+++ b/web-nginx-mysql/rhel/Dockerfile
@@ -90,9 +90,11 @@ RUN set -eux && REPOLIST="rhel-8-for-x86_64-baseos-rpms,rhel-8-for-x86_64-appstr
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/web-nginx-mysql/rhel/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-mysql/rhel/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-mysql/rhel/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-mysql/rhel/docker-entrypoint.sh b/web-nginx-mysql/rhel/docker-entrypoint.sh
index 38122c352..e43c89af1 100755
--- a/web-nginx-mysql/rhel/docker-entrypoint.sh
+++ b/web-nginx-mysql/rhel/docker-entrypoint.sh
@@ -260,6 +260,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-mysql/ubuntu/Dockerfile b/web-nginx-mysql/ubuntu/Dockerfile
index 110208752..a0ef7d8db 100644
--- a/web-nginx-mysql/ubuntu/Dockerfile
+++ b/web-nginx-mysql/ubuntu/Dockerfile
@@ -89,9 +89,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     ./locale/make_mo.sh && \
     mkdir -p /var/lib/locales/supported.d/ && \
     rm -f /var/lib/locales/supported.d/local && \
diff --git a/web-nginx-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-mysql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-mysql/ubuntu/docker-entrypoint.sh b/web-nginx-mysql/ubuntu/docker-entrypoint.sh
index 89dcfe779..dc8db00b9 100755
--- a/web-nginx-mysql/ubuntu/docker-entrypoint.sh
+++ b/web-nginx-mysql/ubuntu/docker-entrypoint.sh
@@ -183,6 +183,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-pgsql/alpine/Dockerfile b/web-nginx-pgsql/alpine/Dockerfile
index 3afa26cb4..610990143 100644
--- a/web-nginx-pgsql/alpine/Dockerfile
+++ b/web-nginx-pgsql/alpine/Dockerfile
@@ -72,9 +72,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     chown --quiet -R zabbix:root /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chgrp -R 0 /etc/zabbix/ /usr/share/zabbix/modules/ && \
     chmod -R g=u /etc/zabbix/ /usr/share/zabbix/modules/ && \
diff --git a/web-nginx-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-pgsql/alpine/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-pgsql/alpine/docker-entrypoint.sh b/web-nginx-pgsql/alpine/docker-entrypoint.sh
index 9956ce804..e346b60ce 100755
--- a/web-nginx-pgsql/alpine/docker-entrypoint.sh
+++ b/web-nginx-pgsql/alpine/docker-entrypoint.sh
@@ -169,6 +169,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-pgsql/centos/Dockerfile b/web-nginx-pgsql/centos/Dockerfile
index b6c7af13c..c2596b207 100644
--- a/web-nginx-pgsql/centos/Dockerfile
+++ b/web-nginx-pgsql/centos/Dockerfile
@@ -66,9 +66,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/web-nginx-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-pgsql/centos/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-pgsql/centos/docker-entrypoint.sh b/web-nginx-pgsql/centos/docker-entrypoint.sh
index 88e2b01ca..674f173b6 100755
--- a/web-nginx-pgsql/centos/docker-entrypoint.sh
+++ b/web-nginx-pgsql/centos/docker-entrypoint.sh
@@ -169,6 +169,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/web-nginx-pgsql/ubuntu/Dockerfile b/web-nginx-pgsql/ubuntu/Dockerfile
index fc74fa605..374d83469 100644
--- a/web-nginx-pgsql/ubuntu/Dockerfile
+++ b/web-nginx-pgsql/ubuntu/Dockerfile
@@ -89,9 +89,11 @@ RUN set -eux && \
