You can find Vesper on Github at https://github.com/aszs/vesper or download the latest code as eggs, zips or tarballs at http://onecommons.org/vesper/dist/.
Vesper requires Python 2.4 or later. To install using easy_install, pass it an URL to the egg, for example easy_install http://onecommons.org/vesper/dist/vesper-LATEST-py2.6.egg. If you are installing from the source directory run either python setup.py install or run python setup.py develop if you don’t want to reinstall it everytime its source is updated.
If you’ve downloaded the source you can verify it working properly by running the unit tests: cd tests && python __init__.py
Once installed, you should be able to start the vesper admin server with vesper-admin. If not, it’s possible that easy_install didn’t put the script on your path. Where these scripts are placed is platform dependent, but the most common locations are:
| Platform | Path |
|---|---|
| OS X | /usr/local/bin |
| Debian/Ubuntu | /usr/bin or /usr/local/bin |
| Redhat/Fedora | /usr/bin |
| Windows | c:\Python2.6\Scripts |
But first, you’ll need to specify a datastore for it to open. If you downloaded the vesper.tgz file, examples are in the top level under ‘examples’. If you installed via easy_install or from an egg, the files will be in your site-packages inside the vesper egg directory. (If you need help finding this directory, try: "import vesper; print vesper.__file__")
From the examples directory, use the following command to open a sample datastore:
vesper-admin -s file://sample.mjson
On your terminal, you should see something like:
Using FileStore at sample.mjson
Starting HTTP on port 8000...
You should also be able to see the vesper admin server on port 8000.
For starters, enter the following query in the query field and click ‘Go’:
{ * }
This will show all objects in the sample datastore. (There should be XXX)
One way to think of the query syntax is specifying a template of the JSON that you’d like to have matched. In this case, it’s matching against a JSON object with anything inside - in other words all objects.
If you’d like to narrow down the objects to only those that have a certain attribute, use a query like:
{ "created":* }
which will match any top-level object (XXX) with a ‘created’ attribute.
For more information on making queries, see the query guide XXX
As you saw earlier, vesper-admin requires an URL that specifies which datastore it opens. This URL is of the form protocol://location and indicates both the type and location of the datastore. The most common types are:
| protocol | type |
|---|---|
| file | JSON or YAML text file |
| bdb | Berkeley DB |
| mem | In-memory store (not persistent) |
How the location portion of the URL is interpreted depends on the protocol, but for the file and bdb stores it’s just a path to a file. If a path to a nonexistent datastore is specified, a new one will be created.
The memory store doesn’t require an argument, it simply creates a private, in-memory store that can’t be shared with other processes (so there’s really no point in trying to give it a name).
For more information on the different datastores, see XXX.