caddyhttp: Implement handler abort; new 'abort' directive (close #3871) (#3983)

* caddyhttp: Implement handler abort; new 'abort' directive (close #3871)

* Move abort directive ordering; clean up redirects

Seems logical for the end-all of handlers to go at the... end.

The Connection header no longer needs to be set there, since Close is
true, and the static_response handler now does that.

2 files changed, 11 insertions, 0 deletions

diff --git a/caddyconfig/httpcaddyfile/builtins.go b/caddyconfig/httpcaddyfile/builtins.go
index 08dfa886a..2de808b92 100644
--- a/caddyconfig/httpcaddyfile/builtins.go
+++ b/caddyconfig/httpcaddyfile/builtins.go
@@ -40,6 +40,7 @@ func init() {
 	RegisterHandlerDirective("root", parseRoot)
 	RegisterHandlerDirective("redir", parseRedir)
 	RegisterHandlerDirective("respond", parseRespond)
+	RegisterHandlerDirective("abort", parseAbort)
 	RegisterHandlerDirective("route", parseRoute)
 	RegisterHandlerDirective("handle", parseHandle)
 	RegisterDirective("handle_errors", parseHandleErrors)
@@ -502,6 +503,15 @@ func parseRespond(h Helper) (caddyhttp.MiddlewareHandler, error) {
 	return sr, nil
 }
 
+// parseAbort parses the abort directive.
+func parseAbort(h Helper) (caddyhttp.MiddlewareHandler, error) {
+	h.Next() // consume directive
+	for h.Next() || h.NextBlock(0) {
+		return nil, h.ArgErr()
+	}
+	return &caddyhttp.StaticResponse{Abort: true}, nil
+}
+
 // parseRoute parses the route directive.
 func parseRoute(h Helper) (caddyhttp.MiddlewareHandler, error) {
 	sr := new(caddyhttp.Subroute)
diff --git a/caddyconfig/httpcaddyfile/directives.go b/caddyconfig/httpcaddyfile/directives.go
index b79b81165..7f77f49f2 100644
--- a/caddyconfig/httpcaddyfile/directives.go
+++ b/caddyconfig/httpcaddyfile/directives.go
@@ -69,6 +69,7 @@ var directiveOrder = []string{
 	"php_fastcgi",
 	"file_server",
 	"acme_server",
+	"abort",
 }
 
 // directiveIsOrdered returns true if dir is