Migrate go code to function in go 1.22+ (#873)

* Migrate go code to function in go 1.22+

* ci: attempt to bump golang from 1.19 to 1.23 in testing images

.github/workflows/build-publish-python-packages.yaml

@@ -68,7 +68,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.21"
+          go-version: "1.23"
           cache-dependency-path: "**/*.sum"
       - uses: actions/setup-python@v5
         with:

.github/workflows/test.yaml

@@ -58,13 +58,13 @@ jobs:
           #   that would be fine.
           #
           - python-version: "3.10"
-            go-version: "1.20"
+            go-version: "1.22"
           - python-version: "3.11"
-            go-version: "1.20"
+            go-version: "1.22"
           - python-version: "3.12"
-            go-version: "1.21"
+            go-version: "1.23"
           - python-version: "3.13"
-            go-version: "1.21"
+            go-version: "1.23"
 
     steps:
       - uses: actions/checkout@v4

continuous_integration/docker/base/Dockerfile

@@ -8,7 +8,10 @@
 FROM centos:7
 
 ARG python_version="3.11"
-ARG go_version="1.19"
+# go_version was 1.19 until it was updated to 1.23.6 (2025-02-07) by adding a
+# layer on top of the previous image, as it is no longer able to build and it
+# was an easy way to update the golang version.
+ARG go_version="1.23.6"
 
 # Set labels based on the Open Containers Initiative (OCI):
 # https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
@@ -66,7 +69,7 @@ RUN yum install -y bzip2 \
  && rm -rf /var/cache/yum
 
 # Install go
-RUN curl -sL https://dl.google.com/go/go${go_version}.linux-amd64.tar.gz \
+RUN curl -sL https://go.dev/dl/go${go_version}.linux-amd64.tar.gz \
   | tar --extract --verbose --gzip --directory=/opt/
 
 # Put Python and Go environments on PATH

dask-gateway-server/dask-gateway-proxy/go.mod

@@ -1,8 +1,8 @@
 module github.com/dask/dask-gateway/dask-gateway-proxy
 
-go 1.21
+go 1.22
 
-require github.com/stretchr/testify v1.8.4
+require github.com/stretchr/testify v1.10.0
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect

dask-gateway-server/dask-gateway-proxy/pkg/sni/sni.go

@@ -8,6 +8,18 @@ import (
 	"net"
 )
 
+// hideWriteTo is a workaround introduced to make the code functional in 1.22+,
+// where io.Copy would no longer make use of peekedTCPConn.Read after
+// net.TCPConn.WriteTo was added, so the workaround is to hide it again.
+//
+// The workaround was developed inspecting:
+// https://github.com/golang/go/commit/f664031bc17629080332a1c7bede38d67fd32e47
+//
+type hideWriteTo struct{}
+func (hideWriteTo) WriteTo(io.Writer) (int64, error) {
+       panic("can't happen")
+}
+
 type TcpConn interface {
 	net.Conn
 	CloseWrite() error
@@ -16,6 +28,7 @@ type TcpConn interface {
 
 type peekedTCPConn struct {
 	peeked []byte
+	hideWriteTo
 	*net.TCPConn
 }