aeroxis / sower

Sower

Sower "plants" directories, files and symlinks on your filesystem based on a contract you tell it.

How to Install

$ pip install sower

Why Do You Need Sower?

The Problem

Have you ever been in a situation where you needed to create a large set of files, that may span multiple subdirectories? You might need to do this for testing, especially if your application that you're testing is supposed to be tested for how it manages a set of files based on their directory structure.

The Solution - Part 1

Sower is the solution for this problem! You simply define a contract in YAML or JSON like the following:

---
sower:
    plan:
        bin:
            start.sh:
                type: file
                content: "echo 'Starting foobar'"
            stop.sh:
                type: file
                content: "echo 'Stopping foobar'"
        data:
            test-data.tar.gz:
                type: file
                content: "!random!"
                size: 1Mb
        src:
            foobar:
                __init__.py:
                    type: file
                    content: "# just a comment"
                main.py:
                    type: file
                    content: >
                        import os\n
                        print('Foo Bar: %s' % os.path.abspath('.'))\n\n
                link_main.py:
                    type: symlink
                    target: ../foobar/main.py

{
    "sower": {
        "plan": {
            "bin": {
                "start.sh": {
                    "type": "file",
                    "content": "echo'Startingfoobar'"
                },
                "stop.sh": {
                    "type": "file",
                    "content": "echo'Stoppingfoobar'"
                }
            },
            "data": {
                "test-data.tar.gz": {
                    "type": "file",
                    "content": "!random!",
                    "size": "1Mb"
                }
            },
            "src": {
                "foobar": {
                    "__init__.py": {
                        "type": "file",
                        "content": "#justacomment"
                    },
                    "main.py": {
                        "type": "file",
                        "content": "importos\nprint('FooBar: %s'%os.path.abspath('.')\n\n
                    },
                    "link_main.py": {
                        "type": "symlink",
                        "target": "../foobar/main.py"
                    }
                }
            }
        }
    }
}

Save the Contract to disk (choose either YAML or JSON listing from above). Now we simply tell Sower where to create these files, and the path to this contract.

If we want to create files based on this contract on /home/davydany/foobar, we would do the following:

If you chose the YAML, run the following: .. code:: bash

$ sower sow /home/davydany/foobar /tmp/sower-contract.yml

If you chose the JSON, run the following: .. code:: bash

$ sower sow /home/davydany/foobar /tmp/sower-contract.json

This would create the following structure:

/home/davydany/foobar
├── bin
│   ├── start.sh
│   └── stop.sh
├── data
│   └── test-data.tar.gz
└── src
    └── foobar
        ├── __init__.py
        ├── link_main.py -> /tmp/foobar/src/foobar/main.py
        └── main.py

4 directories, 6 files

The Solution - Part 2

Now, suppose you need to do this in your integration tests that use python's unittest. You can still leverage this with the Sower API.

You would have something like this in your test's setUp method.

import tempfile
import unittest
from sower.sow import perform_sow

class TestMyApp(unittest.TestCase):

    def setUp(self):

        self.root = tempfile.mkdtemp('_farmer_test')
        self.contract = """

        ---
        sower:
            plan:
                bin:
                    start.sh:
                        type: file
                        content: "echo 'Starting foobar'"
                    stop.sh:
                        type: file
                        content: "echo 'Stopping foobar'"
                data:
                    test-data.tar.gz:
                        type: file
                        content: "!random!"
                        size: 1Mb
                src:
                    foobar:
                        __init__.py:
                            type: file
                            content: "# just a comment"
                        main.py:
                            type: file
                            content: >
                                import os\n
                                print('Foo Bar: %s' % os.path.abspath('.'))\n\n
                        link_main.py:
                            type: symlink
                            target: ../foobar/main.py
        """
        perform_sow(self.root, self.contract)