Checkmk – SMS integration manual

Send Checkmk alerts and notifications via SMSEagle hardware SMS gateway.

SMSEagle enables reliable SMS alerting directly from your infrastructure, without relying on external cloud SMS providers. Messages are sent through a physical on-premise device over the cellular network, which makes this integration a strong fit for secure environments, industrial networks, and installations with limited or no Internet access.

The current Checkmk integration is based on a notification script for Checkmk 2.x and uses SMSEagle APIv2 with token-based authentication. It is simple to deploy, works natively with Checkmk notifications, and supports flexible per-rule or per-user configuration.

Requirements

Before you begin, make sure your environment includes:

- Checkmk 2.x (CEE, CRE, or CME)
- SMSEagle firmware with APIv2 support (v5.0 or newer)
- curl installed on the Checkmk server

Step 1: Configure SMSEagle

1. Log in to the SMSEagle web GUI
2. Go to Users
3. Create a new user, or use an existing one
4. Open Access to API for that user
5. Enable APIv2
6. Generate an access token
7. Enable permission for SMS sending
8. Copy the token for later use in Checkmk
9. Go to Settings > SSL and set Forward HTTP to HTTPS to No

Step 2: Install the notification script in Checkmk

Copy the SMSEagle notification script to your Checkmk site and make it executable:

# Switch to your Checkmk site user
su – mysite

# Copy the script to the notifications directory
cp check_mk_smseagle-notify.sh ~/local/share/check_mk/notifications/

# Make it executable
chmod 755 ~/local/share/check_mk/notifications/check_mk_smseagle-notify.sh

# Restart the site
omd restart

This is the installation flow described in the current SMSEagle Checkmk repository.

Step 3: Create a notification rule in Checkmk

In Checkmk:

Go to Setup > Events > Notifications
Click Add rule
Set Notification Method to SMSEagle
Fill in the required parameters:

SMSEagle device URL
Example: https://192.168.0.100
API Access Token
Your SMSEagle APIv2 token

Optional parameters:

Verify SSL — yes or no
SMS priority — value from 0 to 9
Encoding — standard or unicode
Modem number — optional, for multi-modem devices

Step 4: Define recipients

Under Contact selection, choose the users or contact groups that should receive SMS alerts.

Make sure each contact has the Pager field filled in with a valid phone number in international format, for example:

+48123456789

Optional: Use Custom User Attributes

If you want more flexibility, you can define SMSEagle settings per contact using Checkmk Custom User Attributes instead of rule-level parameters.

Supported attributes:

SMSEAGLE_URL
SMSEAGLE_TOKEN
SMSEAGLE_VERIFY_SSL
SMSEAGLE_PRIORITY
SMSEAGLE_ENCODING
SMSEAGLE_MODEM_NO

When these attributes are defined, they take precedence over the notification rule parameters. This is useful when different users or teams should use different devices, priorities, or SSL settings.

SSL note

The integration uses HTTPS communication between Checkmk and the SMSEagle device. If your SMSEagle device uses a self-signed certificate, you can either trust that certificate on the Checkmk server or disable SSL verification in the notification parameters.

Troubleshooting

To inspect notification debug output, check the Checkmk notification log:

tail -f ~/var/log/notify.log

Debug entries are prefixed with DEBUG: and errors with ERROR:.

Legacy installations

Older environments may still use the legacy Python script notify_smseagle.py, which relies on the older SMSEagle HTTP API. That version is kept only for backward compatibility and is available in the obsolete directory of the repository.

For new deployments, use the current Checkmk 2.x integration with APIv2 token authentication.

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