chore: add linter (#69)

Author: thevilledev

.github/workflows/lint.yaml

@@ -12,7 +12,7 @@ jobs:
         with:
           go-version-file: 'go.mod'
       - name: Lint
-        uses: golangci/golangci-lint-action@639cd343e1d3b897ff35927a75193d57cfcba299 # v3.6.0
+        uses: golangci/golangci-lint-action@4afd733a84b1f43292c63897423277bb7f4313a9 # v8.0.0
         with:
           version: latest
           args: --timeout 10m

.golangci.yml

@@ -3,14 +3,16 @@ package upcloud
 import (
 	"fmt"
 	"log"
+	"strconv"
 	"strings"
 
+	"github.com/hashicorp/packer-plugin-sdk/packer/registry/image"
+
 	"github.com/UpCloudLtd/packer-plugin-upcloud/internal/driver"
 	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
-	"github.com/hashicorp/packer-plugin-sdk/packer/registry/image"
 )
 
-// packersdk.Artifact implementation
+// packersdk.Artifact implementation.
 type Artifact struct {
 	config    *Config
 	driver    driver.Driver
@@ -21,15 +23,15 @@ type Artifact struct {
 	StateData map[string]interface{}
 }
 
-func (*Artifact) BuilderId() string {
-	return BuilderId
+func (*Artifact) BuilderId() string { //nolint:revive // method is required by packer-plugin-sdk
+	return BuilderID
 }
 
 func (a *Artifact) Files() []string {
 	return []string{}
 }
 
-func (a *Artifact) Id() string {
+func (a *Artifact) Id() string { //nolint:revive // method is required by packer-plugin-sdk
 	result := []string{}
 	for _, t := range a.Templates {
 		result = append(result, t.UUID)
@@ -59,7 +61,7 @@ func (a *Artifact) Destroy() error {
 	for _, t := range a.Templates {
 		err := a.driver.DeleteTemplate(ctx, t.UUID)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to delete template %s: %w", t.UUID, err)
 		}
 	}
 	return nil
@@ -68,11 +70,15 @@ func (a *Artifact) Destroy() error {
 func (a *Artifact) buildHCPPackerRegistryMetadata() ([]*image.Image, error) {
 	var sourceTemplateUUID, sourceTemplateTitle string
 	if v, ok := a.StateData["source_template_uuid"]; ok {
-		sourceTemplateUUID = v.(string)
+		if uuid, ok := v.(string); ok {
+			sourceTemplateUUID = uuid
+		}
 	}
 
 	if v, ok := a.StateData["source_template_title"]; ok {
-		sourceTemplateTitle = v.(string)
+		if title, ok := v.(string); ok {
+			sourceTemplateTitle = title
+		}
 	}
 
 	images := make([]*image.Image, 0)
@@ -83,15 +89,15 @@ func (a *Artifact) buildHCPPackerRegistryMetadata() ([]*image.Image, error) {
 			image.WithProvider("upcloud"),
 		)
 		if err != nil {
-			return images, err
+			return images, fmt.Errorf("failed to create registry image for template %s: %w", template.UUID, err)
 		}
 
 		img.SourceImageID = sourceTemplateUUID
 		img.Labels["source_id"] = sourceTemplateUUID
 		img.Labels["source"] = sourceTemplateTitle
 		img.Labels["name"] = template.Title
 		img.Labels["name_prefix"] = a.config.TemplatePrefix
-		img.Labels["size"] = fmt.Sprint(template.Size)
+		img.Labels["size"] = strconv.Itoa(template.Size)
 		images = append(images, img)
 	}
 	return images, nil

builder/upcloud/artifact.go

@@ -1,27 +1,29 @@
-package upcloud
+package upcloud //nolint:testpackage // not all fields can be exported in Artifact
 
 import (
 	"fmt"
 	"testing"
 
-	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
 	packersdk "github.com/hashicorp/packer-plugin-sdk/packer"
 	"github.com/hashicorp/packer-plugin-sdk/packer/registry/image"
 	"github.com/stretchr/testify/assert"
+
+	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
 )
 
 func TestArtifact_impl(t *testing.T) {
+	t.Parallel()
 	var _ packersdk.Artifact = new(Artifact)
 }
 
 func TestArtifact_Id(t *testing.T) {
+	t.Parallel()
 	uuid1 := "some-uuid-1"
 	uuid2 := "some-uuid-2"
 	expected := fmt.Sprintf("%s,%s", uuid1, uuid2)
 
 	templates := []*upcloud.Storage{}
-	templates = append(templates, &upcloud.Storage{UUID: uuid1})
-	templates = append(templates, &upcloud.Storage{UUID: uuid2})
+	templates = append(templates, &upcloud.Storage{UUID: uuid1}, &upcloud.Storage{UUID: uuid2})
 
 	a := &Artifact{Templates: templates}
 	result := a.Id()
@@ -32,6 +34,7 @@ func TestArtifact_Id(t *testing.T) {
 }
 
 func TestArtifact_String(t *testing.T) {
+	t.Parallel()
 	expected := `Storage template created, UUID: some-uuid`
 
 	templates := []*upcloud.Storage{}
@@ -46,6 +49,7 @@ func TestArtifact_String(t *testing.T) {
 }
 