     rm -rf /usr/share/zabbix-${ZBX_VERSION}/ && \
     cd /usr/share/zabbix/ && \
     rm -f conf/zabbix.conf.php && \
+    rm -f conf/maintenance.inc.php && \
     rm -rf tests && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     ./locale/make_mo.sh && \
     mkdir -p /var/lib/locales/supported.d/ && \
     rm -f /var/lib/locales/supported.d/local && \
diff --git a/web-nginx-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php b/web-nginx-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/web-nginx-pgsql/ubuntu/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}
diff --git a/web-nginx-pgsql/ubuntu/docker-entrypoint.sh b/web-nginx-pgsql/ubuntu/docker-entrypoint.sh
index 697f464a5..05dca7834 100755
--- a/web-nginx-pgsql/ubuntu/docker-entrypoint.sh
+++ b/web-nginx-pgsql/ubuntu/docker-entrypoint.sh
@@ -169,6 +169,10 @@ prepare_zbx_web_config() {
         echo "listen.group = nginx" >> "$PHP_CONFIG_FILE"
     fi
 
+    export ZBX_DENY_GUI_ACCESS=${ZBX_DENY_GUI_ACCESS:-"false"}
+    export ZBX_GUI_ACCESS_IP_RANGE=${ZBX_GUI_ACCESS_IP_RANGE:-"['127.0.0.1']"}
+    export ZBX_GUI_WARNING_MSG=${ZBX_GUI_WARNING_MSG:-"Zabbix is under maintenance."}
+
     export ZBX_MAXEXECUTIONTIME=${ZBX_MAXEXECUTIONTIME:-"600"}
     export ZBX_MEMORYLIMIT=${ZBX_MEMORYLIMIT:-"128M"}
     export ZBX_POSTMAXSIZE=${ZBX_POSTMAXSIZE:-"16M"}
diff --git a/zabbix-appliance/rhel/Dockerfile b/zabbix-appliance/rhel/Dockerfile
index fcef8f943..d4b50d919 100644
--- a/zabbix-appliance/rhel/Dockerfile
+++ b/zabbix-appliance/rhel/Dockerfile
@@ -189,10 +189,12 @@ RUN set -eux && REPOLIST="rhel-8-for-x86_64-baseos-rpms,rhel-8-for-x86_64-appstr
     cd /tmp/ && \
     rm -rf /tmp/zabbix-${ZBX_VERSION}/ && \
     rm -f /usr/share/zabbix/conf/zabbix.conf.php && \
+    rm -f /usr/share/zabbix/conf/maintenance.inc.php && \
     rm -rf /usr/share/zabbix/tests/ && \
     cd /usr/share/zabbix/ && \
     ./locale/make_mo.sh && \
     ln -s "/etc/zabbix/web/zabbix.conf.php" "/usr/share/zabbix/conf/zabbix.conf.php" && \
+    ln -s "/etc/zabbix/web/maintenance.inc.php" "/usr/share/zabbix/conf/maintenance.inc.php" && \
     cat /usr/share/zabbix/include/locales.inc.php | grep display | grep true | awk '{$1=$1};1' | \
                 cut -d"'" -f 2 | sort | \
                 xargs -I '{}' bash -c 'echo "{}" && localedef -c -i {} -f UTF-8 {}.UTF-8 2>/dev/null' && \
diff --git a/zabbix-appliance/rhel/conf/etc/zabbix/web/maintenance.inc.php b/zabbix-appliance/rhel/conf/etc/zabbix/web/maintenance.inc.php
new file mode 100644
index 000000000..4bd4791e0
--- /dev/null
+++ b/zabbix-appliance/rhel/conf/etc/zabbix/web/maintenance.inc.php
@@ -0,0 +1,32 @@
+<?php
+/*
+** Zabbix
+** Copyright (C) 2001-2016 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+
+// Maintenance mode
+if (getenv('ZBX_DENY_GUI_ACCESS') == 'true') {
+    define('ZBX_DENY_GUI_ACCESS', 1);
+
+    // IP range, who are allowed to connect to FrontEnd
+    $ip_range = str_replace("'","\"",getenv('ZBX_GUI_ACCESS_IP_RANGE'));
+    $ZBX_GUI_ACCESS_IP_RANGE = (json_decode($ip_range)) ? json_decode($ip_range) : array();
+
+    // MSG shown on Warning screen!
+    $_REQUEST['warning_msg'] = getenv('ZBX_GUI_WARNING_MSG');
+}