packer/command/build.go

package command

import (
	"bytes"
	"context"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/hclparse"
	packersdk "github.com/hashicorp/packer-plugin-sdk/packer"
	"github.com/hashicorp/packer-plugin-sdk/template"
	"github.com/hashicorp/packer/hcl2template"
	"github.com/hashicorp/packer/packer"
	"github.com/hashicorp/packer/version"
	"golang.org/x/sync/semaphore"

	"github.com/hako/durafmt"
	"github.com/posener/complete"
)

type BuildCommand struct {
	Meta
}

func (c *BuildCommand) Run(args []string) int {
	ctx, cleanup := handleTermInterrupt(c.Ui)
	defer cleanup()

	cfg, ret := c.ParseArgs(args)
	if ret != 0 {
		return ret
	}

	return c.RunContext(ctx, cfg)
}

func (c *BuildCommand) ParseArgs(args []string) (*BuildArgs, int) {
	var cfg BuildArgs
	flags := c.Meta.FlagSet("build", FlagSetBuildFilter|FlagSetVars)
	flags.Usage = func() { c.Ui.Say(c.Help()) }
	cfg.AddFlagSets(flags)
	if err := flags.Parse(args); err != nil {
		return &cfg, 1
	}

	if cfg.ParallelBuilds < 1 {
		cfg.ParallelBuilds = math.MaxInt64
	}

	args = flags.Args()
	if len(args) != 1 {
		flags.Usage()
		return &cfg, 1
	}
	cfg.Path = args[0]
	return &cfg, 0
}

func (m *Meta) GetConfigFromHCL(cla *MetaArgs) (*hcl2template.PackerConfig, int) {
	parser := &hcl2template.Parser{
		CorePackerVersion:       version.SemVer,
		CorePackerVersionString: version.FormattedVersion(),
		Parser:                  hclparse.NewParser(),
		PluginConfig:            m.CoreConfig.Components.PluginConfig,
	}
	cfg, diags := parser.Parse(cla.Path, cla.VarFiles, cla.Vars)
	return cfg, writeDiags(m.Ui, parser.Files(), diags)
}

func writeDiags(ui packersdk.Ui, files map[string]*hcl.File, diags hcl.Diagnostics) int {
	// write HCL errors/diagnostics if any.
	b := bytes.NewBuffer(nil)
	err := hcl.NewDiagnosticTextWriter(b, files, 80, false).WriteDiagnostics(diags)
	if err != nil {
		ui.Error("could not write diagnostic: " + err.Error())
		return 1
	}
	if b.Len() != 0 {
		if diags.HasErrors() {
			ui.Error(b.String())
			return 1
		}
		ui.Say(b.String())
	}
	return 0
}

func (m *Meta) GetConfig(cla *MetaArgs) (packer.Handler, int) {
	cfgType, err := cla.GetConfigType()
	if err != nil {
		m.Ui.Error(fmt.Sprintf("%q: %s", cla.Path, err))
		return nil, 1
	}
	cla.ConfigType = cfgType

	switch cfgType {
	case ConfigTypeHCL2:
		// TODO(azr): allow to pass a slice of files here.
		return m.GetConfigFromHCL(cla)
	default:
		return m.GetConfigFromJSON(cla)
	}
}

//DisplayLegacyConfigWarning displays Packer defined legacy warnings
// This is an internal-only method that should be called by commands that don't have
// a different mode when handling legacy JSON templates; mainly build, validate.
func DisplayLegacyConfigWarning(ui packersdk.Ui) {
	if v := os.Getenv(PackerLegacyModeEnv); strings.ToUpper(v) == packerLegacyModeOn {
		return
	}

	coloredUi := packer.ColoredUi{
		Color: packer.UiColorRed,
		Ui:    ui,
	}

	coloredUi.Say(`
Legacy JSON Configuration Mode enabled.
The template will be parsed in the legacy configuration style. Legacy style
templates will continue to work but users are encouraged to move HCL style templates.
See: https://learn.hashicorp.com/tutorials/packer/hcl2-upgrade
`)

	coloredUi.Say(fmt.Sprintf(`In JSON mode automatic loading of bundled plugins is enabled by default.
In the future this feature will be removed and Packer will rely only on system installed plugins.
To disable automatic loading of bundled plugins set %s=%s
See: https://packer.io/docs/templates/legacy-mode
`, PackerLegacyModeEnv, packerLegacyModeOff))

