This module aims to be a minimal, but (mostly) standards-compliant web server for use within Hammerspoon. Expanding upon the Hammerspoon module, hs.httpserver, this module adds support for serving static pages stored at a specified document root as well as serving dynamic content from Lua Template Files interpreted within the Hammerspoon environment and external executables which support the CGI/1.1 framework.
This module aims to provide a fully functional, and somewhat extendable, web server foundation, but will never replace a true dedicated web server application. Some limitations include:
It is single threaded within the Hammerspoon environment and can only serve one resource at a time
As with all Hammerspoon modules, while dynamic content is being generated, Hammerspoon cannot respond to other callback functions -- a complex or time consuming script may block other Hammerspoon activity in a noticeable manner.
All document requests and responses are handled in memory only -- because of this, maximum resource size is limited to what you are willing to allow Hammerspoon to consume and memory limitations of your computer.
While some of these limitations may be mitigated to an extent in the future with additional modules and additions to hs.httpserver, Hammerspoon's web serving capabilities will never replace a dedicated web server when volume or speed is required.
An example web site is provided in the hsdocs folder of the hs.doc module. This web site can serve documentation for Hammerspoon dynamically generated from the json file included with the Hammerspoon application for internal documentation. It serves as a basic example of what is possible with this module.
You can start this web server by typing the following into your Hammerspoon console: require("hs.doc.hsdocs").start() and then visiting http://localhost:12345/ with your web browser.
A format string, usable with os.date, which will display a date in the format expected for HTTP communications as described in RFC 822, updated by RFC 1123.
Accessed as self._accessLog. If query logging is enabled for the web server, an Apache style common log entry will be appended to this string for each request. See hs.httpserver.hsminweb:queryLogging.
Accessed as self._serverAdmin. A string containing the administrator for the web server. Defaults to the currently logged in user's short form username and the computer's localized name as returned by hs.host.localizedName() (e.g. "user@computer").
Returns the current or specified time in the format expected for HTTP communications as described in RFC 822, updated by RFC 1123.
Parameters
date - an optional integer specifying the date as the number of seconds since 00:00:00 UTC on 1 January 1970. Defaults to the current time as returned by os.time()
Returns
the time indicated as a string in the format expected for HTTP communications as described in RFC 822, updated by RFC 1123.
Parse the specified URL into its constituent parts.
Parameters
url - the url to parse
Returns
a table containing the constituent parts of the provided url. The table will contain one or more of the following key-value pairs:
fragment - the anchor name a URL refers to within an HTML document. Appears after '#' at the end of a URL. Note that not all web clients include this in an HTTP request since its normal purpose is to indicate where to scroll to within a page after the content has been retrieved.
host - the host name portion of the URL, if any
lastPathComponent - the last component of the path portion of the URL
password - the password specified in the URL. Note that this is not the password that would be entered when using Basic or Digest authentication; rather it is a password included in the URL itself -- for security reasons, use of this field has been deprecated in most situations and modern browsers will often prompt for confirmation before allowing URL's which contain a password to be transmitted.
path - the full path specified in the URL
pathComponents - an array containing the path components as individual strings. Components which specify a sub-directory of the path will end with a "/" character.
pathExtension - if the final component of the path refers to a file, the file's extension, if any.
port - the port specified in the URL, if any
query - the portion of the URL after a '?' character, if any; used to contain query information often from a form submitting it's input with the GET method.
resourceSpecifier - the portion of the URL after the scheme
scheme - the URL scheme; for web traffic, this will be "http" or "https"
standardizedURL - the URL with any path components of ".." or "." normalized. The use of ".." that would cause the URL to refer to something preceding its root is simply removed.
URL - the URL as it was provided to this function (no changes)
user - the user name specified in the URL. Note that this is not the user name that would be entered when using Basic or Digest authentication; rather it is a user name included in the URL itself -- for security reasons, use of this field has been deprecated in most situations and modern browsers will often prompt for confirmation before allowing URL's which contain a user name to be transmitted.
Notes
This function differs from the similar function hs.http.urlParts in a few ways:
To simplify the logic used by this module to determine if a request for a directory is properly terminated with a "/", the path components returned by this function do not remove this character from the component, if present.
Some extraneous or duplicate keys have been removed.
