Documentation Index
Fetch the complete documentation index at: https://docs.bunny.net/llms.txt
Use this file to discover all available pages before exploring further.
Edge Rules allow you to define logic that runs directly on bunny.net’s
edge servers before a request reaches your origin. Rules can modify
caching behavior, redirect traffic, route requests to different origins,
apply security actions, and more based on request conditions.
Edge Rule conditions often evaluate values such as:
- Cookie Value
- Country Code (2 letter)
- Country State Code
- File Extension
- Origin Retry Attempt Count
- Query String
- Random Chance (%)
- Remote IP
- Request Header
- Request Method
- Request URL
- Response Header
- Response Status Code
In many cases, simple string or wildcard matching is sufficient.
However, modern applications frequently generate URLs and request values
that follow predictable patterns rather than fixed strings.
Examples include:
- Streaming manifests
- Versioned build assets
- Dynamically generated API routes
To make these scenarios easier to handle, Edge Rules support pattern
matching using Lua patterns.
Using Pattern Matching
Pattern matching can be used in any Edge Rule condition that evaluates a
request value.
To enable pattern matching, prefix the value with:
Example:
pattern:^.*/video_chunk%-[^%-]+%-[^%-]+%.dash$
pattern: prefix instructs the Edge Rule engine to evaluate the
value using Lua pattern matching instead of a standard string
comparison.
Lua patterns are similar to regular expressions but intentionally
simpler and optimized for performance.
Anchoring the Pattern
Patterns should normally be wrapped with:
This ensures the entire value is matched, rather than matching a
substring.
If the pattern: prefix is not used, the condition behaves as a normal
string comparison.
Example
Pattern:
pattern:^.*/video_chunk%-[^%-]+%-[^%-]+%.dash$
/live/video_chunk-us-12345.dash
/live/video_chunk-es-54321.dash
string.find
function. This provides efficient pattern matching without requiring a
full regular expression engine.
Example Use Cases
Matching Streaming Manifests
Streaming platforms often generate manifest files containing region
identifiers or session identifiers in the filename.
Example URLs:
/live/video_chunk-us-12345.dash
/live/video_chunk-es-54321.dash
- Custom cache control
- Edge redirects
- Request routing
Targeting Versioned Assets
Many build systems generate versioned assets:
/assets/app-1.4.7.js
/assets/app-1.4.8.js
/assets/app-1.5.0.js
- Cache rules
- Rate limiting
- Header modification
Security Filtering
Pattern matching can also be used in security rules.
Example scenarios:
- Blocking administrative endpoints
- Detecting suspicious request patterns
- Filtering specific URL structures
These rules can be combined with conditions such as cookie presence or
header values.
Lua Pattern Cheat Sheet
Edge Rules use Lua patterns, which are simpler than full regular
expressions.
Edge Rules evaluate patterns using Lua’s string.find.
Anchors
| Symbol | Meaning |
|---|
| ^ | Start of string |
| $ | End of string |
Character Classes
| Pattern | Meaning |
|---|
| %d | Digit |
| %a | Letter |
| %w | Alphanumeric + _ |
| . | Any character |
| [abc] | Match a, b, or c |
| [^abc] | Match any character except a, b, or c |
Repeaters
| Pattern | Meaning |
|---|
| + | 1 or more |
| * | 0 or more (greedy) |
| - | 0 or more (non-greedy) |
Escaping Characters
Use % to escape special characters.
Examples:
%. # literal dot
%- # literal hyphen
Limitations
Lua patterns are intentionally simpler than full regular expressions.
Unsupported features include:
- Alternation (
|)
- Lookaheads / lookbehinds
- Full PCRE syntax
These limitations help ensure pattern evaluation remains fast and
predictable across the edge network.
