diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 000000000..9642e92f6
--- /dev/null
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,22 @@
+## The problem
+
+...
+
+## Solution
+
+...
+
+## PR Status
+
+...
+
+## How to test
+
+...
+
+## Validation
+
+- [ ] Principle agreement 0/2 : 
+- [ ] Quick review 0/1 : 
+- [ ] Simple test 0/1 : 
+- [ ] Deep review 0/1 : 
diff --git a/data/helpers.d/backend b/data/helpers.d/backend
index c32ef02ac..8fef412cf 100644
--- a/data/helpers.d/backend
+++ b/data/helpers.d/backend
@@ -22,12 +22,12 @@ ynh_use_logrotate () {
 	fi
 	if [ $# -gt 0 ]; then
 		if [ "$(echo ${1##*.})" == "log" ]; then	# Keep only the extension to check if it's a logfile
-			logfile=$1	# In this case, focus logrotate on the logfile
+			local logfile=$1	# In this case, focus logrotate on the logfile
 		else
-			logfile=$1/*.log	# Else, uses the directory and all logfile into it.
+			local logfile=$1/*.log	# Else, uses the directory and all logfile into it.
 		fi
 	else
-		logfile="/var/log/${app}/*.log" # Without argument, use a defaut directory in /var/log
+		local logfile="/var/log/${app}/*.log" # Without argument, use a defaut directory in /var/log
 	fi
 	cat > ./${app}-logrotate << EOF	# Build a config file for logrotate
 $logfile {
@@ -97,7 +97,7 @@ ynh_add_systemd_config () {
 #
 # usage: ynh_remove_systemd_config
 ynh_remove_systemd_config () {
-	finalsystemdconf="/etc/systemd/system/$app.service"
+	local finalsystemdconf="/etc/systemd/system/$app.service"
 	if [ -e "$finalsystemdconf" ]; then
 		sudo systemctl stop $app
 		sudo systemctl disable $app
@@ -124,7 +124,7 @@ ynh_add_nginx_config () {
 	# Substitute in a nginx config file only if the variable is not empty
 	if test -n "${path_url:-}"; then
 		# path_url_slash_less is path_url, or a blank value if path_url is only '/'
-		path_url_slash_less=${path_url%/}
+		local path_url_slash_less=${path_url%/}
 		ynh_replace_string "__PATH__/" "$path_url_slash_less/" "$finalnginxconf"
 		ynh_replace_string "__PATH__" "$path_url" "$finalnginxconf"
 	fi
diff --git a/data/helpers.d/filesystem b/data/helpers.d/filesystem
index 6fb073e06..6361d278e 100644
--- a/data/helpers.d/filesystem
+++ b/data/helpers.d/filesystem
@@ -180,12 +180,12 @@ ynh_restore_file () {
     local ARCHIVE_PATH="$YNH_CWD${ORIGIN_PATH}"
     # Default value for DEST_PATH = /$ORIGIN_PATH
     local DEST_PATH="${2:-$ORIGIN_PATH}"
-    
+
     # If ARCHIVE_PATH doesn't exist, search for a corresponding path in CSV
     if [ ! -d "$ARCHIVE_PATH" ] && [ ! -f "$ARCHIVE_PATH" ] && [ ! -L "$ARCHIVE_PATH" ]; then
         ARCHIVE_PATH="$YNH_BACKUP_DIR/$(_get_archive_path \"$ORIGIN_PATH\")"
     fi
-    
+
     # Restore ORIGIN_PATH into DEST_PATH
     mkdir -p $(dirname "$DEST_PATH")
 
@@ -258,7 +258,7 @@ ynh_backup_if_checksum_is_different () {
 	then	# Proceed only if a value was stored into the app settings
 		if ! echo "$checksum_value $file" | sudo md5sum -c --status
 		then	# If the checksum is now different
-			backup_file="/home/yunohost.conf/backup/$file.backup.$(date '+%Y%m%d.%H%M%S')"
+			local backup_file="/home/yunohost.conf/backup/$file.backup.$(date '+%Y%m%d.%H%M%S')"
 			sudo mkdir -p "$(dirname "$backup_file")"
 			sudo cp -a "$file" "$backup_file"	# Backup the current file
 			echo "File $file has been manually modified since the installation or last upgrade. So it has been duplicated in $backup_file" >&2
@@ -272,8 +272,8 @@ ynh_backup_if_checksum_is_different () {
 # usage: ynh_secure_remove path_to_remove
 # | arg: path_to_remove - File or directory to remove
 ynh_secure_remove () {
-	path_to_remove=$1
-	forbidden_path=" \
+	local path_to_remove=$1
+	local forbidden_path=" \
 	/var/www \
 	/home/yunohost.app"
 
