Flatcar support

Signed-off-by: Salvatore Mazzarino <dev@mazzarino.cz>

nodeup/pkg/distros/distribution.go

@@ -31,6 +31,7 @@ var (
 	DistributionRhel7       Distribution = "rhel7"
 	DistributionCentos7     Distribution = "centos7"
 	DistributionCoreOS      Distribution = "coreos"
+	DistributionFlatcar     Distribution = "flatcar"
 	DistributionContainerOS Distribution = "containeros"
 )
 
@@ -52,6 +53,8 @@ func (d Distribution) BuildTags() []string {
 		t = []string{"_rhel7"}
 	case DistributionCoreOS:
 		t = []string{"_coreos"}
+	case DistributionFlatcar:
+		t = []string{"_flatcar"}
 	case DistributionContainerOS:
 		t = []string{"_containeros"}
 	default:
@@ -78,7 +81,7 @@ func (d Distribution) IsDebianFamily() bool {
 		return true
 	case DistributionCentos7, DistributionRhel7:
 		return false
-	case DistributionCoreOS, DistributionContainerOS:
+	case DistributionCoreOS, DistributionFlatcar, DistributionContainerOS:
 		return false
 	default:
 		klog.Fatalf("unknown distribution: %s", d)
@@ -92,7 +95,7 @@ func (d Distribution) IsRHELFamily() bool {
 		return true
 	case DistributionJessie, DistributionXenial, DistributionBionic, DistributionDebian9:
 		return false
-	case DistributionCoreOS, DistributionContainerOS:
+	case DistributionCoreOS, DistributionFlatcar, DistributionContainerOS:
 		return false
 	default:
 		klog.Fatalf("unknown distribution: %s", d)
@@ -106,7 +109,7 @@ func (d Distribution) IsSystemd() bool {
 		return true
 	case DistributionCentos7, DistributionRhel7:
 		return true
-	case DistributionCoreOS:
+	case DistributionCoreOS, DistributionFlatcar:
 		return true
 	case DistributionContainerOS:
 		return true

nodeup/pkg/distros/identify.go

@@ -80,12 +80,15 @@ func FindDistribution(rootfs string) (Distribution, error) {
 	}
 
 	// CoreOS uses /usr/lib/os-release
+	// Flatcar uses /usr/lib/os-release
 	usrLibOsRelease, err := ioutil.ReadFile(path.Join(rootfs, "usr/lib/os-release"))
 	if err == nil {
 		for _, line := range strings.Split(string(usrLibOsRelease), "\n") {
 			line = strings.TrimSpace(line)
 			if line == "ID=coreos" {
 				return DistributionCoreOS, nil
+			} else if line == "ID=flatcar" {
+				return DistributionFlatcar, nil
 			}
 		}
 		klog.Warningf("unhandled os-release info %q", string(usrLibOsRelease))

nodeup/pkg/model/context.go

@@ -80,6 +80,8 @@ func (c *NodeupModelContext) SSLHostPaths() []string {
 		// Because /usr is read-only on CoreOS, we can't have any new directories; docker will try (and fail) to create them
 		// TODO: Just check if the directories exist?
 		paths = append(paths, "/usr/share/ca-certificates")
+	case distros.DistributionFlatcar:
+		paths = append(paths, "/usr/share/ca-certificates")
 	case distros.DistributionContainerOS:
 		paths = append(paths, "/usr/share/ca-certificates")
 	default:
@@ -412,6 +414,9 @@ func (c *NodeupModelContext) KubectlPath() string {
 	if c.Distribution == distros.DistributionCoreOS {
 		kubeletCommand = "/opt/bin"
 	}
+	if c.Distribution == distros.DistributionFlatcar {
+		kubeletCommand = "/opt/bin"
+	}
 	if c.Distribution == distros.DistributionContainerOS {
 		kubeletCommand = "/home/kubernetes/bin"
 	}

nodeup/pkg/model/docker.go

@@ -812,6 +812,13 @@ func (b *DockerBuilder) Build(c *fi.ModelBuilderContext) error {
 		}
 		return nil
 
+	case distros.DistributionFlatcar:
+		klog.Infof("Detected Flatcar; won't install Docker")
+		if err := b.buildContainerOSConfigurationDropIn(c); err != nil {
+			return err
+		}
+		return nil
+
 	case distros.DistributionContainerOS:
 		klog.Infof("Detected ContainerOS; won't install Docker")
 		if err := b.buildContainerOSConfigurationDropIn(c); err != nil {

nodeup/pkg/model/etcd.go

@@ -42,6 +42,10 @@ func (b *EtcdBuilder) Build(c *fi.ModelBuilderContext) error {
 		klog.Infof("Detected CoreOS; skipping etcd user installation")
 		return nil
 