}

func (m *Meta) GetConfigFromJSON(cla *MetaArgs) (packer.Handler, int) {
	// Parse the template
	var tpl *template.Template
	var err error
	if cla.Path == "" {
		// here cla validation passed so this means we want a default builder
		// and we probably are in the console command
		tpl, err = template.Parse(TiniestBuilder)
	} else {
		tpl, err = template.ParseFile(cla.Path)
	}

	if err != nil {
		m.Ui.Error(fmt.Sprintf("Failed to parse file as legacy JSON template: "+
			"if you are using an HCL template, check your file extensions; they "+
			"should be either *.pkr.hcl or *.pkr.json; see the docs for more "+
			"details: https://www.packer.io/docs/templates/hcl_templates. \n"+
			"Original error: %s", err))
		return nil, 1
	}

	// Get the core
	core, err := m.Core(tpl, cla)
	ret := 0
	if err != nil {
		m.Ui.Error(err.Error())
		ret = 1
	}
	return &CoreWrapper{core}, ret
}

func (c *BuildCommand) RunContext(buildCtx context.Context, cla *BuildArgs) int {
	packerStarter, ret := c.GetConfig(&cla.MetaArgs)
	if ret != 0 {
		return ret
	}

	if cla.ConfigType == ConfigTypeJSON {
		DisplayLegacyConfigWarning(c.Ui)
	}

	diags := packerStarter.Initialize(packer.InitializeOptions{})
	ret = writeDiags(c.Ui, nil, diags)
	if ret != 0 {
		return ret
	}

	// This build currently enforces a 1:1 mapping that one publisher can be assigned to a single packer config file.
	// It also requires that each config type implements this ConfiguredArtifactMetadataPublisher to return a configured bucket.
	// TODO find an option that is not managed by a globally shared Publisher.
	ArtifactMetadataPublisher, diags := packerStarter.ConfiguredArtifactMetadataPublisher()
	if diags.HasErrors() {
		return writeDiags(c.Ui, nil, diags)
	}

	// We need to create a bucket and an empty iteration before we retrieve builds
	// so that we can add the iteration ID to the build's eval context
	if ArtifactMetadataPublisher != nil {
		if err := ArtifactMetadataPublisher.Initialize(buildCtx); err != nil {
			diags := hcl.Diagnostics{
				&hcl.Diagnostic{
					Summary:  "HCP Packer Registry iteration initialization failed",
					Detail:   fmt.Sprintf("Failed to initialize iteration for %q\n %s", ArtifactMetadataPublisher.Slug, err),
					Severity: hcl.DiagError,
				},
			}
			return writeDiags(c.Ui, nil, diags)
		}
	}

	builds, diags := packerStarter.GetBuilds(packer.GetBuildsOptions{
		Only:    cla.Only,
		Except:  cla.Except,
		Debug:   cla.Debug,
		Force:   cla.Force,
		OnError: cla.OnError,
	})

	// here, something could have gone wrong but we still want to run valid
	// builds.
	ret = writeDiags(c.Ui, nil, diags)

	if cla.Debug {
		c.Ui.Say("Debug mode enabled. Builds will not be parallelized.")
	}

	// Now that builds have been retrieved, we can populate the iteration with
	// the builds we expect to run.
	if ArtifactMetadataPublisher != nil {
		if err := ArtifactMetadataPublisher.PopulateIteration(buildCtx); err != nil {
			diags := hcl.Diagnostics{
				&hcl.Diagnostic{
					Summary:  "HCP Packer Registry build initialization failed",
					Detail:   fmt.Sprintf("Failed to initialize build for %q\n %s", ArtifactMetadataPublisher.Slug, err),
					Severity: hcl.DiagError,
				},
			}
			return writeDiags(c.Ui, nil, diags)
		}
	}