diff --git a/data/helpers.d/ip b/data/helpers.d/ip
index cb507b35a..874675c9d 100644
--- a/data/helpers.d/ip
+++ b/data/helpers.d/ip
@@ -8,12 +8,12 @@
 ynh_validate_ip()
 {
   # http://stackoverflow.com/questions/319279/how-to-validate-ip-address-in-python#319298
-  
-  IP_ADDRESS_FAMILY=$1
-  IP_ADDRESS=$2
-  
+
+  local IP_ADDRESS_FAMILY=$1
+  local IP_ADDRESS=$2
+
   [ "$IP_ADDRESS_FAMILY" == "4" ] || [ "$IP_ADDRESS_FAMILY" == "6" ] || return 1
-  
+
   python /dev/stdin << EOF
 import socket
 import sys
diff --git a/data/helpers.d/mysql b/data/helpers.d/mysql
index 42c204f95..56741ec0e 100644
--- a/data/helpers.d/mysql
+++ b/data/helpers.d/mysql
@@ -40,9 +40,9 @@ ynh_mysql_execute_file_as_root() {
 # | arg: user - the user to grant privilegies
 # | arg: pwd - the password to identify user by
 ynh_mysql_create_db() {
-    db=$1
+    local db=$1
 
-    sql="CREATE DATABASE ${db};"
+    local sql="CREATE DATABASE ${db};"
 
     # grant all privilegies to user
     if [[ $# -gt 1 ]]; then
@@ -159,6 +159,6 @@ ynh_mysql_remove_db () {
 # | arg: name - name to correct/sanitize
 # | ret: the corrected name
 ynh_sanitize_dbid () {
-	dbid=${1//[-.]/_}	# We should avoid having - and . in the name of databases. They are replaced by _
+	local dbid=${1//[-.]/_}	# We should avoid having - and . in the name of databases. They are replaced by _
 	echo $dbid
 }
diff --git a/data/helpers.d/network b/data/helpers.d/network
index c6764c1f5..f9e37e6cc 100644
--- a/data/helpers.d/network
+++ b/data/helpers.d/network
@@ -11,7 +11,7 @@
 # usage: ynh_normalize_url_path path_to_normalize
 # | arg: url_path_to_normalize - URL path to normalize before using it
 ynh_normalize_url_path () {
-	path_url=$1
+	local path_url=$1
 	test -n "$path_url" || ynh_die "ynh_normalize_url_path expect a URL path as first argument and received nothing."
 	if [ "${path_url:0:1}" != "/" ]; then    # If the first character is not a /
 		path_url="/$path_url"    # Add / at begin of path variable
@@ -29,7 +29,7 @@ ynh_normalize_url_path () {
 # usage: ynh_find_port begin_port
 # | arg: begin_port - port to start to search
 ynh_find_port () {
-	port=$1
+	local port=$1
 	test -n "$port" || ynh_die "The argument of ynh_find_port must be a valid port."
 	while netcat -z 127.0.0.1 $port       # Check if the port is free
 	do
diff --git a/data/helpers.d/package b/data/helpers.d/package
index 2e60d723e..c616105d1 100644
--- a/data/helpers.d/package
+++ b/data/helpers.d/package
@@ -80,15 +80,15 @@ ynh_package_autopurge() {
 # usage: ynh_package_install_from_equivs controlfile
 # | arg: controlfile - path of the equivs control file
 ynh_package_install_from_equivs () {
-    controlfile=$1
+    local controlfile=$1
 
     # Check if the equivs package is installed. Or install it.
     ynh_package_is_installed 'equivs' \
         || ynh_package_install equivs
 
     # retrieve package information
-    pkgname=$(grep '^Package: ' $controlfile | cut -d' ' -f 2)	# Retrieve the name of the debian package
-    pkgversion=$(grep '^Version: ' $controlfile | cut -d' ' -f 2)	# And its version number
+    local pkgname=$(grep '^Package: ' $controlfile | cut -d' ' -f 2)	# Retrieve the name of the debian package
+    local pkgversion=$(grep '^Version: ' $controlfile | cut -d' ' -f 2)	# And its version number
     [[ -z "$pkgname" || -z "$pkgversion" ]] \
         && echo "Invalid control file" && exit 1	# Check if this 2 variables aren't empty.
 