 func TestArtifact_Metadata(t *testing.T) {
+	t.Parallel()
 	templates := []*upcloud.Storage{}
 	templates = append(templates,
 		&upcloud.Storage{
@@ -74,7 +78,11 @@ func TestArtifact_Metadata(t *testing.T) {
 			"source_template_uuid":  "source-uuid",
 		},
 	}
-	got := a.State(image.ArtifactStateURI).([]*image.Image)
+	result := a.State(image.ArtifactStateURI)
+	got, ok := result.([]*image.Image)
+	if !ok {
+		t.Fatalf("Expected []*image.Image, got %T", result)
+	}
 	want := &image.Image{
 		ImageID:        "some-uuid",
 		ProviderName:   "upcloud",

builder/upcloud/artifact_test.go

@@ -2,21 +2,23 @@ package upcloud
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
-	"github.com/UpCloudLtd/packer-plugin-upcloud/internal/driver"
-	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
 	"github.com/hashicorp/hcl/v2/hcldec"
 	"github.com/hashicorp/packer-plugin-sdk/communicator"
 	"github.com/hashicorp/packer-plugin-sdk/multistep"
 	"github.com/hashicorp/packer-plugin-sdk/multistep/commonsteps"
 	"github.com/hashicorp/packer-plugin-sdk/packer"
 	"github.com/hashicorp/packer-plugin-sdk/packerbuilderdata"
+
+	"github.com/UpCloudLtd/packer-plugin-upcloud/internal/driver"
+	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
 )
 
 const (
-	BuilderId                    = "upcloud.builder"
+	BuilderID                    = "upcloud.builder"
 	defaultTimeout time.Duration = 1 * time.Hour
 )
 
@@ -28,7 +30,7 @@ type Builder struct {
 
 func (b *Builder) ConfigSpec() hcldec.ObjectSpec { return b.config.FlatMapstructure().HCL2Spec() }
 
-func (b *Builder) Prepare(raws ...interface{}) (generatedVars []string, warnings []string, err error) {
+func (b *Builder) Prepare(raws ...interface{}) (generatedVars, warnings []string, err error) {
 	warnings, errs := b.config.Prepare(raws...)
 	if errs != nil {
 		return nil, warnings, errs
@@ -65,43 +67,32 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 	generatedData := &packerbuilderdata.GeneratedData{State: state}
 
 	// Build the steps
-	steps := []multistep.Step{
-		&StepCreateSSHKey{
-			Debug:        b.config.PackerDebug,
-			DebugKeyPath: fmt.Sprintf("ssh_key-%s.pem", b.config.PackerBuildName),
-		},
-		&StepCreateServer{
-			Config:        &b.config,
-			GeneratedData: generatedData,
-		},
-		b.communicatorStep(),
-		&commonsteps.StepProvision{},
-		&commonsteps.StepCleanupTempKeys{
-			Comm: &b.config.Comm,
-		},
-		&StepTeardownServer{},
-		&StepCreateTemplate{
-			Config:        &b.config,
-			GeneratedData: generatedData,
-		},
-	}
+	steps := b.buildSteps(generatedData)
 
 	// Run
 	b.runner = commonsteps.NewRunner(steps, b.config.PackerConfig, ui)
 	b.runner.Run(ctx, state)
 
 	// If there was an error, return that
 	if err, ok := state.GetOk("error"); ok {
-		return nil, err.(error)
+		if errVal, ok := err.(error); ok {
+			return nil, errVal
+		}
+		return nil, fmt.Errorf("unknown error type: %T", err)
 	}
 
 	templates, ok := state.GetOk("templates")
 	if !ok {
-		return nil, fmt.Errorf("No template found in state, the build was probably cancelled")
+		return nil, errors.New("no template found in state, the build was probably cancelled")
+	}
+
+	templatesVal, ok := templates.([]*upcloud.Storage)
+	if !ok {
+		return nil, fmt.Errorf("templates is not of expected type []*upcloud.Storage, got %T", templates)
 	}
 
 	artifact := &Artifact{
-		Templates: templates.([]*upcloud.Storage),
+		Templates: templatesVal,
 		config:    &b.config,
 		driver:    b.driver,
 		StateData: map[string]interface{}{
@@ -116,9 +107,33 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 	return artifact, nil
 }
 
+// buildSteps creates and returns the sequence of steps for the build process.
+func (b *Builder) buildSteps(generatedData *packerbuilderdata.GeneratedData) []multistep.Step {
+	return []multistep.Step{
+		&StepCreateSSHKey{
+			Debug:        b.config.PackerDebug,
+			DebugKeyPath: fmt.Sprintf("ssh_key-%s.pem", b.config.PackerBuildName),
+		},
+		&StepCreateServer{
+			Config:        &b.config,
+			GeneratedData: generatedData,
+		},
+		b.communicatorStep(),
+		&commonsteps.StepProvision{},
+		&commonsteps.StepCleanupTempKeys{
+			Comm: &b.config.Comm,
+		},
+		&StepTeardownServer{},
+		&StepCreateTemplate{
+			Config:        &b.config,
+			GeneratedData: generatedData,
+		},
+	}
+}
+
 // CommunicatorStep returns step based on communicator type
 // We currently support only SSH communicator but 'none' type
-// can also be used for e.g. testing purposes
+// can also be used for e.g. testing purposes.
 func (b *Builder) communicatorStep() multistep.Step {
 	switch b.config.Comm.Type {
 	case "none":