vhost: Hostname matching library for nginx-module-lua

Installation

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CentOS/RHEL 7 or Amazon Linux 2

yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install lua-resty-vhost

CentOS/RHEL 8+, Fedora Linux, Amazon Linux 2023

yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install lua5.1-resty-vhost

To use this Lua library with NGINX, ensure that nginx-module-lua is installed.

This document describes lua-resty-vhost v0.1 released on Oct 14 2016.

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Library for matching hostnames to values. Supports wildcard and .hostname.tld syntax in the same way as Nginx's server_name directive.

Keys beginning with . or *. will match apex and all sub-domains, longest match wins. Non-wildcard matches always win.

Regex matches and prefix wildcards are not supported.

Overview

init_by_lua_block {
    local vhost = require("resty.vhost")
    my_vhost = vhost:new()
    local ok, err = my_vhost:insert("example.com",      { key = "example.com.key",          cert = "example.com.crt" })
    local ok, err = my_vhost:insert("www.example.com",  { key = "example.com.key",          cert = "example.com.crt" })
    local ok, err = my_vhost:insert(".sub.example.com", { key = "star.sub.example.com.key", cert = "star.sub.example.com.crt" })
    local ok, err = my_vhost:insert("www.example2.com", { key = "www.example2.com.key",     cert = "www.example2.com.crt" })
}

server {
    listen 80 default_server;
    listen 443 ssl default_server;
    server_name vhost;

    ssl_certificate         /path/to/default/cert.crt;
    ssl_certificate_key     /path/to/default/key.crt;

    ssl_certificate_by_lua_block {
        local val, err = my_vhost:lookup(require("ngx.ssl").server_name())
        if not val then
            ngx.log(ngx.ERR, err)
        else
            ngx.log(ngx.DEBUG, "Match, setting certs: ", val.cert, " ", val.key)
            -- set_certs_somehow(val)
        end
    }

    location / {
        content_by_lua_block {
            local val, err = my_vhost:lookup(ngx.var.host)
            if val then
                -- do something based on val
                ngx.say("Matched: ", val.cert)
            else
                if err then
                    ngx.log(ngx.ERR, err)
                end
                ngx.exit(404)
            end
        }
    }
}

Methods

new

syntax: my_vhost, err = vhost:new(size?)

Creates a new instance of resty-vhost with an optional initial size

insert

syntax: ok, err = my_vhost:insert(key, value)

Adds a new hostname key with associated value.

Keys must be strings.

Returns false and an error message on failure.

lookup

syntax: val, err = my_vhost:lookup(hostname)

Retrieves value for best matching hostname entry.

Returns nil and an error message on failure

TODO

• Regex matches
• Prefix matches
• Trie compression

GitHub

You may find additional configuration tips and documentation for this module in the GitHub repository for nginx-module-vhost.