snmp_notifier receives alerts from the Prometheus' Alertmanager and routes them as SNMP traps.
The SNMP notifier receives alerts and sends them as SNMP traps to any given SNMP poller.
It has been created to handle older monitoring and alerting systems such as Nagios or Centreon.
Prometheus' Alertmanager sends the alerts to the SNMP notifier on its HTTP API. The SNMP notifier then looks for OID in the given alerts' labels. Each trap is sent with a unique ID, which allows, if the alert is updated or once it is resolved, to send additional traps with updated status and data.
There are various ways to install the SNMP notifier:
The SNMP notifier chart is available via the Prometheus Community Kubernetes Helm Charts:
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm install snmp-notifier prometheus-community/alertmanager-snmp-notifier --set 'snmpNotifier.snmpDestinations={my-snmp-server:162}'Refer to the chart values to see the available options.
Docker images are available on the Docker Hub.
Precompiled binaries are available in the release section of this repository.
Check out the source code and build it manually:
git clone https://github.com/maxwo/snmp_notifier.git
cd snmp_notifier
make build
./snmp_notifierOID may be added to the alert labels to identify the kind of trap to be sent:
A default OID is specified in the SNMP notifier if none is found in the alert. This can be useful if you want all the alerts to share the same OID.
groups:
- name: service
rules:
- alert: ServiceIsDown
expr: up == 0
for: 5m
labels:
severity: "critical"
type: "service"
oid: "1.3.6.1.4.1.123.0.10.1.1.1.5.1"
environment: "production"
annotations:
description: "Service {{ $labels.job }} on {{ $labels.instance }} is down"
summary: "A service is down."The Alertmanager should be configured with the SNMP notifier as alert receiver:
receivers:
- name: "snmp_notifier"
webhook_configs:
- send_resolved: true
url: http://snmp.notifier.service:9464/alertsNote that the send_resolved option allows the notifier to update the trap status to normal.
Launch the snmp_notifier executable with the help flag to see the available options.
$ ./snmp_notifier --help
usage: snmp_notifier [<flags>]
A tool to relay Prometheus alerts as SNMP traps
Flags:
-h, --[no-]help Show context-sensitive help (also try
--help-long and --help-man).
--[no-]web.systemd-socket Use systemd socket activation listeners instead
of port listeners (Linux only).
--web.listen-address=:9464 ...
Addresses on which to expose metrics and web
interface. Repeatable for multiple addresses.
--web.config.file="" Path to configuration file that can
enable TLS or authentication. See:
https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md
--alert.severity-label="severity"
Label where to find the alert severity.
--alert.severities="critical,warning,info"
The ordered list of alert severities, from more
priority to less priority.
--alert.default-severity="critical"
The alert severity if none is provided via
labels.
--snmp.version=V2c SNMP version. V2c and V3 are currently
supported.
--snmp.destination=127.0.0.1:162 ...
SNMP trap server destination.
--snmp.retries=1 SNMP number of retries
--snmp.trap-oid-label="oid"
Label where to find the trap OID.
--snmp.trap-default-oid="1.3.6.1.4.1.98789"
Trap OID to send if none is found in the alert
labels.
--snmp.trap-description-template=description-template.tpl
SNMP description template.
--snmp.extra-field-template=4=extra-field-template.tpl ...
SNMP extra field templates, eg.
--snmp.extra-field-templates=4=new-field.template.tpl
to add a 4th field to the trap, with the given
template file. You may add several fields using
that flag several times.
--snmp.timeout=5s SNMP timeout duration
--snmp.sub-object-default-oid=1.3.6.1.4.1.123.456
OID to use as the base of the sub-objects of
each trap.
--snmp.community="public" SNMP community (V2c only). Passing secrets to
the command line is not recommended, consider
using the SNMP_NOTIFIER_COMMUNITY environment
variable instead. ($SNMP_NOTIFIER_COMMUNITY)
--[no-]snmp.authentication-enabled
Enable SNMP authentication (V3 only).
--snmp.authentication-protocol=MD5
Protocol for password encryption (V3 only).
MD5 and SHA are currently supported.
--snmp.authentication-username=USERNAME
SNMP authentication username (V3 only). Passing
secrets to the command line is not recommended,
consider using the SNMP_NOTIFIER_AUTH_USERNAME
environment variable instead.
($SNMP_NOTIFIER_AUTH_USERNAME)
--snmp.authentication-password=PASSWORD
SNMP authentication password (V3 only). Passing
secrets to the command line is not recommended,
consider using the SNMP_NOTIFIER_AUTH_PASSWORD
environment variable instead.
($SNMP_NOTIFIER_AUTH_PASSWORD)
--[no-]snmp.private-enabled
Enable SNMP encryption (V3 only).
