Enable error linting (#733)

.golangci.yml

@@ -19,14 +19,15 @@ linters:
   - decorder
   - dogsled
   - dupword
+  - durationcheck
+  # - err113 - TODO(ben): maybe consider later
+  # - errcheck
+  # - errchkjson
+  - errname
+  - errorlint
+
 
 # TODO(ben): Enable those linters step by step and fix existing issues.
-# - durationcheck
-# - err113
-# - errcheck
-# - errchkjson
-# - errname
-# - errorlint
 # - exhaustive
 # - exhaustruct
 # - fatcontext
@@ -327,3 +328,4 @@ issues:
     - path: "_test\\.go"
       linters:
         - dupword
+        - err113

src/k8s/pkg/client/helm/client.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"path/filepath"
 
@@ -57,7 +58,7 @@ func (h *client) Apply(ctx context.Context, c InstallableChart, desired State, v
 	get := action.NewGet(cfg)
 	release, err := get.Run(c.Name)
 	if err != nil {
-		if err != driver.ErrReleaseNotFound {
+		if !errors.Is(err, driver.ErrReleaseNotFound) {
 			return false, fmt.Errorf("failed to get status of release %s: %w", c.Name, err)
 		}
 		isInstalled = false

src/k8s/pkg/client/kubernetes/status.go

@@ -36,7 +36,7 @@ func (c *Client) HasReadyNodes(ctx context.Context) (bool, error) {
 	nodes, err := c.CoreV1().Nodes().List(ctx, metav1.ListOptions{})
 
 	if err != nil {
-		return false, fmt.Errorf("failed to list nodes: %v", err)
+		return false, fmt.Errorf("failed to list nodes: %w", err)
 	}
 
 	for _, node := range nodes.Items {

src/k8s/pkg/client/snapd/refresh_status.go

@@ -21,12 +21,12 @@ func (c *Client) GetRefreshStatus(changeID string) (*types.RefreshStatus, error)
 
 	resBody, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("client: could not read response body: %s", err)
+		return nil, fmt.Errorf("client: could not read response body: %w", err)
 	}
 
 	var changeResponse snapdChangeResponse
 	if err := json.Unmarshal(resBody, &changeResponse); err != nil {
-		return nil, fmt.Errorf("client: could not unmarshal response body: %s", err)
+		return nil, fmt.Errorf("client: could not unmarshal response body: %w", err)
 	}
 
 	return &changeResponse.Result, nil

src/k8s/pkg/docgen/godoc.go

@@ -79,7 +79,7 @@ func getPackageDoc(packagePath string, projectDir string) (*doc.Package, error)
 
 	packageDir, err := getGoPackageDir(packagePath, projectDir)
 	if err != nil {
-		return nil, fmt.Errorf("couldn't retrieve package dir, error: %v", err)
+		return nil, fmt.Errorf("couldn't retrieve package dir, error: %w", err)
 	}
 
 	pkg, err := parsePackageDir(packageDir)

src/k8s/pkg/docgen/gomod.go

@@ -2,11 +2,12 @@ package docgen
 
 import (
 	"fmt"
-	"golang.org/x/mod/modfile"
-	"golang.org/x/mod/module"
 	"os"
 	"path"
 	"strings"
+
+	"golang.org/x/mod/modfile"
+	"golang.org/x/mod/module"
 )
 
 func getGoDepModulePath(name string, version string) (string, error) {
@@ -22,21 +23,21 @@ func getGoDepModulePath(name string, version string) (string, error) {
 	escapedPath, err := module.EscapePath(name)
 	if err != nil {
 		return "", fmt.Errorf(
-			"couldn't escape module path: %s %v", name, err)
+			"couldn't escape module path %s: %w", name, err)
 	}
 
 	escapedVersion, err := module.EscapeVersion(version)
 	if err != nil {
 		return "", fmt.Errorf(
-			"couldn't escape module version: %s %v", version, err)
+			"couldn't escape module version %s: %w", version, err)
 	}
 
 	path := path.Join(cachePath, escapedPath+"@"+escapedVersion)
 
 	// Validate the path.
 	if _, err := os.Stat(path); err != nil {
 		return "", fmt.Errorf(
-			"Go module path not accessible: %s %s %s, error: %v.",
+			"go module path not accessible %s %s %s: %w",
 			name, version, path, err)
 	}
 
@@ -46,11 +47,11 @@ func getGoDepModulePath(name string, version string) (string, error) {
 func getDependencyVersionFromGoMod(goModPath string, packageName string, directOnly bool) (string, string, error) {
 	goModContents, err := os.ReadFile(goModPath)
 	if err != nil {
-		return "", "", fmt.Errorf("could not read go.mod file %s, error: %v", goModPath, err)
+		return "", "", fmt.Errorf("could not read go.mod file %s: %w", goModPath, err)
 	}
 	goModFile, err := modfile.ParseLax(goModPath, goModContents, nil)
 	if err != nil {
-		return "", "", fmt.Errorf("could not parse go.mod file %s, error: %v", goModPath, err)
+		return "", "", fmt.Errorf("could not parse go.mod file %s: %w", goModPath, err)
 	}
 
 	for _, dep := range goModFile.Require {

src/k8s/pkg/docgen/json_struct.go

@@ -57,8 +57,7 @@ func MarkdownFromJsonStructToFile(i any, outFilePath string, projectDir string)
 
