diff --git a/data/helpers.d/backend b/data/helpers.d/backend
index c96315238..e710da9c7 100644
--- a/data/helpers.d/backend
+++ b/data/helpers.d/backend
@@ -288,3 +288,149 @@ ynh_remove_fpm_config () {
 	ynh_secure_remove --file="$fpm_config_dir/conf.d/20-$app.ini" 2>&1
 	sudo systemctl reload $fpm_service
 }
+
+# Create a dedicated fail2ban config (jail and filter conf files)
+#
+# usage 1: ynh_add_fail2ban_config --logpath=log_file --failregex=filter [--max_retry=max_retry] [--ports=ports]
+# | arg: -l, --logpath=   - Log file to be checked by fail2ban
+# | arg: -r, --failregex= - Failregex to be looked for by fail2ban
+# | arg: -m, --max_retry= - Maximum number of retries allowed before banning IP address - default: 3
+# | arg: -p, --ports=     - Ports blocked for a banned IP address - default: http,https
+#
+# -----------------------------------------------------------------------------
+#
+# usage 2: ynh_add_fail2ban_config --use_template [--others_var="list of others variables to replace"]
+# | arg: -t, --use_template - Use this helper in template mode
+# | arg: -v, --others_var=  - List of others variables to replace separeted by a space
+# |                           for example : 'var_1 var_2 ...'
+#
+# This will use a template in ../conf/f2b_jail.conf and ../conf/f2b_filter.conf
+#   __APP__      by  $app
+#
+#  You can dynamically replace others variables by example :
+#   __VAR_1__    by $var_1
+#   __VAR_2__    by $var_2
+#
+# Generally your template will look like that by example (for synapse):
+#
+# f2b_jail.conf:
+#     [__APP__]
+#     enabled = true
+#     port = http,https
+#     filter = __APP__
+#     logpath = /var/log/__APP__/logfile.log
+#     maxretry = 3
+#
+# f2b_filter.conf:
+#     [INCLUDES]
+#     before = common.conf
+#     [Definition]
+#
+#     # Part of regex definition (just used to make more easy to make the global regex)
+#     __synapse_start_line = .? \- synapse\..+ \-
+#
+#    # Regex definition.
+#    failregex = ^%(__synapse_start_line)s INFO \- POST\-(\d+)\- <HOST> \- \d+ \- Received request\: POST /_matrix/client/r0/login\??<SKIPLINES>%(__synapse_start_line)s INFO \- POST\-\1\- Got login request with identifier: \{u'type': u'm.id.user', u'user'\: u'(.+?)'\}, medium\: None, address: None, user\: u'\5'<SKIPLINES>%(__synapse_start_line)s WARNING \- \- (Attempted to login as @\5\:.+ but they do not exist|Failed password login for user @\5\:.+)$
+#
+#     ignoreregex =
+#
+# -----------------------------------------------------------------------------
+#
+# Note about the "failregex" option:
+#          regex to match the password failure messages in the logfile. The
+#          host must be matched by a group named "host". The tag "<HOST>" can
+#          be used for standard IP/hostname matching and is only an alias for
+#          (?:::f{4,6}:)?(?P<host>[\w\-.^_]+)
+#
+#          You can find some more explainations about how to make a regex here :
+#          https://www.fail2ban.org/wiki/index.php/MANUAL_0_8#Filters
+#
+# Note that the logfile need to exist before to call this helper !!
+#
+# To validate your regex you can test with this command:
+# fail2ban-regex /var/log/YOUR_LOG_FILE_PATH /etc/fail2ban/filter.d/YOUR_APP.conf
+#
+ynh_add_fail2ban_config () {
+  # Declare an array to define the options of this helper.
+  declare -Ar args_array=( [l]=logpath= [r]=failregex= [m]=max_retry= [p]=ports= [t]=use_template [v]=others_var=)
+  local logpath
+  local failregex
+  local max_retry
+  local ports
+  local others_var
+  local use_template
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  use_template="${use_template:-0}"
+  max_retry=${max_retry:-3}
+  ports=${ports:-http,https}
+
+  finalfail2banjailconf="/etc/fail2ban/jail.d/$app.conf"
+  finalfail2banfilterconf="/etc/fail2ban/filter.d/$app.conf"
+  ynh_backup_if_checksum_is_different "$finalfail2banjailconf"
+  ynh_backup_if_checksum_is_different "$finalfail2banfilterconf"
+
+  if [ $use_template -eq 1 ]
+  then
+    # Usage 2, templates
+    cp ../conf/f2b_jail.conf $finalfail2banjailconf
+    cp ../conf/f2b_filter.conf $finalfail2banfilterconf
+
+    if [ -n "${app:-}" ]
+    then
+      ynh_replace_string "__APP__" "$app" "$finalfail2banjailconf"
+      ynh_replace_string "__APP__" "$app" "$finalfail2banfilterconf"
+    fi
+
+    # Replace all other variable given as arguments
+    for var_to_replace in ${others_var:-}; do
+      # ${var_to_replace^^} make the content of the variable on upper-cases
+      # ${!var_to_replace} get the content of the variable named $var_to_replace
+      ynh_replace_string --match_string="__${var_to_replace^^}__" --replace_string="${!var_to_replace}" --target_file="$finalfail2banjailconf"
+      ynh_replace_string --match_string="__${var_to_replace^^}__" --replace_string="${!var_to_replace}" --target_file="$finalfail2banfilterconf"
+    done
+
+  else
+    # Usage 1, no template. Build a config file from scratch.
+    test -n "$logpath" || ynh_die "ynh_add_fail2ban_config expects a logfile path as first argument and received nothing."
+    test -n "$failregex" || ynh_die "ynh_add_fail2ban_config expects a failure regex as second argument and received nothing."
+
+    tee $finalfail2banjailconf <<EOF
+[$app]
+enabled = true
+port = $ports
+filter = $app
+logpath = $logpath
+maxretry = $max_retry
+EOF
+
+    tee $finalfail2banfilterconf <<EOF
+[INCLUDES]
+before = common.conf
+[Definition]
+failregex = $failregex
+ignoreregex =
+EOF
+  fi
+
+  # Common to usage 1 and 2.
+  ynh_store_file_checksum "$finalfail2banjailconf"
+  ynh_store_file_checksum "$finalfail2banfilterconf"
+
+  systemctl try-reload-or-restart fail2ban
+
+  local fail2ban_error="$(journalctl -u fail2ban | tail -n50 | grep "WARNING.*$app.*")"
+  if [[ -n "$fail2ban_error" ]]; then
+    ynh_print_err --message="Fail2ban failed to load the jail for $app"
+    ynh_print_warn --message="${fail2ban_error#*WARNING}"
+  fi
+}
+
+# Remove the dedicated fail2ban config (jail and filter conf files)
+#
+# usage: ynh_remove_fail2ban_config
+ynh_remove_fail2ban_config () {
+  ynh_secure_remove "/etc/fail2ban/jail.d/$app.conf"
+  ynh_secure_remove "/etc/fail2ban/filter.d/$app.conf"
+  systemctl try-reload-or-restart fail2ban
+}