# Installing debshots

The easiest way to deploy the application is using Ansible.

Take a fresh Debian Buster server (8 GB RAM recommended).
You can use an existing server but be aware that the Ansible
playbook will assume it can use the TCP ports 80 and 443 and
be able to add PostgreSQL database users.

On the server check out this Git repository from
https://salsa.debian.org/debian/debshots

Also install PIP to get a recent version of Ansible there:

    apt install python3-pip
    pip3 install ansible

Change to the *ansible* subdirectory and run the main playbook:

    cd ansible
    ansible-playbook debshots.yml

This will install PostgreSQL and Nginx, create a database, create a system user
and do various configuration.

Make sure that you set the environment variables as described in README.SSO.md before
you start the Rails application. Otherwise most single sign-on providers cannot work.
You also need to get the https://salsa.debian.org/debsso-team/debsso/raw/master/update-debsso-ca
script and run it in /etc/nginx to update the certficate and CRL used by the Debian
single-sign-on provider.

The production configuration uses Nginx that decrypts HTTPS and either serves static
assets (images, Javascript, CSS) itself or requests for dynamic content to the
Rails application. You will need a SSL certificate for Nginx. Just get one from
LetsEncrypt using the *certbot* tool.

Finally create an admin user for moderation:

Start a Rails console:

    rails c -e production

Create a new user record:

    user = User.create(realname: 'Christoph Haas', password: 'foobartest', email: 'email@christoph-haas.de')
    user.save!

## Cron jobs

Parse Nginx access logs to count the number of visits of each package:

    RAILS_ENV=production bundle exec rake debshots:accesslog2visits[/var/log/nginx/cache-access.log.1]

As a cron job:

    41 9 * * * cd $HOME/debshots ; RAILS_ENV=production /home/debshots/.rbenv/shims/bundle exec rake debshots:accesslog2visits[/var/log/nginx/cache-access.log.1]

Get the latest information on packages from the Debian repositories.

    bundle exec rails debshots:update_from_deb_repos RAILS_ENV=production
    bundle exec rails debshots:update_longdescription_from_deb_repos RAILS_ENV=production

# Authentication

This web application tries to avoid to create yet another directory
of user accounts. So it leverages other common web sites like StackExchange,
Debian SSO (using browser/client certificates) or GitHub as single-sign-on
services. It is still possible to create local user accounts for administrators
but registration is disabled.

Anonymous uploads are possible but they have to be moderated by an administrator.

# Authorization (not yet implemented)

A user can have one of these access levels.

## Anonymous

Without authentication all user actions are moderated. Such users can upload
screenshots or report existing/published screenshots as inappropriate. However
a user with level 'admin' will have to approve that action.

## Authenticated by single-sign-login (SSO)

Users can use different authentication services to login - like Github or
StackExchange. Such users internally get an account with a random password
created but they will keep logging in via SSO.

The first upload will have to be moderated. Subsequent uploads will be
approved automatically.

## Authenticated by Debian signle-sign-login (SSO)

If a user authenticates using a Debian SSO client certificate they will be
able to upload screenshots without moderation.
(Anohter idea was to restrict them to uploading only screenshots for the
packages they maintain. But that may be reliable and is not implemented at
this time.)

## Administrator

Such a user has an internal user account. The database record has the
'admin' field set to 1. Admins can freely upload, moderate and delete
screenshots. They can also read the log files.

# Nginx during development

During development it is advised to run Nginx to proxy ports 3000 (HTTP)
and 3001 (HTTPS) to the rails application.

    cd nginx
    nginx -c `pwd`/nginx.conf

The SSL certitificate is just a self-signed certificate with the
common name "localhost". It was generated using:

    openssl req -x509 -newkey 4096 -nodes -keyout localhost.key -out localhost.crt -days 3650

Run "rails s" in another window. That will use the built-in Ruby 'Puma'
application server that can also be used in production. It requires less
configuration than Phusion Passenger but may be slower in regard to
performance and multi-threading / multi-core support.

If you get "400 Bad Request / The SSL certificate error" in the browser then
please check the error log (/tmp/error*). Once cause is that the CRL of
the Debian SSO has expired and needs to be updated.

# Tidy up the screenshot data:

bundle exec rake debshots:remove_broken_screenshots

bundle exec rake debshots:remove_duplicate_images

# Frequent update of Debian SSO certificate

Run /etc/nginx/update-sso-ca regularly to update the CA certificate and the CRL.
The CRL (certificate revocation list) is only valid for three days. So make sure
you have a daily cron job for the updates. Do not forget to restart Nginx afterwards.

Otherwise you will end up with this error message:

    400 Bad Request
    The SSL certificate error
    nginx
