From e094139b05244c5eab0e62172f92ac5e90feb73b Mon Sep 17 00:00:00 2001
From: Madhav Jivrajani <madhav.jiv@gmail.com>
Date: Thu, 25 Apr 2024 14:12:51 +0530
Subject: [PATCH 1/2] scripts: default to using .go-version's version for tests
 and builds

Additionally, provide ability to opt-out of the .go-version and use a
custom one via env vars: FORCE_HOST_GO and GO_VERSION.

Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>
---
 scripts/test_lib.sh | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/scripts/test_lib.sh b/scripts/test_lib.sh
index b521a06ee58..41e9a5e1531 100644
--- a/scripts/test_lib.sh
+++ b/scripts/test_lib.sh
@@ -456,3 +456,27 @@ function git_assert_branch_in_sync {
     log_warning "Cannot verify consistency with the origin, as git is on detached branch."
   fi
 }
+
+# The version present in the .go-verion is the default version that test and build scripts will use.
+# However, it is possible to control the version that should be used with the help of env vars:
+# - FORCE_HOST_GO: if set to a non-empty value, use the version of go installed in system's $PATH.
+# - GO_VERSION: desired version of go to be used, might differ from what is present in .go-version.
+#               If empty, the value defaults to the version in .go-version.
+function determine_go_version {
+  # Borrowing from how Kubernetes does this:
+  #  https://github.com/kubernetes/kubernetes/blob/17854f0e0a153b06f9d0db096e2cd8ab2fa89c11/hack/lib/golang.sh#L510-L520
+  #
+  # default GO_VERSION to content of .go-version
+  GO_VERSION="${GO_VERSION:-"$(cat "${ETCD_ROOT_DIR}/.go-version")"}"
+  if [ "${GOTOOLCHAIN:-auto}" != 'auto' ]; then
+    # no-op, just respect GOTOOLCHAIN
+    :
+  elif [ -n "${FORCE_HOST_GO:-}" ]; then
+    export GOTOOLCHAIN='local'
+  else
+    GOTOOLCHAIN="go${GO_VERSION}"
+    export GOTOOLCHAIN
+  fi
+}
+
+determine_go_version

From f6a35f8786f1ecc2a1065ec78336567a33c6eed8 Mon Sep 17 00:00:00 2001
From: Madhav Jivrajani <madhav.jiv@gmail.com>
Date: Thu, 25 Apr 2024 14:13:24 +0530
Subject: [PATCH 2/2] .*: sync go toolchain version and add ability to verify
 versions

This commit adds a script to sync the version present in .go-version
across all go.mod files as the toolchain directive. As part of that,
this commit also modifies go.mod files that did not have synced toolchain
directives.

Additionally, this also adds a script to verify all toolchain and go
directives against the version present in .go-version as follows:
(1) The go directive <= version in .go-version
(2) The toolchain directive == version in .go-version

This script runs as part of the `make verify` target, making it run
as a presbumit by default.

Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>
---
 Makefile                               | 10 ++++-
 api/go.mod                             |  2 +
 client/internal/v2/go.mod              |  2 +
 client/pkg/go.mod                      |  2 +
 client/v3/go.mod                       |  2 +
 etcdctl/go.mod                         |  2 +
 etcdutl/go.mod                         |  2 +
 pkg/go.mod                             |  2 +
 scripts/fix.sh                         |  2 +
 scripts/sync_go_toolchain_directive.sh | 14 +++++++
 scripts/verify_go_versions.sh          | 53 ++++++++++++++++++++++++++
 server/go.mod                          |  2 +
 tests/go.mod                           |  2 +
 tools/rw-heatmaps/go.mod               |  2 +
 tools/testgrid-analysis/go.mod         |  2 +
 15 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100755 scripts/sync_go_toolchain_directive.sh
 create mode 100755 scripts/verify_go_versions.sh

diff --git a/Makefile b/Makefile
index 07bebc0dc43..50b9a31ff2e 100644
--- a/Makefile
+++ b/Makefile
@@ -55,7 +55,7 @@ fuzz:
 verify: verify-gofmt verify-bom verify-lint verify-dep verify-shellcheck verify-goword \
 	verify-govet verify-license-header verify-receiver-name verify-mod-tidy \
 	verify-shellws verify-proto-annotations verify-genproto verify-yamllint \
-	verify-govet-shadow verify-markdown-marker
+	verify-govet-shadow verify-markdown-marker verify-go-versions
 