--snmp.private-protocol=DES
Protocol for SNMP data transmission (V3 only).
DES and AES are currently supported.
--snmp.private-password=SECRET
SNMP private password (V3 only). Passing
secrets to the command line is not recommended,
consider using the SNMP_NOTIFIER_PRIV_PASSWORD
environment variable instead.
($SNMP_NOTIFIER_PRIV_PASSWORD)
--snmp.security-engine-id=SECURITY_ENGINE_ID
SNMP security engine ID (V3 only).
--snmp.context-engine-id=CONTEXT_ENGINE_ID
SNMP context engine ID (V3 only).
--snmp.context-name=CONTEXT_ENGINE_NAME
SNMP context name (V3 only).
--log.level=info Only log messages with the given severity or
above. One of: [debug, info, warn, error]
--log.format=logfmt Output format of log messages. One of: [logfmt,
json]
--[no-]version Show application version.Also, it is recommended to use the following environment variables to set the SNMP secrets:
| Environment variable | Configuration | Default |
|---|---|---|
| SNMP_NOTIFIER_COMMUNITY | SNMP community for SNMP v2c | public |
| SNMP_NOTIFIER_AUTH_USERNAME | SNMP authentication username for SNMP v3 | |
| SNMP_NOTIFIER_AUTH_PASSWORD | SNMP authentication password for SNMP v3 | |
| SNMP_NOTIFIER_PRIV_PASSWORD | SNMP private (or server) password for SNMP v3 |
Any Go template directive may be used in the snmp.trap-description-template file.
Here are 2 example traps received with the default configuration. It includes 2 firing alerts sharing the same OID, and 1 resolved alert.
Traps include 3 fields:
- a trap unique ID;
- the alert/trap status;
- a description of the alerts.
$ snmptrapd -m ALL -m +SNMP-NOTIFIER-MIB -f -Of -Lo -c scripts/snmptrapd.conf
Agent Address: 0.0.0.0
Agent Hostname: localhost
Date: 1 - 0 - 0 - 1 - 1 - 1970
Enterprise OID: .
Trap Type: Cold Start
Trap Sub-Type: 0
Community/Infosec Context: TRAP2, SNMP v2c, community public
Uptime: 0
Description: Cold Start
PDU Attribute/Value Pair Array:
.iso.org.dod.internet.mgmt.mib-2.system.sysUpTime.sysUpTimeInstance = Timeticks: (853395100) 98 days, 18:32:31.00
.iso.org.dod.internet.snmpV2.snmpModules.snmpMIB.snmpMIBObjects.snmpTrap.snmpTrapOID.0 = OID: .iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierDefaultTrap
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertId = STRING: "1.3.6.1.4.1.98789[environment=production,label=test]"
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertSeverity = STRING: "critical"
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertDescription = STRING: "2/3 alerts are firing:
Status: critical
- Alert: TestAlert
Summary: this is the summary
Description: this is the description on job1
Status: warning
- Alert: TestAlert
Summary: this is the random summary
Description: this is the description of alert 1"
--------------You may add additional fields thanks to the --snmp.extra-field-template arguments.
For instance, the template {{ len .Alerts }} alerts are firing. given in the --snmp.extra-field-template=4=alert-count.tpl argument will produce:
$ snmptrapd -m ALL -m +SNMP-NOTIFIER-MIB -f -Of -Lo -c scripts/snmptrapd.conf
Agent Address: 0.0.0.0
Agent Hostname: localhost
Date: 1 - 0 - 0 - 1 - 1 - 1970
Enterprise OID: .
Trap Type: Cold Start
Trap Sub-Type: 0
Community/Infosec Context: TRAP2, SNMP v2c, community public
Uptime: 0
Description: Cold Start
PDU Attribute/Value Pair Array:
.iso.org.dod.internet.mgmt.mib-2.system.sysUpTime.sysUpTimeInstance = Timeticks: (2665700) 7:24:17.00
.iso.org.dod.internet.snmpV2.snmpModules.snmpMIB.snmpMIBObjects.snmpTrap.snmpTrapOID.0 = OID: .iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierDefaultTrap
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertId = STRING: "1.3.6.1.4.1.98789[environment=production,label=test]"
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertSeverity = STRING: "critical"
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.snmpNotifierAlertDescription = STRING: "2/3 alerts are firing:
Status: critical
- Alert: TestAlert
Summary: this is the summary
Description: this is the description on job1
Status: warning
- Alert: TestAlert
Summary: this is the random summary
Description: this is the description of alert 1"
.iso.org.dod.internet.private.enterprises.snmpNotifier.snmpNotifierAlertsObjects.4 = STRING: "2 alerts are firing."
--------------Issues, feedback, PR welcome.
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