@@ -96,7 +96,7 @@ ynh_package_install_from_equivs () {
     ynh_package_update
 
     # Build and install the package
-    TMPDIR=$(mktemp -d)
+    local TMPDIR=$(mktemp -d)
     # Note that the cd executes into a sub shell
     # Create a fake deb package with equivs-build and the given control file
     # Install the fake package without its dependencies with dpkg
@@ -118,16 +118,17 @@ ynh_package_install_from_equivs () {
 # usage: ynh_install_app_dependencies dep [dep [...]]
 # | arg: dep - the package name to install in dependence
 ynh_install_app_dependencies () {
-    dependencies=$@
-    manifest_path="../manifest.json"
+    local dependencies=$@
+    local manifest_path="../manifest.json"
     if [ ! -e "$manifest_path" ]; then
     	manifest_path="../settings/manifest.json"	# Into the restore script, the manifest is not at the same place
     fi
-    version=$(grep '\"version\": ' "$manifest_path" | cut -d '"' -f 4)	# Retrieve the version number in the manifest file.
+
+    local version=$(grep '\"version\": ' "$manifest_path" | cut -d '"' -f 4)	# Retrieve the version number in the manifest file.
     if [ ${#version} -eq 0 ]; then
         version="1.0"
     fi
-    dep_app=${app//_/-}	# Replace all '_' by '-'
+    local dep_app=${app//_/-}	# Replace all '_' by '-'
 
     cat > /tmp/${dep_app}-ynh-deps.control << EOF	# Make a control file for equivs-build
 Section: misc
@@ -151,6 +152,6 @@ EOF
 #
 # usage: ynh_remove_app_dependencies
 ynh_remove_app_dependencies () {
-    dep_app=${app//_/-}	# Replace all '_' by '-'
+    local dep_app=${app//_/-}	# Replace all '_' by '-'
     ynh_package_autopurge ${dep_app}-ynh-deps	# Remove the fake package and its dependencies if they not still used.
 }
diff --git a/data/helpers.d/print b/data/helpers.d/print
index 36f4a120e..d9c8f1ec4 100644
--- a/data/helpers.d/print
+++ b/data/helpers.d/print
@@ -10,10 +10,10 @@ ynh_die() {
 # Simply duplicate the log, execute the yunohost command and replace the log without the result of this command
 # It's a very badly hack...
 ynh_no_log() {
-  ynh_cli_log=/var/log/yunohost/yunohost-cli.log
+  local ynh_cli_log=/var/log/yunohost/yunohost-cli.log
   sudo cp -a ${ynh_cli_log} ${ynh_cli_log}-move
   eval $@
-  exit_code=$?
+  local exit_code=$?
   sudo mv ${ynh_cli_log}-move ${ynh_cli_log}
   return $?
 }
diff --git a/data/helpers.d/string b/data/helpers.d/string
index fbf598738..43c4aab1a 100644
--- a/data/helpers.d/string
+++ b/data/helpers.d/string
@@ -24,19 +24,36 @@ ynh_replace_string () {
 	local delimit=@
 	local match_string=$1
 	local replace_string=$2
-	local workfile=$3
-
-        # Escape any backslash to preserve them as simple backslash.
-        match_string=${match_string//\\/"\\\\"}
-        replace_string=${replace_string//\\/"\\\\"}
-
-        # Escape the & character, who has a special function in sed.
-        match_string=${match_string//&/"\&"}
-        replace_string=${replace_string//&/"\&"}
-
+	local workfile=$
+  
 	# Escape the delimiter if it's in the string.
 	match_string=${match_string//${delimit}/"\\${delimit}"}
 	replace_string=${replace_string//${delimit}/"\\${delimit}"}
 
