common/command: introduce this package for common cmmand stuff

command/build/command.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	cmdcommon "github.com/mitchellh/packer/common/command"
 	"github.com/mitchellh/packer/packer"
 	"io/ioutil"
 	"log"
@@ -22,15 +23,13 @@ func (Command) Help() string {
 func (c Command) Run(env packer.Environment, args []string) int {
 	var cfgDebug bool
 	var cfgForce bool
-	var cfgExcept []string
+	buildFilters := new(cmdcommon.BuildFilters)
-	var cfgOnly []string
 
 	cmdFlags := flag.NewFlagSet("build", flag.ContinueOnError)
 	cmdFlags.Usage = func() { env.Ui().Say(c.Help()) }
 	cmdFlags.BoolVar(&cfgDebug, "debug", false, "debug mode for builds")
 	cmdFlags.BoolVar(&cfgForce, "force", false, "force a build if artifacts exist")
-	cmdFlags.Var((*stringSliceValue)(&cfgExcept), "except", "build all builds except these")
+	cmdcommon.BuildFilterFlags(cmdFlags, buildFilters)
-	cmdFlags.Var((*stringSliceValue)(&cfgOnly), "only", "only build the given builds by name")
 	if err := cmdFlags.Parse(args); err != nil {
 		return 1
 	}
@@ -41,8 +40,9 @@ func (c Command) Run(env packer.Environment, args []string) int {
 		return 1
 	}
 
-	if len(cfgOnly) > 0 && len(cfgExcept) > 0 {
+	if err := buildFilters.Validate(); err != nil {
-		env.Ui().Error("Only one of '-except' or '-only' may be specified.\n")
+		env.Ui().Error(err.Error())
+		env.Ui().Error("")
 		env.Ui().Error(c.Help())
 		return 1
 	}
@@ -72,49 +72,12 @@ func (c Command) Run(env packer.Environment, args []string) int {
 	}
 
 	// Go through each builder and compile the builds that we care about
-	buildNames := tpl.BuildNames()
+	builds, err := buildFilters.Builds(tpl, components)
-	builds := make([]packer.Build, 0, len(buildNames))
-	for _, buildName := range buildNames {
-		if len(cfgExcept) > 0 {
-			found := false
-			for _, only := range cfgExcept {
-				if buildName == only {
-					found = true
-					break
-				}
-			}
-
-			if found {
-				log.Printf("Skipping build '%s' because specified by -except.", buildName)
-				continue
-			}
-		}
-
-		if len(cfgOnly) > 0 {
-			found := false
-			for _, only := range cfgOnly {
-				if buildName == only {
-					found = true
-					break
-				}
-			}
-
-			if !found {
-				log.Printf("Skipping build '%s' because not specified by -only.", buildName)
-				continue
-			}
-		}
-
-		log.Printf("Creating build: %s", buildName)
-		build, err := tpl.Build(buildName, components)
 	if err != nil {
-			env.Ui().Error(fmt.Sprintf("Failed to create build '%s': \n\n%s", buildName, err))
+		env.Ui().Error(err.Error())
 		return 1
 	}
 
-		builds = append(builds, build)
-	}
-
 	if cfgDebug {
 		env.Ui().Say("Debug mode enabled. Builds will not be parallelized.")
 	}

command/build/string_slice_value.go

@@ -1,14 +0,0 @@
-package build
-
-import "strings"
-
-type stringSliceValue []string
-
-func (s *stringSliceValue) String() string {
-	return strings.Join(*s, ",")
-}
-
-func (s *stringSliceValue) Set(value string) error {
-	*s = strings.Split(value, ",")
-	return nil
-}

common/command/build_flags.go

@@ -0,0 +1,12 @@
+package command
+
+import (
+	"flag"
+)
+
+// BuildFilterFlags sets the proper command line flags needed for
+// build filters.
+func BuildFilterFlags(fs *flag.FlagSet, f *BuildFilters) {
+	fs.Var((*SliceValue)(&f.Except), "except", "build all builds except these")
+	fs.Var((*SliceValue)(&f.Only), "only", "only build the given builds by name")
+}

