ci: Update to Go 1.21 (#5719)

* ci: Update to Go 1.21

* Bump quic-go to v0.37.4

* Check EnableFullDuplex err

* Linter bug suppression

See https://github.com/timakin/bodyclose/issues/52

---------

Co-authored-by: Francis Lavoie <[email protected]>

9 files changed, 22 insertions, 17 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3ab72421d..deebc7d7a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,7 @@ jobs:
           - windows-latest
         go: 
           - '1.20'
-          # - '1.21'
+          - '1.21'
 
         include:
         # Set the minimum Go patch version for the given Go minor
@@ -32,8 +32,8 @@ jobs:
         - go: '1.20'
           GO_SEMVER: '~1.20.6'
 
-        # - go: '1.21'
-        #   GO_SEMVER: '~1.21.0'
+        - go: '1.21'
+          GO_SEMVER: '~1.21.0'
 
         # Set some variables per OS, usable via ${{ matrix.VAR }}
         # CADDY_BIN_PATH: the path to the compiled Caddy binary, for artifact publishing
diff --git a/.github/workflows/cross-build.yml b/.github/workflows/cross-build.yml
index 4d04cfa7d..678ac178b 100644
--- a/.github/workflows/cross-build.yml
+++ b/.github/workflows/cross-build.yml
@@ -28,13 +28,13 @@ jobs:
           - 'darwin'
           - 'netbsd'
         go: 
-          - '1.20'
+          - '1.21'
 
         include:
         # Set the minimum Go patch version for the given Go minor
         # Usable via ${{ matrix.GO_SEMVER }}
-        - go: '1.20'
-          GO_SEMVER: '~1.20.6'
+        - go: '1.21'
+          GO_SEMVER: '~1.21.0'
 
     runs-on: ubuntu-latest
     continue-on-error: true
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 964e48f06..a2b569d05 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -31,7 +31,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: '~1.20.6'
+          go-version: '~1.21.0'
           check-latest: true
 
           # Workaround for https://github.com/golangci/golangci-lint-action/issues/135
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 0e9e29ec5..ec9c97260 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -13,13 +13,13 @@ jobs:
         os: 
           - ubuntu-latest
         go: 
-          - '1.20'
+          - '1.21'
 
         include:
         # Set the minimum Go patch version for the given Go minor
         # Usable via ${{ matrix.GO_SEMVER }}
-        - go: '1.20'
-          GO_SEMVER: '~1.20.6'
+        - go: '1.21'
+          GO_SEMVER: '~1.21.0'
 
     runs-on: ${{ matrix.os }}
     # https://github.com/sigstore/cosign/issues/1258#issuecomment-1002251233
diff --git a/go.mod b/go.mod
index 78c354e63..f2a1cd671 100644
--- a/go.mod
+++ b/go.mod
@@ -17,7 +17,7 @@ require (
 	github.com/mastercactapus/proxyprotocol v0.0.4
 	github.com/mholt/acmez v1.2.0
 	github.com/prometheus/client_golang v1.14.0
-	github.com/quic-go/quic-go v0.37.3
+	github.com/quic-go/quic-go v0.37.4
 	github.com/smallstep/certificates v0.24.3-rc.5
 	github.com/smallstep/nosql v0.6.0
 	github.com/smallstep/truststore v0.12.1
diff --git a/go.sum b/go.sum
index 245a07d6d..daa4bdc4f 100644
--- a/go.sum
+++ b/go.sum
@@ -863,8 +863,8 @@ github.com/quic-go/qpack v0.4.0 h1:Cr9BXA1sQS2SmDUWjSofMPNKmvF6IiIfDRmgU0w1ZCo=
 github.com/quic-go/qpack v0.4.0/go.mod h1:UZVnYIfi5GRk+zI9UMaCPsmZ2xKJP7XBUvVyT1Knj9A=
 github.com/quic-go/qtls-go1-20 v0.3.1 h1:O4BLOM3hwfVF3AcktIylQXyl7Yi2iBNVy5QsV+ySxbg=
 github.com/quic-go/qtls-go1-20 v0.3.1/go.mod h1:X9Nh97ZL80Z+bX/gUXMbipO6OxdiDi58b/fMC9mAL+k=
-github.com/quic-go/quic-go v0.37.3 h1:pkHH3xaMNUNAh6OtgEV/0K6Fz+YIJXhPzgd/ShiRDm4=
-github.com/quic-go/quic-go v0.37.3/go.mod h1:YsbH1r4mSHPJcLF4k4zruUkLBqctEMBDR6VPvcYjIsU=
+github.com/quic-go/quic-go v0.37.4 h1:ke8B73yMCWGq9MfrCCAw0Uzdm7GaViC3i39dsIdDlH4=
+github.com/quic-go/quic-go v0.37.4/go.mod h1:YsbH1r4mSHPJcLF4k4zruUkLBqctEMBDR6VPvcYjIsU=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/fastuuid v1.1.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
diff --git a/modules/caddyhttp/duplex_go120.go b/modules/caddyhttp/duplex_go120.go
index 462f2c0c1..065ccf282 100644
--- a/modules/caddyhttp/duplex_go120.go
+++ b/modules/caddyhttp/duplex_go120.go
@@ -20,6 +20,7 @@ import (
 	"net/http"
 )
 
-func enableFullDuplex(w http.ResponseWriter) {
+func enableFullDuplex(w http.ResponseWriter) error {
 	// Do nothing, Go 1.20 and earlier do not support full duplex
+	return nil
 }
diff --git a/modules/caddyhttp/duplex_go121.go b/modules/caddyhttp/duplex_go121.go
index 4f3851c12..a17d3afe7 100644
--- a/modules/caddyhttp/duplex_go121.go
+++ b/modules/caddyhttp/duplex_go121.go
@@ -20,6 +20,7 @@ import (
 	"net/http"
 )
 
-func enableFullDuplex(w http.ResponseWriter) {
-	http.NewResponseController(w).EnableFullDuplex()
+func enableFullDuplex(w http.ResponseWriter) error {
+	//nolint:bodyclose
+	return http.NewResponseController(w).EnableFullDuplex()
 }
diff --git a/modules/caddyhttp/server.go b/modules/caddyhttp/server.go
index b31e6e529..daef7770e 100644
--- a/modules/caddyhttp/server.go
+++ b/modules/caddyhttp/server.go
@@ -291,7 +291,10 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if s.EnableFullDuplex {
 		// TODO: Remove duplex_go12*.go abstraction once our
 		// minimum Go version is 1.21 or later
-		enableFullDuplex(w)
+		err := enableFullDuplex(w)
+		if err != nil {
+			s.accessLogger.Warn("failed to enable full duplex", zap.Error(err))
+		}
 	}
 
 	// encode the request for logging purposes before