dashboard, cmd/makemac: drop macOS 10.12 builder

Go 1.16 was the last Go release to support macOS 10.12, so that builder
has become unused and its capacity can be reallocated to other builders.

While here, also update makemac to support parsing host types without a
"_0" suffix, so we can start using "host-darwin-amd64-13" instead of
"host-darwin-amd64-13_0", similar to the new arm64 host type names.

For golang/go#23011.
Updates golang/go#49149.

Change-Id: I6bc0948e716ee62f4b5519cb069aa0f06a2ec1af
Reviewed-on: https://go-review.googlesource.com/c/build/+/419194
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>

Author: dmitshur

Diff for: cmd/makemac/makemac.go

@@ -642,8 +642,7 @@ func autoAdjust() {
 		}
 	}()
 
-	req, _ := http.NewRequest("GET", "https://farmer.golang.org/status/reverse.json", nil)
-	req = req.WithContext(ctx)
+	req, _ := http.NewRequestWithContext(ctx, "GET", "https://farmer.golang.org/status/reverse.json", nil)
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		errors = append(errors, fmt.Sprintf("getting /status/reverse.json from coordinator: %v", err))
@@ -739,40 +738,45 @@ func (v Version) String() string {
 }
 
 // hostTypeToVersion determines the version of macOS from the host type.
-// Sample host types would be: host-darwin-10_12 and host-darwin-arm64-11_0.
+// Sample host types would be: host-darwin-10_15 and host-darwin-arm64-11_0.
 func hostTypeToVersion(hostType string) (*Version, error) {
 	v := &Version{}
 	var err error
 	if !strings.HasPrefix(hostType, "host-darwin-") {
 		return nil, errors.New("unrecognized version")
 	}
 	htv := strings.TrimPrefix(hostType, "host-darwin-")
-	vs := strings.Split(htv, "-")
-	if len(vs) > 2 {
-		return nil, errors.New("unrecognized version")
-	}
 	var majorMinor string
-	if len(vs) == 2 {
+	switch vs := strings.Split(htv, "-"); len(vs) {
+	case 2:
 		if vs[0] != "amd64" && vs[0] != "arm64" {
 			return nil, errors.New("unrecognized version")
 		}
 		v.Arch = vs[0]
 		majorMinor = vs[1]
-	} else {
+	case 1:
 		v.Arch = "amd64"
 		majorMinor = vs[0]
-	}
-	mms := strings.Split(majorMinor, "_")
-	if len(mms) != 2 {
+	default:
 		return nil, errors.New("unrecognized version")
 	}
-	v.Major, err = strconv.Atoi(mms[0])
-	if err != nil {
-		return nil, err
-	}
-	v.Minor, err = strconv.Atoi(mms[1])
-	if err != nil {
-		return nil, err
+	switch mms := strings.Split(majorMinor, "_"); len(mms) {
+	case 1:
+		v.Major, err = strconv.Atoi(mms[0])
+		if err != nil {
+			return nil, err
+		}
+	case 2:
+		v.Major, err = strconv.Atoi(mms[0])
+		if err != nil {
+			return nil, err
+		}
+		v.Minor, err = strconv.Atoi(mms[1])
+		if err != nil {
+			return nil, err
+		}
+	default:
+		return nil, errors.New("unrecognized version")
 	}
 	return v, nil
 }
@@ -781,10 +785,10 @@ func hostTypeToVersion(hostType string) (*Version, error) {
 // or nil to not make anything. It gets the latest reverse buildlet
 // status from the coordinator.
 func wantedMacVersionNext(st *State, rstat *types.ReverseBuilderStatus) *Version {
-	// TODO: improve this logic now that the coordinator has a
-	// proper scheduler. Instead, don't create anything
-	// proactively until there's demand from it from the
-	// scheduler. (will need to add that to the coordinator's
+	// TODO(go.dev/issue/35698): improve this logic now that
+	// the coordinator has a proper scheduler. Instead, don't
+	// create anything proactively until there's demand from it
+	// from the scheduler. (will need to add that to the coordinator's
 	// status JSON) And maybe add a streaming endpoint to the
 	// coordinator so we don't need to poll every N seconds. Or
 	// just poll every few seconds, perhaps at a lighter endpoint
@@ -893,8 +897,7 @@ var (
 )
 
