Gufo SNMP Example: Multi Items Get Request

We have mastered the requesting of single item in our get example. But SNMP allows to query multiple keys in single request. Let's consider the example.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Let's see the details.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Gufo SNMP is an async library. In our case we should run the client from our synchronous script, so we need to import asyncio to use asyncio.run().

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Import sys module to parse the CLI argument.

Warning

We use sys.argv only for demonstration purposes. Use argsparse or alternatives in real-world applications.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Gufo SNMP is a typed library and it is good practice to place type hints in your code, so we import required type hints from Python's typing module.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

SnmpSession object holds all necessary API, so import it from gufo.snmp.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Asynchronous code must be executed in the asynchronous functions or coroutines. So we define our function as async. We expect the following arguments:

• Address of the agent.
• SNMP community to authorize.
• List of OIDs to query.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

First, we need to create SnmpSession object which wraps the client's session. The SnmpSession may be used as an instance directly or operated as async context manager with the async with clause. When used as a context manager, the client automatically closes all connections on the exit of context, so its lifetime is defined explicitly.

SnmpSession constructor offers lots of configuration variables for fine-tuning. Refer to the SnmpSession reference for further details. In our example, we set the agent's address and SNMP community to the given values.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

We use SnmpSession.get_many() function to query multiple OIDs. The function is asynchronous and must be awaited. See SnmpSession.get() reference for further details.

get_many() returns a dict, where keys are the requested OIDs, and values are the query results.

Note

get_many() ignores non-existent OIDs, so it is up to the application to check the resulting dict for missed keys.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

It is up to the application how to deal with the result. In our example we just print all the items.

import asyncio
import sys
from typing import List

from gufo.snmp import SnmpSession


async def main(addr: str, community: str, oids: List[str]) -> None:
    async with SnmpSession(addr=addr, community=community) as session:
        r = await session.get_many(oids)
        for k, v in r.items():
            print(f"{k}: {v}")


asyncio.run(main(sys.argv[1], sys.argv[2], list(sys.argv[3:])))

Lets run our asynchronous main() function via asyncio.run and pass first command-line parameters as address, community and OIDs. We use the rest of command line as the list of OIDs to query.

Running

Let's check our script. Run example as:

$ python3 examples/async/getmany.py 127.0.0.1 public 1.3.6.1.2.1.1.6.0 1.3.6.1.2.1.1.4.0
1.3.6.1.2.1.1.6.0: Gufo SNMP Test
1.3.6.1.2.1.1.4.0: test <me@example.com>