 .PHONY: fix
 fix: fix-bom fix-lint fix-yamllint
@@ -187,3 +187,11 @@ clean:
 	rm -rf ./tests/e2e/default.proxy
 	rm -rf ./bin/shellcheck*
 	find ./ -name "127.0.0.1:*" -o -name "localhost:*" -o -name "*.log" -o -name "agent-*" -o -name "*.coverprofile" -o -name "testname-proxy-*" -delete
+
+.PHONY: verify-go-versions
+verify-go-versions:
+	./scripts/verify_go_versions.sh
+
+.PHONY: sync-toolchain-directive
+sync-toolchain-directive:
+	./scripts/sync_go_toolchain_directive.sh
diff --git a/api/go.mod b/api/go.mod
index 708fd25f228..becaf89378b 100644
--- a/api/go.mod
+++ b/api/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/api/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/coreos/go-semver v0.3.1
 	github.com/gogo/protobuf v1.3.2
diff --git a/client/internal/v2/go.mod b/client/internal/v2/go.mod
index b66163f6b32..b215067570a 100644
--- a/client/internal/v2/go.mod
+++ b/client/internal/v2/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/client/v2
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	go.etcd.io/etcd/api/v3 v3.6.0-alpha.0
 	go.etcd.io/etcd/client/pkg/v3 v3.6.0-alpha.0
diff --git a/client/pkg/go.mod b/client/pkg/go.mod
index 397898bd155..1072a4231eb 100644
--- a/client/pkg/go.mod
+++ b/client/pkg/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/client/pkg/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/coreos/go-systemd/v22 v22.5.0
 	github.com/stretchr/testify v1.9.0
diff --git a/client/v3/go.mod b/client/v3/go.mod
index 47fc7a682d8..8ef2e219feb 100644
--- a/client/v3/go.mod
+++ b/client/v3/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/client/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/coreos/go-semver v0.3.1
 	github.com/dustin/go-humanize v1.0.1
diff --git a/etcdctl/go.mod b/etcdctl/go.mod
index b20ab98b3c4..6c816b4024c 100644
--- a/etcdctl/go.mod
+++ b/etcdctl/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/etcdctl/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/bgentry/speakeasy v0.1.0
 	github.com/cheggaaa/pb/v3 v3.1.5
diff --git a/etcdutl/go.mod b/etcdutl/go.mod
index d0e66a078a0..a77dd870494 100644
--- a/etcdutl/go.mod
+++ b/etcdutl/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/etcdutl/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 replace (
 	go.etcd.io/etcd/api/v3 => ../api
 	go.etcd.io/etcd/client/pkg/v3 => ../client/pkg
diff --git a/pkg/go.mod b/pkg/go.mod
index 06af488e904..1b62117ea27 100644
--- a/pkg/go.mod
+++ b/pkg/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/pkg/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/creack/pty v1.1.18
 	github.com/dustin/go-humanize v1.0.1
diff --git a/scripts/fix.sh b/scripts/fix.sh
index 7936a2cf3d4..165e201bfb4 100755
--- a/scripts/fix.sh
+++ b/scripts/fix.sh
@@ -36,5 +36,7 @@ run_for_modules run ${GO_CMD} fmt || exit 2
 run_for_module tests bom_fix || exit 2
 bash_ws_fix || exit 2
 
+log_callout "Syncing go toolchain directives"
+run ./scripts/sync_go_toolchain_directive.sh || exit 2
 
