Upgrade the linter and fix all new linter warnings

Also fix some tests that were broken by bumping golang and dependencies
in the previous commits.

Note that in addition to changes made to satisfy the linter which do not
impact the behavior of the code, this commit also adds ReadHeaderTimeout
to all usages of http.Server to satisfy the linter (and because it
seemed like a good suggestion).

test/testlib/access.go

@@ -1,11 +1,10 @@
-// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package testlib
 
 import (
 	"context"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"testing"
@@ -154,7 +153,7 @@ func runKubectlGetNamespaces(t *testing.T, kubeConfigYAML string) (string, error
 
 	f := writeStringToTempFile(t, "pinniped-generated-kubeconfig-*", kubeConfigYAML)
 
-	//nolint: gosec // It's okay that we are passing f.Name() to an exec command here. It was created above.
+	//nolint:gosec // It's okay that we are passing f.Name() to an exec command here. It was created above.
 	output, err := exec.Command(
 		"kubectl", "get", "namespace", "--kubeconfig", f.Name(),
 	).CombinedOutput()
@@ -164,7 +163,7 @@ func runKubectlGetNamespaces(t *testing.T, kubeConfigYAML string) (string, error
 
 func writeStringToTempFile(t *testing.T, filename string, kubeConfigYAML string) *os.File {
 	t.Helper()
-	f, err := ioutil.TempFile("", filename)
+	f, err := os.CreateTemp("", filename)
 	require.NoError(t, err)
 	deferMe := func() {
 		err := os.Remove(f.Name())

test/testlib/cli.go

@@ -1,10 +1,9 @@
-// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package testlib
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -17,7 +16,7 @@ import (
 	"go.pinniped.dev/internal/testutil"
 )
 
-//nolint: gochecknoglobals
+//nolint:gochecknoglobals
 var pinnipedCLIBinaryCache struct {
 	buf   []byte
 	mutex sync.Mutex
@@ -38,7 +37,7 @@ func PinnipedCLIPath(t *testing.T) string {
 	path := filepath.Join(testutil.TempDir(t), "pinniped")
 	if pinnipedCLIBinaryCache.buf != nil {
 		t.Log("using previously built pinniped CLI binary")
-		require.NoError(t, ioutil.WriteFile(path, pinnipedCLIBinaryCache.buf, 0500))
+		require.NoError(t, os.WriteFile(path, pinnipedCLIBinaryCache.buf, 0500))
 		return path
 	}
 
@@ -49,7 +48,7 @@ func PinnipedCLIPath(t *testing.T) string {
 	t.Logf("built CLI binary in %s", time.Since(start).Round(time.Millisecond))
 
 	// Fill our cache so we don't have to do this again.
-	pinnipedCLIBinaryCache.buf, err = ioutil.ReadFile(path)
+	pinnipedCLIBinaryCache.buf, err = os.ReadFile(path)
 	require.NoError(t, err, string(output))
 
 	return path

test/testlib/client.go

@@ -1,4 +1,4 @@
-// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package testlib
@@ -10,7 +10,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -54,7 +53,7 @@ func NewClientsetForKubeConfig(t *testing.T, kubeConfig string) kubernetes.Inter
 }
 
 func NewRestConfigFromKubeconfig(t *testing.T, kubeConfig string) *rest.Config {
-	kubeConfigFile, err := ioutil.TempFile("", "pinniped-cli-test-*")
+	kubeConfigFile, err := os.CreateTemp("", "pinniped-cli-test-*")
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, os.Remove(kubeConfigFile.Name()))

test/testlib/env.go

@@ -5,7 +5,6 @@ package testlib
 
 import (
 	"encoding/base64"
-	"io/ioutil"
 	"os"
 	"sort"
 	"strings"
@@ -118,7 +117,7 @@ func (e *TestEnv) ProxyEnv() []string {
 
 // memoizedTestEnvsByTest maps *testing.T pointers to *TestEnv. It exists so that we don't do all the
 // environment parsing N times per test and so that any implicit assertions happen only once.
-var memoizedTestEnvsByTest sync.Map //nolint: gochecknoglobals
+var memoizedTestEnvsByTest sync.Map //nolint:gochecknoglobals
 
 // IntegrationEnv gets the integration test environment from OS environment variables. This
 // method also implies SkipUnlessIntegration().
@@ -137,7 +136,7 @@ func IntegrationEnv(t *testing.T) *TestEnv {
 		"must specify either PINNIPED_TEST_CLUSTER_CAPABILITY_YAML or PINNIPED_TEST_CLUSTER_CAPABILITY_FILE env var for integration tests",
 	)
 	if capabilitiesDescriptionYAML == "" {
-		bytes, err := ioutil.ReadFile(capabilitiesDescriptionFile)
+		bytes, err := os.ReadFile(capabilitiesDescriptionFile)
 		capabilitiesDescriptionYAML = string(bytes)
 		require.NoError(t, err)
 	}

test/testlib/iplookup.go

@@ -1,6 +1,7 @@
-// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+//go:build !go1.14
 // +build !go1.14
 
 package testlib

test/testlib/iplookup_go1.14.go

@@ -1,7 +1,7 @@
 // Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-//nolint:goimports // not an import
+//go:build go1.14
 // +build go1.14
 
 package testlib