SNMP

snmp module implements SNMP communication protocol.

note

SNMP is available since Gateway version 2.3.

snmp.new()

-- @param connection_string string
-- @return table
function snmp.new(connection_string)
end 

Creates a new SNMP client instance with the given configuration. The configuration is represented as a connection_string in URI format enapter-snmp://host:port?community=public:

• enapter-snmp://: internal SNMP scheme definition;
• host:port: SNMP target host and port;
• community: community string value.

Example

local client = snmp.new("enapter-snmp://snmpserver:161?community=public")

client Object

client:get()

-- @param oids table Object Identifiers
-- @return table|nil, string|nil Variables and error
function client:get(oids)
end 

Retrieves variables based on entered Object Identifiers. If the method call fails, the error will contain a non-nil string. If the method call succeeds error will be nil. The result represents a table of variable objects, where each object contains type and value fields. The variables are returned in the order they were requested.

Example

function utf8_from(t)
  local bytearr = {}
  for _, v in ipairs(t) do
    local utf8byte = v < 0 and (0xff + v + 1) or v
    table.insert(bytearr, string.char(utf8byte))
  end
  return table.concat(bytearr)
end

local client = snmp.new("enapter-snmp://snmpserver:161?community=public")
local vars, err = client:get({".1.3.6.1.2.1.1.4.0", ".1.3.6.1.2.1.1.6.0"})
if err then
  enapter.log("Error get: "..err, "error")
else
  for _, v in ipairs(vars) do
    enapter.log(v.type..": "..utf8_from(v.value))
  end
end