Add jinja helper for apps

scripts/change_url

@@ -1,5 +1,6 @@
 #!/bin/bash
 
+source ./experimental_helper.sh
 source _common.sh
 source /usr/share/yunohost/helpers
 
@@ -7,9 +8,7 @@ ynh_systemd_action --service_name=$app --action="stop" --log_path="/var/log/$app
 
 ynh_change_url_nginx_config
 
-ynh_backup_if_checksum_is_different --file="$install_dir/coin/settings_local.py"
-ynh_render_template ../conf/local.py.j2 "$install_dir/coin/settings_local.py"
-ynh_store_file_checksum --file="$install_dir/coin/settings_local.py"
+ynh_add_jinja_config --template=local.py.j2 --destination="$install_dir/coin/settings_local.py"
 
 chmod 400 "$install_dir/coin/settings_local.py"
 chown $app "$install_dir/coin/settings_local.py"

scripts/experimental_helper.sh

@@ -0,0 +1,135 @@
+# Create a dedicated config file from a jinja template
+#
+# usage: ynh_add_jinja_config --template="template" --destination="destination"
+# | arg: -t, --template=     - Template config file to use
+# | arg: -d, --destination=  - Destination of the config file
+# | arg: -i, --ignore_vars=  - List separated by space of script variables to ignore and don't pass in the jinja context.
+# |                            This could be useful mainly for special share which can't be retried by reference name (like the array).
+#
+# examples:
+#    ynh_add_jinja_config --template="app.conf" --destination="$install_dir/app.conf"
+#    ynh_add_jinja_config --template="app-env" --destination="$install_dir/app-env" --ignore_vars="complex_array yolo"
+#
+# The template can be by default the name of a file in the conf directory
+#
+# The helper will verify the checksum and backup the destination file
+# if it's different before applying the new template.
+#
+# And it will calculate and store the destination file checksum
+# into the app settings when configuration is done.
+#
+##
+## About the variables passed to the template:
+##
+#
+# All variable defined in the script are available into the template (as string) except someone described below.
+# If a variable make crash the helper for some reason (by example if the variable is of type array)
+# or you just want to don't pass a specific variable for some other reason you can add it in the '--ignore_vars=' parameter as described above.
+# Here are the list of ignored variable and so there won't never be available in the template:
+# - All system environment variable like (TERM, USER, PATH, LANG, etc).
+#   If you need someone you just need to declare an other variable with the same value.
+#   Note that all Yunohost variable whose name begins by 'YNH_' are available and can be used in the template.
+# - This following list:
+#        legacy_args args_array template destination ignore_vars template_path python_env_var ignore_var_regex
+#        progress_scale progress_string0 progress_string1 progress_string2
+#        old changed binds types file_hash formats
+#
+##
+## Usage in templates:
+##
+#
+# For a full documentation of the template you can refer to: https://jinja.palletsprojects.com/en/3.1.x/templates/
+# In Yunohost context there are no really some specificity except that all variable passed are of type string.
+# So here are some example of recommended usage:
+#
+# If you need a conditional block
+#
+# {% if should_my_block_be_shown == 'true' %}
+# ...
+# {% endif %}
+#
+# or
+#
+# {% if should_my_block_be_shown == '1' %}
+# ...
+# {% endif %}
+#
+# If you need to iterate with loop:
+#
+# {% for yolo in var_with_multiline_value.splitlines() %}
+# ...
+# {% endfor %}
+#
+# or
+#
+# {% for jail in my_var_with_coma.split(',') %}
+# ...
+# {% endfor %}
+#
+ynh_add_jinja_config() {
+    # Declare an array to define the options of this helper.
+    local legacy_args=tdi
+    local -A args_array=([t]=template= [d]=destination= [i]=ignore_vars= )
+    local template
+    local destination
+    local ignore_vars
+    # Manage arguments with getopts
+    ynh_handle_getopts_args "$@"
+    local template_path
+
+    #
+    ## List of all vars ignored and not passed to the template
+    # WARNING Update the list on the helper documentation at the top of the helper, if you change this list
+    #
+
+    # local vars used in the helper
+    ignore_vars+=" legacy_args args_array template destination ignore_vars template_path python_env_var ignore_var_regex"
+    # yunohost helpers
+    ignore_vars+=" progress_scale progress_string0 progress_string1 progress_string2"
+    # Arrays used in config panel
+    ignore_vars+=" old changed binds types file_hash formats"
+
+    if [ -f "$YNH_APP_BASEDIR/conf/$template" ]; then
+        template_path="$YNH_APP_BASEDIR/conf/$template"
+    elif [ -f "$template" ]; then
+        template_path=$template
+    else
+        ynh_die --message="The provided template $template doesn't exist"
+    fi
+
+    ynh_backup_if_checksum_is_different --file="$destination"
+
+    # Make sure to set the permissions before we copy the file
+    # This is to cover a case where an attacker could have
+    # created a file beforehand to have control over it
+    # (cp won't overwrite ownership / modes by default...)
+    touch "$destination"
+    chown root:root "$destination"
+    chmod 640 "$destination"
+
+    local python_env_var=''
+    local ignore_var_regex
+    ignore_var_regex="$(echo "$ignore_vars" | sed -E 's@^\s*(.*\w)\s*$@\1@g' | sed -E 's@(\s+)@|@g')"
+    while read -r one_var; do
+        # Blacklist of var to not pass to template
+        if { [[ "$one_var" =~ ^[A-Z0-9_]+$ ]] && [[ "$one_var" != YNH_* ]]; } \
+            || [[ "$one_var" =~ ^($ignore_var_regex)$ ]]; then
+            continue
+        fi
+        # Well python is very bad for the last character on raw string
+        # https://stackoverflow.com/questions/647769/why-cant-pythons-raw-string-literals-end-with-a-single-backslash
+        # So the solution here is to add one last char '-' so we know what it is
+        # and we are sure that it not \ or ' or something else which will be problematic with python
+        # And then we remove it while we are processing
+        python_env_var+="$one_var=r'''${!one_var}-'''[:-1],"
+    done <<< "$(compgen -v)"
+
+    _ynh_apply_default_permissions "$destination"
+    (
+        python3 -c 'import os, sys, jinja2; sys.stdout.write(
+                    jinja2.Template(source=sys.stdin.read(),
+                                    undefined=jinja2.StrictUndefined,
+                    ).render('"$python_env_var"'));' <"$template_path" >"$destination"
+    )
+    ynh_store_file_checksum --file="$destination"
+}

scripts/install

@@ -1,9 +1,10 @@
 #!/bin/bash
 
+source ./experimental_helper.sh
 source _common.sh
 source /usr/share/yunohost/helpers
 
-export secret=$(ynh_string_random 24)
+secret=$(ynh_string_random 24)
 ynh_app_setting_set --app=$app --key=secret --value=$secret
 
 #=================================================
@@ -37,10 +38,9 @@ popd
 #=================================================
 ynh_script_progression --message="Configuring application..."
 
-export prefix="${path#"/"}/"
+prefix="${path#"/"}/"
 prefix=${prefix%"/"}
-ynh_render_template ../conf/local.py.j2 "$install_dir/coin/settings_local.py"
-ynh_store_file_checksum --file="$install_dir/coin/settings_local.py"
+ynh_add_jinja_config --template=local.py.j2 --destination="$install_dir/coin/settings_local.py"
 chmod 400 "$install_dir/coin/settings_local.py"
 chown $app "$install_dir/coin/settings_local.py"