This function is patterned after RFC 3986 while hs.http.urlParts uses OS X API functions which are patterned after RFC 1808. RFC 3986 obsoletes 1808. The primary distinction that affects this module is in regards to parameters for path components in the URI -- RFC 3986 disallows them in schema based URI's (like the URL's that are used for web based traffic).
Create a new hsminweb table object representing a Hammerspoon Web Server.
Parameters
documentRoot - an optional string specifying the document root for the new web server. Defaults to the Hammerspoon users Sites sub-directory (i.e. os.getenv("HOME").."/Sites").
Returns
a table representing the hsminweb object.
Notes
a web server's document root is the directory which contains the documents or files to be served by the web server.
while an hs.minweb object is actually represented by a Lua table, it has been assigned a meta-table which allows methods to be called directly on it like a user-data object. For most purposes, you should think of this table as the module's userdata.
Get or set the access-list table for the hsminweb web server
Parameters
table - an optional table or nil containing the access list for the web server, default nil.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
The access-list feature works by comparing the request headers against a list of tests which either accept or reject the request. If no access list is set (i.e. it is assigned a value of nil), then all requests are served. If a table is passed into this method, then any request which is not explicitly accepted by one of the tests provided is rejected (i.e. there is an implicit "reject" at the end of the list).
The access-list table is a list of tests which are evaluated in order. The first test which matches a given request determines whether or not the request is accepted or rejected.
Each entry in the access-list table is also a table with the following format:
{ 'header', 'value', isPattern, isAccepted }
header - a string value matching the name of a header. While the header name must match exactly, the comparison is case-insensitive (i.e. "X-Remote-addr" and "x-remote-addr" will both match the actual header name used, which is "X-Remote-Addr").
value - a string value specifying the value to compare the header key's value to.
isPattern - a boolean indicating whether or not the header key's value should be compared to value as a pattern match (true) -- see Lua documentation 6.4.1, help.lua._man._6_4_1 in the console, or as an exact match (false)
isAccepted - a boolean indicating whether or not a match should be accepted (true) or rejected (false)
A special entry of the form { '*', '*', '*', true } accepts all further requests and can be used as the final entry if you wish for the access list to function as a list of requests to reject, but to accept any requests which do not match a previous test.
A special entry of the form { '*', '*', '*', false } rejects all further requests and can be used as the final entry if you wish for the access list to function as a list of requests to accept, but to reject any requests which do not match a previous test. This is the implicit "default" final test if a table is assigned with the access-list method and does not actually need to be specified, but is included for completeness.
Note that any entry after an entry in which the first two parameters are equal to '*' will never actually be used.
The tests are performed in order; if you wich to allow one IP address in a range, but reject all others, you should list the accepted IP addresses first. For example:
{
{ 'X-Remote-Addr', '192.168.1.100', false, true }, -- accept requests from 192.168.1.100
{ 'X-Remote-Addr', '^192%.168%.1%.', true, false }, -- reject all others from the 192.168.1 subnet
{ '*', '*', '*', true } -- accept all other requests
}
Most of the headers available are provided by the requesting web browser, so the exact headers available will vary. You can find some information about common HTTP request headers at: https://en.wikipedia.org/wiki/List_of_HTTP_header_fields.
The following headers are inserted automatically by hs.httpserver and are probably the most useful for use in an access list:
X-Remote-Addr - the remote IPv4 or IPv6 address of the machine making the request,
X-Remote-Port - the TCP port of the remote machine where the request originated.
X-Server-Addr - the server IPv4 or IPv6 address that the web server received the request from. For machines with multiple interfaces, this will allow you to determine which interface the request was received on.
X-Server-Port - the TCP port of the web server that received the request.
Get or set the whether or not a directory index is returned when the requested URL specifies a directory and no file matching an entry in the directory indexes table is found.
Parameters
flag - an optional boolean, defaults to false, indicating whether or not a directory index can be returned when a default file cannot be located.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
if this value is false, then an attempt to retrieve a URL specifying a directory that does not contain a default file as identified by one of the entries in the hs.httpserver.hsminweb:directoryIndex list will result in a "403.2" error.
Get or set the file extensions which identify files which should be executed as CGI scripts to provide the results to an HTTP request.
