From a285fe41296cf786b21f637ebe9e5f265eddaa8a Mon Sep 17 00:00:00 2001
From: Matthew Holt <mholt@users.noreply.github.com>
Date: Wed, 3 Jun 2020 09:59:36 -0600
Subject: [PATCH] caddypki: Add 'acme_server' Caddyfile directive

---
 caddyconfig/httpcaddyfile/directives.go   |  3 +-
 modules/caddypki/acmeserver/acmeserver.go |  9 +++++-
 modules/caddypki/acmeserver/caddyfile.go  | 38 +++++++++++++++++++++++
 3 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 modules/caddypki/acmeserver/caddyfile.go

diff --git a/caddyconfig/httpcaddyfile/directives.go b/caddyconfig/httpcaddyfile/directives.go
index cde97438..c9f4ad96 100644
--- a/caddyconfig/httpcaddyfile/directives.go
+++ b/caddyconfig/httpcaddyfile/directives.go
@@ -56,14 +56,15 @@ var directiveOrder = []string{
 
 	// special routing directives
 	"handle",
-	"route",
 	"handle_path",
+	"route",
 
 	// handlers that typically respond to requests
 	"respond",
 	"reverse_proxy",
 	"php_fastcgi",
 	"file_server",
+	"acme_server",
 }
 
 // directiveIsOrdered returns true if dir is
diff --git a/modules/caddypki/acmeserver/acmeserver.go b/modules/caddypki/acmeserver/acmeserver.go
index 8dc0f01b..6023e064 100644
--- a/modules/caddypki/acmeserver/acmeserver.go
+++ b/modules/caddypki/acmeserver/acmeserver.go
@@ -48,13 +48,20 @@ type Handler struct {
 	// The hostname or IP address by which ACME clients
 	// will access the server. This is used to populate
 	// the ACME directory endpoint. Default: localhost.
-	// TODO: this is probably not needed - check with smallstep
+	// COMPATIBILITY NOTE / TODO: This property may go away in the
+	// future, as it is currently only required due to
+	// limitations in the underlying library. Do not rely
+	// on this property long-term; check release notes.
 	Host string `json:"host,omitempty"`
 
 	// The path prefix under which to serve all ACME
 	// endpoints. All other requests will not be served
 	// by this handler and will be passed through to
 	// the next one. Default: "/acme/"
+	// COMPATIBILITY NOTE / TODO: This property may go away in the
+	// future, as it is currently only required due to
+	// limitations in the underlying library. Do not rely
+	// on this property long-term; check release notes.
 	PathPrefix string `json:"path_prefix,omitempty"`
 
 	acmeEndpoints http.Handler
diff --git a/modules/caddypki/acmeserver/caddyfile.go b/modules/caddypki/acmeserver/caddyfile.go
new file mode 100644
index 00000000..66874604
--- /dev/null
+++ b/modules/caddypki/acmeserver/caddyfile.go
@@ -0,0 +1,38 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package acmeserver
+
+import (
+	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+)
+
+func init() {
+	httpcaddyfile.RegisterHandlerDirective("acme_server", parseACMEServer)
+}
+
+// parseACMEServer sets up an ACME server handler from Caddyfile tokens.
+//
+//     acme_server [<matcher>]
+//
+func parseACMEServer(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
+	var as Handler
+	for h.Next() {
+		if h.NextArg() {
+			return nil, h.ArgErr()
+		}
+	}
+	return as, nil
+}