:title: Sharing data between 2 couchdb databases
:description: Sharing data between 2 couchdb databases
:keywords: docker, example, package installation, networking, couchdb, data volumes

.. _running_couchdb_service:

CouchDB Service
===============

.. include:: example_header.inc

Here's an example of using data volumes to share the same data between
2 CouchDB containers.  This could be used for hot upgrades, testing
different versions of CouchDB on the same data, etc.

Create first database
---------------------

Note that we're marking ``/var/lib/couchdb`` as a data volume.

.. code-block:: bash

    COUCH1=$(sudo docker run -d -v /var/lib/couchdb shykes/couchdb:2013-05-03)

Add data to the first database
------------------------------

We're assuming your docker host is reachable at `localhost`. If not,
replace `localhost` with the public IP of your docker host.

.. code-block:: bash

    HOST=localhost
    URL="http://$HOST:$(sudo docker port $COUCH1 5984)/_utils/"
    echo "Navigate to $URL in your browser, and use the couch interface to add data"

Create second database
----------------------

This time, we're requesting shared access to $COUCH1's volumes.

.. code-block:: bash

    COUCH2=$(sudo docker run -d -volumes-from $COUCH1 shykes/couchdb:2013-05-03)

Browse data on the second database
----------------------------------

.. code-block:: bash

    HOST=localhost
    URL="http://$HOST:$(sudo docker port $COUCH2 5984)/_utils/"
    echo "Navigate to $URL in your browser. You should see the same data as in the first database"'!'

Congratulations, you are running 2 Couchdb containers, completely
isolated from each other *except* for their data.
