Installation and configuration¶
Download Enhydris¶
Download Enhydris from https://github.com/openmeteo/enhydris/ (if you are uncomfortable with git and github, click on the “Download ZIP” button).
Prerequisites¶
Prerequisite | Version |
---|---|
Python | 2.6 [1] |
PostgreSQL | [2] |
PostGIS | 1.4 [3] |
GDAL | 1.9 |
psycopg2 | 2.2 [4] |
setuptools | 0.6 [5] |
pip | 1.1 [5] |
PIL with freetype | 1.1.7 [6] |
Dickinson | 0.1.0 [7] |
The Python modules listed in requirements.txt |
See file |
Note for production installations
These prerequisites are for development installations. For production installations you also need a web server.
[1] Enhydris runs on Python 2.6 and 2.7. It should also run on any later 2.x version. Enhydris does not run on Python 3.
[2] Enhydris should run on all supported PostgreSQL versions. In order to avoid possible incompatibilities with psycopg2, it is better to use the version prepackaged by your operating system when running on GNU/Linux, and to use the latest PostgreSQL version when running on Windows. If there is a problem with your version of PostgreSQL, email us and we’ll check if it is easy to fix.
[3] Except for PostGIS, more libraries, namely geos and proj, are needed; however, you probably not need to worry about that, because in most GNU/Linux distributions PostGIS has a dependency on them and therefore they will be installed automatically, whereas in Windows the installation file of PostGIS includes them. Enhydris is known to run on PostGIS 1.4 and 1.5. It probably can run on later versions as well. It is not known whether it can run on earlier versions.
[4] psycopg2 is listed in requirements.txt
together with the
other Python modules. However, in contrast to them, it can be tricky
to install (because it needs compilation and has a dependency on
PostgreSQL client libraries), and it is therefore usually better to
not leave its installation to pip. It’s better to install a
prepackaged version for your operating system.
[5] setuptools and pip are needed in order to install the rest of the Python modules; Enhydris does not actually need it.
[6] PIL is not directly required by Enhydris, but by other python
modules required my Enhydris. In theory, installing the requirements
listed in requirements.txt
will indirectly result in
pip installing it. However, it can be tricky to install,
and it may be better to not leave its installation to pip;
it’s better to install a prepackaged version for your operating
system. It must be compiled with libfreetype support. This is common
in Linux distributions. In Windows, however, the official packages
are not thus compiled. One solution is to get the unofficial version
from http://www.lfd.uci.edu/~gohlke/pythonlibs/. If there is any
difficulty, Pillow might work instead of PIL.
[7] Dickinson is not required directly by Enhydris, but by pthelma,
which is required by Enhydris and is listed in
requirements.txt
.
Example: Installing prerequisites on Debian/Ubuntu
These instructions are for Debian wheezy. For Ubuntu they are similar, except that the postgis package version may be different:
aptitude install python postgresql postgis postgresql-9.1-postgis \
python-psycopg2 python-setuptools git python-pip python-imaging \
python-gdal
# Install Dickinson
cd /tmp
wget https://github.com/openmeteo/dickinson/archive/0.1.0.tar.gz
tar xzf 0.1.0.tar.gz
cd dickinson-0.1.0
./configure
make
sudo make install
pip install -r requirements.txt
It is a good idea to use a virtualenv before running the last command, but you are on your own with that, sorry.
Example: Installing prerequisites on Windows
Important
We don’t support Enhydris very well on Windows. We do provide instructions, and we do fix bugs, but honestly we can’t install it; we get an error message related to “geos” at some point. Some people have had success by installing Enhydris using OSGeo4W, but we haven’t tried it. So, if you face installation problems, we won’t be able to help (unless you provide funding).
Also note that we don’t think Enhydris on Windows can easily run on 64-bit Python or 64-bit PostgreSQL; the 32-bit versions of everything should be installed. This is because some prerequisites are not available for Windows in 64-bit versions, or they may be difficult to install. Such dependencies are PostGIS and some Python packages.
That said, we provide instructions below on how it should (in theory) be installed. If you choose to use OSGeo4W, some things will be different - you are on your own anyway.
Download and install the latest Python 2.x version from http://python.org/ (use the Windows Installer package).
Add the Python installation directory (such as
C:\Python27
) and its Scripts
subdirectory (such as
C:\Python27\Scripts
) to the system path (right-click on
My Computer, Properties, Advanced, Environment variables, under
“System variables” double-click on Path, and add the two new
directory names at the end, using semicolon to delimit them).
Download and install an appropriate PostgreSQL version from http://postgresql.org/ (use a binary Windows installer). Important: at some time the installer will create an operating system user and ask you to define a password for that user; keep the password; you will need it later.
Go to Start, All programs, PostgreSQL, Application Stack Builder, select your PostgreSQL installation on the first screen, then, on the application selection screen, select Spatial Extensions, PostGIS. Allow it to install (you don’t need to create a spatial database at this stage).
Download and install psycopg2 for Windows from http://www.stickpeople.com/projects/python/win-psycopg/.
