98 lines
3.8 KiB
Markdown
98 lines
3.8 KiB
Markdown
# nodemcu-httpserver
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A (very) simple web server written in Lua for the ESP8266 firmware NodeMCU.
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## Features
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* GET
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* Multiple MIME types
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* Error pages (404 and others)
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* Remote execution of Lua scripts
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* Query string argument parsing
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## How to use
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1. Upload server files using [luatool.py](https://github.com/4refr0nt/luatool) or equivalent.
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Or, even better, use GNU Make with the bundled makefile. Type the following to upload
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server, init, and some example files.
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make upload
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Add the following to your init.lua in order to start the server:
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require("httpserver")
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server = httpserver.start(80, 10)
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In this example, 80 is the port your server is listening to, and 10 is the timeout (in seconds) for clients.
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2. Upload files you want to serve.
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Again, use luatool.py or similar and upload the HTML and other files.
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All the files you upload must be prefixed with "http/". Wait, what?
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Yes: NodeMCU's filesystem does not support folders, but filenames *can* contain slashes.
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Only files that begin with "http/" will be accessible through the server.
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3. Visit your server from a web browser.
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__Example:__ Say the IP for your ESP8266 is 2.2.2.2 and the server is
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running in the default port 80. Go to http://2.2.2.2/index.html using your web browser. The ESP8266 will serve you with the contents
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of the file "http/myPage.html" (if it exists). If you visit the root (/)
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then index.html is served. By the way, unlike some http servers, the URLs are case-sensitive.
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## How to create dynamic Lua scripts
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Similar to static files, upload a Lua script called "http/[name].lua where you replace [name] with the script's name.
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The script should return a function that takes two parameters:
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return function (connection, args)
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-- code goes here
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end
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Use the _connection_ parameter to send the response back to the client. Note that you are in charge of sending the HTTP header.
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The _args_ parameter is a Lua table that contains any arguments sent by the client in the GET request.
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For example, if the client requests _http://2.2.2.2/foo.lua?color=red_ then the server will execute the function
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in your Lua script _foo.lua_ and pass in _connection_ and _args_, where _args.color == "red"_.
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The easiest is to look at some of the included example scripts.
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## Not supported
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* Other methods: HEAD, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, PATCH
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* HTTP authentication
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* Encryption
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## Open issues
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* File system doesn't like long names, need to protect:
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PANIC: unprotected error in call to Lua API (httpserver.lua:78: filename too long)
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* nodemcu firmware with floating point doesn't have enough memory to compile nor run the server. See below.
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* Binary files haven't been tested yet since luatool.py doesn't support uploading anything but text files.
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If anyone has any luck with this, let us know!
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## A note on memory usage.
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The chip is very, very memory constrained. If you find yourself having trouble running the server or anything beyond the most trivial scripts,
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then try some of the following:
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* Use a recent build of nodemcu-firmware that supports node.compile().
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Compiled Lua code has extension .lc and has smaller memory footprint.
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After uploading the server code (httpserver.lua) but before running anything,
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type:
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node.compile("httpserver.lua")
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* If you can't even compile the server code, then you may need a build of the firmware without
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floating point. In file nodemcu-firmware/app/lua/luaconf.h right around line 572 (line number
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may change in the future) add
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#define LUA_NUMBER_INTEGRAL
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Then rebuild and re-flash the firmware. But if you **must** have floating point numbers and
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run this server code, you may be out of luck.
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* Any help reducing the memory needs of the server without crippling its features are appreciated!
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