2023-07-01
postgresql tech open-source Linux
Packaging PostgreSQL extensions in Debian/Ubuntu Systems
A simple writeup to remeber how to package a pg extension on Debain/Ubuntu Linux

art Hi everyone,

PostgreSQL has a great extensibility in features using extensions. Any feature that a user needs which isnt there natively can be added using extensions. to distribute extensions on different systems, packaging becomes important.

This blog lists down the steps to package a PostgreSQL extension in debian/ubuntu systems. I would be packaging a simple base36 extension to list down the steps.

1. Adding the sources list

To install postgresql packages in debian, the apt.postgresql.org apt list needs to be added. 

# Reference: https://wiki.postgresql.org/wiki/Apt
# Add gpg keys for verification
curl https://www.postgresql.org/media/keys/ACCC4CF8.asc | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/apt.postgresql.org.gpg >/dev/nul
#For downloading packages
sudo echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list
#To also be able to download source files of packages deb-src also needs to be added
sudo echo "deb-src http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" >> /etc/apt/sources.list.d/pgdg.list

Run apt install to update the apt list repositry and be able to search for packages using apt command.

2. Setting up the directory

Get your extension source code in a directory. Next from the root of the extension directory, call dh_make_pgxs to setup the boilerplate for the debian folder. 

vagrant@ubuntu-focal:/vagrant/base36-0.0.1$ dh_make_pgxs
Upstream (-n): base36
Version (-v):  0.0.1
Source:        base36 (0.0.1-1)
Binaries:      postgresql-PGVERSION-base36 (0.0.1-1)
Uploader:       <vagrant@localhost>
Homepage (-h): https://FIXME/base36

Press Enter to continue, ^C to abort
Installing debian/control.in
Installing debian/copyright
Installing debian/gitlab-ci.yml
Installing debian/pgversions
Installing debian/rules
Creating debian/source/
Installing debian/source/format
Creating debian/tests/
Installing debian/tests/control
Installing debian/tests/installcheck
Installing debian/watch
Updating debian/control from debian/control.in
Creating debian/changelog

Post this a debian folder would be created. It has same structure of what dh_make creates hence the meaning of the files can be found anywhere on the internet.

3. Updating necessary files

After updating the nexecassry parts, the folder is ready to be built(incase of procedural languages) and packaged.

4. Build the extension

PostgreSQL has a cli tool pg_buildext which is extremely helpful in building the package. A great documentation of it is available on the manpage .

5. Package the extension

The final step comes to packaging the extension. To just verify there must be a README.* file in the root of the extension. Run the dpkg_buildpackage if a tarball of the source code already exists and dpkg_buildpackage -b if not. This would test the extension on the supported pg versions and then create the necessary deb files ready to be shipped.

vagrant@ubuntu-focal:/vagrant/base36-0.0.1$ dpkg-buildpackage -b
dpkg-buildpackage: info: source package base36
dpkg-buildpackage: info: source version 0.0.1-1
dpkg-buildpackage: info: source distribution UNRELEASED
dpkg-buildpackage: info: source changed by  <vagrant@localhost>
dpkg-buildpackage: info: host architecture amd64
 dpkg-source --before-build .
 debian/rules clean
dh clean --with pgxs
   dh_auto_clean --buildsystem=pgxs
        pg_buildext clean build-%v postgresql-%v-base36
rm -rf build-10/ build-11/ build-12/ build-13/ build-14/ build-15/
rm -rf debian/postgresql-10-base36/ debian/postgresql-11-base36/ debian/postgresql-12-base36/ debian/postgresql-13-base36/ debian/postgresql-14-base36/ debian/postgresql-15-base36/ debian/postgresql-10-base36.substvars debian/postgresql-11-base36.substvars debian/postgresql-12-base36.substvars debian/postgresql-13-base36.substvars debian/postgresql-14-base36.substvars debian/postgresql-15-base36.substvars
make[1]: Entering directory '/vagrant/base36-0.0.1'
rm -rf results/ regression.diffs regression.out tmp_check/ tmp_check_iso/ log/ output_iso/
make[1]: Leaving directory '/vagrant/base36-0.0.1'
   dh_clean
   pg_buildext checkcontrol
 debian/rules binary
dh binary --with pgxs
   dh_update_autotools_config
   dh_autoreconf
   dh_auto_configure
   dh_auto_build --buildsystem=pgxs
        pg_buildext build build-%v
---
building for each postgresql version
---
   create-stamp debian/debhelper-build-stamp
   dh_testroot
   dh_prep
   dh_auto_install --buildsystem=pgxs
        pg_buildext install build-%v postgresql-%v-base36
--- 
installing extension for each postgresql version 
make[1]: Entering directory '/vagrant/base36-0.0.1'
dh_installdocs --all README.*
make[1]: Leaving directory '/vagrant/base36-0.0.1'
   dh_installchangelogs
   dh_perl
   dh_link
   dh_pgxs_test
        pg_buildext installcheck . build-%v postgresql-%v-base36
---
running tests on each version
---

