Web Server Configuration

The web interface provided by ARA is a simple Flask application. There are many ways to deploy and host a Flask application, here we cover two different ways which should help you get started.

In any case, ARA will need to be installed before you proceed. Refer to the documentation if you need to know how to install ARA.

Embedded server

ARA comes bundled with an embedded server meant for development or debugging purposes.

Note that any serious deployment should probably not be running off of this as it is not meant to be serving clients directly at any kind of scale.

To start the development server, use the provided ara-manage runserver command:

$ ara-manage runserver --help
usage: ara-manage runserver [-?] [-h HOST] [-p PORT] [--threaded]
                            [--processes PROCESSES] [--passthrough-errors]
                            [-d] [-D] [-r] [-R]

Runs the Flask development server i.e. app.run()

optional arguments:
  -?, --help            show this help message and exit
  -h HOST, --host HOST
  -p PORT, --port PORT
  --threaded
  --processes PROCESSES
  --passthrough-errors
  -d, --debug           enable the Werkzeug debugger (DO NOT use in production
                        code)
  -D, --no-debug        disable the Werkzeug debugger
  -r, --reload          monitor Python files for changes (not 100% safe for
                        production use)
  -R, --no-reload       do not monitor Python files for changes

To expose any non-default configurations to the development server (such as the database location), the same principles as usual apply – you need to have an ansible.cfg file or declare environment variables.

For example, to fire the server to listen on all IPv4 addresses on port 8080 while using a database at /tmp/ara.sqlite:

$ export ARA_DATABASE="sqlite:////tmp/ara.sqlite"
$ ara-manage runserver -h 0.0.0.0 -p 8080
 * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)

Apache+mod_wsgi

Note

ARA needs to be installed on the server where Apache will be running. Refer to the documentation if you need to know how to install ARA.

Fedora/CentOS/RHEL

Install Apache+mod_wsgi

yum install httpd mod_wsgi
systemctl enable httpd
systemctl start httpd

Create a directory for Ansible and ARA

This directory is where we will store the files that Apache will need to read and write to.

mkdir -p /var/www/ara

Copy ARA’s WSGI script to the web directory

ARA provides a WSGI script when it is installed: ara-wsgi. We need to copy it to the directory we just created, /var/www/ara.

The location where ara-wsgi is installed depends on how you installed ARA and the distribution you are running. You can use which to find where it is located:

cp -p $(which ara-wsgi) /var/www/ara/

Create the Ansible and ARA configuration

The defaults provided by ARA and Ansible are not suitable for a use case where we are deploying with Apache. We need to provide different settings:

cat <<EOF >/var/www/ara/ansible.cfg
[defaults]
# This directory is required to store temporary files for Ansible and ARA
local_tmp = /var/www/ara/.ansible/tmp

[ara]
# This will default the database and logs location to be inside that directory.
dir = /var/www/ara/.ara
EOF

For additional parameters, such as the database location or backend, look at the configuration documentation.

File permissions and SElinux

Make sure everything is owned by Apache so it can read and write to the directory:

chown -R apache:apache /var/www/ara

Additionally, if you are running with selinux enforcing, you need to allow Apache to manage the files in /var/www/ara. You can toggle the httpd_unified boolean for that:

setsebool -P httpd_unified 1

Apache configuration

Set up the Apache virtual host at /etc/httpd/conf.d/ara.conf:

<VirtualHost *:80>
    # Replace ServerName by your hostname
    ServerName ara.domain.tld

    ErrorLog /var/log/httpd/ara-error.log
    LogLevel warn
    CustomLog /var/log/httpd/ara-access.log combined

    WSGIDaemonProcess ara user=apache group=apache processes=4 threads=1
    WSGIScriptAlias / /var/www/ara/ara-wsgi

    SetEnv ANSIBLE_CONFIG /var/www/ara/ansible.cfg

    <Directory /var/www/ara>
        WSGIProcessGroup ara
        WSGIApplicationGroup %{GLOBAL}
        Require all granted
    </Directory>
</VirtualHost>

Restart Apache and you’re done:

systemctl restart httpd

You should now be able to access the web interface at the domain you set up !

Debian/Ubuntu

Install Apache+mod_wsgi

apt-get install apache2 libapache2-mod-wsgi
systemctl enable apache2
systemctl start apache2

Create the directory for Ansible and ARA

This directory is where we will store the files that Apache will need to read and write to.

mkdir -p /var/www/ara

Copy ARA’s WSGI script to the web directory

ARA provides a WSGI script when it is installed: ara-wsgi. We need to copy it to the directory we just created, /var/www/ara.

The location where ara-wsgi is installed depends on how you installed ARA and the distribution you are running. You can use which to find where it is located:

cp -p $(which ara-wsgi) /var/www/ara/

Create the Ansible and ARA configuration

The defaults provided by ARA and Ansible are not suitable for a use case where we are deploying with Apache. We need to provide different settings:

cat <<EOF >/var/www/ara/ansible.cfg
[defaults]
# This directory is required to store temporary files for Ansible and ARA
local_tmp = /var/www/ara/.ansible/tmp

[ara]
# This will default the database and logs location to be inside that directory.
dir = /var/www/ara/.ara
EOF

For additional parameters, such as the database location or backend, look at the configuration documentation.

File permissions

Make sure everything is owned by Apache so it can read and write to the directory:

chown -R www-data:www-data /var/www/ara

Apache configuration

Set up the Apache virtual host at /etc/apache2/sites-available/ara.conf:

<VirtualHost *:80>
    # Replace ServerName by your hostname
    ServerName ara.domain.tld

    ErrorLog /var/log/apache2/ara-error.log
    LogLevel warn
    CustomLog /var/log/apache2/ara-access.log combined

    WSGIDaemonProcess ara user=www-data group=www-data processes=4 threads=1
    WSGIScriptAlias / /var/www/ara/ara-wsgi

    SetEnv ANSIBLE_CONFIG /var/www/ara/ansible.cfg

    <Directory /var/www/ara>
        WSGIProcessGroup ara
        WSGIApplicationGroup %{GLOBAL}
        Require all granted
    </Directory>
</VirtualHost>

Ensure the configuration is enabled:

a2ensite ara

Restart Apache and you’re done:

systemctl restart apache2

You should now be able to access the web interface at the domain you set up !