crankshaft

CartoDB Spatial Analysis extension for PostgreSQL.

Code organization

• doc documentation
• src source code
• • src/pg contains the PostgreSQL extension source code
• • src/py Python module source code
• release reseleased versions
• env base directory for Python virtual environments

Requirements

• pip, virtualenv, PostgreSQL
• python-scipy system package (see src/py/README.md)

Working Process

We use the default develop branch as the basis for development. This branch and master are maintained by the Release Manager. The master branch is used to merge and tag releases to be deployed in production.

In addition to these two permanent branches, temporal topic branches must be used for all modifications.

Development

For any modification of crankshaft, including adding new features, a topic branch must be created out of the develop branch and be used for the development process; see src/py/README.md for further details about the Pyhton package development.

Modifications are done inside src/pg/sql and src/py/crankshaft. Take into account:

• Test must be added for any new functionality (src/pg/test, src/py/crankshaft/test) as well as for detected any bugs corrected.
• Add or modify the corresponding documentation files in the doc folder. Since we expect to have highly technical functions here, an extense background explanation would be of great help to users of this extension.
• Convention: snake case(i.e. snake_case and not CamelCase) shall be used for all function names. Prefix function names intended for public use with cdb_ and private functions (to be used only internally inside the extension) with _cdb_.

Once the code is ready to be tested, update the local development installation with sudo make install. This will update the 'dev' version of the extension in src/pg/ and make it available to PostgreSQL. It will also install the python package (crankshaft) in a virtual environment env/dev.

The version number of the Python package, defined in src/pg/crankshaft/setup.py will be overridden when the package is released and always match the extension version number, but for development it shall be kept as '0.0.0'.

Run the tests with make test.

To use the python extension for custom tests, activate the virtual environment with:

source envs/dev/bin/activate

Update extension in a working database with:

• ALTER EXTENSION crankshaft VERSION TO 'current'; ALTER EXTENSION crankshaft VERSION TO 'dev';

Note: we keep the current development version install as 'dev' always; we update through the 'current' alias to allow changing the extension contents but not the version identifier. This will fail if the changes involve incompatible function changes such as a different return type; in that case the offending function (or the whole extension) should be dropped manually before the update.

If the extension has not previously been installed in a database, it can be installed directly with:

• CREATE EXTENSION crankshaft WITH VERSION 'dev';

Note: the development extension uses the development python virtual environment automatically.

Once the tests are succeeding a new Pull-Request can be created to the develop branch. CI-tests must be checked to be successful.

Before proceeding to the release process peer code reviewing of the code is a must.

When the code is accepted by the peer reviewing (and CI tests succeed) a request for release will be send to the Release Manager.

Release

The release process of a new version of the extension shall be performed by the designated Release Manager.

Note that we expect to gradually automate more of this process.

Having checked the topic branch of the PR to be released it shall be merged back into the develop branch to prepare the new release.

The version number in pg/cranckshaft.control must first be updated. To do so Semantic Versioning 2.0 is in order.

Thew NEWS.md will be updated.

We now will explain the process for the case of backwards-compatible releases (updating the minor or patch version numbers).

TODO: document the complex case of major releases.

The next command must be executed to produce the main installation script for the new release, release/cranckshaft--X.Y.Z.sql and also to copy the python package to release/python/X.Y.Z/crankshaft.

make release

Then, the release manager shall produce upgrade and downgrade scripts to migrate to/from the previous release. In the case of minor/patch releases this simply consist in extracting the functions that have changed and placing them in the proper release/cranckshaft--X.Y.Z--A.B.C.sql file.

The new release can be deployed for staging/smoke tests with this command:

sudo make deploy

This will copy the current 'X.Y.Z' released version of the extension to PostgreSQL. The corresponding Python extension will be installed in a virtual environment in envs/X.Y.Z.

It can be activated with:

source envs/X.Y.Z/bin/activate

But note that this is needed only for using the package directly; the 'X.Y.Z' version of the extension will automatically use the python package from this virtual environment.

The sudo make deploy operation can be also used for installing the new version after it has been released.

To install a specific version 'X.Y.Z' different from the current one (which must be present in releases/) you can:

sudo make deploy RELEASE_VERSION=X.Y.Z

TODO: testing procedure for the new release.

TODO: procedure for staging deployment.

TODO: procedure for merging to master, tagging and deploying in production.