make[1]: Leaving directory '/vagrant/base36-0.0.1/build-15'
Dropping cluster 15/regress ...
### End 15 installcheck ###
   dh_strip_nondeterminism
   dh_compress
   dh_fixperms
   dh_missing
   dh_dwz
   dh_strip
   dh_makeshlibs
   dh_shlibdeps
   dh_installdeb
   dh_gencontrol
dpkg-gencontrol: warning: Depends field of package postgresql-13-base36: substitution variable ${shlibs:Depends} used, but is not defined
dpkg-gencontrol: warning: Depends field of package postgresql-10-base36: substitution variable ${shlibs:Depends} used, but is not defined
dpkg-gencontrol: warning: Depends field of package postgresql-14-base36: substitution variable ${shlibs:Depends} used, but is not defined
dpkg-gencontrol: warning: Depends field of package postgresql-11-base36: substitution variable ${shlibs:Depends} used, but is not defined
dpkg-gencontrol: warning: Depends field of package postgresql-15-base36: substitution variable ${shlibs:Depends} used, but is not defined
dpkg-gencontrol: warning: Depends field of package postgresql-12-base36: substitution variable ${shlibs:Depends} used, but is not defined
   dh_md5sums
   dh_builddeb
dpkg-deb: building package 'postgresql-10-base36' in '../postgresql-10-base36_0.0.1-1_amd64.deb'.
dpkg-deb: building package 'postgresql-13-base36' in '../postgresql-13-base36_0.0.1-1_amd64.deb'.
dpkg-deb: building package 'postgresql-11-base36' in '../postgresql-11-base36_0.0.1-1_amd64.deb'.
dpkg-deb: building package 'postgresql-14-base36' in '../postgresql-14-base36_0.0.1-1_amd64.deb'.
dpkg-deb: building package 'postgresql-12-base36' in '../postgresql-12-base36_0.0.1-1_amd64.deb'.
dpkg-deb: building package 'postgresql-15-base36' in '../postgresql-15-base36_0.0.1-1_amd64.deb'.
 dpkg-genbuildinfo --build=binary
 dpkg-genchanges --build=binary >../base36_0.0.1-1_amd64.changes
dpkg-genchanges: info: binary-only upload (no source code included)
 dpkg-source --after-build .
dpkg-buildpackage: info: binary-only upload (no source included)

After this the parent of the root directory would have deb of each version of the extension would be created.

vagrant@ubuntu-focal:/vagrant/base36-0.0.1$ ls -la ..
drwxr-xr-x  1 vagrant vagrant   4096 Jul  1 20:21 base36-0.0.1
-rw-r--r--  1 vagrant vagrant  11760 Jul  1 18:11 base36_0.0.1-1_amd64.buildinfo
-rw-r--r--  1 vagrant vagrant   2910 Jul  1 18:11 base36_0.0.1-1_amd64.changes
-rw-r--r--  1 vagrant vagrant    820 Jul  1 12:10 base36_0.0.1.orig.tar.gz
-rw-r--r--  1 vagrant vagrant   2552 Jul  1 18:11 postgresql-10-base36_0.0.1-1_amd64.deb
-rw-r--r--  1 vagrant vagrant   2552 Jul  1 18:11 postgresql-11-base36_0.0.1-1_amd64.deb
-rw-r--r--  1 vagrant vagrant   2552 Jul  1 18:11 postgresql-12-base36_0.0.1-1_amd64.deb
-rw-r--r--  1 vagrant vagrant   2556 Jul  1 18:11 postgresql-13-base36_0.0.1-1_amd64.deb
-rw-r--r--  1 vagrant vagrant   2552 Jul  1 18:11 postgresql-14-base36_0.0.1-1_amd64.deb
-rw-r--r--  1 vagrant vagrant   2556 Jul  1 18:11 postgresql-15-base36_0.0.1-1_amd64.deb

Gotchas:

  • The name of the folder of the source code of the extension should be of the form <extension_name>_.
  • The debian/pgversions file should have a newline otherwise any pg_buildext would neither return any output or any error(status code 0).
  • The postgresql-all package would be needed to build, install and test the extension on all the supported versions of PostgreSQL.

Fin.

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