This could have just as easily been a tls directive property in the
Caddyfile, but I figure if these challenges are being disabled, it's
because of port availability or process privileges, both of which would
affect all sites served by this process. The names of the flag are long
but descriptive.

I've never needed this but I hear of quite a few people who say they
need this ability, so here it is.

httpserver: Flags to customize HTTP and HTTPS ports (including for ACME challenges)

Adding ServerIP context

See: https://forum.caddyserver.com/t/reloading-template-files-as-they-change/1483/3?u=matt

The server takes a moment to start; if USR1 is received before the
instance is saved, it would panic because no instances have been saved.
Instead, we just ignore the signal since no config has finished loading.

This commit removes _almost_ all instances of hard-coded ports 80 and
443 strings, and now allows the user to define what the HTTP and HTTPS
ports are by the -http-port and -https-ports flags.

(One instance of "80" is still hard-coded in tls.go because it cannot
import httpserver to get access to the HTTP port variable. I don't
suspect this will be a problem in practice, but one workaround would be
to define an exported variable in the caddytls package and let the
httpserver package set it as well as its own HTTPPort variable.)

The port numbers required by the ACME challenges HTTP-01 and TLS-SNI-01
are hard-coded into the spec as ports 80 and 443 for good reasons,
but the big question is whether they necessarily need to be the HTTP
and HTTPS ports. Although the answer is probably no, they chose those
ports for convenience and widest compatibility/deployability. So this
commit also assumes that the "HTTP port" is necessarily the same port
on which to serve the HTTP-01 challenge, and the "HTTPS port" is
necessarily the same one on which to serve the TLS-SNI-01 challenge. In
other words, changing the HTTP and HTTPS ports also changes the ports
the challenges will be served on.

If you change the HTTP and HTTPS ports, you are responsible for
configuring your system to forward ports 80 and 443 properly.

Closes #918 and closes #1293. Also related: #468.

* feat(request placeholders): adds {?arg}

* test(request placeholders): test query argument extractor {?arg}

* Use RequestURI when redirecting to canonical path.

Caddy may trim a request's URL path when it starts with the path that's
associated with the virtual host. This change uses the path from the request's
RequestURI when performing a redirect.

Fix issue #1327.

* Rename redirurl to redirURL.

* Redirect to the full URL.

The scheme and host from the virtual host's site configuration is used
in order to redirect to the full URL.

* Add comment and remove redundant check.

* Store the original URL path in request context.

By storing the original URL path as a value in the request context,
middlewares can access both it and the sanitized path. The default
default FileServer handler will use the original URL on redirects.

* Replace contextKey type with CtxKey.

In addition to moving the CtxKey definition to the caddy package, this
change updates the CtxKey references in the httpserver, fastcgi, and
basicauth packages.

* httpserver: Fix reference to CtxKey

Timeouts are important for mitigating slowloris, yes. But after a number
of complaints and seeing that default timeouts are a sore point of
confusion, we're disabling them now. However, the code that sets
default timeouts remains intact; the defaults are just the zero value.

While Caddy aims to be secure by default, Caddy also aims to serve a
worldwide audience. Even my own internet here in Utah is poor at times,
with bad WiFi signal, causing some connections to take over 10s to
be established. Many use the Internet while commuting on slower
connection speeds. Latency across country borders is another concern.

As such, disabling default timeouts will serve a greater population of
users than enabling them, as slowloris is easy to mitigate and does
not seem to be reported often (I've only seen it once). It's also very
difficult sometimes to distinguish slowloris from genuine slow networks.
That decision is best left to the site owner for now.

* tls: Refactor TLS config innards with a few minor syntax changes

muststaple -> must_staple
"http2 off" -> "alpn" with list of ALPN values

* Fix typo

* Fix QUIC handler

* Inline struct field assignments

Revert removed method IncrNest

* Disable TLS completely if there is no listener with tls enabled

* Format code

* Revised fileserver Accept-Encoding and ETag

* calculateEtag improved following microbenchmarking

* Push down headers from client

* Push first, serve later

* After review fixes

* Remove manual TLS clone method

* WiP tls

* Use GetClientConfig for tls.Config

* gofmt -s -w

* GetConfig

* Handshake

* Removed comment

* Disable HTTP2 on demand

* Remove junk

* Remove http2 enable (no-op)

* Store name of authenticated user in basicauth for use by upstream middleware such as fastcgi and cgi.

* Use request context to transfer name of authorized user from basicauth to upstream middleware. Test retrieval of name from context.

* Remove development code that was inadvertently left in place

* Use keys of type httpserver.CtxKey to access Context values

* WIP: Implement HTTPS interception detection by Durumeric, et. al.

Special thanks to @FiloSottile for guidance with the custom listener.

* Add {{.IsMITM}} context action and {mitm} placeholder

* Improve MITM detection heuristics for Firefox and Edge

* Add tests for MITM detection heuristics

* Improve Safari heuristics for interception detection

* Read ClientHello during first Read() instead of during Accept()

As far as I can tell, reading the ClientHello during Accept() prevents
new connections from being accepted during the read. Since Read() should
be called in its own goroutine, this keeps Accept() non-blocking.

* Clean up MITM detection handler; make possible to close connection

* Use standard lib cipher suite values when possible

* Improve Edge heuristics and test cases

* Refactor MITM checking logic; add some debug statements for now

* Fix bug in MITM heuristic tests and actual heuristic code

* Fix gofmt

* Remove debug statements; preparing for merge

* WIP

* HTTP2/Push for golang 1.8

* Push plugin completed for review

* Correct build tag

* Move push plugin position

* Add build tags to tests

* Gofmt that code

* Add header/method validations

* Load push plugin

* Fixes for wrapping writers

* Push after delivering file

* Fixes, review changes

* Remove build tags, support new syntax

* Fix spelling

* gofmt -s -w .

* Gogland time

* Add interface guards

* gofmt

* After review fixes

proxy: handle encoded path in URL

fix issue #1362
Signed-off-by: Tw <tw19881113@gmail.com>

* Implement curve X25519

* caddytls: Added a default curves list

* caddytls: Improve tests

Replace our old faithful gracefulListener with Go 1.8's Shutdown()

Set Go 1.8's ReadHeaderTimeout and IdleTimeout

Set session ticket keys properly (fixed in Go 1.8)

* fixing panic when root is symlink
checking root path is a symlink before os.Stat which panics

* fixing formatting

* adding test to verify symlink root path check

* fixing typo

* Add request placeholder support for querying request cookies.

This adds the ability to query the request cookies for placeholders
using the syntax "@cookiename".

For example, this would allow rewriting based on a cookie:
  rewrite {
    if @version is 'dev'
    to /dev/index.html
  }

* Switch cookie special char from @ to :

* Switch special char for cookies from : to ~

return 404 for "not a directory" errors

redirect: determine the FromScheme at runtime (#1297)

* Fix data race for max connection limiting in proxy directive.

The Conns and Unhealthy fields are updated concurrently across all active
requests.  Because of this, they must use atomic operations for reads and
writes.

Prior to this change, Conns was incremented atomically, but read unsafely.
Unhealthly was updated & read unsafely.  The new test
TestReverseProxyMaxConnLimit exposes this race when run with -race.

Switching to atomic operations makes the race detector happy.

* oops, remove leftover dead code.

Added Sourcegraph badge to README