Friday 20 December 2013

CouchDB on Linux Mint - Cheat sheet

Here's my cheat sheet for working with CouchDB on a Linux Mint server.

Installation

Installation is trivial
sudo apt-get install couchdb -y

Test to see that it works.
curl http://127.0.0.1:5984/

should return something like

{"couchdb":"Welcome","version":"1.2.0"}

Create a database named 'johantest'
curl -X PUT http://127.0.0.1:5984/johantest

Delete the same database
curl -X DELETE http://127.0.0.1:5984/johantest


Adding documents

Assume you didn't delete the database, add a document like this
curl -X POST http://127.0.0.1:5984/johantest \
-H 'Content-Type: application/json' \
-d '{"SomeProperty":"Test1","AnotherProperty":"Test2","Age":32,"PropList":["Prop1","Prop2","Prop3"]}'

To retrieve all documents in a database

curl -X GET http://127.0.0.1:5984/johantest/_all_docs

Gives
{"total_rows":1,"offset":0,"rows":[
{"id":"4571d772c7d61fa34a7579ce6f04d47b","key":"4571d772c7d61fa34a7579ce6f04d47b","value":{"rev":"1-a268e2541be30dae295fb88015bd1a5c"}}
]}

That will only give references so you can GET each document detail. To fetch the contents of an individual document, fetch using the key from the provious GET.
curl -X GET http://127.0.0.1:5984/johantest/4571d772c7d61fa34a7579ce6f04d47b

Gives
{"_id":"4571d772c7d61fa34a7579ce6f04d47b","_rev":"1-a268e2541be30dae295fb88015bd1a5c","SomeProperty":"Test1","AnotherProperty":"Test2","Age":32,"PropList":["Prop1","Prop2","Prop3"]}

 If you wish to fetch all documents in one large JSON blob
curl -X GET http://127.0.0.1:5984/johantest/_all_docs?include_docs=true 

Gives
{"total_rows":1,"offset":0,"rows":[
{"id":"4571d772c7d61fa34a7579ce6f04d47b","key":"4571d772c7d61fa34a7579ce6f04d47b","value":{"rev":"1-a268e2541be30dae295fb88015bd1a5c"},"doc":{"_id":"4571d772c7d61fa34a7579ce6f04d47b","_rev":"1-a268e2541be30dae295fb88015bd1a5c","SomeProperty":"Test1","AnotherProperty":"Test2","Age":32,"PropList":["Prop1","Prop2","Prop3"]}}
]}

Settings and logs

Settings are stored in /etc/couchdb/default.ini
To be able to connect to the databse via HTTP from other machines on network, change
bind_address = 0.0.0.0

The actual database is stored by default at
/var/lib/couchdb/1.2.0 and is named in this case johantest.couch

If you wish to move it to another partition or similar, change the settings
database_dir = /var/lib/couchdb/1.2.0
view_index_dir = /var/lib/couchdb/1.2.0

To get a feel of the amount of disk used by Couch I notice that my Weather Station application has stored 8800 JSON documents in a format like this

{"id":"6ea52d20ab226121a325d0e3c5ffe4b5","key":"6ea52d20ab226121a325d0e3c5ffe4b5","value":{"rev":"1-087372f223546fb03c75605decb4a442"},"doc":{"_id":"6ea52d20ab226121a325d0e3c5ffe4b5","_rev":"1-087372f223546fb03c75605decb4a442","temperature":23.75858110517378563,"rawDate":1385961273368,"key":"holmon"}}

That will occupy 28.9 MB of disk with the default settings of compression etcetera.

To see what requests has been made against the database, the log is placed at
 /var/log/couchdb/couch.log
which can be changed in the settings file as well. Output for the tests above

[Sat, 28 Dec 2013 09:08:41 GMT] [info] [<0.2082.8>] 127.0.0.1 - - PUT /johantest 201
[Sat, 28 Dec 2013 09:34:03 GMT] [info] [<0.28823.7>] 127.0.0.1 - - DELETE /johantest 200
[Sat, 28 Dec 2013 09:34:07 GMT] [info] [<0.25248.7>] 127.0.0.1 - - PUT /johantest 201
[Sat, 28 Dec 2013 09:34:13 GMT] [info] [<0.3856.8>] 127.0.0.1 - - POST /johantest 201
[Sat, 28 Dec 2013 09:34:22 GMT] [info] [<0.2437.8>] 127.0.0.1 - - GET /johantest/_all_docs?include_docs=true 200
[Sat, 28 Dec 2013 09:35:29 GMT] [info] [<0.2449.8>] 127.0.0.1 - - GET /johantest/_all_docs 200
[Sat, 28 Dec 2013 09:35:41 GMT] [info] [<0.2339.8>] 127.0.0.1 - - GET /johantest/4571d772c7d61fa34a7579ce6f04d47b 200


4 comments:

  1. Hey! Mind-blowing blog. Keep writing such beautiful blogs. In case you are struggling with issues on QuickBooks software, dial QuickBooks For MAC Support (855)756-1077. The team, on the other end, will assist you with the best technical services.

    ReplyDelete
  2. Hey! Lovely blog. Your blog contains all the details and information related to the topic. In case you are a QuickBooks user, here is good news for you. You may encounter any error like QuickBooks Error, visit at QuickBooks Support Phone Number for quick help.

    ReplyDelete
  3. Szukaj najbardziej atrakcyjnych bonusów w naszym wyborze witryn kasynowych! https://top10casino.pl/kasino/slottyway-casino/

    ReplyDelete