selftest: fix kernel version compare on 14.04 selftestfix-selftest

2 files changed, 27 insertions, 2 deletions

diff --git a/selftest/version.go b/selftest/version.go
index dc0d599328..e14cfa6057 100644
--- a/selftest/version.go
+++ b/selftest/version.go
@@ -21,7 +21,9 @@ package selftest
 
 import (
	"fmt"
+	"strings"
 
+	"github.com/snapcore/snapd/logger"
	"github.com/snapcore/snapd/osutil"
	"github.com/snapcore/snapd/release"
	"github.com/snapcore/snapd/strutil"
@@ -31,7 +33,16 @@ import (
 // encounter and provides advice on how to resolve them.
 func checkKernelVersion() error {
	if release.OnClassic && release.ReleaseInfo.ID == "ubuntu" && release.ReleaseInfo.VersionID == "14.04" {
-	if cmp, _ := strutil.VersionCompare(osutil.KernelVersion(), "3.13"); cmp <= 0 {
+	kver := osutil.KernelVersion()
+	// a kernel version looks like this: "4.4.0-112-generic" and
+	// we are only interested in the bits before the "-"
+	kver = strings.SplitN(kver, "-", 2)[0]
+	cmp, err := strutil.VersionCompare(kver, "3.13.0")
+	if err != nil {
+	logger.Noticef("cannot check kernel: %v", err)
+	return nil
+	}
+	if cmp <= 0 {
	return fmt.Errorf("you need to reboot into a 4.4 kernel to start using snapd")
	}
	}
diff --git a/selftest/version_test.go b/selftest/version_test.go
index c36fe6a705..94392c6b81 100644
--- a/selftest/version_test.go
+++ b/selftest/version_test.go
@@ -32,7 +32,7 @@ type versionSuite struct{}
 var _ = Suite(&versionSuite{})
 
 func (s *selftestSuite) TestFreshInstallOfSnapdOnTrusty(c *C) {
-	// Mock an Ubuntu 14.04 system running a 3.13 kernel
+	// Mock an Ubuntu 14.04 system running a 3.13.0 kernel
	restore := release.MockOnClassic(true)
	defer restore()
	restore = release.MockReleaseInfo(&release.OS{ID: "ubuntu", VersionID: "14.04"})
@@ -44,3 +44,17 @@ func (s *selftestSuite) TestFreshInstallOfSnapdOnTrusty(c *C) {
	err := selftest.CheckKernelVersion()
	c.Assert(err, ErrorMatches, "you need to reboot into a 4.4 kernel to start using snapd")
 }
+
+func (s *selftestSuite) TestRebootedOnTrusty(c *C) {
+	// Mock an Ubuntu 14.04 system running a 4.4.0 kernel
+	restore := release.MockOnClassic(true)
+	defer restore()
+	restore = release.MockReleaseInfo(&release.OS{ID: "ubuntu", VersionID: "14.04"})
+	defer restore()
+	restore = osutil.MockKernelVersion("4.4.0-112-generic")
+	defer restore()
+
+	// Check for the given advice.
+	err := selftest.CheckKernelVersion()
+	c.Assert(err, IsNil)
+}