Mroll migration tool

Database migration tool around MonetDB and pymonetdb.

Install

Install mroll from PyPi

$ pip install mroll

Usage

With MonetDB installed and running a project database, following commands can be used to set up migration process in your project.

$ mroll --help
Usage: commands.py [OPTIONS] COMMAND1 [ARGS]... [COMMAND2 [ARGS]...]...

Options:
  --help  Show this message and exit.

Commands:
  all_revisions
  config         Set up mroll configuration under $HOME/.config/mroll
  downgrade      Downgrades to the previous revison or to the revision with...
  history        Shows applied revisions.
  init           Creates mroll_revisions tbl.
  new_revisions  Shows revisions not applied yet
  revision       Creates new revision file from a template.
  rollback       Downgrades to the previous revision.
  setup          Set up work directory.
  show
  upgrade        Applies all revisions not yet applied in work dir.
  version

To set working directory use setup command.

mroll setup --help

, use -p/--path option to specify location. For an example lets use "/tmp/migration" location.

$ mroll setup -p "/tmp/migrations"
ok

If no path specified defaults to setting "migrations" folder in current working directory. To update/set mroll configuartion use 'config' command. For example to update configuration setting for working directory path run.

mroll config -p <workdir_path>

In the working directory modify mroll.ini with specific connection options

$ vi /tmp/migrations/mroll.ini 

, then run "init" command to create revisions table

$ mroll init

create first revision with brief description

$ mroll revision -m "create table foo"
ok
$ mroll show all_revisions
<Revision id=fe00de6bfa19 description=create table foo>

A new revison file was added under "/tmp/migrations/versions". Open and fill under "-- migration:upgrade" and "-- migration:downgrade" sections.

-- identifiers used by mroll
-- id=fe00de6bfa19
-- description=create tbl foo
-- ts=2020-05-08T14:19:46.839773
-- migration:upgrade
	create table foo (a string, b string);
	alter table foo add constraint foo_pk primary key (a);
-- migration:downgrade
	drop table foo;

Then run "upgrade" command.

$ mroll upgrade
Done

Inspect what has being applied with "history" command

$ mroll history
<Revision id=fe00de6bfa19 description=create tbl foo>

To revert last applied revision run "rollback" command. That will run the sql under "migration:downgrade" section.

$ mroll rollback 
Rolling back id=fe00de6bfa19 description=create tbl foo ...
Done

Development

• Developer notes

mroll is developed using [[https://python-poetry.org/][Poetry]], for dependency management and packaging.

** Installation for development In order to install mroll do the following:

  pip3 install --user poetry
  PYTHON_BIN_PATH="$(python3 -m site --user-base)/bin"
  export PATH="$PATH:$PYTHON_BIN_PATH"

  git clone git@github.com:MonetDBSolutions/mroll.git
  cd mroll
  poetry install
  poetry run mroll/commands.py --help

On 30/04/2020 [[https://github.com/gijzelaerr/pymonetdb/releases/tag/1.3.1][pymonetdb 1.3.1]] was released, which includes a feature needed to connect transparently to the MonetDB server. If you have installed the development version of mroll, before that date you need to update:

  cd monetdb-pystethoscope
  git pull
  poetry update

, install project dependencies with

poetry install

, this will create virtual environment and install dependencies from poetry.lock file. Any of the above commands then can be run with poetry

poetry run mroll/commands.py <command>

Testing

Run all unit tests

make test