Fix panic in parsing /etc/os-release

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

pkg/parsers/operatingsystem/operatingsystem_linux.go

@@ -3,9 +3,14 @@
 package operatingsystem
 
 import (
+	"bufio"
 	"bytes"
-	"errors"
+	"fmt"
 	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/mattn/go-shellwords"
 )
 
 var (
@@ -18,15 +23,34 @@ var (
 
 // GetOperatingSystem gets the name of the current operating system.
 func GetOperatingSystem() (string, error) {
-	b, err := ioutil.ReadFile(etcOsRelease)
+	osReleaseFile, err := os.Open(etcOsRelease)
 	if err != nil {
 		return "", err
 	}
-	if i := bytes.Index(b, []byte("PRETTY_NAME")); i >= 0 {
-		b = b[i+13:]
-		return string(b[:bytes.IndexByte(b, '"')]), nil
+	defer osReleaseFile.Close()
+
+	var prettyName string
+	scanner := bufio.NewScanner(osReleaseFile)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "PRETTY_NAME=") {
+			data := strings.SplitN(line, "=", 2)
+			prettyNames, err := shellwords.Parse(data[1])
+			if err != nil {
+				return "", fmt.Errorf("PRETTY_NAME is invalid: %s", err.Error())
+			}
+			if len(prettyNames) != 1 {
+				return "", fmt.Errorf("PRETTY_NAME needs to be enclosed by quotes if they have spaces: %s", data[1])
+			}
+			prettyName = prettyNames[0]
+		}
 	}
-	return "", errors.New("PRETTY_NAME not found")
+	if prettyName != "" {
+		return prettyName, nil
+	}
+	// If not set, defaults to PRETTY_NAME="Linux"
+	// c.f. http://www.freedesktop.org/software/systemd/man/os-release.html
+	return "Linux", nil
 }
 
 // IsContainerized returns true if we are running inside a container.

pkg/parsers/operatingsystem/operatingsystem_unix_test.go

@@ -10,9 +10,74 @@ import (
 )
 
