Packaging PostGIS dev releases with Docker

We recently added support for GML curves to PostGIS, which enables TinyOWS to deliver WFS requests with curve geometries. More on this in a later post. This enhancement is in the current PostGIS developement version (SVN master) and not released yet. To enable our customer testing this functionality, we had to build packages for their server environment which is Ubuntu Precise with UbuntuGIS repositories. After working with Linux LXC containers and it's predecessor VServer for years, Docker was a logical choice for a clean reproducible build environment.

Rebuilding a Debian package is usually quite easy:

apt-get build-dep <package>
apt-get source <package>
cd <packagedir>
#Make your changes
dch -i
dpkg-buildpackage

But getting build dependencies for PostGIS currently fails with libssl-dev conflicts, maybe because the dev packages got out of sync after the recent Heartblead updates. So the Dockerfile uses equivs to build a dummy package which satisfies the dependencies.

The command

docker run -v /tmp:/pkg sourcepole/postgis-svn-build-env sh -c 'cp /root/*postgis*.deb /pkg'

loads the Docker image with packages built from the latest SVN version of PostGIS in /root and copies the deb files from the containter into /tmp.

Now we're ready to install these packages on the Ubuntu server:

sudo dpkg -i /tmp/*postgis*.deb

Thats it. Feedback welcome!

@PirminKalberer

P.S.

If you happen to be a developer, then you may prefer running a cutting-edge version of PostGIS in a Docker container instead of building packages. Our colleagues from Oslandia just published how to do this.

Packaging PostGIS dev releases with Docker

We recently added support for GML curves to PostGIS, which enables TinyOWS to deliver WFS requests with curve geometries. More on this in a later post. This enhancement is in the current PostGIS developement version (SVN master) and not released yet. To enable our customer testing this functionality, we had to build packages for their server environment which is Ubuntu Precise with UbuntuGIS repositories. After working with Linux LXC containers and it's predecessor VServer for years, Docker was a logical choice for a clean reproducible build environment.

Rebuilding a Debian package is usually quite easy:

apt-get build-dep <package>
cd <packagedir>
#Make your changes
dch -i
dpkg-buildpackage

But getting build dependencies for PostGIS currently fails with libssl-dev conflicts, maybe because the dev packages got out of sync after the recent Heartblead updates. So the Dockerfile uses equivs to build a dummy package which satisfies the dependencies.

The command

docker run -v /tmp:/pkg sourcepole/postgis-svn-build-env sh -c 'cp /root/*postgis*.deb /pkg'

loads the Docker image with packages built from the latest SVN version of PostGIS in /root and copies the deb files from the containter into /tmp.

Now we're ready to install these packages on the Ubuntu server:

sudo dpkg -i /tmp/*postgis*.deb

Thats it. Feedback welcome!

@PirminKalberer

P.S.

If you happen to be a developer, then you may prefer running a cutting-edge version of PostGIS in a Docker container instead of building packages. Our colleagues from Oslandia just published how to do this.

Sourcepole bietet Grundlagen- und Aufbau-Kurse für den Betrieb von Geodaten-Infrastrukturen auf der Basis von PostgreSQL/PostGIS und Quantum GIS an. Detaillierte Informationen zu den Kursen, die im Herbst 2012 stattfinden, entnehmen Sie bitte dem Kursprogramm. Die Anmeldung ist ab sofort online möglich. Wir freuen uns darauf Sie in Zürich begüssen zu können.

A while ago I’ve compiled PostGIS 1.5.2 for PostgreSQL 9.0.

To install it on Ubuntu the following steps are required:

apt-get install python-software-properties

add-apt-repository ppa:ubuntugis/ubuntugis-unstable
add-apt-repository ppa:pitti/postgresql
add-apt-repository ppa:pi-deb/gis

apt-get update

apt-get install postgresql-9.0-postgis

A basic template database can be created with the following commands:

sudo su - postgres

createdb template_postgis
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/postgis.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/spatial_ref_sys.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis_comments.sql
cat <<EOS | psql -d template_postgis
UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template_postgis';
REVOKE ALL ON SCHEMA public FROM public;
GRANT USAGE ON SCHEMA public TO public;
GRANT ALL ON SCHEMA public TO postgres;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.geometry_columns TO PUBLIC;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.spatial_ref_sys TO PUBLIC;
EOS

To test database creation you can do the following:

createdb --template template_postgis test_gis
psql -d test_gis -c "select postgis_lib_version();"

Ubuntu supports parallel installations of different PostgreSQL versions. So if you have already PostgreSQL 8.x installed, PostgreSQL 9.0 will probably be configured to listen on port 5433. So you have to add the option -p 5433 to each command and to specify the full path for the executables. For example:

/usr/lib/postgresql/9.0/bin/psql -p 5433 -d test_gis -c "select postgis_lib_version();"

A while ago I’ve compiled PostGIS 1.5.2 for PostgreSQL 9.0.

To install it on Ubuntu the following steps are required:

apt-get install python-software-properties

add-apt-repository ppa:ubuntugis/ubuntugis-unstable
add-apt-repository ppa:pitti/postgresql
add-apt-repository ppa:pi-deb/gis

apt-get update

apt-get install postgresql-9.0-postgis

A basic template database can be created with the following commands:

sudo su - postgres

createdb template_postgis
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/postgis.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/spatial_ref_sys.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis_comments.sql
cat <<EOS | psql -d template_postgis
UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template_postgis';
REVOKE ALL ON SCHEMA public FROM public;
GRANT USAGE ON SCHEMA public TO public;
GRANT ALL ON SCHEMA public TO postgres;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.geometry_columns TO PUBLIC;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.spatial_ref_sys TO PUBLIC;
EOS

To test database creation you can do the following:

createdb --template template_postgis test_gis
psql -d test_gis -c "select postgis_lib_version();"

Ubuntu supports parallel installations of different PostgreSQL versions. So if you have already PostgreSQL 8.x installed, PostgreSQL 9.0 will probably be configured to listen on port 5433. So you have to add the option -p 5433 to each command and to specify the full path for the executables. For example:

/usr/lib/postgresql/9.0/bin/psql -p 5433 -d test_gis -c "select postgis_lib_version();"

For data collection, it is a common situation to work with a laptop or a phone offline in the field. Upon returning to the network, the changes need to be synchronized with the master data source, e.g. a PostGIS database. If several persons are working simultaneously on the same datasets, it is difficult to merge the edits by hand, even if people don’t change the same features.

Therefore, Mathias Walker implemented an offline plugin for QGIS. This plugin automates the synchronisation by copying the content of a datasource (usually PostGIS or WFS-T) to a spatialite database and storing the offline edits to dedicated tables. After being connected to the network again, it is possible to apply the offline edits to the master dataset.

To give the plugin a try, unpack the sources, apply the patch ‘qgissvn.diff’ to a current svn version of QGIS. Then copy the offlineediting folder to $PREFIX/src/plugins and recompile QGIS.

The usage of the plugin is straightforward:

• Open some vector layers, e.g. from a PostGIS or WFS-T datasource
• Save the project
• Press the ‘Convert to offline project’ button and select the layers to save. The content of the layers is saved to spatialite tables.
• Edit the layers offline
• After being connected again, upload the changes with the ‘Synchronize’ button

Screenshot

Presumably, the offline editing plugin will be part of the next QGIS version (1.6)