 	sudo sed --in-place "s${delimit}${match_string}${delimit}${replace_string}${delimit}g" "$workfile"
 }
+
+# Substitute/replace a special string by another in a file
+#
+# usage: ynh_replace_special_string match_string replace_string target_file
+# | arg: match_string - String to be searched and replaced in the file
+# | arg: replace_string - String that will replace matches
+# | arg: target_file - File in which the string will be replaced.
+#
+# This helper will use ynh_replace_string, but as you can use special
+# characters, you can't use some regular expressions and sub-expressions.
+ynh_replace_special_string () {
+	local match_string=$1
+	local replace_string=$2
+	local workfile=$3
+
+  # Escape any backslash to preserve them as simple backslash.
+  match_string=${match_string//\\/"\\\\"}
+  replace_string=${replace_string//\\/"\\\\"}
+
+	# Escape the & character, who has a special function in sed.
+	match_string=${match_string//&/"\&"}
+	replace_string=${replace_string//&/"\&"}
+
+	ynh_replace_string "$match_string" "$replace_string" "$workfile"
+}
diff --git a/data/helpers.d/system b/data/helpers.d/system
index 5f2ad385b..4bb941b7d 100644
--- a/data/helpers.d/system
+++ b/data/helpers.d/system
@@ -14,7 +14,7 @@
 # Usage: ynh_exit_properly is used only by the helper ynh_abort_if_errors.
 # You must not use it directly.
 ynh_exit_properly () {
-	exit_code=$?
+	local exit_code=$?
 	if [ "$exit_code" -eq 0 ]; then
 			exit 0	# Exit without error if the script ended correctly
 	fi
diff --git a/data/helpers.d/user b/data/helpers.d/user
index 0bb0736af..8e214691c 100644
--- a/data/helpers.d/user
+++ b/data/helpers.d/user
@@ -48,9 +48,9 @@ ynh_system_user_create () {
 	if ! ynh_system_user_exists "$1"	# Check if the user exists on the system
 	then	# If the user doesn't exist
 		if [ $# -ge 2 ]; then	# If a home dir is mentioned
-			user_home_dir="-d $2"
+			local user_home_dir="-d $2"
 		else
-			user_home_dir="--no-create-home"
+			local user_home_dir="--no-create-home"
 		fi
 		sudo useradd $user_home_dir --system --user-group $1 --shell /usr/sbin/nologin || ynh_die "Unable to create $1 system account"
 	fi
diff --git a/data/helpers.d/utils b/data/helpers.d/utils
index 2cb18c5c0..030fddcde 100644
--- a/data/helpers.d/utils
+++ b/data/helpers.d/utils
@@ -5,9 +5,9 @@
 # usage: ynh_get_plain_key key [subkey [subsubkey ...]]
 # | ret: string - the key's value
 ynh_get_plain_key() {
-    prefix="#"
-    founded=0
-    key=$1
+    local prefix="#"
+    local founded=0
+    local key=$1
     shift
     while read line; do
         if [[ "$founded" == "1" ]] ; then
@@ -36,7 +36,7 @@ ynh_get_plain_key() {
 #
 ynh_restore_upgradebackup () {
 	echo "Upgrade failed." >&2
-	app_bck=${app//_/-}	# Replace all '_' by '-'
+	local app_bck=${app//_/-}	# Replace all '_' by '-'
 	
         # Check if an existing backup can be found before removing and restoring the application.
 	if sudo yunohost backup list | grep -q $app_bck-pre-upgrade$backup_number
@@ -64,9 +64,9 @@ ynh_backup_before_upgrade () {
 		echo "This app doesn't have any backup script." >&2
 		return
 	fi
-	backup_number=1
-	old_backup_number=2
-	app_bck=${app//_/-}	# Replace all '_' by '-'
+	local backup_number=1
+	local old_backup_number=2
+	local app_bck=${app//_/-}	# Replace all '_' by '-'
 
