Building conda packages for general code projects¶
Conda packages can be built from projects written in any language. This tutorial
will show you how to write a recipe for the
postgis package. At the end you
will build the package, upload it to anaconda.org and
install the package through conda.
Who is this for?¶
This tutorial is designed for Linux and Mac users who wish to make conda packages for source code projects in languages other than Python. The user should already know how to configure, compile and install C/C++ packages.
Before you start¶
conda install conda-build
It is recommended that you use the latest versions of conda and conda-build. To upgrade both packages run:
conda upgrade conda conda upgrade conda-build
Now you are ready to start building your own conda packages.
When creating conda recipes the most important aspect is to correctly list the dependencies.
The README.postgis file states that the following packages are required along with the minimum required version.
postgresql version 9.1 proj4 version 4.0.6 geos version 3.4 libxml2 version 2.5 json-c version 0.9 gdal version 1.9
There must exist a conda package for each of these dependencies that is available for install using conda-install.
This is because conda-build will create a private environment from which the source code for
postgis will be installed and conda must install all required dependencies into that environment.
We begin by searching for each of these packages using conda-search. The only package that cannot
be found in the default channel is
json-c. To install this package you will have to add the
jlaura channel using the conda-config command.
conda config --add channels jlaura
Now that you have identified that all of the dependent packages can be installed the next step is to write the conda recipe.
The first step is to create a directory to store conda recipe files.
mkdir postgis cd postgis
The conda recipe has three main components, the package name and version, the location of the source code and the dependent packages that are required to build and run the package being built.
There are a number of ways to specify the location of the source code in a conda recipe. Here we are going to provide the path to the Github repository and the specific revision tag we wish to use.
NOTE: Not all Github repositories make use of revision tags. In some cases the most recent commit is suitable.
Open a text editor and write the following to a file called meta.yaml inside the postgis directory.
package: name: postgis version: "2.2.2" source: git_rev: 2.2.2 git_url: https://github.com/postgis/postgis.git build: number: 0 requirements: build: - gdal - geos - proj4 - json-c - libxml2 - postgresql >=9.1 run: - gdal - geos - proj4 - json-c - libxml2 - postgresql >=9.1 about: home: http://postgis.net license: GPL2
NOTE: Conda-build will build the package in an isolated environment, which is created from the packages specified as build dependencies. Installing the packages into your own working environment does not affect conda-build at all.
The final step in preparing the conda build recipe is to write the build script. Since
being build for Linux and Mac we are only going to write a build.sh file in the postgis directory.
The build script file contains all of the commands required to configure, build and install the source project. This script must run without user intervention.
By Looking at the postgis compilation documentation you can see that several flags need to be provided to the configure command to indicate the location of the dependent packages.
During execution of the conda-build command the
$PREFIX environment variable is used to refer to the install path
of conda packages. We will use
$PREFIX to inform the configure command of the location of the dependent packages
listed in the build and run requirements of the conda recipe.
In a text editor make a new file called build.sh with the following content in the postgis directory.
sh autogen.sh ./configure \ --prefix=$PREFIX \ --with-pgconfig=$PREFIX/bin/pg_config \ --with-gdalconfig=$PREFIX/bin/gdal-config \ --with-xml2config=$PREFIX/bin/xml2-config \ --with-geosconfig=$PREFIX/bin/geos-config \ --with-projdir=$PREFIX \ --with-jsondir=$PREFIX \ --without-raster \ --without-topology make make install
NOTE: without references to the
$PREFIX environment variable the configure command would look in the default
system directories for required packages and even if the package were to build correctly there is no guarantee
that other users could install the compiled conda package correctly.
NOTE: You will have to install a C/C++ compiler, autoconf and automake in order to run conda-build on this recipe. These packages must be installed at the system level and not through conda.
Build the package¶
Now that the recipe is complete you can build the conda package with the conda-build command from within the postgis directory.
conda build .
The start of the conda-build output should read
Removing old build environment Removing old work directory BUILD START: postgis-2.2.2-0 Using Anaconda Cloud api site https://api.anaconda.org Fetching package metadata: .......... Solving package specifications: .........
If conda-build was able to successfully install the dependent packages and compile the source code conda-build should terminate with the following message.
BUILD END: postgis-2.2.2-0 Nothing to test for: postgis-2.2.2-0 # If you want to upload this package to anaconda.org later, type: # # $ anaconda upload /Users/adefusco/Applications/anaconda3/conda-bld/osx-64/postgis-2.2.2-0.tar.bz2 # # To have conda build upload to anaconda.org automatically, use # $ conda config --set anaconda_upload yes
BUILD END: postgis-2.2.2-0 Nothing to test for: postgis-2.2.2-0 # If you want to upload this package to anaconda.org later, type: # # $ anaconda upload /home/adefusco/anaconda3/conda-bld/linux-64/postgis-2.2.2-0.tar.bz2 # # To have conda build upload to anaconda.org automatically, use # $ conda config --set anaconda_upload yes
NOTE: Your path may be different depending on the install location of Anaconda.
NOTE: See the troubleshooting section for help diagnosing conda-build errors.
NOTE: The package can only be installed on systems of the same architecture. You will have run the conda-build command separately on Mac and Linux systems to make packages for both architectures.
Distribute and Install the package¶
At this point you can install the package on your local machine by running the following command
conda install postgis --use-local
Alternatively, you can upload the package to your anaconda.org channel by using the anaconda-upload command displayed at the end of the conda-build output. This will make the package available to install by any user with the following command.
conda install -c CHANNEL postgis
NOTE: Change CHANNEL to your anaconda.org username.