 func getLatestMacBuildlet(ctx context.Context) (bin []byte, err error) {
-	req, _ := http.NewRequest("HEAD", "https://storage.googleapis.com/go-builder-data/buildlet.darwin-amd64", nil)
-	req = req.WithContext(ctx)
+	req, _ := http.NewRequestWithContext(ctx, "HEAD", "https://storage.googleapis.com/go-builder-data/buildlet.darwin-amd64", nil)
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return nil, err
@@ -917,8 +920,7 @@ func getLatestMacBuildlet(ctx context.Context) (bin []byte, err error) {
 	buildletMu.Unlock()
 
 	log.Printf("fetching buildlet from GCS...")
-	req, _ = http.NewRequest("GET", "https://storage.googleapis.com/go-builder-data/buildlet.darwin-amd64", nil)
-	req = req.WithContext(ctx)
+	req, _ = http.NewRequestWithContext(ctx, "GET", "https://storage.googleapis.com/go-builder-data/buildlet.darwin-amd64", nil)
 	res, err = http.DefaultClient.Do(req)
 	if err != nil {
 		return nil, err

Diff for: cmd/makemac/makemac_test.go

@@ -18,19 +18,19 @@ func TestHostTypeToVersion(t *testing.T) {
 	}{
 		{
 			desc:     "valid original darwin host type",
-			hostType: "host-darwin-10_11",
+			hostType: "host-darwin-10_14",
 			wantVersion: &Version{
 				Major: 10,
-				Minor: 11,
+				Minor: 14,
 				Arch:  "amd64",
 			},
 		},
 		{
 			desc:     "valid original darwin host type",
-			hostType: "host-darwin-10_12",
+			hostType: "host-darwin-10_15",
 			wantVersion: &Version{
 				Major: 10,
-				Minor: 12,
+				Minor: 15,
 				Arch:  "amd64",
 			},
 		},
@@ -52,6 +52,15 @@ func TestHostTypeToVersion(t *testing.T) {
 				Arch:  "amd64",
 			},
 		},
+		{
+			desc:     "valid newer darwin host AMD64",
+			hostType: "host-darwin-amd64-13",
+			wantVersion: &Version{
+				Major: 13,
+				Minor: 0,
+				Arch:  "amd64",
+			},
+		},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.desc, func(t *testing.T) {

Diff for: dashboard/builders.go

@@ -468,19 +468,9 @@ var Hosts = map[string]*HostConfig{
 		IsReverse:          true,
 		ExpectNum:          5,
 	},
-	"host-darwin-10_12": &HostConfig{
-		IsReverse: true,
-		ExpectNum: 2,
-		Notes:     "MacStadium OS X 10.12 VM under VMWare ESXi",
-		env: []string{
-			"GOROOT_BOOTSTRAP=/Users/gopher/go1.4",
-		},
-		SSHUsername:     "gopher",
-		HermeticReverse: true, // we destroy the VM when done & let cmd/makemac recreate
-	},
 	"host-darwin-10_14": &HostConfig{
 		IsReverse: true,
-		ExpectNum: 2,
+		ExpectNum: 3,
 		Notes:     "MacStadium macOS Mojave (10.14) VM under VMWare ESXi",
 		env: []string{
 			"GOROOT_BOOTSTRAP=/Users/gopher/goboot", // Go 1.12.1
@@ -500,7 +490,7 @@ var Hosts = map[string]*HostConfig{
 	},
 	"host-darwin-amd64-11_0": &HostConfig{
 		IsReverse: true,
-		ExpectNum: 4,
+		ExpectNum: 5,
 		Notes:     "MacStadium macOS Big Sur (11.0) VM under VMWare ESXi",
 		env: []string{
 			"GOROOT_BOOTSTRAP=/Users/gopher/goboot", // Go 1.13.4
@@ -2421,15 +2411,6 @@ func init() {
 		},
 		KnownIssues: []int{51019},
 	})
-	addBuilder(BuildConfig{
-		Name:           "darwin-amd64-10_12",
-		HostType:       "host-darwin-10_12",
-		distTestAdjust: macTestPolicy,
-		buildsRepo: func(repo, branch, goBranch string) bool {
-			// macOS 10.12 not supported after Go 1.16
-			return atMostGo1(goBranch, 16) && buildRepoByDefault(repo)
-		},
-	})
 	addBuilder(BuildConfig{
 		Name:           "darwin-amd64-10_14",
 		HostType:       "host-darwin-10_14",

