Upgrade go minimum to 1.15

.github/workflows/check_formatting.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/check_make_parser.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/check_make_visitor.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/cluster_endtoend.yml

@@ -12,7 +12,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/cluster_initial_sharding_multi.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/create_release.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/docker_test_1.yml

@@ -11,7 +11,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/e2e_race.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+      go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/endtoend.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/golangci-linter.yml

@@ -7,10 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.13
+    - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/legacy_local_example.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/local_example.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/region_example.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/sonar_analysis.yml

@@ -12,7 +12,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v1
         with:
-          go-version: 1.13
+          go-version: 1.15
 
       - name: Check out code
         uses: actions/checkout@v2

.github/workflows/unit.yml

@@ -12,7 +12,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

.github/workflows/unit_race.yml

@@ -10,7 +10,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
+        go-version: 1.15
 
     - name: Check out code
       uses: actions/checkout@v2

build.env

@@ -17,7 +17,7 @@
 source ./tools/shell_functions.inc
 
 go version >/dev/null 2>&1 || fail "Go is not installed or is not in \$PATH. See https://vitess.io/contributing/build-from-source for install instructions."
-goversion_min 1.13 || fail "Go version reported: `go version`. Version 1.13+ required. See https://vitess.io/contributing/build-from-source for install instructions."
+goversion_min 1.15 || fail "Go version reported: `go version`. Version 1.15+ required. See https://vitess.io/contributing/build-from-source for install instructions."
 
 mkdir -p dist
 mkdir -p bin

docker/bootstrap/Dockerfile.common

@@ -1,4 +1,4 @@
-FROM golang:1.13-buster
+FROM golang:1.15-buster
 
 # Install Vitess build dependencies
 RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \

go.mod

@@ -1,6 +1,6 @@
 module vitess.io/vitess
 
-go 1.13
+go 1.15
 
 require (
 	cloud.google.com/go v0.45.1

go/netutil/netutil_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package netutil
 
 import (
+	"fmt"
 	"math/rand"
 	"net"
 	"reflect"
@@ -56,7 +57,7 @@ func testUniformity(t *testing.T, size int, margin float64) {
 	rand.Seed(1)
 	data := make([]*net.SRV, size)
 	for i := 0; i < size; i++ {
-		data[i] = &net.SRV{Target: string('a' + i), Weight: 1}
+		data[i] = &net.SRV{Target: fmt.Sprint('a' + i), Weight: 1}
 	}
 	checkDistribution(t, data, margin)
 }

go/trace/fake.go

@@ -25,8 +25,10 @@ import (
 
 type noopTracingServer struct{}
 
-func (noopTracingServer) New(Span, string) Span                                     { return NoopSpan{} }
-func (noopTracingServer) NewClientSpan(parent Span, serviceName, label string) Span { return NoopSpan{} }
+func (noopTracingServer) New(Span, string) Span { return NoopSpan{} }
+func (noopTracingServer) NewClientSpan(parent Span, serviceName, label string) Span {
+	return NoopSpan{}
+}
 func (noopTracingServer) FromContext(context.Context) (Span, bool)                  { return nil, false }
 func (noopTracingServer) NewFromString(parent, label string) (Span, error)          { return NoopSpan{}, nil }
 func (noopTracingServer) NewContext(parent context.Context, _ Span) context.Context { return parent }

go/vt/topo/k8stopo/version.go

@@ -17,6 +17,8 @@ limitations under the License.
 package k8stopo
 
 import (
+	"fmt"
+
 	"vitess.io/vitess/go/vt/topo"
 )
 
@@ -36,5 +38,5 @@ func VersionFromInt(version int64) topo.Version {
 	if version == -1 {
 		return nil
 	}
-	return KubernetesVersion(version)
+	return KubernetesVersion(fmt.Sprint(version))
 }