add basic webserver that can do most of what i need

- serve static files, serving index.html or optionally listings for directories - redirects - reverse-proxy, forwarding requests to a backend these are configurable through the config file. a domain and path regexp have to be configured. path prefixes can be stripped. configured domains are added to the autotls allowlist, so acme automatically fetches certificates for them. all webserver requests now have (access) logging, metrics, rate limiting. on http errors, the error message prints an encrypted cid for relating with log files. this also adds a new mechanism for example config files.
2025-07-10 07:14:40 +03:00 · 2023-02-28 22:12:27 +01:00
parent fbfbd97947
commit 6706c5c84a
13 changed files with 1171 additions and 60 deletions
--- a/config/doc.go
+++ b/config/doc.go
@ -269,6 +269,22 @@ describe-static" and "mox config describe-domains":
 				# useful when the mta-sts domain is reverse proxied. (optional)
 				NonTLS: false

+			# All configured WebHandlers will serve on an enabled listener. (optional)
+			WebserverHTTP:
+				Enabled: false
+
+				# Port for plain HTTP (non-TLS) webserver. (optional)
+				Port: 0
+
+			# All configured WebHandlers will serve on an enabled listener. Either ACME must
+			# be configured, or for each WebHandler domain a TLS certificate must be
+			# configured. (optional)
+			WebserverHTTPS:
+				Enabled: false
+
+				# Port for HTTPS webserver. (optional)
+				Port: 0
+
 	# Destination for emails delivered to postmaster address.
 	Postmaster:
 		Account:
@ -540,6 +556,176 @@ describe-static" and "mox config describe-domains":
 					# Occurrences in word database until a word is considered rare and its influence
 					# in calculating probability reduced. E.g. 1 or 2. (optional)
 					RareWords: 0
+
+	# Handle webserver requests by serving static files, redirecting or
+	# reverse-proxying HTTP(s). The first matching WebHandler will handle the request.
+	# Built-in handlers for autoconfig and mta-sts always run first. If no handler
+	# matches, the response status code is file not found (404). If functionality you
+	# need is missng, simply forward the requests to an application that can provide
+	# the needed functionality. (optional)
+	WebHandlers:
+		-
+
+			# Name to use in logging and metrics. (optional)
+			LogName:
+
+			# Both Domain and PathRegexp must match for this WebHandler to match a request.
+			# Exactly one of WebStatic, WebRedirect, WebForward must be set.
+			Domain:
+
+			# Regular expression matched against request path, must always start with ^ to
+			# ensure matching from the start of the path. The matching prefix can optionally
+			# be stripped by WebForward. The regular expression does not have to end with $.
+			PathRegexp:
+
+			# If set, plain HTTP requests are not automatically permanently redirected (308)
+			# to HTTPS. If you don't have a HTTPS webserver configured, set this to true.
+			# (optional)
+			DontRedirectPlainHTTP: false
+
+			# Serve static files. (optional)
+			WebStatic:
+
+				# Path to strip from the request URL before evaluating to a local path. If the
+				# requested URL path does not start with this prefix and ContinueNotFound it is
+				# considered non-matching and next WebHandlers are tried. If ContinueNotFound is
+				# not set, a file not found (404) is returned in that case. (optional)
+				StripPrefix:
+
+				# Directory to serve files from for this handler. Keep in mind that relative paths
+				# are relative to the working directory of mox.
+				Root:
+
+				# If set, and a directory is requested, and no index.html is present that can be
+				# served, a file listing is returned. Results in 403 if ListFiles is not set. If a
+				# directory is requested and the URL does not end with a slash, the response is a
+				# redirect to the path with trailing slash. (optional)
+				ListFiles: false
+
+				# If a requested URL does not exist, don't return a file not found (404) response,
+				# but consider this handler non-matching and continue attempts to serve with later
+				# WebHandlers, which may be a reverse proxy generating dynamic content, possibly
+				# even writing a static file for a next request to serve statically. If
+				# ContinueNotFound is set, HTTP requests other than GET and HEAD do not match.
