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Simply checking whether a site is “up” is not enough for reliable monitoring.
Even if the login page itself loads, users may still be unable to access the service if the actual login process fails.

By using Zabbix’s Web Scenario feature, you can simulate a real login request and verify the response to monitor whether login is truly successful.

While HTTP availability monitoring is straightforward—and plenty of guides exist online—guides that explain functional monitoring including login validation are much harder to find.

Below is a walkthrough of how this was implemented in a real environment.

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1. Identify the Login URL and Payload

First, determine which URL the login request is sent to and what parameters are included.
This can be done easily using Chrome Developer Tools (F12):

1. Open the login page → press F12 → go to the Network tab
2. Apply the Fetch/XHR filter and click the login button
3. Find the first sign-in request and click it
4. Check the URL and Method (should be POST)
5. Check Request Headers to confirm the Content-Type
6. Inspect the Payload to see the fields being sent

Example (dummy values):

• URL: https://example.com/member-user/auth/sign-in
• Method: POST
• Content-Type: multipart/form-data; boundary=----WebKitFormBoundary6x5o981HvBL2rDUC
• Payload: clientname: example username: test_user@example.com password: MySecurePassword123!

👉 Key points:

• clientname → identifies the service. This varies by site and must be checked.
• username → the actual login account. Use a dedicated monitoring account, not a real admin user.
• password → the password for that account.

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2. Test with curl

Before applying to Zabbix, always test manually with curl.

curl -X POST https://example.com/member-user/auth/sign-in \
  -H "Content-Type: multipart/form-data; boundary=----WebKitFormBoundary6x5o981HvBL2rDUC" \
  -F "clientname=example" \
  -F "username=test_user@example.com" \
  -F "password=MySecurePassword123!"

• If the response is 200 OK → it works.
• If you get 401, 403, or 500 → either the URL, payload, or headers are incorrect.

Tip. If it doesn’t work correctly, try removing the -H option (Content-Type) to avoid boundary mismatches and let curl handle it automatically.

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3. Configure Zabbix Web Scenario

(1) Scenario basics

• Name: Login Check
• URL: https://example.com/member-user/auth/sign-in
• Update interval and attempts: adjust as needed
• Agent: Zabbix server

(2) Add a Step

• Name: Login Attempt
• URL: login processing URL from Developer Tools
• Post type: Raw data

Raw post body (example):

------WebKitFormBoundaryTest123
Content-Disposition: form-data; name="clientname"

example
------WebKitFormBoundaryTest123
Content-Disposition: form-data; name="username"

test_user@example.com
------WebKitFormBoundaryTest123
Content-Disposition: form-data; name="password"

MySecurePassword123!
------WebKitFormBoundaryTest123--

👉 Important notes:

• Boundary string (WebKitFormBoundaryTest123) → you can copy it from Developer Tools or create your own.
• The boundary string must match exactly in both the header and the raw data body.
• example, test_user@example.com, and MySecurePassword123! are just sample values—replace with your environment’s monitoring account.

(3) Add headers

Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryTest123
user-agent: curl/7.68.0

• Content-Type must match the boundary used above.
• user-agent can be arbitrary (curl, Mozilla/...).

(4) Timeout & status code

• Timeout: 15s (adjust for your environment)
• Required status code: 200

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4. Login Method Considerations

This approach does not work in every case—login flows differ by implementation:

• Simple form login → ✅ Works exactly as shown
• Session cookie based → Requires at least 2 steps in Zabbix Web Scenario to follow cookies
• CSRF token required → Must extract and send the hidden token value as part of the payload
• JavaScript encryption or reCAPTCHA → ❌ Not possible with Web Scenario alone (requires API or custom integration)

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5. Summary

1. Use Chrome Developer Tools to capture the URL, headers, and payload.
2. Test with curl to verify 200 OK.
3. Configure Zabbix Web Scenario with the same raw data and headers.
4. Boundary values can be arbitrary but must match between body and header.
5. For advanced login flows (session, CSRF, captcha), extra work or a different approach is required.

👉 With this, Zabbix goes beyond “HTTP is alive” checks and validates whether login is truly working.

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Zabbix Web Scenario: Adding a Login Check Trigger

Once the Web Scenario is in place, you need a trigger so alerts are generated.
The key metric here is web.test.fail.

• 0 → Normal (login succeeded)
• 1 → Problem (login failed)

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1. Trigger configuration

(1) Name

portal.example.com portal login has a problem

Clear naming helps operators immediately understand what failed.

(2) Problem expression

last(/Host/web.test.fail[portal web monitoring])=1

• Meaning: if the latest value is 1, the login failed → trigger fires.

(3) Recovery expression

last(/Host/web.test.fail[portal web monitoring])=0

• Meaning: if the latest value is 0, login is working again → trigger resolves.

(4) Severity

• Since login failure blocks all users, severity should be set to High or Critical.

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2. Other trigger options

• OK event generation: based on recovery expression
• Problem event generation mode: Single
• Close OK events: All problems
• Allow manual close: optional

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3. Final example

• Trigger name:
  portal.example.com portal login has a problem
• Problem condition:
  last(/Host/web.test.fail[portal web monitoring])=1
• Recovery condition:
  last(/Host/web.test.fail[portal web monitoring])=0
• Severity:
  Critical

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4. Summary

• web.test.fail → 0 normal / 1 problem
• Trigger expression: =1 for problem, =0 for recovery
• This ensures Zabbix alerts not only on HTTP availability, but on real login failures.

👉 With this setup, you’ll be notified immediately when users can’t log in—even if the site itself looks “up.”

🛠 마지막 수정일: 2025.12.12