Enhance install process by generating config files from templates (#275)

* Add a command to generate configuration examples

Config files are generated from templates (which remplace previous example files).

- solve the issue of hard-to-explain configuration examples
- ease pkg path seeking (avoid it, actually)
- add working defaults for sqlite and unix socket paths (instead of
  /replace/me/path/example)
- move settings comments from default_settings.py to ihatemoney.cfg.j2, as it is
  the one that will be facing user.

* Use generate-config command  in install doc

Also follow the new working defaults of templates for socket and db path.

* Fix doc settings table

On the long term, plaintext tables might destroy humanity.

* Mention templates dir URL in documentation

As requested by @almet

7 files changed, 138 insertions, 30 deletions

diff --git a/ihatemoney/conf-templates/apache-vhost.conf.j2 b/ihatemoney/conf-templates/apache-vhost.conf.j2
new file mode 100644
index 0000000..cb0167f
--- /dev/null
+++ b/ihatemoney/conf-templates/apache-vhost.conf.j2
@@ -0,0 +1,19 @@
+<VirtualHost *:80>
+    ServerAdmin admin@example.com      # CUSTOMIZE
+    ServerName ihatemoney.example.com  # CUSTOMIZE
+
+    WSGIDaemonProcess ihatemoney user=www-data group=www-data threads=5 python-path={{ pkg_path }} {% if venv_path %}python-home={{ venv_path }}{% endif %}
+    WSGIScriptAlias / {{ pkg_path }}/wsgi.py
+
+    ErrorLog /var/log/apache2/ihatemoney.example.com_error.log
+    CustomLog /var/log/apache2/ihatemoney.example.com_access.log combined
+
+    <Directory {{ pkg_path }}>
+       WSGIProcessGroup ihatemoney
+       WSGIApplicationGroup %{GLOBAL}
+       Order deny,allow
+       Allow from all
+    </Directory>
+
+    Alias /static/ {{ pkg_path }}/static/
+</VirtualHost>
diff --git a/ihatemoney/conf-templates/gunicorn.conf.py.j2 b/ihatemoney/conf-templates/gunicorn.conf.py.j2
new file mode 100644
index 0000000..2c4492d
--- /dev/null
+++ b/ihatemoney/conf-templates/gunicorn.conf.py.j2
@@ -0,0 +1,8 @@
+backlog = 2048
+daemon = False
+debug = True
+workers = 3
+# log to stdout,
+logfile = "-"   # Is the default setting for gunicorn>=20
+loglevel = "info"
+bind = "unix:/tmp/ihatemoney.gunicorn.sock"
diff --git a/ihatemoney/conf-templates/ihatemoney.cfg.j2 b/ihatemoney/conf-templates/ihatemoney.cfg.j2
new file mode 100644
index 0000000..5dfb9d4
--- /dev/null
+++ b/ihatemoney/conf-templates/ihatemoney.cfg.j2
@@ -0,0 +1,36 @@
+# You can find more information about what these settings mean in the
+# documentation, available online at
+# http://ihatemoney.readthedocs.io/en/latest/installation.html#configuration
+
+# Turn this on if you want to have more output on what's happening under the
+# hood. DO NOT TURN IT ON IN PRODUCTION.
+DEBUG = False
+
+# The database URI, reprensenting the type of database and how to connect to it.
+# Enter an absolute path here.
+SQLALCHEMY_DATABASE_URI = 'sqlite:///var/lib/ihatemoney/ihatemoney.sqlite'
+SQLACHEMY_ECHO = DEBUG
+
+# Will likely become the default value in flask-sqlalchemy >=3 ; could be removed
+# then:
+SQLALCHEMY_TRACK_MODIFICATIONS = False
+
+# This secret key is random and auto-generated, it protects cookies and user sessions
+SECRET_KEY = "{{ secret_key }}"
+
+# A python tuple describing the name and email adress of the sender of the mails.
+MAIL_DEFAULT_SENDER = ("Budget manager", "budget@notmyidea.org") # CUSTOMIZE
+
+# If set to True, a demonstration project will be activated.
+ACTIVATE_DEMO_PROJECT = True
+
+# If not empty, the specified password must be entered to create new projects.
+# DO NOT enter the password in cleartext. Generate a password hash with
+# "ihatemoney generate_password_hash" instead.
+ADMIN_PASSWORD = ""
+
+# If set to True (default value) anyone can create a new project.
+ALLOW_PUBLIC_PROJECT_CREATION = True
+
+# If set to True, an administration dashboard is available.
+ACTIVATE_ADMIN_DASHBOARD = False
diff --git a/ihatemoney/conf-templates/nginx.conf.j2 b/ihatemoney/conf-templates/nginx.conf.j2
new file mode 100644
index 0000000..42b45fc
--- /dev/null
+++ b/ihatemoney/conf-templates/nginx.conf.j2
@@ -0,0 +1,28 @@
+server {
+    server_name ihatemoney.example.com;  # CUSTOMIZE
+    keepalive_timeout 5;
+
+    location /static/ {
+        alias   {{ pkg_path }}/static/;
+    }
+    location / {
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header Host $http_host;
+        proxy_redirect off;
+        proxy_connect_timeout 90;
+        proxy_send_timeout 180;
+        proxy_read_timeout 180;
+        proxy_buffer_size 16k;
+        proxy_buffers 8 16k;
+        proxy_busy_buffers_size 32k;
+        proxy_intercept_errors on;
+        if (!-f $request_filename) {
+            proxy_pass http://ihatemoney_backend;
+            break;
+        }
+    }
+}
+
+upstream ihatemoney_backend {
+        server unix:/tmp/ihatemoney.gunicorn.sock;
+}
diff --git a/ihatemoney/conf-templates/supervisord.conf.j2 b/ihatemoney/conf-templates/supervisord.conf.j2
new file mode 100644
index 0000000..fa16c0c
--- /dev/null
+++ b/ihatemoney/conf-templates/supervisord.conf.j2
@@ -0,0 +1,6 @@
+[program:ihatemoney]
+command={{ venv_path }}/bin/gunicorn -c /etc/ihatemoney/gunicorn.conf.py ihatemoney.wsgi:application
+user=ihatemoney
+autostart=true
+autorestart=true
+redirect_stderr=true
diff --git a/ihatemoney/default_settings.py b/ihatemoney/default_settings.py
index c7ce297..6033d0a 100644
--- a/ihatemoney/default_settings.py
+++ b/ihatemoney/default_settings.py
@@ -1,37 +1,10 @@
-# You can find more information about what these settings mean in the
-# documentation, available online at
-# http://ihatemoney.readthedocs.io/en/latest/installation.html#configuration
-
-# Turn this on if you want to have more output on what's happening under the
-# hood.
-DEBUG = False
-
-# The database URI, reprensenting the type of database and how to connect to it.
-# Enter an absolute path here.
+# Verbose and documented settings are in conf-templates/ihatemoney.cfg.j2
+DEBUG = SQLACHEMY_ECHO = False
 SQLALCHEMY_DATABASE_URI = 'sqlite:////tmp/ihatemoney.db'
-SQLACHEMY_ECHO = DEBUG
-
-# Will likely become the default value in flask-sqlalchemy >=3 ; could be removed
-# then:
 SQLALCHEMY_TRACK_MODIFICATIONS = False
-
-# You need to change this secret key, otherwise bad things might happen to your
-# users.
 SECRET_KEY = "tralala"
-
-# A python tuple describing the name and email adress of the sender of the mails.
 MAIL_DEFAULT_SENDER = ("Budget manager", "budget@notmyidea.org")
-
-# If set to True, a demonstration project will be activated.
 ACTIVATE_DEMO_PROJECT = True
-
-# If not empty, the specified password must be entered to create new projects.
-# DO NOT enter the password in cleartext. Generate a password hash with
-# "ihatemoney generate_password_hash" instead.
 ADMIN_PASSWORD = ""
-
-# If set to True (default value) anyone can create a new project.
 ALLOW_PUBLIC_PROJECT_CREATION = True
-
-# If set to True, an administration dashboard is available.
 ACTIVATE_ADMIN_DASHBOARD = False
diff --git a/ihatemoney/manage.py b/ihatemoney/manage.py
index 6f63a98..c1821c5 100755
--- a/ihatemoney/manage.py
+++ b/ihatemoney/manage.py
@@ -1,8 +1,13 @@
 #!/usr/bin/env python
 