	// Compile all the UIs for the builds
	colors := [5]packer.UiColor{
		packer.UiColorGreen,
		packer.UiColorCyan,
		packer.UiColorMagenta,
		packer.UiColorYellow,
		packer.UiColorBlue,
	}
	buildUis := make(map[packersdk.Build]packersdk.Ui)
	for i := range builds {
		ui := c.Ui
		if cla.Color {
			// Only set up UI colors if -machine-readable isn't set.
			if _, ok := c.Ui.(*packer.MachineReadableUi); !ok {
				ui = &packer.ColoredUi{
					Color: colors[i%len(colors)],
					Ui:    ui,
				}
				ui.Say(fmt.Sprintf("%s: output will be in this color.", builds[i].Name()))
				if i+1 == len(builds) {
					// Add a newline between the color output and the actual output
					c.Ui.Say("")
				}
			}
		}
		// Now add timestamps if requested
		if cla.TimestampUi {
			ui = &packer.TimestampedUi{
				Ui: ui,
			}
		}

		buildUis[builds[i]] = ui
	}
	log.Printf("Build debug mode: %v", cla.Debug)
	log.Printf("Force build: %v", cla.Force)
	log.Printf("On error: %v", cla.OnError)

	// Get the start of the build command
	buildCommandStart := time.Now()

	// Run all the builds in parallel and wait for them to complete
	var wg sync.WaitGroup
	var artifacts = struct {
		sync.RWMutex
		m map[string][]packersdk.Artifact
	}{m: make(map[string][]packersdk.Artifact)}
	// Get the builds we care about
	var errors = struct {
		sync.RWMutex
		m map[string]error
	}{m: make(map[string]error)}
	limitParallel := semaphore.NewWeighted(cla.ParallelBuilds)
	for i := range builds {
		if err := buildCtx.Err(); err != nil {
			log.Println("Interrupted, not going to start any more builds.")
			break
		}

		b := builds[i]
		name := b.Name()
		ui := buildUis[b]
		if err := limitParallel.Acquire(buildCtx, 1); err != nil {
			ui.Error(fmt.Sprintf("Build '%s' failed to acquire semaphore: %s", name, err))
			errors.Lock()
			errors.m[name] = err
			errors.Unlock()
			break
		}
		// Increment the waitgroup so we wait for this item to finish properly
		wg.Add(1)

		// Run the build in a goroutine
		go func() {
			// Get the start of the build
			buildStart := time.Now()

			defer wg.Done()

			defer limitParallel.Release(1)

			log.Printf("Starting build run: %s", name)
			runArtifacts, err := b.Run(buildCtx, ui)

			// Get the duration of the build and parse it
			buildEnd := time.Now()
			buildDuration := buildEnd.Sub(buildStart)
			fmtBuildDuration := durafmt.Parse(buildDuration).LimitFirstN(2)

			if err != nil {
				ui.Error(fmt.Sprintf("Build '%s' errored after %s: %s", name, fmtBuildDuration, err))
				errors.Lock()
				errors.m[name] = err
				errors.Unlock()
			} else {
				ui.Say(fmt.Sprintf("Build '%s' finished after %s.", name, fmtBuildDuration))
				if runArtifacts != nil {
					artifacts.Lock()
					artifacts.m[name] = runArtifacts
					artifacts.Unlock()
				}
			}
		}()

		if cla.Debug {
			log.Printf("Debug enabled, so waiting for build to finish: %s", b.Name())
			wg.Wait()
		}

		if cla.ParallelBuilds == 1 {
			log.Printf("Parallelization disabled, waiting for build to finish: %s", b.Name())
			wg.Wait()
		}

	}

	// Wait for both the builds to complete and the interrupt handler,
	// if it is interrupted.
	log.Printf("Waiting on builds to complete...")
	wg.Wait()