 	# Check if a backup already exists with the prefix 1
 	if sudo yunohost backup list | grep -q $app_bck-pre-upgrade1
@@ -94,7 +94,7 @@ ynh_backup_before_upgrade () {
 # Download, check integrity, uncompress and patch the source from app.src
 #
 # The file conf/app.src need to contains:
-# 
+#
 # SOURCE_URL=Address to download the app archive
 # SOURCE_SUM=Control sum
 # # (Optional) Program to check the integrity (sha256sum, md5sum...)
@@ -113,9 +113,9 @@ ynh_backup_before_upgrade () {
 # Details:
 # This helper downloads sources from SOURCE_URL if there is no local source
 # archive in /opt/yunohost-apps-src/APP_ID/SOURCE_FILENAME
-# 
+#
 # Next, it checks the integrity with "SOURCE_SUM_PRG -c --status" command.
-# 
+#
 # If it's ok, the source archive will be uncompressed in $dest_dir. If the
 # SOURCE_IN_SUBDIR is true, the first level directory of the archive will be
 # removed.
@@ -130,7 +130,7 @@ ynh_backup_before_upgrade () {
 ynh_setup_source () {
     local dest_dir=$1
     local src_id=${2:-app} # If the argument is not given, source_id equals "app"
-    
+
     # Load value from configuration file (see above for a small doc about this file
     # format)
     local src_url=$(grep 'SOURCE_URL=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
@@ -139,7 +139,7 @@ ynh_setup_source () {
     local src_format=$(grep 'SOURCE_FORMAT=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
     local src_in_subdir=$(grep 'SOURCE_IN_SUBDIR=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
     local src_filename=$(grep 'SOURCE_FILENAME=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
-    
+
     # Default value
     src_sumprg=${src_sumprg:-sha256sum}
     src_in_subdir=${src_in_subdir:-true}
@@ -216,10 +216,11 @@ ynh_setup_source () {
 # | arg: ...         - (Optionnal) More POST keys and values
 ynh_local_curl () {
 	# Define url of page to curl
-	full_page_url=https://localhost$path_url$1
+	local full_page_url=https://localhost$path_url$1
 
 	# Concatenate all other arguments with '&' to prepare POST data
-	POST_data=""
+	local POST_data=""
+	local arg=""
 	for arg in "${@:2}"
 	do
 		POST_data="${POST_data}${arg}&"
diff --git a/data/templates/ssh/sshd_config b/data/templates/ssh/sshd_config
index 695ea0d36..8c5a7fb95 100644
--- a/data/templates/ssh/sshd_config
+++ b/data/templates/ssh/sshd_config
@@ -66,6 +66,9 @@ PrintLastLog yes
 TCPKeepAlive yes
 #UseLogin no
 
+# keep ssh sessions fresh
+ClientAliveInterval 60
+
 #MaxStartups 10:30:60
 Banner /etc/issue.net
 
diff --git a/locales/en.json b/locales/en.json
index 8dac6e799..0aa8798fd 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -16,24 +16,26 @@
     "app_change_url_success": "Successfully changed {app:s} url to {domain:s}{path:s}",
     "app_extraction_failed": "Unable to extract installation files",
     "app_id_invalid": "Invalid app id",
-    "app_incompatible": "The app is incompatible with your YunoHost version",
+    "app_incompatible": "The app {app} is incompatible with your YunoHost version",
     "app_install_files_invalid": "Invalid installation files",
-    "app_location_already_used": "An app is already installed in this location",
-    "app_location_install_failed": "Unable to install the app in this location",
+    "app_location_already_used": "The app '{app}' is already installed on that location ({path})",
+    "app_make_default_location_already_used": "Can't make the app '{app}' the default on the domain {domain} is already used by the other app '{other_app}'",
+    "app_location_install_failed": "Unable to install the app in this location because it conflit with the app '{other_app}' already installed on '{other_path}'",
     "app_location_unavailable": "This url is not available or conflicts with an already installed app",
     "app_manifest_invalid": "Invalid app manifest: {error}",
     "app_no_upgrade": "No app to upgrade",
     "app_not_correctly_installed": "{app:s} seems to be incorrectly installed",
     "app_not_installed": "{app:s} is not installed",
     "app_not_properly_removed": "{app:s} has not been properly removed",
-    "app_package_need_update": "The app package needs to be updated to follow YunoHost changes",
+    "app_package_need_update": "The app {app} package needs to be updated to follow YunoHost changes",
     "app_removed": "{app:s} has been removed",
-    "app_requirements_checking": "Checking required packages...",
-    "app_requirements_failed": "Unable to meet requirements: {error}",
-    "app_requirements_unmeet": "Requirements are not met, the package {pkgname} ({version}) must be {spec}",
+    "app_requirements_checking": "Checking required packages for {app}...",
+    "app_requirements_failed": "Unable to meet requirements for {app}: {error}",
+    "app_requirements_unmeet": "Requirements are not met for {app}, the package {pkgname} ({version}) must be {spec}",
     "app_sources_fetch_failed": "Unable to fetch sources files",
     "app_unknown": "Unknown app",
     "app_unsupported_remote_type": "Unsupported remote type used for the app",
+    "app_upgrade_app_name": "Upgrading app {app}...",
     "app_upgrade_failed": "Unable to upgrade {app:s}",
     "app_upgrade_some_app_failed": "Unable to upgrade some applications",
     "app_upgraded": "{app:s} has been upgraded",
diff --git a/src/yunohost/app.py b/src/yunohost/app.py
index 403e76cc4..15855753c 100644
--- a/src/yunohost/app.py
+++ b/src/yunohost/app.py
@@ -330,6 +330,9 @@ def app_info(app, show_status=False, raw=False):
     if not _is_installed(app):
         raise MoulinetteError(errno.EINVAL,
                               m18n.n('app_not_installed', app=app))
+
+    app_setting_path = APPS_SETTING_PATH + app
+
     if raw:
         ret = app_list(filter=app, raw=True)[app]
         ret['settings'] = _get_app_settings(app)
@@ -345,11 +348,10 @@ def app_info(app, show_status=False, raw=False):
             upgradable = "no"
 
