mod_wasmplugin

Introduction

Bfe supports calling user-defined wasm plugins (following the proxy-wasm specification, https://github.com/proxy-wasm/spec) in the processing flow of http request/response. The mod_wasmplugin module is responsible for running wasm plugins and invoking them according to user-defined rules.。

Module Configuration

Description

conf/mod_wasm/mod_wasm.conf

Config Item	Description
Basic.DataPath	String Path of rule configuration
Basic.WasmPluginPath	String Folder path for storing wasm plugin files
Log.OpenDebug	Boolean Debug flag of module Default value: False

Example

[Basic]
DataPath = mod_wasm/mod_wasm.data
WasmPluginPath=wasm_plugin/

Rule Configuration

Description

Config Item	Description
Version	String Version of config file
BeforeLocationRules	Object List of wasm plugin rules for the HandleBeforeLocation callback point
BeforeLocationRules[]	Object A rule
BeforeLocationRules[].Cond	String Condition expression, See Condition
BeforeLocationRules[].PluginList	Object List of wasm plugins to invoke when the condition is matched
BeforeLocationRules[].PluginList[]	String Name of the wasm plugin
ProductRules	Object Wasm plugin rules for each product
ProductRules{k}	String Product name
ProductRules{v}	Object List of wasm plugin rules
ProductRules{v}[]	Object A rule
ProductRules{v}[].Cond	String Condition expression, See Condition
ProductRules{v}[].PluginList	Object List of wasm plugins to invoke when the condition is matched
ProductRules{v}[].PluginList[]	String Name of the wasm plugin
PluginMap	Object Dictionary of wasm plugins
PluginMap{k}	String Name of the wasm plugin
PluginMap{v}	Object A wasm plugin
PluginMap{v}.Name	String Name of the wasm plugin
PluginMap{v}.WasmVersion	String Version of the wasm file
PluginMap{v}.ConfVersion	String Version of the configuration file
PluginMap{v}.InstanceNum	Integer Number of running instances of the wasm plugin

Example

{
    "Version": "20240101000000",
    "BeforeLocationRules": [{
        "Cond": "req_path_prefix_in(\"/headers\", false)",
        "PluginList": [ "headers" ]
    }],
    "ProductRules": {
        "local_product": [{
            "Cond": "default_t()",
            "PluginList": []
        }]
    },
    "PluginMap": {
        "headers": {
            "Name": "headers",
            "WasmVersion": "20240101000000",
            "ConfVersion": "20240101000000",
            "InstanceNum": 20
        }
    }
}

Wasm Plugin Files

For any wasm plugin (with name PlugName for example) in the PluginMap, the following files need to be prepared in advance and stored in the path: <WasmPluginPath>/PlugName/

File Name	Description
PlugName.wasm	wasm file
PlugName.md5	md5 file of PlugName.wasm
PlugName.conf	Custom configuration file for the plugin