Connection

Requring the module will return a function that creates a Mongo object when called:

local mongol = require "resty-mongol"
local mongo = mongol() -- return a connection object

Methods:

• connect
• databases
• set_db_handle
• close
• set_timeout
• set_keepalive
• get_reused_times
• ismaster
• getprimary
• shutdown

Connection

:connect

Connect to a Mongo instance.

Parameters

Name	Description	Default	Required
host	The Mongo host address	"localhost"	No
port	The Mongo port number	27017	No

Returns

On success returns 1, or nil and error message.

local ok, err = mongo:connect( host, port )

:databases

Get available databases from this Mongo instance.

Parameters

None

Returns

A Lua table array describing databases on the server.

Namespace	Type
databases.name	String
databases.empty	Boolean
databases.sizeOnDisk	Number

local dbs = mongo:databases()
for _, db in ipairs( dbs ) do
  ngx.say( db.name )
end

:set_db_handle

Select a Mongo database to use.

Parameters

Name	Description	Default	Required
database_str	The name of a database	none	Yes

Returns

Mongo database object, or nil.

local db = mongo:new_db_handle( database_str )

:close

Close the connection to the Mongo instance.

Parameters

None

Returns

On success returns 1, or nil and error message.

local ok, err = mongo:close()

:set_timeout

Sets socket connecting, reading, writing timeout value, unit is milliseconds.

Parameters

Name	Description	Default	Required
timeout_ms	The socket timeout in milliseconds	30000	No

Returns

On success returns 1, or nil and error message.

local ok, err = mongo:set_timeout( timeout_ms )

:set_keepalive

Keeps the socket alive for msec by ngx_lua cosocket.

Parameters

Name	Description	Default	Required
msec	The socket keep-alive in milliseconds	30000	No
pool_size	The size of the keep-alive socket pool	?	No

Returns

On success returns 1, or nil and error message.

local ok, err = mongo:set_keepalive( msec, pool_size )

:get_reused_times

Returns the how many times this socket has been reused (see set_keepalive).

Parameters

None

Returns

On success returns times reused, or nil and error message.

local times_reused, err = mongo:get_reused_times()

:ismaster

Returns a boolean indicating if this is the master server and a table of other hosts this server is replicating with.

Parameters

None

Returns

On success returns Boolean and a table of hosts, or nil and error message.

local is_master, hostsOrErr = mongo:get_reused_times()

:getprimary

Returns a new connection object that is connected to the primary server.

Parameters

Name	Description	Default	Required
already_checked	Boolean (usage unknown)	?	No

Returns

On success returns connection object, or nil and error message.

local new_conn, err = mongo:getprimary()

:shutdown

Shuts down the Mongo database server.

You probably don't want to use this. See :close() instead.

Parameters

None

Returns

Nothing

mongo:shutdown()