         ret['upgradable'] = upgradable
+        ret['change_url'] = os.path.exists(os.path.join(app_setting_path, "scripts", "change_url"))
 
         return ret
 
-    app_setting_path = APPS_SETTING_PATH + app
-
     # Retrieve manifest and status
     with open(app_setting_path + '/manifest.json') as f:
         manifest = json.loads(str(f.read()))
@@ -555,6 +557,7 @@ def app_upgrade(auth, app=[], url=None, file=None):
     logger.info("Upgrading apps %s", ", ".join(app))
 
     for app_instance_name in apps:
+        logger.warning(m18n.n('app_upgrade_app_name', app=app_instance_name))
         installed = _is_installed(app_instance_name)
         if not installed:
             raise MoulinetteError(errno.ENOPKG,
@@ -580,7 +583,7 @@ def app_upgrade(auth, app=[], url=None, file=None):
             continue
 
         # Check requirements
-        _check_manifest_requirements(manifest)
+        _check_manifest_requirements(manifest, app_instance_name=app_instance_name)
 
         app_setting_path = APPS_SETTING_PATH + '/' + app_instance_name
 
@@ -621,10 +624,13 @@ def app_upgrade(auth, app=[], url=None, file=None):
             with open(app_setting_path + '/status.json', 'w+') as f:
                 json.dump(status, f)
 
-            # Replace scripts and manifest
-            os.system('rm -rf "%s/scripts" "%s/manifest.json"' % (app_setting_path, app_setting_path))
+            # Replace scripts and manifest and conf (if exists)
+            os.system('rm -rf "%s/scripts" "%s/manifest.json %s/conf"' % (app_setting_path, app_setting_path, app_setting_path))
             os.system('mv "%s/manifest.json" "%s/scripts" %s' % (extracted_app_folder, extracted_app_folder, app_setting_path))
 
+            if os.path.exists(os.path.join(extracted_app_folder, "conf")):
+                os.system('cp -R %s/conf %s' % (extracted_app_folder, app_setting_path))
+
             # So much win
             upgraded_apps.append(app_instance_name)
             logger.success(m18n.n('app_upgraded', app=app_instance_name))
@@ -683,7 +689,7 @@ def app_install(auth, app, label=None, args=None, no_remove_on_failure=False):
     app_id = manifest['id']
 
     # Check requirements
-    _check_manifest_requirements(manifest)
+    _check_manifest_requirements(manifest, app_id)
 
     # Check if app can be forked
     instance_number = _installed_instance_number(app_id, last=True) + 1
@@ -733,6 +739,9 @@ def app_install(auth, app, label=None, args=None, no_remove_on_failure=False):
     os.system('cp %s/manifest.json %s' % (extracted_app_folder, app_setting_path))
     os.system('cp -R %s/scripts %s' % (extracted_app_folder, app_setting_path))
 
