Refactor: Extract helper conduit: oscal_source

cli/cmd/generate/catalog.go

@@ -5,11 +5,11 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io/ioutil"
-	"os"
 
 	"github.com/sirupsen/logrus"
 
 	"github.com/docker/oscalkit/generator"
+	"github.com/docker/oscalkit/pkg/oscal_source"
 	"github.com/urfave/cli"
 )
 
@@ -45,23 +45,13 @@ var Catalog = cli.Command{
 		return nil
 	},
 	Action: func(c *cli.Context) error {
-
-		profilePath, err := generator.GetAbsolutePath(profilePath)
-		if err != nil {
-			return cli.NewExitError(fmt.Sprintf("cannot get absolute path, err: %v", err), 1)
-		}
-
-		_, err = os.Stat(profilePath)
-		if err != nil {
-			return cli.NewExitError(fmt.Sprintf("cannot fetch file, err %v", err), 1)
-		}
-		f, err := os.Open(profilePath)
+		os, err := oscal_source.Open(profilePath)
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}
-		defer f.Close()
+		defer os.Close()
 
-		profile, err := generator.ReadProfile(f)
+		profile, err := generator.ReadProfile(os.OSCAL())
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}

cli/cmd/generate/code.go

@@ -8,6 +8,7 @@ import (
 	"regexp"
 
 	"github.com/docker/oscalkit/generator"
+	"github.com/docker/oscalkit/pkg/oscal_source"
 	"github.com/docker/oscalkit/templates"
 	"github.com/docker/oscalkit/types/oscal/catalog"
 	"github.com/sirupsen/logrus"
@@ -53,22 +54,13 @@ var Code = cli.Command{
 			return cli.NewExitError(err, 1)
 		}
 
-		profilePath, err := generator.GetAbsolutePath(profilePath)
-		if err != nil {
-			return cli.NewExitError(fmt.Sprintf("cannot get absolute path, err: %v", err), 1)
-		}
-
-		_, err = os.Stat(profilePath)
-		if err != nil {
-			return cli.NewExitError(fmt.Sprintf("cannot fetch file, err %v", err), 1)
-		}
-		f, err := os.Open(profilePath)
+		osource, err := oscal_source.Open(profilePath)
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}
-		defer f.Close()
+		defer osource.Close()
 
-		profile, err := generator.ReadProfile(f)
+		profile, err := generator.ReadProfile(osource.OSCAL())
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}

cli/cmd/info.go

@@ -2,10 +2,8 @@ package cmd
 
 import (
 	"fmt"
-	"os"
 
-	"github.com/docker/oscalkit/generator"
-	"github.com/docker/oscalkit/types/oscal"
+	"github.com/docker/oscalkit/pkg/oscal_source"
 	"github.com/docker/oscalkit/types/oscal/catalog"
 	"github.com/urfave/cli"
 )
@@ -17,25 +15,13 @@ var Info = cli.Command{
 	ArgsUsage: "[file]",
 	Action: func(c *cli.Context) error {
 		for _, filePath := range c.Args() {
-			profilePath, err := generator.GetAbsolutePath(filePath)
+			os, err := oscal_source.Open(filePath)
 			if err != nil {
-				return cli.NewExitError(fmt.Sprintf("cannot get absolute path, err: %v", err), 1)
+				return cli.NewExitError(fmt.Sprintf("Could not open oscal file: %v", err), 1)
 			}
+			defer os.Close()
 
-			_, err = os.Stat(profilePath)
-			if err != nil {
-				return cli.NewExitError(fmt.Sprintf("cannot fetch file, err %v", err), 1)
-			}
-			f, err := os.Open(profilePath)
-			if err != nil {
-				return cli.NewExitError(err, 1)
-			}
-			defer f.Close()
-
-			o, err := oscal.New(f)
-			if err != nil {
-				return cli.NewExitError(err, 1)
-			}
+			o := os.OSCAL()
 			if o.Profile != nil {
 				fmt.Println("OSCAL Profile (represents subset of controls from OSCAL catalog(s))")
 				fmt.Println("ID:\t", o.Profile.Id)

generator/reader.go

@@ -37,13 +37,8 @@ func ReadCatalog(r io.Reader) (*catalog.Catalog, error) {
 
 }
 
-// ReadProfile reads profile from byte array
-func ReadProfile(r io.Reader) (*profile.Profile, error) {
-
-	o, err := oscal.New(r)
-	if err != nil {
-		return nil, fmt.Errorf("cannot read oscal profile from file. err: %v,", err)
-	}
+// ReadProfile reads profile from OSCAL
+func ReadProfile(o *oscal.OSCAL) (*profile.Profile, error) {
 	if o.Profile == nil {
 		return nil, fmt.Errorf("unable to marshall profile")
 	}

pkg/oscal_source/oscal_source.go

@@ -0,0 +1,53 @@
+package oscal_source
+
+import (
+	"fmt"
+	"github.com/docker/oscalkit/types/oscal"
+	"os"
+	"path/filepath"
+)
+
+// OSCALSource is intermediary that handles IO and low-level common operations consistently for oscalkit
+type OSCALSource struct {
+	UserPath string
+	file     *os.File
+	oscal    *oscal.OSCAL
+}
+
+// Open creates new OSCALSource and load it up
+func Open(path string) (*OSCALSource, error) {
+	result := OSCALSource{UserPath: path}
+	return &result, result.open()
+}
+
+func (s *OSCALSource) open() error {
+	var err error
+	path := s.UserPath
+	if !filepath.IsAbs(path) {
+		if path, err = filepath.Abs(path); err != nil {
+			return fmt.Errorf("Cannot get absolute path: %v", err)
+		}
+	}
+	if _, err = os.Stat(path); err != nil {
+		return fmt.Errorf("Cannot stat %s, %v", path, err)
+	}
+	if s.file, err = os.Open(path); err != nil {
+		return fmt.Errorf("Cannot open file %s: %v", path, err)
+	}
+	if s.oscal, err = oscal.New(s.file); err != nil {
+		return fmt.Errorf("Cannot parse file: %v", err)
+	}
+	return nil
+}
+
+func (s *OSCALSource) OSCAL() *oscal.OSCAL {
+	return s.oscal
+}
+
+// Close the OSCALSource
+func (s *OSCALSource) Close() {
+	if s.file != nil {
+		s.file.Close()
+		s.file = nil
+	}
+}