rrthomas / verdure

Because another version is always greener, and some versions are evergreen.

Verdure

© 2020 Reuben Thomas [email protected]
https://github.com/rrthomas/verdure

Verdure runs a particular version of a program, first installing it if necessary. (Users might be interested in the more capable Spack.)

Verdure is free software, licensed under the GNU GPL version 3 (or, at your option, any later version).

Please send questions, comments, and bug reports to the maintainer, or report them on the project’s web page (see above for addresses).

Installation

Verdure requires Python 3.6 or later. To install it, run:

python3 setup.py install

Use

Sometimes you want to run a particular version of a program: to track down a bug in a program you use, to test a particular commit of code you’re working on, or because you’ve never gotten around to updating that crucial script to use the latest version of that program.

With verdure, you can say

verdure foo 1.3 --frobnicate wibble bar

and verdure will run foo --frobnicate wibble bar with foo version 1.3.

Programs are installed in $XDG_CACHE_DIR/verdure/PROGRAM/VERSION. There must be an executable in that directory called PROGRAM, and any other files required for the installation can be stored there.

See verdure --help for further options.

Installing programs automatically

Programs can be installed manually, but verdure’s can install them automatically. To do this, use the --install-cmd argument:

verdure --install-cmd="wget https://www.example.com/$PROGRAM/$VERSION/$PROGRAM; chmod +x $PROGRAM" foo 1.3 --frobnicate wibble bar

The command is passed to sh -c with the environment variables PROGRAM and VERSION set to the values passed to verdure and PROGRAM_ENV set to the name of a shell file that can have environment variables and commands appended to it, and executed in the installation directory.

Installation packages, source tarballs, Git checkouts and similar directories of files used to build and install a program should be unpacked, checked out etc. into a directory called PROGRAM-VERSION.

Installation helpers

Automatic installation alone is still not that useful! Verdure’s real usefulness is its pre-written installation helpers. These are programs whose name starts verdure-, so you can see what is available by typing verdure- and pressing TAB in most shells. The supplied scripts will tell you more about themselves with --help.

An example that mixes some helpers with custom code:

verdure --install-cmd \
    'verdure-git https://github.com/rrthomas/$PROGRAM && \
    verdure-cpanm File::Slurp File::Which && \
    (cd $PROGRAM-$VERSION && ./setup-git-config && make) && \
    ln -s $PROGRAM-$VERSION/$PROGRAM .' \
    nancy 6.4 --version

First we check out the correct version of Nancy with verdure-git. verdure-cpanm installs Nancy’s Perl dependencies, and sets up the PERL5LIB path. The next line initializes the repository and builds the nancy script. Finally, we link the script into the main verdure directory, so that verdure can run it.

The first three lines are adapted from Nancy’s installation instructions.

We request version 6.4 of Nancy, and run it with the command-line argument --version.

It is simpler to install from a release:

verdure --install-cmd \
    'wget https://github.com/rrthomas/$PROGRAM/releases/download/v$VERSION/$PROGRAM-$VERSION.zip && \
    unzip $PROGRAM-$VERSION.zip && \
    verdure-cpanm File::Slurp File::Which && \
    ln -s $PROGRAM-$VERSION/$PROGRAM .' \
    nancy 6.4 --version

With a standard build system, things can be simpler still:

verdure --install-cmd
    'verdure-git https://github.com/rrthomas/$PROGRAM -- --recursive && \
    (cd $PROGRAM-$VERSION && verdure-autotools-bootstrap) && \
    ln -s $PROGRAM-$VERSION/src/$PROGRAM .' \
    beetle v2.0.8 --version

Note the extra argument --recursive to verdure-git: this should not be needed, but is, owing to a bug in Beetle’s build system. Verdure can cope! The bug is fixed on master, and see an alternative form of --install-cmd:

echo 'verdure-git https://github.com/rrthomas/$PROGRAM && \
    (cd $PROGRAM-$VERSION && verdure-autotools-bootstrap) && \
    ln -s $PROGRAM-$VERSION/src/$PROGRAM .' | \
    verdure --install-cmd=- beetle master --version

Finally, --install-prog allows an arbitrary executable to be used for installation:

echo 'verdure-git https://github.com/rrthomas/$PROGRAM && \
    (cd $PROGRAM-$VERSION && verdure-autotools-bootstrap) && \
    ln -s $PROGRAM-$VERSION/src/$PROGRAM .' > ./install-beetle
verdure --install-prog=./install-beetle beetle master --version