 log_success -e "\\nSUCCESS: etcd code is fixed :)"
diff --git a/scripts/sync_go_toolchain_directive.sh b/scripts/sync_go_toolchain_directive.sh
new file mode 100755
index 00000000000..643138e1d0a
--- /dev/null
+++ b/scripts/sync_go_toolchain_directive.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+# This script looks at the version present in the .go-version file and treats
+# that to be the value of the toolchain directive that go should use. It then
+# updates the toolchain directives of all go.mod files to reflect this version.
+#
+# We do this to ensure that .go-version acts as the source of truth for go versions.
+
+set -euo pipefail
+
+source ./scripts/test_lib.sh
+
+TARGET_GO_VERSION="${TARGET_GO_VERSION:-"$(cat "${ETCD_ROOT_DIR}/.go-version")"}"
+find . -name 'go.mod' -exec go mod edit -toolchain=go"${TARGET_GO_VERSION}" {} \;
diff --git a/scripts/verify_go_versions.sh b/scripts/verify_go_versions.sh
new file mode 100755
index 00000000000..11d34f92a51
--- /dev/null
+++ b/scripts/verify_go_versions.sh
@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+
+# This script verifies that the value of the toolchain directive in the
+# go.mod files always match that of the .go-version file to ensure that
+# we accidentally don't test and release with differing versions of Go.
+
+set -euo pipefail
+
+source ./scripts/test_lib.sh
+
+target_go_version="${target_go_version:-"$(cat "${ETCD_ROOT_DIR}/.go-version")"}"
+log_info "expected go toolchain directive: go${target_go_version}"
+log_info
+
+toolchain_out_of_sync="false"
+go_line_violation="false"
+
+# verify_go_versions takes a go.mod filepath as an argument
+# and checks if:
+#  (1) go directive <= version in .go-version
+#  (2) toolchain directive == version in .go-version
+function verify_go_versions() {
+    # shellcheck disable=SC2086
+    toolchain_version="$(go mod edit -json $1 | jq -r .Toolchain)"
+    # shellcheck disable=SC2086
+    go_line_version="$(go mod edit -json $1 | jq -r .Go)"
+    if [[ "go${target_go_version}" != "${toolchain_version}" ]]; then
+        log_error "go toolchain directive out of sync for $1, got: ${toolchain_version}"
+        toolchain_out_of_sync="true"
+    fi
+    if ! printf '%s\n' "${go_line_version}" "${target_go_version}" | sort --check=silent --version-sort; then
+        log_error "go directive in $1 is greater than maximum allowed: go${target_go_version}"
+        go_line_violation="true"
+    fi
+}
+
+while read -r mod; do
+    verify_go_versions "${mod}";
+done < <(find . -name 'go.mod')
+
+if [[ "${toolchain_out_of_sync}" == "true" ]]; then
+    log_error
+    log_error "Please run scripts/sync_go_toolchain_directive.sh or update .go-version to rectify this error"
+fi
+
+if [[ "${go_line_violation}" == "true" ]]; then
+    log_error
+    log_error "Please update .go-version to rectify this error, any go directive should be <= .go-version"
+fi
+
+if [[ "${go_line_violation}" == "true" ]] || [[ "${toolchain_out_of_sync}" == "true" ]]; then
+    exit 1
+fi
diff --git a/server/go.mod b/server/go.mod
index 598364b11ce..a339af7bf19 100644
--- a/server/go.mod
+++ b/server/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/server/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/coreos/go-semver v0.3.1
 	github.com/coreos/go-systemd/v22 v22.5.0
diff --git a/tests/go.mod b/tests/go.mod
index 7c59aa224ad..d5987ab1a4c 100644
--- a/tests/go.mod
+++ b/tests/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/tests/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 replace (
 	go.etcd.io/etcd/api/v3 => ../api
 	go.etcd.io/etcd/client/pkg/v3 => ../client/pkg
diff --git a/tools/rw-heatmaps/go.mod b/tools/rw-heatmaps/go.mod
index db64003f833..344f9a54382 100644
--- a/tools/rw-heatmaps/go.mod
+++ b/tools/rw-heatmaps/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/tools/rw-heatmaps/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/spf13/cobra v1.8.0
 	github.com/spf13/pflag v1.0.5
diff --git a/tools/testgrid-analysis/go.mod b/tools/testgrid-analysis/go.mod
index 0e0056067f2..75b8e3884c2 100644
--- a/tools/testgrid-analysis/go.mod
+++ b/tools/testgrid-analysis/go.mod
@@ -2,6 +2,8 @@ module go.etcd.io/etcd/tools/testgrid-analysis/v3
 
 go 1.22
 
+toolchain go1.22.2
+
 require (
 	github.com/GoogleCloudPlatform/testgrid v0.0.173
 	github.com/google/go-github/v60 v60.0.0