Joelipu

Gemini server written for my capsule (gemini://gmi.hen6003.xyz/)

Features

• Static file hosting
• CGI file hosting
• Plugins via dynamic libarys

Config

The server is configured in TOML from a config.toml file in the directory the program is ran.

Content

• root: The directory (relative) holding the sites files (defualts to root)
• index: What file to use if a directory is requested (defualts to index.gmi)
• plugins: The directory (relative) holding plugins to be loaded (defualts to plugins)

Net

• port: Port to host on (defualts to 1965)
• host: Server name (defaults to localhost)

Certs

• cert: Path to certificate
• key: Path to private key

Example

[Content]
root = "root"
index = "index.gmi"
plugins = "plugins"

[Net]
port = 1965
host = "server.name"

[Certs]
cert = "certs/server.crt"
key  = "certs/server.key"

CGI

If a file is executable the server will execute the file and serve the output. The following enviroment variables will be set:

Request info

• SCRIPT_FILENAME: The absolute path to the script
• SCRIPT_NAME: The relative path to the script from DOCUMENT_ROOT
• REQUEST_URI: The complete URI that was requested
• QUERY_STRING: The query string in the URI

Remote info

• REMOTE_ADDR: The IP address of the visitor
• REMOTE_HOST: Their IP address again (For compatability with the spec)

Server info

• GATEWAY_INTERFACE: "CGI/1.1" (For compatability with the spec)
• DOCUMENT_ROOT: The root of the hosted content
• SERVER_NAME: The servers hostname (e.g. gmi.hen6003.xyz)
• SERVER_PORT: The port the server is hosting on
• SERVER_SOFTWARE: "Joelipu" (For compatability with the spec)

Plugins

Plugins are done via go plugins, they allow a more direct use of the connection, and can emulate a directory. The plugin must provide a path it handles with HandlePath() (this path is inaccessable in the root directory even if it exists). If the visitors request matches the plugins path the plugins HandleGemini() function is called, with info about the request and the server.

Example plugin

package main

import (
	"github.com/hen6003/joelipu/plugins"
)

type PluginImpl struct{}

func (p PluginImpl) HandleGemini(vars plugins.GeminiVars) string {
	return "10 Hello World\r\n"
}

func (p PluginImpl) HandlePath() string {
	return "hello"
}

var Impl plugins.Plugin = PluginImpl{}

Compile command

$ go build -buildmode=plugin plugin.go

Setup certificates

Make a folder called 'certs', and use openssl to create the certificates

$ mkdir certs
$ openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:4096 -keyout certs/server.key -out certs/server.crt

Name

"jo e lipu" is Toki Pona for "Having paper". "pana" (giving) is probally a better word than "jo", however "panaelipu" looks worse ¯\_(ツ)_/¯.