	// Get the duration of the buildCommand command and parse it
	buildCommandEnd := time.Now()
	buildCommandDuration := buildCommandEnd.Sub(buildCommandStart)
	fmtBuildCommandDuration := durafmt.Parse(buildCommandDuration).LimitFirstN(2)
	c.Ui.Say(fmt.Sprintf("\n==> Wait completed after %s", fmtBuildCommandDuration))

	if err := buildCtx.Err(); err != nil {
		c.Ui.Say("Cleanly cancelled builds after being interrupted.")
		return 1
	}

	if len(errors.m) > 0 {
		c.Ui.Machine("error-count", strconv.FormatInt(int64(len(errors.m)), 10))

		c.Ui.Error("\n==> Some builds didn't complete successfully and had errors:")
		for name, err := range errors.m {
			// Create a UI for the machine readable stuff to be targeted
			ui := &packer.TargetedUI{
				Target: name,
				Ui:     c.Ui,
			}

			ui.Machine("error", err.Error())

			c.Ui.Error(fmt.Sprintf("--> %s: %s", name, err))
		}
	}

	if len(artifacts.m) > 0 {
		c.Ui.Say("\n==> Builds finished. The artifacts of successful builds are:")
		for name, buildArtifacts := range artifacts.m {
			// Create a UI for the machine readable stuff to be targeted
			ui := &packer.TargetedUI{
				Target: name,
				Ui:     c.Ui,
			}

			// Machine-readable helpful
			ui.Machine("artifact-count", strconv.FormatInt(int64(len(buildArtifacts)), 10))

			for i, artifact := range buildArtifacts {
				var message bytes.Buffer
				fmt.Fprintf(&message, "--> %s: ", name)

				if artifact != nil {
					fmt.Fprint(&message, artifact.String())
				} else {
					fmt.Fprint(&message, "<nothing>")
				}

				iStr := strconv.FormatInt(int64(i), 10)
				if artifact != nil {
					ui.Machine("artifact", iStr, "builder-id", artifact.BuilderId())
					ui.Machine("artifact", iStr, "id", artifact.Id())
					ui.Machine("artifact", iStr, "string", artifact.String())

					files := artifact.Files()
					ui.Machine("artifact",
						iStr,
						"files-count", strconv.FormatInt(int64(len(files)), 10))
					for fi, file := range files {
						fiStr := strconv.FormatInt(int64(fi), 10)
						ui.Machine("artifact", iStr, "file", fiStr, file)
					}
				} else {
					ui.Machine("artifact", iStr, "nil")
				}

				ui.Machine("artifact", iStr, "end")
				c.Ui.Say(message.String())

			}

		}
	} else {
		c.Ui.Say("\n==> Builds finished but no artifacts were created.")
	}

	if len(errors.m) > 0 {
		// If any errors occurred, exit with a non-zero exit status
		ret = 1
	}

	return ret
}

func (*BuildCommand) Help() string {
	helpText := `
Usage: packer build [options] TEMPLATE

  Will execute multiple builds in parallel as defined in the template.
  The various artifacts created by the template will be outputted.

Options:

  -color=false                  Disable color output. (Default: color)
  -debug                        Debug mode enabled for builds.
  -except=foo,bar,baz           Run all builds and post-processors other than these.
  -only=foo,bar,baz             Build only the specified builds.
  -force                        Force a build to continue if artifacts exist, deletes existing artifacts.
  -machine-readable             Produce machine-readable output.
  -on-error=[cleanup|abort|ask|run-cleanup-provisioner] If the build fails do: clean up (default), abort, ask, or run-cleanup-provisioner.
  -parallel-builds=1            Number of builds to run in parallel. 1 disables parallelization. 0 means no limit (Default: 0)
  -timestamp-ui                 Enable prefixing of each ui output with an RFC3339 timestamp.
  -var 'key=value'              Variable for templates, can be used multiple times.
  -var-file=path                JSON or HCL2 file containing user variables.
`

	return strings.TrimSpace(helpText)
}

func (*BuildCommand) Synopsis() string {
	return "build image(s) from template"
}

func (*BuildCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictNothing
}

func (*BuildCommand) AutocompleteFlags() complete.Flags {
	return complete.Flags{
		"-color":            complete.PredictNothing,
		"-debug":            complete.PredictNothing,
		"-except":           complete.PredictNothing,
		"-only":             complete.PredictNothing,
		"-force":            complete.PredictNothing,
		"-machine-readable": complete.PredictNothing,
		"-on-error":         complete.PredictNothing,
		"-parallel":         complete.PredictNothing,
		"-timestamp-ui":     complete.PredictNothing,
		"-var":              complete.PredictNothing,
		"-var-file":         complete.PredictNothing,
	}
}