 	err = os.WriteFile(outFilePath, []byte(content), 0644)
 	if err != nil {
-		return fmt.Errorf("failed to write markdown documentation to %s, error: %v.",
-			outFilePath, err)
+		return fmt.Errorf("failed to write markdown documentation to %s: %w", outFilePath, err)
 	}
 	return nil
 }
@@ -105,7 +104,7 @@ func ParseStruct(i any, projectDir string) ([]Field, error) {
 			fieldIface := reflect.ValueOf(i).FieldByName(field.Name).Interface()
 			nestedFields, err := ParseStruct(fieldIface, projectDir)
 			if err != nil {
-				return nil, fmt.Errorf("couldn't parse %s.%s, error: %v", inType, field.Name, err)
+				return nil, fmt.Errorf("couldn't parse %s.%s: %w", inType, field.Name, err)
 			}
 
 			outField := Field{

src/k8s/pkg/k8sd/database/schema.go

@@ -36,7 +36,7 @@ func schemaApplyMigration(migrationPath ...string) schema.Update {
 	path := filepath.Join(append([]string{"sql", "migrations"}, migrationPath...)...)
 	b, err := sqlMigrations.ReadFile(path)
 	if err != nil {
-		panic(fmt.Errorf("invalid migration file %s: %s", path, err))
+		panic(fmt.Errorf("invalid migration file %s: %w", path, err))
 	}
 	return func(ctx context.Context, tx *sql.Tx) error {
 		if _, err := tx.ExecContext(ctx, string(b)); err != nil {
@@ -51,7 +51,7 @@ func MustPrepareStatement(queryPath ...string) int {
 	path := filepath.Join(append([]string{"sql", "queries"}, queryPath...)...)
 	b, err := sqlQueries.ReadFile(path)
 	if err != nil {
-		panic(fmt.Errorf("invalid query file %s: %s", path, err))
+		panic(fmt.Errorf("invalid query file %s: %w", path, err))
 	}
 	return cluster.RegisterStmt(string(b))
 }

src/k8s/pkg/k8sd/features/calico/network.go

@@ -81,7 +81,7 @@ func ApplyNetwork(ctx context.Context, snap snap.Snap, apiserver types.APIServer
 	serviceCIDRs := []string{}
 	ipv4ServiceCIDR, ipv6ServiceCIDR, err := utils.SplitCIDRStrings(network.GetServiceCIDR())
 	if err != nil {
-		err = fmt.Errorf("invalid service cidr: %v", err)
+		err = fmt.Errorf("invalid service cidr: %w", err)
 		return types.FeatureStatus{
 			Enabled: false,
 			Version: CalicoTag,

src/k8s/pkg/k8sd/features/cilium/network.go

@@ -52,7 +52,7 @@ func ApplyNetwork(ctx context.Context, snap snap.Snap, apiserver types.APIServer
 
 	ipv4CIDR, ipv6CIDR, err := utils.SplitCIDRStrings(network.GetPodCIDR())
 	if err != nil {
-		err = fmt.Errorf("invalid kube-proxy --cluster-cidr value: %v", err)
+		err = fmt.Errorf("invalid kube-proxy --cluster-cidr value: %w", err)
 		return types.FeatureStatus{
 			Enabled: false,
 			Version: CiliumAgentImageTag,

src/k8s/pkg/k8sd/setup/templates.go

@@ -16,7 +16,7 @@ func mustTemplate(parts ...string) *template.Template {
 	path := filepath.Join(append([]string{"embed"}, parts...)...)
 	b, err := templates.ReadFile(path)
 	if err != nil {
-		panic(fmt.Errorf("invalid template %s: %s", path, err))
+		panic(fmt.Errorf("invalid template %s: %w", path, err))
 	}
 	return template.Must(template.New(path).Parse(string(b)))
 }

src/k8s/pkg/snap/util/arguments.go

@@ -104,7 +104,7 @@ func UpdateServiceArguments(snap snap.Snap, serviceName string, updateMap map[st
 	sort.Strings(newArguments)
 
 	if err := os.WriteFile(argumentsFile, []byte(strings.Join(newArguments, "\n")+"\n"), 0600); err != nil {
-		return false, fmt.Errorf("failed to write arguments for service %s: %q", serviceName, err)
+		return false, fmt.Errorf("failed to write arguments for service %s: %w", serviceName, err)
 	}
 	return changed, nil
 }

src/k8s/pkg/utils/control/retry_test.go

@@ -42,7 +42,7 @@ func TestRetryFor(t *testing.T) {
 			return errors.New("failed")
 		})
 
-		if err != context.Canceled {
+		if !errors.Is(err, context.Canceled) {
 			t.Errorf("Expected context.Canceled error, got: %v", err)
 		}
 	})

src/k8s/pkg/utils/control/wait_test.go

@@ -12,11 +12,11 @@ func mockCheckFunc() (bool, error) {
 	return true, nil
 }
 
-var testError = errors.New("test error")
+var errTest = errors.New("test error")
 
 // Mock check function that returns an error.
 func mockErrorCheckFunc() (bool, error) {
-	return false, testError
+	return false, errTest
 }
 
 func TestWaitUntilReady(t *testing.T) {
@@ -34,7 +34,7 @@ func TestWaitUntilReady(t *testing.T) {
 	cancel2() // Cancel the context immediately
 
 	err2 := WaitUntilReady(ctx2, mockCheckFunc)
-	if err2 == nil || err2 != context.Canceled {
+	if err2 == nil || !errors.Is(err2, context.Canceled) {
 		t.Errorf("Expected context.Canceled error, got: %v", err2)
 	}
 
@@ -52,7 +52,7 @@ func TestWaitUntilReady(t *testing.T) {
 	defer cancel4()
 
 	err4 := WaitUntilReady(ctx4, mockErrorCheckFunc)
-	if err4 == nil || !errors.Is(err4, testError) {
+	if err4 == nil || !errors.Is(err4, errTest) {
 		t.Errorf("Expected test error, got: %v", err4)
 	}
 }