prometheus-webhook-snmp is a Prometheus Alertmanager receiver that translates incoming notifications into SNMP v2c traps.

Features

• Independent from specific SNMP OID's
• The SNMP OID's of variable binds can be customized via prefix
• Extract SNMP OID from alert label
• Use a default SNMP OID for all alerts without an OID label
• Export Prometheus metrics from this receiver

Start the receiver

To start the receiver execute the command:

$ ./prometheus-webhook-snmp run

To start with HTTPS, pass the certificate and key parameters:

$ ./prometheus-webhook-snmp --cert "certificate.pem" --key "key.pem" run

Note: Both '--cert' and '--key' are needed to enable HTTPS.

Send a test SNMP trap

If you want to send a test SNMP trap, then simply execute the following command. This can be used to test your command line parameters.

$ ./prometheus-webhook-snmp test

Command line parameters

Command line parameters have precedence over global configuration settings.

Global

--snmp-host

The host (IPv4, IPv6 or FQDN) of the SNMP trap receiver. Defaults to localhost.

--snmp-port

The port of the SNMP trap receiver. Defaults to 162.

--snmp-community

The SNMP community string. Defaults to public.

--snmp-retries

Maximum number of request retries. Defaults to 5.

--snmp-timeout

Response timeout in seconds. Defaults to 1.

--alert-oid-label

The label where to find the OID. Defaults to oid.

Example Prometheus alert rule:

groups:
- name: mon
  rules:
  - alert: low monitor quorum count
    expr: sum(ceph_mon_quorum_status) < 3
    labels:
      severity: critical
      type: ceph_default
      oid: 1.3.6.1.4.1.50495.15.1.2.3.1
    annotations:
      description: Monitor count in quorum is low.

--trap-oid-prefix

The OID prefix for trap variable bindings. Defaults to 1.3.6.1.4.1.50495.15.

--trap-default-oid

The trap OID if none is found in the Prometheus alert labels. Defaults to 1.3.6.1.4.1.50495.15.1.2.1.

--trap-default-severity

The trap severity if none is found in the Prometheus alert labels. Defaults to an empty string.

Command run

--host

The host to use, defaults to localhost.

--port

Port to listen for Prometheus Alertmanager notifications. Defaults to 9099.

Example Prometheus Alertmanager configuration:

receivers:
  - name: 'prometheus-webhook-snmp'
    webhook_configs:
    - url: 'http://localhost:9099'

--metrics

Provide Prometheus metrics from this receiver under the URL /metrics.

Example Prometheus configuration:

scrape_configs:
  - job_name: 'prometheus-webhook-snmp'
    scrape_interval: 30s
    static_configs:
      - targets: ['localhost:9099']

Global configuration file

The Prometheus Alertmanager receiver can be configured via configuration file, too. Command line arguments have precedence over the settings in the configuration file. The configuration file is written in YAML format. The file will be loaded in the following order and precedence from /etc/prometheus-webhook-snmp.conf and the directory in which the prometheus-webhook-snmp command is located. Parameters in these files have precedence over default configuration settings. Please replace hyphens in parameter names with underscores.

Example configuration:

debug: True
snmp_retries: 1
snmp_community: private
host: promalertmgr.foo.com
port: 9101

SNMP schema

Traps

OID	Description
trap-oid-prefix.1.2.1	The default trap. This is used if no OID is specified in the alert labels.
trap-oid-prefix.1.2.[2...N]	Custom traps.

Objects

The following objects are appended as variable binds to a SNMP trap.

OID	Type	Description
trap-oid-prefix.1.1.1	String	The name of the Prometheus alert.
trap-oid-prefix.1.1.2	String	The status of the Prometheus alert.
trap-oid-prefix.1.1.3	String	The severity of the Prometheus alert.
trap-oid-prefix.1.1.4	String	Unique identifier for the Prometheus instance.
trap-oid-prefix.1.1.5	String	The name of the Prometheus job.
trap-oid-prefix.1.1.6	String	The Prometheus alert description field.
trap-oid-prefix.1.1.7	String	Additional Prometheus alert labels as JSON string.
trap-oid-prefix.1.1.8	Unix timestamp	The time when the Prometheus alert occurred.
trap-oid-prefix.1.1.9	String	The raw Prometheus alert as JSON string.

Docker

Pull the container

To get the container image, execute the following command:

$ docker pull registry.opensuse.org/opensuse/prometheus-webhook-snmp:latest
$ docker pull registry.opensuse.org/opensuse/prometheus-webhook-snmp:1.4

Networking

You need to publish the port the Prometheus receiver is listening on by using the command line argument --publish <HOST_PORT>:<CONTAINER_PORT> when running the container because the port is not exposed automatically because it is configurable. The default port is 9099.

Alternatively simply connect the container to the host network by using the command line argument --network=host. Additionally the SNMP host needs to be configured. Use the container's network gateway to be able to receive SNMP traps outside the container.

Run the container

There are two options for configuring the container:

1. Environment variables
2. Configuration file

Environment variables

Use ARGS to set global options and RUN_ARGS for the run command options. The environment variable ARGS defaults to --debug.

$ docker run --env ARGS="--debug --snmp-community=foo" --env RUN_ARGS="--metrics" ...

Configuration file

Use a configuration file by mounting it into the container.

$ docker run -v $(pwd)/prometheus-webhook-snmp.conf:/etc/prometheus-webhook-snmp.conf ...