Diff for: dashboard/builders_test.go

@@ -543,7 +543,6 @@ func TestBuilderConfig(t *testing.T) {
 		{b("darwin-amd64-10_14", "exp"), onlyPost},
 		{b("darwin-amd64-10_15", "exp"), onlyPost},
 		// ... but not on most others:
-		{b("darwin-amd64-10_12", "exp"), none},
 		{b("freebsd-386-11_4", "exp"), none},
 		{b("freebsd-386-12_3", "exp"), none},
 		{b("freebsd-amd64-11_4", "exp"), none},
@@ -560,7 +559,6 @@ func TestBuilderConfig(t *testing.T) {
 		{b("linux-amd64", "build"), both},
 		{b("linux-amd64-longtest", "build"), onlyPost},
 		{b("windows-amd64-2016", "build"), both},
-		{b("darwin-amd64-10_12", "build"), none},
 		{b("darwin-amd64-10_14", "build"), none},
 		{b("darwin-amd64-10_15", "build"), onlyPost},
 		{b("openbsd-amd64-68", "build"), none},
@@ -582,14 +580,10 @@ func TestBuilderConfig(t *testing.T) {
 		{b("android-amd64-emu", "build"), none},
 
 		// Only use latest macOS for subrepos, and only amd64:
-		{b("[email protected]", "net"), onlyPost},
-		{b("darwin-amd64-10_12", "net"), none},
 		{b("darwin-amd64-10_14", "net"), onlyPost},
 
 		{b("darwin-amd64-10_15", "go"), onlyPost},
 		{b("darwin-amd64-10_14", "go"), onlyPost},
-		{b("darwin-amd64-10_12", "go"), none},
-		{b("[email protected]", "go"), onlyPost},
 
 		// plan9 only lived at master. We didn't support any past releases.
 		// But it's off for now as it's always failing.
@@ -739,7 +733,6 @@ func TestShouldRunDistTest(t *testing.T) {
 		{"linux-amd64", "reboot", tryMode, true},
 		{"linux-amd64-race", "reboot", tryMode, false},
 
-		{"darwin-amd64-10_12", "test:foo", postSubmit, false},
 		{"darwin-amd64-10_14", "test:foo", postSubmit, false},
 		{"darwin-amd64-10_14", "reboot", postSubmit, false},
 		{"darwin-amd64-10_14", "api", postSubmit, false},
@@ -944,9 +937,10 @@ func TestMiscCompileLinuxGOARM5(t *testing.T) {
 	}
 }
 
-// TestExpectedMacstadiumVMCount ensures that only 20 instances of macOS virtual machines
-// are expected at MacStadium.
-// TODO: remove once the scheduler allocates VMs based on demand https://golang.org/issue/35698
+// TestExpectedMacstadiumVMCount ensures that the right number of
+// instances of macOS virtual machines are expected at MacStadium.
+//
+// TODO(go.dev/issue/35698): remove once the scheduler allocates VMs based on demand.
 func TestExpectedMacstadiumVMCount(t *testing.T) {
 	got := 0
 	for host, config := range Hosts {