From 23d626392c999e6d2d3318afc9ec08f3231c42aa Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Sat, 4 Jan 2025 11:51:31 +0000
Subject: [PATCH 1/3] feat: match block for header directive

---
 .../caddyfile_adapt/header.caddyfiletest      |  8 +++++++
 modules/caddyhttp/headers/caddyfile.go        |  7 ++++++
 modules/caddyhttp/headers/headers_test.go     | 22 +++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/caddytest/integration/caddyfile_adapt/header.caddyfiletest b/caddytest/integration/caddyfile_adapt/header.caddyfiletest
index ec2a842a3d3..c76e5e95210 100644
--- a/caddytest/integration/caddyfile_adapt/header.caddyfiletest
+++ b/caddytest/integration/caddyfile_adapt/header.caddyfiletest
@@ -12,6 +12,9 @@
 	@images path /images/*
 	header @images {
 		Cache-Control "public, max-age=3600, stale-while-revalidate=86400"
+		match {
+			status 200
+		}
 	}
 	header {
 		+Link "Foo"
@@ -42,6 +45,11 @@
 								{
 									"handler": "headers",
 									"response": {
+										"require": {
+											"status_code": [
+												200
+											]
+										},
 										"set": {
 											"Cache-Control": [
 												"public, max-age=3600, stale-while-revalidate=86400"
diff --git a/modules/caddyhttp/headers/caddyfile.go b/modules/caddyhttp/headers/caddyfile.go
index e55e9fab2fa..713b28bf653 100644
--- a/modules/caddyhttp/headers/caddyfile.go
+++ b/modules/caddyhttp/headers/caddyfile.go
@@ -99,6 +99,13 @@ func parseCaddyfile(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error)
 			handler.Response.Deferred = true
 			continue
 		}
+		if field == "match" {
+			responseMatchers := make(map[string]caddyhttp.ResponseMatcher)
+			caddyhttp.ParseNamedResponseMatcher(h.NewFromNextSegment(), responseMatchers)
+			matcher := responseMatchers["match"]
+			handler.Response.Require = &matcher
+			continue
+		}
 		if hasArgs {
 			return nil, h.Err("cannot specify headers in both arguments and block") // because it would be weird
 		}
diff --git a/modules/caddyhttp/headers/headers_test.go b/modules/caddyhttp/headers/headers_test.go
index d74e6fc3a07..9808c29c98d 100644
--- a/modules/caddyhttp/headers/headers_test.go
+++ b/modules/caddyhttp/headers/headers_test.go
@@ -143,6 +143,28 @@ func TestHandler(t *testing.T) {
 				"Cache-Control": []string{"no-cache"},
 			},
 		},
+		{ // same as above, but checks that response headers are left alone when "Require" conditions are unmet
+			handler: Handler{
+				Response: &RespHeaderOps{
+					Require: &caddyhttp.ResponseMatcher{
+						Headers: http.Header{
+							"Cache-Control": nil,
+						},
+					},
+					HeaderOps: &HeaderOps{
+						Add: http.Header{
+							"Cache-Control": []string{"no-cache"},
+						},
+					},
+				},
+			},
+			respHeader: http.Header{
+				"Cache-Control": []string{"something"},
+			},
+			expectedRespHeader: http.Header{
+				"Cache-Control": []string{"something"},
+			},
+		},
 		{
 			handler: Handler{
 				Response: &RespHeaderOps{

From aa3f21a218df902a9a3c6f74badc3d84a90dd8e0 Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Wed, 8 Jan 2025 07:15:07 +0530
Subject: [PATCH 2/3] check for parse error

---
 modules/caddyhttp/headers/caddyfile.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/modules/caddyhttp/headers/caddyfile.go b/modules/caddyhttp/headers/caddyfile.go
index 713b28bf653..f060471b100 100644
--- a/modules/caddyhttp/headers/caddyfile.go
+++ b/modules/caddyhttp/headers/caddyfile.go
@@ -101,7 +101,10 @@ func parseCaddyfile(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error)
 		}
 		if field == "match" {
 			responseMatchers := make(map[string]caddyhttp.ResponseMatcher)
-			caddyhttp.ParseNamedResponseMatcher(h.NewFromNextSegment(), responseMatchers)
+			err := caddyhttp.ParseNamedResponseMatcher(h.NewFromNextSegment(), responseMatchers)
+			if err != nil {
+				return nil, err
+			}
 			matcher := responseMatchers["match"]
 			handler.Response.Require = &matcher
 			continue

From f1cabf4b8019670592791736c9d9a8d802fa296d Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Wed, 8 Jan 2025 08:17:07 +0530
Subject: [PATCH 3/3] Add inline match parsing test case

---
 caddytest/integration/caddyfile_adapt/header.caddyfiletest | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/caddytest/integration/caddyfile_adapt/header.caddyfiletest b/caddytest/integration/caddyfile_adapt/header.caddyfiletest
index c76e5e95210..a0af24ff682 100644
--- a/caddytest/integration/caddyfile_adapt/header.caddyfiletest
+++ b/caddytest/integration/caddyfile_adapt/header.caddyfiletest
@@ -19,6 +19,7 @@
 	header {
 		+Link "Foo"
 		+Link "Bar"
+		match status 200
 	}
 	header >Set Defer
 	header >Replace Deferred Replacement
@@ -144,6 +145,11 @@
 												"Foo",
 												"Bar"
 											]
+										},
+										"require": {
+											"status_code": [
+												200
+											]
 										}
 									}
 								},