Bitrix Nginx Routing

Bitrix uses its own URL rewriting layer. nginx must pass Bitrix-friendly requests and variables to PHP-FPM, otherwise human-readable URLs, subdomains, or legacy URL-building code can behave differently from Apache-based hosting.

What Must Be True

For the Bitrix profile, nginx config should include:

• fallback to /bitrix/urlrewrite.php for Bitrix SEF/CHPU URLs
• client_max_body_size 64m for common Bitrix uploads
• SERVER_NAME and HTTP_HOST forwarded to PHP-FPM
• root domain and wildcard hostnames when wildcard host mode is enabled

bitrix status and site doctor check the most important nginx contract pieces.

SEF/CHPU Fallback

For normal human-readable URLs, nginx must fall back to:

/bitrix/urlrewrite.php?$args

not directly to:

/index.php

This matters for pages such as:

/news/10487/
/doc/personal-data/
/sveden-camp/about-camp/document-camp/

If these URLs are routed directly to /index.php, Bitrix can open the wrong content, skip route rules, or behave differently from the same project on Apache.

SERVER_NAME And HTTP_HOST

The Bitrix profile forwards Apache-like request variables to PHP-FPM, including:

SERVER_NAME
HTTP_HOST
REQUEST_SCHEME
SERVER_PORT
HTTPS

Use HTTP_HOST when application logic must know the exact incoming host, especially on wildcard/subdomain sites:

camp.example.ru
test.example.ru
b24.example.ru

SERVER_NAME can be normalized by nginx/server config. Legacy Bitrix code may still read it, so the profile forwards it, but host-sensitive project logic should prefer HTTP_HOST where possible.

Wildcard Host Mode

When a site is created with:

Serve all first-level subdomains too? -> yes

nginx should serve both:

example.ru
*.example.ru

This only routes requests to the same Bitrix project. It does not automatically make Bitrix multi-tenant. The application must still decide what to do for each host.

Wildcard host mode covers first-level subdomains only:

camp.example.ru

It does not cover multi-level subdomains:

a.b.example.ru

How To Check

Menu:

Sites -> Site info
Applications -> Bitrix -> Bitrix status
Diagnostics -> Site health check

CLI:

sudo /root/simai-env/simai-admin.sh site info --domain <domain>
sudo /root/simai-env/simai-admin.sh bitrix status --domain <domain>
sudo /root/simai-env/simai-admin.sh site doctor --domain <domain>

Expected Bitrix nginx checks:

Bitrix SEF fallback: /bitrix/urlrewrite.php
Bitrix upload body limit: client_max_body_size 64m

For wildcard sites, site info should show host mode and hostnames:

Host mode: wildcard
Hostnames: example.ru, *.example.ru

How To Reproduce Host-Specific Issues

From the server, test the same local nginx site with different hosts:

curl -I -H "Host: <domain>" http://127.0.0.1/
curl -I -H "Host: test.<domain>" http://127.0.0.1/

For a Bitrix route:

curl -I -H "Host: <domain>" http://127.0.0.1/news/10487/
curl -I -H "Host: test.<domain>" http://127.0.0.1/news/10487/

This checks nginx routing without waiting for external DNS.

Common Symptoms

CHPU page opens wrong content:

• check Bitrix SEF fallback
• expected fallback is /bitrix/urlrewrite.php

Subdomain opens root-domain behavior:

• check wildcard host mode in site info
• check DNS wildcard A record
• check application logic that reads HTTP_HOST

$_SERVER["SERVER_NAME"] or $_SERVER["HTTP_HOST"] differs from Apache:

• check bitrix status
• inspect nginx config if the site was migrated before the current Bitrix template
• prefer HTTP_HOST for exact incoming host in application logic

Manual nginx edits disappeared after SSL change:

• regenerate or patch through simai-env where possible
• SSL commands should preserve Bitrix template metadata
• run site doctor after SSL operations

Repair Direction

If site doctor reports missing Bitrix nginx checks, the safe direction is to restore the Bitrix nginx template contract rather than hand-editing unrelated blocks.

Important checks:

client_max_body_size 64m
try_files $uri $uri/ /bitrix/urlrewrite.php?$args
fastcgi_param SERVER_NAME $host
fastcgi_param HTTP_HOST $host

After any nginx change:

sudo nginx -t
sudo systemctl reload nginx
sudo /root/simai-env/simai-admin.sh site doctor --domain <domain>

Handoff Checklist

Before saying Bitrix nginx routing is ready:

• site info shows Profile: bitrix
• bitrix status reports Bitrix SEF fallback ready
• site doctor reports Bitrix nginx checks as pass
• wildcard host mode is enabled when subdomains are required
• root and subdomain hosts open the expected Bitrix application
• large uploads are covered by Uploads