| Experimental and incomplete implementation of Mongo emulation layer so Mongo |
| clients can connect to Usergrid. |
| |
| There are a number of drivers and tools for talking to MongoDB, which has a |
| data model that is very similar to that of Usergrid. In order to make it |
| easier for people to get started quickly with Usergrid, it's desirable for |
| them to be able to integrate it very quickly into their existing applications. |
| The goal here is to support the Mongo native wire protocol and to map enough |
| of the query and CRUD operations so that this can happen. |
| |
| While Mongo is a full-featured database, in practice only a small subset of |
| it's commands are used. To verify this, a Mongo proxy was written at: |
| |
| org.apache.usergrid.mongo.testproxy.MongoProxyServer |
| |
| This proxy serves as a "man in the middle" and decodes and logs all Mongo |
| commands sent to and from an application and MongoDB. Using a couple of GUI |
| tools as well as the Mongo command-line client, we were able to see that only |
| a handful of commands are commonly used for listing databases, collections, |
| and for querying content. |
| |
| Mongo uses a wire protocol described here: |
| |
| http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol |
| |
| Mongo uses BSON, which is a binary JSON format, as part of the wire protocol. |
| For compatibility, we're using the BSON encoder from the Mongo Java driver: |
| |
| https://github.com/mongodb/mongo-java-driver/ |
| |
| However, since we're using Jackson as our JSON library for the rest of |
| Usergrid, the idea is to switch over to Bson4Jackson: |
| |
| https://github.com/michel-kraemer/bson4jackson |
| |
| The commands Mongo supports are listed here: |
| |
| http://www.mongodb.org/display/DOCS/List+of+Database+Commands |
| |
| Mongo's system metadata is listed here: |
| |
| http://www.mongodb.org/display/DOCS/Mongo+Metadata |
| |
| Queries are described here: |
| |
| http://www.mongodb.org/display/DOCS/Mongo+Query+Language |
| |
| |
| Mapping Usergrid Multi-tenancy to Mongo Security |
| |
| First steps are to simply be able to handle a client login and map it to a |
| Usergrid account. |
| |
| Authentication is described here: |
| |
| http://www.mongodb.org/display/DOCS/Security+and+Authentication |
| http://www.mongodb.org/display/DOCS/Implementing+Authentication+in+a+Driver |
| |
| A user who authenticates against the Mongo 'admin' account will be actually |
| logging in as a Usergrid admin user who is a member of one or more Usergrid |
| accounts, each of which contains a set of applications that user is able to |
| administer. While they list the databases via the Mongo API, what they will |
| be seeing is the aggregate list of the applications for all the accounts they |
| are members of. |
| |
| For any database (Usergrid application), they'll be able to list the collections. |
| |
| Note: Internally, Mongo refers to it's collections as "namespaces", which |
| is a potential point of confusion between previous versions of Usergrid which |
| used the term "namespace" to describe applications. |
| |
| |
