Fix alpine support part 2 (#104)

* Fix alpine support (again)

* Lint

* Maybe now

* Install sudo

* Add a test to validate alpine implements the configurer

* More alpine fixes

- Use exteded regexp instead perl regex, since the latter is not
  implemented in busybox grep

- Install kubectl with apk because:
  - It installs slightly faster
  - avoids bashism in checksum check
  - avoids problems with picky busybox sha256sum implementation

- Don't install packages as virtual since it gives unexpected behavior
  (next install will replace the previously installed packages), and we
  don't uninstall the packages, so there is no point with `-t`

Co-authored-by: Natanael Copa <[email protected]>

configurer/linux.go

@@ -130,7 +130,7 @@ const sbinPath = `PATH=/usr/local/sbin:/usr/sbin:/sbin:$PATH`
 
 // PrivateInterface tries to find a private network interface
 func (l Linux) PrivateInterface(h os.Host) (string, error) {
-	output, err := h.ExecOutput(fmt.Sprintf(`%s; (ip route list scope global | grep -P "\b(172|10|192\.168)\.") || (ip route list | grep -m1 default)`, sbinPath))
+	output, err := h.ExecOutput(fmt.Sprintf(`%s; (ip route list scope global | grep -E "\b(172|10|192\.168)\.") || (ip route list | grep -m1 default)`, sbinPath))
 	if err == nil {
 		re := regexp.MustCompile(`\bdev (\w+)`)
 		match := re.FindSubmatch([]byte(output))

configurer/linux/alpine.go

@@ -9,9 +9,32 @@ import (
 	"github.com/k0sproject/rig/os/registry"
 )
 
+// BaseLinux for tricking go interfaces
+type BaseLinux struct {
+	configurer.Linux
+}
+
+var kubectlInstallScript = []string{
+	`curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"`,
+	`curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"`,
+	`echo "$(<kubectl.sha256) kubectl" | sha256sum --check`,
+	`sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl`,
+}
+
+// InstallKubectl installs kubectl using the curl method
+func (l BaseLinux) InstallKubectl(h os.Host) error {
+	for _, c := range kubectlInstallScript {
+		if err := h.Exec(c); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // Alpine provides OS support for Alpine Linux
 type Alpine struct {
-	configurer.Linux
+	os.Linux
+	BaseLinux
 }
 
 func init() {
@@ -27,5 +50,18 @@ func init() {
 
 // InstallPackage installs packages via slackpkg
 func (l Alpine) InstallPackage(h os.Host, pkg ...string) error {
-	return h.Execf("sudo apk add -U -t k0sctl %s", strings.Join(pkg, " "))
+	return h.Execf("sudo apk add --update %s", strings.Join(pkg, " "))
+}
+
+// InstallKubectl installs kubectl using the alpine edge/testing repo
+func (l Alpine) InstallKubectl(h os.Host) error {
+	return l.InstallPackage(h, "--repository https://dl-cdn.alpinelinux.org/alpine/edge/testing kubectl")
+}
+
+func (l Alpine) Prepare(h os.Host) error {
+	if !l.CommandExist(h, "sudo") {
+		return h.Exec("apk add --update sudo")
+	}
+
+	return l.InstallPackage(h, "findutils", "coreutils")
 }

configurer/linux/alpine_test.go

@@ -0,0 +1,12 @@
+package linux
+
+import (
+	"testing"
+
+	"github.com/k0sproject/k0sctl/config/cluster"
+)
+
+func TestAlpineConfigurerInterface(t *testing.T) {
+	h := cluster.Host{}
+	h.Configurer = Alpine{}
+}

configurer/linux/enterpriselinux.go

@@ -1,13 +1,15 @@
 package linux
 
 import (
+	"github.com/k0sproject/k0sctl/configurer"
 	"github.com/k0sproject/rig/os"
 	"github.com/k0sproject/rig/os/linux"
 )
 
 // EnterpriseLinux is a base package for several RHEL-like enterprise linux distributions
 type EnterpriseLinux struct {
 	linux.EnterpriseLinux
+	configurer.Linux
 }
 
 // InstallKubectl installs kubectl using the gcloud kubernetes repo

configurer/linux/slackware.go

@@ -3,15 +3,15 @@ package linux
 import (
 	"strings"
 
-	"github.com/k0sproject/k0sctl/configurer"
 	"github.com/k0sproject/rig"
 	"github.com/k0sproject/rig/os"
 	"github.com/k0sproject/rig/os/registry"
 )
 
 // Slackware provides OS support for Slackware Linux
 type Slackware struct {
-	configurer.Linux
+	BaseLinux
+	os.Linux
 }
 
 func init() {

configurer/linux/sles.go

@@ -1,7 +1,6 @@
 package linux
 
 import (
-	"github.com/k0sproject/k0sctl/configurer"
 	"github.com/k0sproject/rig"
 	"github.com/k0sproject/rig/os"
 	"github.com/k0sproject/rig/os/linux"
@@ -11,7 +10,8 @@ import (
 // SLES provides OS support for Suse SUSE Linux Enterprise Server
 type SLES struct {
 	linux.SLES
-	configurer.Linux
+	os.Linux
+	BaseLinux
 }
 
 func init() {
@@ -24,20 +24,3 @@ func init() {
 		},
 	)
 }
-
-var kubectlInstallScript = []string{
-	`curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"`,
-	`curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"`,
-	`echo "$(<kubectl.sha256) kubectl" | sha256sum --check`,
-	`sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl`,
-}
-
-// InstallKubectl installs kubectl using the curl method
-func (l SLES) InstallKubectl(h os.Host) error {
-	for _, c := range kubectlInstallScript {
-		if err := h.Exec(c); err != nil {
-			return err
-		}
-	}
-	return nil
-}

phase/prepare_hosts.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 
 	"github.com/k0sproject/k0sctl/config/cluster"
+	"github.com/k0sproject/rig/os"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -22,7 +23,17 @@ func (p *PrepareHosts) Run() error {
 	return p.Config.Spec.Hosts.ParallelEach(p.prepareHost)
 }
 
+type prepare interface {
+	Prepare(os.Host) error
+}
+
 func (p *PrepareHosts) prepareHost(h *cluster.Host) error {
+	if c, ok := h.Configurer.(prepare); ok {
+		if err := c.Prepare(h); err != nil {
+			return err
+		}
+	}
+
 	if len(h.Environment) > 0 {
 		log.Infof("%s: updating environment", h)
 		if err := h.Configurer.UpdateEnvironment(h, h.Environment); err != nil {