Download and install setuptools from http://pypi.python.org/pypi/setuptools (you probably need to go to http://pypi.python.org/pypi/setuptools#files and pick the .exe file that corresponds to your Python version).
Download and install PIL from http://www.lfd.uci.edu/~gohlke/pythonlibs/.
Download the latest dickinson DLL from
http://openmeteo.org/downloads/ and put it in
C:\Windows\System32\dickinson.dll
.
Finally, open a Command Prompt and give the following commands
inside the downloaded and unpacked enhydris
directory:
easy_install pip
pip install -r requirements.txt
Creating a spatially enabled database¶
You need to create a database user and a spatially enabled database
(we use enhydris_user
and enhydris_db
in the examples below).
Enhydris will be connecting to the database as that user. The user
should not be a super user, not be allowed to create databases, and
not be allowed to create more users.
GNU example
First, you need to create a spatially enabled database template. For PostGIS 2.0 or later (for earlier version refer to the GeoDjango instructions):
sudo -u postgres -s
createdb template_postgis
psql -d template_postgis -c "CREATE EXTENSION postgis;"
psql -d template_postgis -c \
"UPDATE pg_database SET datistemplate='true' \
WHERE datname='template_postgis';"
exit
The create the database:
sudo -u postgres -s
createuser --pwprompt enhydris_user
createdb --template template_postgis --owner enhydris_user \
enhydris_db
exit
You may also need to edit your pg_hba.conf
file as needed
(under /var/lib/pgsql/data/
or /etc/postgresql/8.x/main/
,
depending on your system). The chapter on client authentication
of the PostgreSQL manual explains this in detail. A simple setup is
to authenticate with username and password, in which case you
should add or modify the following lines in pg_hba.conf
:
local all all md5
host all all 127.0.0.1/32 md5
host all all ::1/128 md5
Restart the server to read the new pg_hba.conf
configuration.
For example, in Ubuntu:
service postgresql restart
Windows example
Assuming PostgreSQL is installed at the default location, run these at a command prompt:
cd C:\Program Files\PostgreSQL\9.0\bin
createdb template_postgis
psql -d template_postgis -c "CREATE EXTENSION postgis;"
psql -d template_postgis -c "UPDATE pg_database SET datistemplate='true'
WHERE datname='template_postgis';"
createuser -U postgres --pwprompt enhydris_user
createdb --template template_postgis --owner enhydris_user enhydris_db
At some point, these commands will ask you for the password of the operating system user.
Configuring Enhydris¶
In the directory enhydris/settings
, copy the file
example.py
to local.py
. Open
local.py
in an editor and make the following changes:
- Set
ADMINS
to a list of admins (the administrators will get all enhydris exceptions by mail and also all user emails, as generated by the contact application). - Under
DATABASES
, setNAME
to the name of the database, andUSER
andPASSWORD
according to the user created above.
Initializing the database¶
In order to initialize your database and create the necessary database
tables for Enhydris to run, run the following commands inside the
enhydris
directory:
python manage.py syncdb --settings=enhydris.settings.local --noinput
python manage.py migrate --settings=enhydris.settings.local dbsync
python manage.py migrate --settings=enhydris.settings.local hcore
python manage.py createsuperuser --settings=enhydris.settings.local
The above commands will also ask you to create a Enhydris superuser.
Confused by users?
There are operating system users, database users, and Enhydris
users. PostgreSQL runs as an operating system user, and so does the
web server, and so does Django and therefore Enhydris. Now the
application (i.e. Enhydris/Django) needs a database connection to
work, and for this connection it connects to the database as a
database user. For the end users, that is, for the actual people
who use Enhydris, Enhydris/Django keeps a list of usernames and
passwords in the database, which have nothing to do with operating
system users or database users. The Enhydris superuser created by
the ./manage.py createsuperuser
command is such an Enhydris
user, and is intended to represent a human.
Advanced Django administrators can also use alternative authentication backends, such as LDAP, for storing the Enhydris users.
Running Enhydris¶
Inside the openmeteo/enhydris
directory, run the following
command:
python manage.py runserver --settings=enhydris.settings.local 8088
The above command will start the Django development server and set it
to listen to port 8088. If you then start your browser and point it to
http://localhost:8088/
, you should see Enhydris in action. Note
that this only listens to the localhost; if you want it to listen on
all interfaces, use 0.0.0.0:8088
instead.
To use Enhydris in production, you need to setup a web server such as apache. This is described in detail in Deploying Django.
Post-install configuration¶
Domain name¶
After you run Enhydris, logon as a superuser, visit the admin panel,
go to Sites
, edit the default site, and enter your domain name
there instead of example.com
. Emails to users for registration
confirmation will appear to be coming from that domain. Restart the
webserver after changing the domain name.
Settings reference¶
These are the settings available to Enhydris, in addition to the Django settings.
-
ENHYDRIS_FILTER_DEFAULT_COUNTRY
¶ When a default country is specified, the station search is locked within that country and the station search filter allows only searches in the selected country. If left blank, the filter allows all countries to be included in the search.