 func TestGetOperatingSystem(t *testing.T) {
-	var (
-		backup       = etcOsRelease
-		ubuntuTrusty = []byte(`NAME="Ubuntu"
+	var backup = etcOsRelease
+
+	invalids := []struct {
+		content       string
+		errorExpected string
+	}{
+		{
+			`PRETTY_NAME=Source Mage GNU/Linux
+PRETTY_NAME=Ubuntu 14.04.LTS`,
+			"PRETTY_NAME needs to be enclosed by quotes if they have spaces: Source Mage GNU/Linux",
+		},
+		{
+			`PRETTY_NAME="Ubuntu Linux
+PRETTY_NAME=Ubuntu 14.04.LTS`,
+			"PRETTY_NAME is invalid: invalid command line string",
+		},
+		{
+			`PRETTY_NAME=Ubuntu'
+PRETTY_NAME=Ubuntu 14.04.LTS`,
+			"PRETTY_NAME is invalid: invalid command line string",
+		},
+		{
+			`PRETTY_NAME'
+PRETTY_NAME=Ubuntu 14.04.LTS`,
+			"PRETTY_NAME needs to be enclosed by quotes if they have spaces: Ubuntu 14.04.LTS",
+		},
+	}
+
+	valids := []struct {
+		content  string
+		expected string
+	}{
+		{
+			`NAME="Ubuntu"
+PRETTY_NAME_AGAIN="Ubuntu 14.04.LTS"
+VERSION="14.04, Trusty Tahr"
+ID=ubuntu
+ID_LIKE=debian
+VERSION_ID="14.04"
+HOME_URL="http://www.ubuntu.com/"
+SUPPORT_URL="http://help.ubuntu.com/"
+BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`,
+			"Linux",
+		},
+		{
+			`NAME="Ubuntu"
+VERSION="14.04, Trusty Tahr"
+ID=ubuntu
+ID_LIKE=debian
+VERSION_ID="14.04"
+HOME_URL="http://www.ubuntu.com/"
+SUPPORT_URL="http://help.ubuntu.com/"
+BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`,
+			"Linux",
+		},
+		{
+			`NAME=Gentoo
+ID=gentoo
+PRETTY_NAME="Gentoo/Linux"
+ANSI_COLOR="1;32"
+HOME_URL="http://www.gentoo.org/"
+SUPPORT_URL="http://www.gentoo.org/main/en/support.xml"
+BUG_REPORT_URL="https://bugs.gentoo.org/"
+`,
+			"Gentoo/Linux",
+		},
+		{
+			`NAME="Ubuntu"
 VERSION="14.04, Trusty Tahr"
 ID=ubuntu
 ID_LIKE=debian
@@ -20,24 +85,28 @@ PRETTY_NAME="Ubuntu 14.04 LTS"
 VERSION_ID="14.04"
 HOME_URL="http://www.ubuntu.com/"
 SUPPORT_URL="http://help.ubuntu.com/"
-BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`)
-		gentoo = []byte(`NAME=Gentoo
-ID=gentoo
-PRETTY_NAME="Gentoo/Linux"
-ANSI_COLOR="1;32"
-HOME_URL="http://www.gentoo.org/"
-SUPPORT_URL="http://www.gentoo.org/main/en/support.xml"
-BUG_REPORT_URL="https://bugs.gentoo.org/"
-`)
-		noPrettyName = []byte(`NAME="Ubuntu"
+BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`,
+			"Ubuntu 14.04 LTS",
+		},
+		{
+			`NAME="Ubuntu"
 VERSION="14.04, Trusty Tahr"
 ID=ubuntu
 ID_LIKE=debian
-VERSION_ID="14.04"
-HOME_URL="http://www.ubuntu.com/"
-SUPPORT_URL="http://help.ubuntu.com/"
-BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`)
-	)
+PRETTY_NAME='Ubuntu 14.04 LTS'`,
+			"Ubuntu 14.04 LTS",
+		},
+		{
+			`PRETTY_NAME=Source
+NAME="Source Mage"`,
+			"Source",
+		},
+		{
+			`PRETTY_NAME=Source
+PRETTY_NAME="Source Mage"`,
+			"Source Mage",
+		},
+	}
 
 	dir := os.TempDir()
 	etcOsRelease = filepath.Join(dir, "etcOsRelease")
@@ -47,21 +116,23 @@ BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`)
 		etcOsRelease = backup
 	}()
 
-	for expect, osRelease := range map[string][]byte{
-		"Ubuntu 14.04 LTS": ubuntuTrusty,
-		"Gentoo/Linux":     gentoo,
-		"":                 noPrettyName,
-	} {
-		if err := ioutil.WriteFile(etcOsRelease, osRelease, 0600); err != nil {
+	for _, elt := range invalids {
+		if err := ioutil.WriteFile(etcOsRelease, []byte(elt.content), 0600); err != nil {
 			t.Fatalf("failed to write to %s: %v", etcOsRelease, err)
 		}
 		s, err := GetOperatingSystem()
-		if s != expect {
-			if expect == "" {
-				t.Fatalf("Expected error 'PRETTY_NAME not found', but got %v", err)
-			} else {
-				t.Fatalf("Expected '%s', but got '%s'. Err=%v", expect, s, err)
-			}
+		if err == nil || err.Error() != elt.errorExpected {
+			t.Fatalf("Expected an error %q, got %q (err: %v)", elt.errorExpected, s, err)
+		}
+	}
+
+	for _, elt := range valids {
+		if err := ioutil.WriteFile(etcOsRelease, []byte(elt.content), 0600); err != nil {
+			t.Fatalf("failed to write to %s: %v", etcOsRelease, err)
+		}
+		s, err := GetOperatingSystem()
+		if err != nil || s != elt.expected {
+			t.Fatalf("Expected %q, got %q (err: %v)", elt.expected, s, err)
 		}
 	}
 }