+	case distros.DistributionFlatcar:
+		klog.Infof("Detected Flatcar; skipping etcd user installation")
+		return nil
+
 	case distros.DistributionContainerOS:
 		klog.Infof("Detected ContainerOS; skipping etcd user installation")
 		return nil

nodeup/pkg/model/kubelet.go

@@ -159,6 +159,9 @@ func (b *KubeletBuilder) kubeletPath() string {
 	if b.Distribution == distros.DistributionCoreOS {
 		kubeletCommand = "/opt/kubernetes/bin/kubelet"
 	}
+	if b.Distribution == distros.DistributionFlatcar {
+		kubeletCommand = "/opt/kubernetes/bin/kubelet"
+	}
 	if b.Distribution == distros.DistributionContainerOS {
 		kubeletCommand = "/home/kubernetes/bin/kubelet"
 	}
@@ -261,6 +264,10 @@ func (b *KubeletBuilder) buildSystemdService() *nodetasks.Service {
 		// We add /opt/kubernetes/bin for our utilities (socat, conntrack)
 		manifest.Set("Service", "Environment", "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/kubernetes/bin")
 	}
+	if b.Distribution == distros.DistributionFlatcar {
+		// We add /opt/kubernetes/bin for our utilities (conntrack)
+		manifest.Set("Service", "Environment", "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/kubernetes/bin")
+	}
 	manifest.Set("Service", "EnvironmentFile", "/etc/sysconfig/kubelet")
 
 	// @check if we are using bootstrap tokens and file checker
@@ -336,6 +343,30 @@ func (b *KubeletBuilder) addStaticUtils(c *fi.ModelBuilderContext) error {
 		}
 	}
 
+	if b.Distribution == distros.DistributionFlatcar {
+		// Flatcar does not ship with conntrack.  Install our own (statically linked) version
+		// TODO: Extract to common function?
+		for _, binary := range []string{"conntrack"} {
+			assetName := binary
+			assetPath := ""
+			asset, err := b.Assets.Find(assetName, assetPath)
+			if err != nil {
+				return fmt.Errorf("error trying to locate asset %q: %v", assetName, err)
+			}
+			if asset == nil {
+				return fmt.Errorf("unable to locate asset %q", assetName)
+			}
+
+			t := &nodetasks.File{
+				Path:     "/opt/kubernetes/bin/" + binary,
+				Contents: asset,
+				Type:     nodetasks.FileType_File,
+				Mode:     s("0755"),
+			}
+			c.AddTask(t)
+		}
+	}
+
 	return nil
 }
 

nodeup/pkg/model/logrotate.go

@@ -45,6 +45,8 @@ func (b *LogrotateBuilder) Build(c *fi.ModelBuilderContext) error {
 		return nil
 	case distros.DistributionCoreOS:
 		klog.Infof("Detected CoreOS; won't install logrotate")
+	case distros.DistributionFlatcar:
+		klog.Infof("Detected Flatcar; won't install logrotate")
 	default:
 		c.AddTask(&nodetasks.Package{Name: "logrotate"})
 	}
@@ -93,7 +95,7 @@ func (b *LogrotateBuilder) Build(c *fi.ModelBuilderContext) error {
 // addLogrotateService creates a logrotate systemd task to act as target for the timer, if one is needed
 func (b *LogrotateBuilder) addLogrotateService(c *fi.ModelBuilderContext) error {
 	switch b.Distribution {
-	case distros.DistributionCoreOS, distros.DistributionContainerOS:
+	case distros.DistributionCoreOS, distros.DistributionFlatcar, distros.DistributionContainerOS:
 		// logrotate service already exists
 		return nil
 	}
@@ -128,6 +130,12 @@ func (b *LogrotateBuilder) addLogRotate(c *fi.ModelBuilderContext, name, path st
 		options.DateFormat = "-%Y%m%d-%s"
 	}
 
+	// Flatcar sets "dateext" options, and maxsize-based rotation will fail if
+	// the file has been previously rotated on the same calendar date.
+	if b.Distribution == distros.DistributionFlatcar {
+		options.DateFormat = "-%Y%m%d-%s"
+	}
+
 	lines := []string{
 		path + "{",
 		"  rotate 5",

nodeup/pkg/model/update_service.go

@@ -57,6 +57,11 @@ func (b *UpdateServiceBuilder) Build(c *fi.ModelBuilderContext) error {
 		c.AddTask(b.buildCoreOSSystemdService())
 	}
 
+	if b.Distribution == distros.DistributionFlatcar {
+		klog.Infof("Detected OS %s; building %s service to disable update scheduler", ServiceName, b.Distribution)
+		c.AddTask(b.buildFlatcarSystemdService())
+	}
+
 	return nil
 }
 
@@ -80,3 +85,24 @@ func (b *UpdateServiceBuilder) buildCoreOSSystemdService() *nodetasks.Service {
 
 	return service
 }
+
+func (b *UpdateServiceBuilder) buildFlatcarSystemdService() *nodetasks.Service {
+	manifest := &systemd.Manifest{}
+	manifest.Set("Unit", "Description", "Disable OS Update Scheduler")
+
+	manifest.Set("Unit", "Before", "locksmithd.service")
+	manifest.Set("Service", "Type", "oneshot")
+	manifest.Set("Service", "ExecStart", "/usr/bin/systemctl mask --now locksmithd.service")
+
+	manifestString := manifest.Render()
+	klog.V(8).Infof("Built service manifest %q\n%s", ServiceName, manifestString)
+
+	service := &nodetasks.Service{
+		Name:       ServiceName + ".service",
+		Definition: s(manifestString),
+	}
+
+	service.InitDefaults()
+
+	return service
+}