+import os
+import pkgutil
+import random
 from getpass import getpass
-from flask_script import Manager, Command
+
+from flask_script import Manager, Command, Option
 from flask_migrate import Migrate, MigrateCommand
+from jinja2 import Template
 from werkzeug.security import generate_password_hash
 
 from ihatemoney.run import create_app
@@ -18,6 +23,38 @@ class GeneratePasswordHash(Command):
         print(generate_password_hash(password))
 
 
+class ConfigTemplate(Command):
+    def get_options(self):
+        return [
+            Option('config_file', choices=[
+                'ihatemoney.cfg',
+                'apache-vhost.conf',
+                'gunicorn.conf.py',
+                'supervisord.conf',
+                'nginx.conf',
+            ]),
+        ]
+
+    @staticmethod
+    def gen_secret_key():
+        return ''.join([
+            random.SystemRandom().choice(
+                'abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*(-_=+)')
+            for i in range(50)])
+
+    def run(self, config_file):
+        template_content = pkgutil.get_data(
+            'ihatemoney',
+            os.path.join('conf-templates/', config_file) + '.j2'
+        ).decode('utf-8')
+
+        print(Template(template_content).render(
+                pkg_path=os.path.abspath(os.path.dirname(__file__)),
+                venv_path=os.environ.get('VIRTUAL_ENV'),
+                secret_key=self.gen_secret_key(),
+        ))
+
+
 def main():
     app = create_app()
     Migrate(app, db)
@@ -25,6 +62,7 @@ def main():
     manager = Manager(app)
     manager.add_command('db', MigrateCommand)
     manager.add_command('generate_password_hash', GeneratePasswordHash)
+    manager.add_command('generate-config', ConfigTemplate)
     manager.run()