+    if os.path.exists(os.path.join(extracted_app_folder, "conf")):
+        os.system('cp -R %s/conf %s' % (extracted_app_folder, app_setting_path))
+
     # Execute the app install script
     install_retcode = 1
     try:
@@ -1016,7 +1025,9 @@ def app_makedefault(auth, app, domain=None):
 
     if '/' in app_map(raw=True)[domain]:
         raise MoulinetteError(errno.EEXIST,
-                              m18n.n('app_location_already_used'))
+                              m18n.n('app_make_default_location_already_used',
+                                     app=app, domain=app_domain,
+                                     other_app=app_map(raw=True)[domain]["/"]["id"]))
 
     try:
         with open('/etc/ssowat/conf.json.persistent') as json_conf:
@@ -1169,10 +1180,13 @@ def app_checkurl(auth, url, app=None):
                 continue
             if path == p:
                 raise MoulinetteError(errno.EINVAL,
-                                      m18n.n('app_location_already_used'))
+                                      m18n.n('app_location_already_used',
+                                             app=a["id"], path=path))
+            # can't install "/a/b/" if "/a/" exists
             elif path.startswith(p) or p.startswith(path):
                 raise MoulinetteError(errno.EPERM,
-                                      m18n.n('app_location_install_failed'))
+                                      m18n.n('app_location_install_failed',
+                                             other_path=p, other_app=a['id']))
 
     if app is not None and not installed:
         app_setting(app, 'domain', value=domain)
@@ -1689,7 +1703,7 @@ def _encode_string(value):
     return value
 
 
-def _check_manifest_requirements(manifest):
+def _check_manifest_requirements(manifest, app_instance_name):
     """Check if required packages are met from the manifest"""
     requirements = manifest.get('requirements', dict())
 
@@ -1707,12 +1721,12 @@ def _check_manifest_requirements(manifest):
         if (not yunohost_req or
                 not packages.SpecifierSet(yunohost_req) & '>= 2.3.6'):
             raise MoulinetteError(errno.EINVAL, '{0}{1}'.format(
-                m18n.g('colon', m18n.n('app_incompatible')),
-                m18n.n('app_package_need_update')))
+                m18n.g('colon', m18n.n('app_incompatible'), app=app_instance_name),
+                m18n.n('app_package_need_update', app=app_instance_name)))
     elif not requirements:
         return
 
-    logger.info(m18n.n('app_requirements_checking'))
+    logger.info(m18n.n('app_requirements_checking', app=app_instance_name))
 
     # Retrieve versions of each required package
     try:
@@ -1721,7 +1735,7 @@ def _check_manifest_requirements(manifest):
     except packages.PackageException as e:
         raise MoulinetteError(errno.EINVAL,
                               m18n.n('app_requirements_failed',
-                                     error=str(e)))
+                                     error=str(e), app=app_instance_name))
 
     # Iterate over requirements
     for pkgname, spec in requirements.items():
@@ -1730,7 +1744,7 @@ def _check_manifest_requirements(manifest):
             raise MoulinetteError(
                 errno.EINVAL, m18n.n('app_requirements_unmeet',
                                      pkgname=pkgname, version=version,
-                                     spec=spec))
+                                     spec=spec, app=app_instance_name))
 
 
 def _parse_args_from_manifest(manifest, action, args={}, auth=None):
diff --git a/src/yunohost/domain.py b/src/yunohost/domain.py
index f828b0973..727a63df3 100644
--- a/src/yunohost/domain.py
+++ b/src/yunohost/domain.py
@@ -188,17 +188,17 @@ def domain_dns_conf(domain, ttl=None):
 
     result = ""
 
-    result += "# Basic ipv4/ipv6 records"
+    result += "; Basic ipv4/ipv6 records"
     for record in dns_conf["basic"]:
         result += "\n{name} {ttl} IN {type} {value}".format(**record)
 
     result += "\n\n"
-    result += "# XMPP"
+    result += "; XMPP"
     for record in dns_conf["xmpp"]:
         result += "\n{name} {ttl} IN {type} {value}".format(**record)
 
     result += "\n\n"
-    result += "# Mail"
+    result += "; Mail"
     for record in dns_conf["mail"]:
         result += "\n{name} {ttl} IN {type} {value}".format(**record)
 
diff --git a/src/yunohost/service.py b/src/yunohost/service.py
index 5401a1fab..f0948c961 100644
--- a/src/yunohost/service.py
+++ b/src/yunohost/service.py
@@ -498,15 +498,12 @@ def _run_service_command(action, service):
         raise MoulinetteError(errno.EINVAL, m18n.n('service_unknown', service=service))
 
     cmd = None
-    if action in ['start', 'stop', 'restart', 'reload']:
-        cmd = 'service %s %s' % (service, action)
-    elif action in ['enable', 'disable']:
-        arg = 'defaults' if action == 'enable' else 'remove'
-        cmd = 'update-rc.d %s %s' % (service, arg)
+    if action in ['start', 'stop', 'restart', 'reload', 'enable', 'disable']:
+        cmd = 'systemctl %s %s' % (action, service)
     else:
         raise ValueError("Unknown action '%s'" % action)
 
