Problem: Add MongoDB query and aggregation features to the BigchainDB API.

[elmadj]

Solution

This PR adds two endpoints to the BIgchainDB API:

• A "query-assets" endpoint which allows the client to pass a json query as defined by MongoDB to query the assets collection. (https://docs.mongodb.com/manual/tutorial/query-documents/)

• An "aggregate-assets" endpoint which allows the client to pass a list of aggregation functions to perform a MongoDB aggregation. (https://docs.mongodb.com/manual/reference/method/db.collection.aggregate/)

BEPs Implemented

bigchaindb/BEPs#96

[codecov-io]

Codecov Report

Merging #2690 into master will decrease coverage by 0.16%.
The diff coverage is 86.15%.

@@            Coverage Diff             @@
##           master    #2690      +/-   ##
==========================================
- Coverage   93.32%   93.15%   -0.17%     
==========================================
  Files          46       46              
  Lines        2712     2777      +65     
==========================================
+ Hits         2531     2587      +56     
- Misses        181      190       +9     

[davie0]

Hi @elmadj really appreciate your contribution! It will be reviewed soon. Meanwhile would you mind to add "sing off:" line to your commits?

[elmadj]

Thanks @zzappie . Will do that soon !