The snap can be installed from a file or directly from the snap store. It is, for the moment, listed in the edge channel.
$ sudo snap install couchdb --edge
The snap installation uses AppArmor to protect your system. CouchDB requests access to two interfaces: mount-observe, which is used by the disk compactor to know when to initiate a cleanup; and process-control, which is used by the indexer to set the priority of couchjs to ‘nice’. These two interfaces, while not required, are useful. If they are not enabled, CouchDB will still run, but you will need to run the compactor manually and couchjs may put a heavy load on the system when indexing.
To connect the interfaces type:
$ sudo snap connect couchdb:mount-observe $ sudo snap connect couchdb:process-control
There are two levels of hierarchy within couchdb configuration.
The default layer is stored in /snap/couchdb/current/rel/couchdb/etc/ the default.ini is first consulted and then any file default.d directory. In the snap installation this is mounted read-only.
The local layer is stored in /var/snap/couchdb/current/etc/ on the writable /var mount. Within this second layer, configurations are set with-in local.ini or superseded by any file within local.d. Configuration management tools (like puppet, chef, ansible, salt) operate here.
The name of the erlang process and the security cookie used is set within vm.args file. This can be set suing the snap native configuration. For example, when setting up a cluster over several machines the convention is to set the erlang name to couchdb@your.ip.address.
$ sudo snap set couchdb name=couchdb@216.3.128.12 setcookie=cutter
Snap Native Configuration changes only come into effect after a restart
$ sudo snap restart couchdb
CouchDB options can be set via configuration over HTTP, as below.
$ curl -X PUT http://localhost:5984/_node/_local/_config/httpd/bind_address -d '"0.0.0.0"'
$ curl -X PUT http://localhost:5984/_node/_local/_config/couchdb/delayed-commits -d '"true"'
Changes here do not require a restart.
For anything else in vm.args or configuration not white listed over http, you can edit the /var/snap/couchdb/current/etc files by hand and restart CouchDB.
See the HOWTO file to see an example of a three node cluster and further notes.
If you want to build your own snap file from source see the BUILD for instructions.