CoreOS support (#309)

* supportos: fedora and rhel coreOS

* fix: add errors import to configurer/linux/coreos

configurer/linux/coreos.go

@@ -0,0 +1,37 @@
+package linux
+
+import (
+	"errors"
+	"github.com/k0sproject/k0sctl/configurer"
+	"github.com/k0sproject/rig"
+	"github.com/k0sproject/rig/os"
+	"github.com/k0sproject/rig/os/registry"
+	"strings"
+)
+
+// CoreOS provides OS support for ostree based Fedora & RHEL systems
+type CoreOS struct {
+	os.Linux
+	BaseLinux
+}
+
+func init() {
+	registry.RegisterOSModule(
+		func(os rig.OSVersion) bool {
+			return os.ID == "fedora" && strings.Contains(os.Name, "CoreOS") || os.ID == "rhel" && strings.Contains(os.Name, "CoreOS")
+		},
+		func() interface{} {
+			linuxType := &CoreOS{}
+			linuxType.PathFuncs = interface{}(linuxType).(configurer.PathFuncs)
+			return linuxType
+		},
+	)
+}
+
+func (l CoreOS) InstallPackage(h os.Host, pkg ...string) error {
+	return errors.New("CoreOS does not support installing packages manually")
+}
+
+func (l CoreOS) K0sBinaryPath() string {
+	return "/opt/bin/k0s"
+}

configurer/linux/enterpriselinux/fedora.go

@@ -5,6 +5,7 @@ import (
 	k0slinux "github.com/k0sproject/k0sctl/configurer/linux"
 	"github.com/k0sproject/rig"
 	"github.com/k0sproject/rig/os/registry"
+	"strings"
 )
 
 // Fedora provides OS support for Fedora
@@ -16,7 +17,7 @@ type Fedora struct {
 func init() {
 	registry.RegisterOSModule(
 		func(os rig.OSVersion) bool {
-			return os.ID == "fedora"
+			return os.ID == "fedora" && !strings.Contains(os.Name, "CoreOS")
 		},
 		func() interface{} {
 			linuxType := &Fedora{}

configurer/linux/enterpriselinux/rhel.go

@@ -5,6 +5,7 @@ import (
 	k0slinux "github.com/k0sproject/k0sctl/configurer/linux"
 	"github.com/k0sproject/rig"
 	"github.com/k0sproject/rig/os/registry"
+	"strings"
 )
 
 // RHEL provides OS support for RedHat Enterprise Linux
@@ -15,7 +16,7 @@ type RHEL struct {
 func init() {
 	registry.RegisterOSModule(
 		func(os rig.OSVersion) bool {
-			return os.ID == "rhel"
+			return os.ID == "rhel" && !strings.Contains(os.Name, "CoreOS")
 		},
 		func() interface{} {
 			linuxType := &RHEL{}