.. _integrator_install_application:

Install an existing application
===============================

On this page we explain the procedure to build an application from
only the current application code.

If you want to use an existing database, you should ignore
all the commands concerning the database.

This guide assumes that:
 - all dependencies described in the :ref:`requirements <integrator_requirements>` are installed,
 - Git is used as revision control.

For specific environments, this page contains some notes to give some help.

Set up the database
-------------------

Any c2cgeoportal application requires a PostgreSQL/PostGIS database. The
application works with its own tables, which store users, layers, etc. These
tables are located in a specific schema of the database.

.. note::

    In a multi-project application architecture, multiple specific schemas
    must be used.

If the application has MapServer layers linked to PostGIS tables, these tables
and the application-specific tables must be in the same database, preferably in
separate schemas. This is required for layer access control (*restricted
layers*), where joining user/role tables to PostGIS layer tables is necessary.

.. _integrator_install_application_create_database:

Create the database
~~~~~~~~~~~~~~~~~~~

To create the database you can use:

.. prompt:: bash

    sudo -u postgres createdb <db_name> -T template_postgis

with ``<db_name>`` replaced by the actual database name.

.. note::

   If you do not have the template_postgis you can use:

   with Postgres >= 9.1 and PostGIS >= 2.1:

   .. prompt:: bash

       sudo -u postgres createdb -E UTF8 -T template0 <db_name>
       sudo -u postgres psql -c "CREATE EXTENSION postgis;" <db_name>

   with older versions:

   .. prompt:: bash

       sudo -u postgres createdb -E UTF8 -T template0 <db_name>
       sudo -u postgres psql -d <db_name> -f /usr/share/postgresql/9.1/contrib/postgis-2.1/postgis.sql
       sudo -u postgres psql -d <db_name> -f /usr/share/postgresql/9.1/contrib/postgis-2.1/spatial_ref_sys.sql

   Note that the path of the postgis scripts and the template name can
   differ on your host.

If you wish to use the "similarity" function within the
full-text search, create the ``pg_trgm`` extension:

.. prompt:: bash

  sudo -u postgres psql -c "CREATE EXTENSION pg_trgm" <db_name>

.. _integrator_install_application_create_schema:

Create the schemas
~~~~~~~~~~~~~~~~~~

Each application needs two application-specific schemas.
To create them, do:

.. prompt:: bash

    sudo -u postgres psql -c "CREATE SCHEMA <schema_name>;" <db_name>
    sudo -u postgres psql -c "CREATE SCHEMA <schema_name>_static;" <db_name>

with ``<db_name>`` and ``<schema_name>`` replaced by the actual database name,
and schema name ('main' by default), respectively.
Note that if you are using a multi-project, you need to define both schemas
for the parent and for each child.

.. _integrator_install_application_create_user:

Create a database user
~~~~~~~~~~~~~~~~~~~~~~

We use a specific user for the application, ``www-data`` by default.

.. note::

   It the user does not already exist in your database, create it first:

   .. prompt:: bash

        sudo -u postgres createuser -P <db_user>

Give the necessary rights to the user:

.. prompt:: bash

    sudo -u postgres psql -c 'GRANT SELECT ON TABLE spatial_ref_sys TO "www-data"' <db_name>
    sudo -u postgres psql -c 'GRANT ALL ON TABLE geometry_columns TO "www-data"' <db_name>
    sudo -u postgres psql -c 'GRANT ALL ON SCHEMA <schema_name> TO "www-data"' <db_name>
    sudo -u postgres psql -c 'GRANT ALL ON SCHEMA <schema_name>_static TO "www-data"' <db_name>

.. note::

   If you do not use the ``www-data`` user for Apache, replace it by the right user.


Install the application
-----------------------

Get the application source tree
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If GitHub is used for the application, use the following command to get the
application source tree:

.. prompt:: bash

    git clone git@github.com:camptocamp/<project>.git
    cd <project>


Non Apt/Dpkg based OS Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

For example Windows or RedHat.

Disable the package checking:

In the ``<package>.mk`` add::

    TEST_PACKAGES = FALSE

Windows Specific Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some Python modules cannot currently be installed through the Python Package
Index (PyPI) and they have to be downloaded manually and stored. This is
because these packages use DLLs and binaries which would have to be compiled
using a C compiler.

Furthermore, some changes in the Apache WSGI and MapServer configurations are
required to make c2cgeoportal work on Windows.

Also, between all the different command interfaces available on Windows (cmd,
Cygwin, git mingw), only Windows default cmd interface handle paths correctly
in all stage of the application setup.

Command interface and environment variable
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Only use Windows default command interface::

    Start > Run... > cmd

Cygwin and git mingw are not compatible. Powershell is untested.

In addition, you need to add all the resource paths to your system PATH
environment variable, for cygwin, git and node binaries.

Cygwin
^^^^^^

You must install the following packages:

* make
* git
* gettext-devel

Python Wheels
^^^^^^^^^^^^^

You should create a "wheels" folder at the root folder of your project.

Then, go to http://www.lfd.uci.edu/~gohlke/pythonlibs/, search and download the
following packages:

* Psycopg2
* Shapely
* Pillow
* Pyproj

If your project is configured for Windows, then ``make`` will expect this folder
to exist and to contain these wheels.

mapserver/mapserver.map.mako
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You must specify the path to the MapServer's EPSG file by uncommenting and adapting
this line under ``MAP`` (use regular slash ``/``) ::

    PROJ_LIB" "C:/PATH/TO/ms4w/proj/nad"

<project>.mk
^^^^^^^^^^^^

The following configuration override must be added to your ``<project>.mk``::

    # Sets that is we use Windows
    OPERATING_SYSTEM ?= WINDOWS
    # Path to cygwin
    CYGWIN_PATH ?= c:/path/to/cygwin

RedHat Specific Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Specific settings are required when the c2cgeoportal application is to be run
on RedHat Enterprise Linux (RHEL) 6.

.. note::

    First of all, note that, with RHEL, you cannot install the c2cgeoportal
    application in your homedir. If you do so, you will get the following error
    in the Apache logs::

        (13)Permission denied: access to /~<your_user_id>/ denied

    So always install the application in an Apache-accessible directory. On
    Camptocamp *puppetized* servers you will typically install the application
    in ``/var/www/vhosts/<vhost>/private/dev/<username>/``, where ``<vhost>``
    is the name of the Apache virtual host, and ``<username>`` is your Unix
    login name.


apache/application.wsgi.mako
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Ensure that the regular expression used in ``apache/application.wsgi.mako`` to modify the ``sys.path``
matches the system directories containing python packages. If you are installing from scratch, this should
already be the case; otherwise look at ``scaffolds/create/apache/application.wsgi.mako`` for an example.


.. _integrator_install_application_install_application:

Install the application
~~~~~~~~~~~~~~~~~~~~~~~

You can build and install the application with the command:

.. prompt:: bash

    ./docker-run make --makefile=<user>.mk build

This previous command will do many things like:

  * adapt the application configuration to your environment,

  * build the JavaScript and CSS resources into compressed files.

Then create the application tables:

.. prompt:: bash

    ./docker-run make --makefile=<user>.mk upgrade-db

For non Docker installation:

.. prompt:: bash

    FINALISE=TRUE make --makefile=<user>.mk build

This previous command will do many things like:

  * download and install the project dependencies,

  * deploy the MapFish Print service if it is configured for building.


Your application should now be available at:
``https://<hostname>/``,
where the ``<hostname>`` is directly linked to the virtual host.

Add in the ``/var/www/vhosts/<vhost_name>/conf/proxies.conf`` file
(create it if it does not exist):

.. code::

   ProxyPass "/<instance>"  "http://localhost:8080/<instance>"
   ProxyPassReverse "/<instance>"  "http://localhost:8080/<instance>"
   ProxyPreserveHost On
   RequestHeader set X-Forwarded-Proto "https"
   RequestHeader set X-Forwarded-Port "443"
   ProxyRequests Off

The root instance should be at the end.

Migrating to a new server
-------------------------

If you are migrating to a new server, keep in mind that your variable
``VISIBLE_WEB_HOST`` must contain the exact host name that browsers should use
to access your site. Consider the following migration scenario:
your current site runs on server ``old-site.customer.ch`` with the visible host name
``gis.customer.ch``. You wish to setup a new server ``new-site.customer.ch``,
install the application and test it, and then switch your DNS so that
``gis.customer.ch`` now points to ``new-site.customer.ch``.
To accomplish this, you must proceed as follows:

  * set ``VISIBLE_WEB_HOST`` to ``new-site.customer.ch``
  * install the application on ``new-site.customer.ch`` and test the application
    at ``http://new-site.customer.ch``

  * later, when going live, you must:

    * change ``VISIBLE_WEB_HOST`` to ``gis.customer.ch``

    * re-build, re-deploy - but do not test yet!

    * change your DNS so that ``gis.customer.ch`` points to ``new-site.customer.ch``.

    * Now test your new live site.