common/command/flag_slice_value.go

@@ -0,0 +1,17 @@
+package command
+
+import "strings"
+
+// SliceValue implements the flag.Value interface and allows a list of
+// strings to be given on the command line and properly parsed into a slice
+// of strings internally.
+type SliceValue []string
+
+func (s *SliceValue) String() string {
+	return strings.Join(*s, ",")
+}
+
+func (s *SliceValue) Set(value string) error {
+	*s = strings.Split(value, ",")
+	return nil
+}

common/command/flag_slice_value_test.go

@@ -0,0 +1,28 @@
+package command
+
+import (
+	"flag"
+	"reflect"
+	"testing"
+)
+
+func TestSliceValue_implements(t *testing.T) {
+	var raw interface{}
+	raw = new(SliceValue)
+	if _, ok := raw.(flag.Value); !ok {
+		t.Fatalf("SliceValue should be a Value")
+	}
+}
+
+func TestSliceValueSet(t *testing.T) {
+	sv := new(SliceValue)
+	err := sv.Set("foo,bar,baz")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	expected := []string{"foo", "bar", "baz"}
+	if !reflect.DeepEqual([]string(*sv), expected) {
+		t.Fatalf("Bad: %#v", sv)
+	}
+}

common/command/template.go

@@ -0,0 +1,71 @@
+package command
+
+import (
+	"errors"
+	"fmt"
+	"github.com/mitchellh/packer/packer"
+	"log"
+)
+
+// BuildFilters is a set of options to filter the builds out of a template.
+type BuildFilters struct {
+	Except []string
+	Only   []string
+}
+
+// Validate validates the filter settings
+func (f *BuildFilters) Validate() error {
+	if len(f.Except) > 0 && len(f.Only) > 0 {
+		return errors.New("Only one of '-except' or '-only' may be specified.")
+	}
+
+	return nil
+}
+
+// Builds returns the builds out of the given template that pass the
+// configured filters.
+func (f *BuildFilters) Builds(t *packer.Template, cf *packer.ComponentFinder) ([]packer.Build, error) {
+	buildNames := t.BuildNames()
+	builds := make([]packer.Build, 0, len(buildNames))
+	for _, buildName := range buildNames {
+		if len(f.Except) > 0 {
+			found := false
+			for _, except := range f.Except {
+				if buildName == except {
+					found = true
+					break
+				}
+			}
+
+			if found {
+				log.Printf("Skipping build '%s' because specified by -except.", buildName)
+				continue
+			}
+		}
+
+		if len(f.Only) > 0 {
+			found := false
+			for _, only := range f.Only {
+				if buildName == only {
+					found = true
+					break
+				}
+			}
+
+			if !found {
+				log.Printf("Skipping build '%s' because not specified by -only.", buildName)
+				continue
+			}
+		}
+
+		log.Printf("Creating build: %s", buildName)
+		build, err := t.Build(buildName, cf)
+		if err != nil {
+			return nil, fmt.Errorf("Failed to create build '%s': \n\n%s", buildName, err)
+		}
+
+		builds = append(builds, build)
+	}
+
+	return builds, nil
+}

common/command/template_test.go

@@ -0,0 +1,37 @@
+package command
+
+import (
+	"testing"
+)
+
+func TestBuildFiltersValidate(t *testing.T) {
+	bf := new(BuildFilters)
+
+	err := bf.Validate()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Both set
+	bf.Except = make([]string, 1)
+	bf.Only = make([]string, 1)
+	err = bf.Validate()
+	if err == nil {
+		t.Fatal("should error")
+	}
+
+	// One set
+	bf.Except = make([]string, 1)
+	bf.Only = make([]string, 0)
+	err = bf.Validate()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	bf.Except = make([]string, 0)
+	bf.Only = make([]string, 1)
+	err = bf.Validate()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}