CrashPlan Pro Server is a pretty cool tool with a lot of great features that can be used to back up client computers. There are a lot of things that CrashPlan Pro is good at out of the box, but there are also a lot of other things that CrashPlan Pro wasn’t intended for that it could be good at, given a little additional flexibility. The REST API that CrashPlan Pro uses provides a little flexibility and as with most APIs I would expect it to provide even more as time goes on.
I often hear people run away screaming when REST comes up, thinking they’re going to have to learn some pretty complex scripting. And while the scripting can be complex, it doesn’t necessarily have to be. You can find a lot of handy information about the options available in the REST API at http://support.crashplanpro.com/doku.php/api. The very first example command that CrashPlan gives is the following:
http://:4280/rest/users?status=Active
Now, to use this in a very simple script, let’s look at it with curl. You are going to need to authenticate, so we’re going to inject that into the URL in much the same was that we would with something like, let’s say, WebDAV, SSH or FTP. If the server name were foundation.lan, the user name was daneel and the password was seldonrulez then the curl command would actually look like so (you could use the -u operator to inject the authentication information, but as you’ll see later I’d like to make those a bit less complex):
curl http://daneel:seldonrulez@foundation.lan:4280/rest/users?status=Active
Note: The default port for the web administration in CrashPlan Pro is 4280.
This is simply going to output a list of Active users on the server. The reason it’s going to output only Active users is that we asked it to (reading from left to right after the rest is shown in the URL) query users, using the status attribute and specifying only to show us users whose status matches as Active. We could just as easily have requested all users by using the following (which just removes ?status=Active):
curl http://daneel:seldonrulez@foundation.lan:4280/rest/users
Each user has a unique attribute in their id. These are assigned in an ascending order, so we could also query for the user with an ID of 3 by simply following the users with their unique ID:
curl http://daneel:seldonrulez@foundation.lan:4280/rest/users/3
We could also query for all users with a given attribute, such as orgId (note that these attributes are case sensitive unlike many other things that start with http). For example, to find users with an orgID of 3:
curl http://daneel:seldonrulez@foundation.lan:4280/rest/users?orgId=3
The API doesn’t just expose looking at users though. You can look at Organizations (aka orgs), targets (aka mountPoints), server statistics (aka serverStats) and Computers (aka computers). These can be discovered by running the following command:
curl -i http://daneel:seldonrulez@foundation.lan:4280/rest/
To then see each Organization:
curl http://daneel:seldonrulez@foundation.lan:4280/rest/orgs
And to see each Computer:
curl http://daneel:seldonrulez@foundation.lan:4280/rest/computers
You can also perform compound searches fairly easily. For example, let’s say that we wanted to see
curl http://daneel:seldonrulez@foundation.lan:4280/rest/computers?userId=3&status=Active
These basic incantations of curl are simply getting information, which programmatically could also be specified using a -X operator (or –request if you like to type a lot) to indicate the type of REQUEST we’re sending (continuing on with our Code42 Sci-fi inspired example):
curl -X GET -H ‘Content-type: application/json’ http://daneel:seldonrulez@foundation.lan:4280/rest/orgs
The important thing about being able to indicate the type of REQUEST is that we can do more than GET: we can also POST and PUT. We also used the -H operator to indicate the type of data, which we’re specifying as application/json (per the output of a curl -i command against the server’s REST API URL). POST is used to create objects in the database whereas PUT is used update objects in the database. This could result in:
curl -i -H ‘Content-Type: application/json’ -d ‘{“username”: “charlesedge”, “password”: “test”, “firstName”: “Charles”, “lastName”: “Edge”, “orgId”: “3”}’ http://daneel:seldonrulez@foundation.lan:4280/rest/users
Perl, Python, Ruby and PHP come with a number of options specifically designed for working with REST, which makes more complicated scripting much easier (such as with php’s curl_setopt); however, these are mostly useful if you already know those languages and the point of this article was to stay in shell scripting land. This allows you knock out simple tasks quickly, even if the good people at Code 42 didn’t think to add the specific features to their software that you might have in mind. Once you start to get into scripting more complex events, look to the Python examples at the bottom of the API Architecture page to get ya’ kickstarted!