-
ENHYDRIS_FILTER_POLITICAL_SUBDIVISION1_NAME
¶
-
ENHYDRIS_FILTER_POLITICAL_SUBDIVISION2_NAME
¶ These are used only if
FILTER_DEFAULT_COUNTRY
is set. They are the names of the first and the second level of political subdivision in a certain country. For example, Greece is first divided in ‘districts’, then in ‘prefecture’, whereas the USA is first divided in ‘states’, then in ‘counties’.
-
ENHYDRIS_USERS_CAN_ADD_CONTENT
¶ This must be configured before syncing the database. If set to
True
, it enables all logged in users to add content to the site (stations, instruments and timeseries). It enables the use of user space forms which are available to all registered users and also allows editing existing data. When set toFalse
(the default), only privileged users are allowed to add/edit/remove data from the db.
-
ENHYDRIS_SITE_CONTENT_IS_FREE
¶ If this is set to
True
, all registered users have access to the timeseries and can download timeseries data. If set toFalse
(the default), the users may be restricted.
-
ENHYDRIS_TSDATA_AVAILABLE_FOR_ANONYMOUS_USERS
¶ Setting this option to
True
will enable all users to download timeseries data without having to login first. The default isFalse
.
-
ENHYDRIS_STORE_TSDATA_LOCALLY
¶ Deprecated.
By default, this is
True
. If set toFalse
, the installation does not store the actual time series records. The purpose of this setting is to be used together with the dbsync application, in order to create a website that contains the collected data (except time series records) of several other Enhydris installations (see thehcore_remotesyncdb
management command). However, all this is under reconsideration.
-
ENHYDRIS_REMOTE_INSTANCE_CREDENTIALS
¶ If the instance is configured as a data aggregator and doesn’t have the actual data locally stored, in order to fetch the data from another instance a user name and password must be provided which correspond to a superuser account in the remote instance. Many instances can be configured using this setting, each with its own user/pass combination following this scheme:
ENHYDRIS_REMOTE_INSTANCE_CREDENTIALS = { 'kyy.hydroscope.gr': ('myusername','mypassword'), 'itia.hydroscope.gr': ('anotheruser','anotherpass') }
-
ENHYDRIS_USE_OPEN_LAYERS
¶ Set this to
False
to disable the map.
-
ENHYDRIS_MIN_VIEWPORT_IN_DEGS
¶ Set a value in degrees. When a geographical query has bounds with dimensions less than
MIN_VIEWPORT_IN_DEGS
, the map will have at least a dimension ofMIN_VIEWPORT_IN_DEGS²
. Useful when showing a single entity, such as a hydrometeorological station. Default value is 0.04, corresponding to an area approximately 4×4 km.
-
ENHYDRIS_MAP_DEFAULT_VIEWPORT
¶ A tuple containing the default viewport for the map in geographical coordinates, in cases of geographical queries that do not return anything. Format is (minlon, minlat, maxlon, maxlat) where lon and lat is in decimal degrees, positive for north/east, negative for west/south.
-
ENHYDRIS_TS_GRAPH_CACHE_DIR
¶ The directory in which timeseries graphs are cached. It is automatically created if it does not exist. The default is subdirectory
enhydris-timeseries-graphs
of the system or user temporary directory.
-
ENHYDRIS_TS_GRAPH_BIG_STEP_DENOMINATOR
¶ -
ENHYDRIS_TS_GRAPH_FINE_STEP_DENOMINATOR
¶ Chart options for time series details page. The big step represents the max num of data points to be plotted, default is 200. The fine step are the max num of points between main data points to search for a maxima, default is 50.
-
ENHYDRIS_SITE_STATION_FILTER
¶ This is a quick-and-dirty way to create a web site that only displays a subset of an Enhydris database. For example, the database of http://deucalionproject.gr/db/ is the same as that of http://openmeteo.org/db/; however, the former only shows stations relevant to the Deucalion project, because it has this setting:
ENHYDRIS_SITE_STATION_FILTER = {'owner__id__exact': '9'}
-
ENHYDRIS_DISPLAY_COPYRIGHT_INFO
¶ If
True
, the station detail page shows copyright information for the station. By default, it isFalse
. If all the stations in the database belong to one organization, you probably want to leave it toFalse
. If the database is going to be openly accessed and contains data that belongs to many owners, you probably want to set it toTrue
.
-
ENHYDRIS_WGS84_NAME
¶ Sometimes Enhydris displays the reference system of the co-ordinates, which is always WGS84. In some installations, it is desirable to show something other than “WGS84”, such as “ETRS89”. This parameter specifies the name that will be displayed; the default is WGS84.
This is merely a cosmetic issue, which does not affect the actual reference system used, which is always WGS84. The purpose of this parameter is merely to enable installations in Europe to display “ETRS89” instead of “WGS84” whenever this is preferred. Given that the difference between WGS84 and ETRS89 is only a few centimeters, which is considerably less that the accuracy with which station co-ordinates are given, whether WGS84 or ETRS89 is displayed is actually irrelevant.