-    need_lock = (services[service].get('need_lock') or False) \
+    need_lock = services[service].get('need_lock', False) \
                 and action in ['start', 'stop', 'restart', 'reload']
 
     try:
diff --git a/src/yunohost/tools.py b/src/yunohost/tools.py
index 042671125..70a757d03 100644
--- a/src/yunohost/tools.py
+++ b/src/yunohost/tools.py
@@ -42,12 +42,13 @@ import apt.progress
 from moulinette import msettings, msignals, m18n
 from moulinette.core import MoulinetteError, init_authenticator
 from moulinette.utils.log import getActionLogger
+from moulinette.utils.process import check_output
 from moulinette.utils.filesystem import read_json, write_to_json
 from yunohost.app import app_fetchlist, app_info, app_upgrade, app_ssowatconf, app_list, _install_appslist_fetch_cron
 from yunohost.domain import domain_add, domain_list, get_public_ip, _get_maindomain, _set_maindomain
 from yunohost.dyndns import _dyndns_available, _dyndns_provides
 from yunohost.firewall import firewall_upnp
-from yunohost.service import service_status, service_regen_conf, service_log
+from yunohost.service import service_status, service_regen_conf, service_log, service_start, service_enable
 from yunohost.monitor import monitor_disk, monitor_system
 from yunohost.utils.packages import ynh_packages_version
 
@@ -398,8 +399,8 @@ def tools_postinstall(domain, password, ignore_dyndns=False):
     os.system('touch /etc/yunohost/installed')
 
     # Enable and start YunoHost firewall at boot time
-    os.system('update-rc.d yunohost-firewall enable')
-    os.system('service yunohost-firewall start &')
+    service_enable("yunohost-firewall")
+    service_start("yunohost-firewall")
 
     service_regen_conf(force=True)
     logger.success(m18n.n('yunohost_configured'))
@@ -589,6 +590,9 @@ def tools_diagnosis(auth, private=False):
             'swap': '%s (%s free)' % (system['memory']['swap']['total'], system['memory']['swap']['free']),
         }
 
+    # nginx -t
+    diagnosis['nginx'] = check_output("nginx -t").strip().split("\n")
+
     # Services status
     services = service_status()
     diagnosis['services'] = {}
diff --git a/src/yunohost/utils/packages.py b/src/yunohost/utils/packages.py
index 9242d22d1..7df311406 100644
--- a/src/yunohost/utils/packages.py
+++ b/src/yunohost/utils/packages.py
@@ -414,13 +414,29 @@ def get_installed_version(*pkgnames, **kwargs):
             if strict:
                 raise UnknownPackage(pkgname)
             logger.warning(m18n.n('package_unknown', pkgname=pkgname))
+            continue
+
         try:
             version = pkg.installed.version
         except AttributeError:
             if strict:
                 raise UninstalledPackage(pkgname)
             version = None
-        versions[pkgname] = version
+
+        try:
+            # stable, testing, unstable
+            repo = pkg.installed.origins[0].component
+        except AttributeError:
+            if strict:
+                raise UninstalledPackage(pkgname)
+            repo = ""
+
+        versions[pkgname] = {
+            "version": version,
+            # when we don't have component it's because it's from a local
+            # install or from an image (like in vagrant)
+            "repo": repo if repo else "local",
+        }
 
     if len(pkgnames) == 1 and not as_dict:
         return versions[pkgnames[0]]
@@ -436,6 +452,9 @@ def meets_version_specifier(pkgname, specifier):
 # YunoHost related methods ---------------------------------------------------
 
 def ynh_packages_version(*args, **kwargs):
+    # from cli the received arguments are:
+    # (Namespace(_callbacks=deque([]), _tid='_global', _to_return={}), []) {}
+    # they don't seem to serve any purpose
     """Return the version of each YunoHost package"""
     return get_installed_version(
         'yunohost', 'yunohost-admin', 'moulinette', 'ssowat',