+				# This mechanism can be used to implement the equivalent of 'try_files' in other
+				# webservers. (optional)
+				ContinueNotFound: false
+
+				# Headers to add to the response. Useful for cache-control, content-type, etc. By
+				# default, Content-Type headers are automatically added for recognized file types,
+				# unless added explicitly through this setting. For directory listings, a
+				# content-type header is skipped. (optional)
+				ResponseHeaders:
+					x:
+
+			# Redirect requests to configured URL. (optional)
+			WebRedirect:
+
+				# Base URL to redirect to. The path must be empty and will be replaced, either by
+				# the request URL path, or byOrigPathRegexp/ReplacePath. Scheme, host, port and
+				# fragment stay intact, and query strings are combined. If empty, the response
+				# redirects to a different path through OrigPathRegexp and ReplacePath, which must
+				# then be set. Use a URL without scheme to redirect without changing the protocol,
+				# e.g. //newdomain/. (optional)
+				BaseURL:
+
+				# Regular expression for matching path. If set and path does not match, a 404 is
+				# returned. The HTTP path used for matching always starts with a slash. (optional)
+				OrigPathRegexp:
+
+				# Replacement path for destination URL based on OrigPathRegexp. Implemented with
+				# Go's Regexp.ReplaceAllString: $1 is replaced with the text of the first
+				# submatch, etc. If both OrigPathRegexp and ReplacePath are empty, BaseURL must be
+				# set and all paths are redirected unaltered. (optional)
+				ReplacePath:
+
+				# Status code to use in redirect, e.g. 307. By default, a permanent redirect (308)
+				# is returned. (optional)
+				StatusCode: 0
+
+			# Forward requests to another webserver, i.e. reverse proxy. (optional)
+			WebForward:
+
+				# Strip the matching WebHandler path from the WebHandler before forwarding the
+				# request. (optional)
+				StripPath: false
+
+				# URL to forward HTTP requests to, e.g. http://127.0.0.1:8123/base. If StripPath
+				# is false the full request path is added to the URL. Host headers are sent
+				# unmodified. New X-Forwarded-{For,Host,Proto} headers are set. Any query string
+				# in the URL is ignored. Requests are made using Go's net/http.DefaultTransport
+				# that takes environment variables HTTP_PROXY and HTTPS_PROXY into account.
+				URL:
+
+				# Headers to add to the response. Useful for adding security- and cache-related
+				# headers. (optional)
+				ResponseHeaders:
+					x:
+
+# Examples
+
+Mox includes configuration files to illustrate common setups. You can see these
+examples with "mox examples", and print a specific example with "mox examples
+<name>". Below are all examples included in mox.
+
+# Example webhandlers
+
+	# Snippet of domains.conf to configure WebHandlers.
+	WebHandlers:
+		-
+			# The name of the handler, used in logging and metrics.
+			LogName: staticmjl
+			# With ACME configured, each configured domain will automatically get a TLS
+			# certificate on first request.
+			Domain: mox.example
+			PathRegexp: ^/who/mjl/
+			WebStatic:
+				StripPrefix: /who/mjl
+				# Requested path /who/mjl/inferno/ resolves to local web/mjl/inferno.
+				# If a directory contains an index.html, it is served when a directory is requested.
+				Root: web/mjl
+				# With ListFiles true, if a directory does not contain an index.html, the contents are listed.
+				ListFiles: true
+				ResponseHeaders:
+					X-Mox: hi
+		-
+			LogName: redir
+			Domain: mox.example
+			PathRegexp: ^/redir/a/b/c
+			# Don't redirect from plain HTTP to HTTPS.
+			DontRedirectPlainHTTP: true
+			WebRedirect:
+				# Just change the domain and add query string set fragment. No change to scheme.
+				# Path will start with /redir/a/b/c (and whathever came after) because no
+				# OrigPathRegexp+ReplacePath is set.
+				BaseURL: //moxest.example?q=1#frag
+				# Default redirection is 308 - Permanent Redirect.
+				StatusCode: 307
+		-
+			LogName: oldnew
+			Domain: mox.example
+			PathRegexp: ^/old/
+			WebRedirect:
+				# Replace path, leaving rest of URL intact.
+				OrigPathRegexp: ^/old/(.*)
+				ReplacePath: /new/$1
+		-
+			LogName: app
+			Domain: mox.example
+			PathRegexp: ^/app/
+			WebForward:
+				# Strip the path matched by PathRegexp before forwarding the request. So original
+				# request /app/api become just /api.
+				StripPath: true
+				# URL of backend, where requests are forwarded to. The path in the URL is kept,
+				# so for incoming request URL /app/api, the outgoing request URL has path /app-v2/api.
+				# Requests are made with Go's net/http DefaultTransporter, including using
+				# HTTP_PROXY and HTTPS_PROXY environment variables.
+				URL: http://127.0.0.1:8900/app-v2/
+				# Add headers to response.
+				ResponseHeaders:
+					X-Frame-Options: deny
+					X-Content-Type-Options: nosniff
 */
 package config