Parameters
table - an optional table or nil, defaults to { "cgi", "pl" }, specifying a list of file extensions which indicate that a file should be executed as CGI scripts to provide the content for an HTTP request.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Get or set the file names to look for when the requested URL specifies a directory.
Parameters
table - an optional table or nil, defaults to { "index.html", "index.htm" }, specifying a list of file names to look for when the requested URL specifies a directory. If a file with one of the names is found in the directory, this file is served instead of the directory.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
Files listed in this table are checked in order, so the first matched is served. If no file match occurs, then the server will return a generated list of the files in the directory, or a "403.2" error, depending upon the value controlled by hs.httpserver.hsminweb:allowDirectory.
Get or set the network interface that the hsminweb web server will listen on
Parameters
interface - an optional string, or nil, specifying the network interface the web server will listen on. An explicit nil specifies that the web server should listen on all active interfaces for the machine. Defaults to nil.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
See hs.httpserver.setInterface for a description of valid values that can be specified as the interface argument to this method.
the interface can only be specified before the hsminweb web server has been started. If you wish to change the listening interface for a running web server, you must stop it with hs.httpserver.hsminweb:stop before invoking this method and then restart it with hs.httpserver.hsminweb:start.
Get or set the extension of files which contain Lua code which should be executed within Hammerspoon to provide the results to an HTTP request.
Parameters
string - an optional string or nil, defaults to nil, specifying the file extension which indicates that a file should be executed as Lua code within the Hammerspoon environment to provide the content for an HTTP request.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
This extension is checked after the extensions given to hs.httpserver.hsminweb:cgiExtensions; this means that if the same extension set by this method is also in the CGI extensions list, then the file will be interpreted as a CGI script and ignore this setting.
Get or set the maximum body size for an HTTP request
Parameters
size - An optional integer value specifying the maximum body size allowed for an incoming HTTP request in bytes. Defaults to 10485760 (10 MB).
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
Because the Hammerspoon http server processes incoming requests completely in memory, this method puts a limit on the maximum size for a POST or PUT request.
If the request body exceeds this size, hs.httpserver will respond with a status code of 405 for the method before this module ever receives the request.
Get or set the name the web server uses in Bonjour advertisement when the web server is running.
Parameters
name - an optional string specifying the name the server advertises itself as when Bonjour is enabled and the web server is running. Defaults to nil, which causes the server to be advertised with the computer's name as defined in the Sharing preferences panel for the computer.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Set a password for the hsminweb web server, or return a boolean indicating whether or not a password is currently set for the web server.
Parameters
password - An optional string that contains the server password, or an explicit nil to remove an existing password.
Returns
the hsminwebTable object if a parameter is provided, or a boolean indicating whether or not a password has been set if no parameter is specified.
Notes
the password, if set, is server wide and causes the server to use the Basic authentication scheme with an empty string for the username.
this module is an extension to the Hammerspoon core module hs.httpserver, so it has the same limitations regarding server passwords. See the documentation for hs.httpserver.setPassword (help.hs.httpserver.setPassword in the Hammerspoon console).
Get or set the name the port the web server listens on
Parameters
port - an optional integer specifying the TCP port the server listens for requests on when it is running. Defaults to nil, which causes the server to randomly choose a port when it is started.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
due to security restrictions enforced by OS X, the port must be a number greater than 1023
integer - an optional integer, defaults to 30, specifying the length of time in seconds a CGI script should be allowed to run before being forcibly terminated if it has not yet completed its task.
Returns
the hsminwebTable object if a parameter is provided, or the current value if no parameter is specified.
Notes
With the current functionality available in hs.httpserver, any script which is expected to return content for an HTTP request must run in a blocking manner -- this means that no other Hammerspoon activity can be occurring while the script is executing. This parameter lets you set the maximum amount of time such a script can hold things up before being terminated.
An alternative implementation of at least some of the methods available in hs.httpserver is being considered which may make it possible to use hs.task for these scripts, which would alleviate this blocking behavior. However, even if this is addressed, a timeout for scripts is still desirable so that a client making a request doesn't sit around waiting forever if a script is malformed.
this module is an extension to the Hammerspoon core module hs.httpserver, so it has the same considerations regarding SSL. See the documentation for hs.httpserver.new (help.hs.httpserver.new in the Hammerspoon console).
