Use dynamic RKE2 data-dir

Signed-off-by: Andrea Mazzotti <[email protected]>

cmd/support/main.go

@@ -21,6 +21,7 @@ import (
 	"bufio"
 	"bytes"
 	"compress/gzip"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -44,7 +45,9 @@ const (
 	k3sKubeConfig              = "/etc/rancher/k3s/k3s.yaml"
 	k3sKubectl                 = "/usr/local/bin/kubectl"
 	rkeKubeConfig              = "/etc/rancher/rke2/rke2.yaml"
-	rkeKubectl                 = "/var/lib/rancher/rke2/bin/kubectl"
+	rkeConfigPath              = "/etc/rancher/rke2/config.yaml.d/50-rancher.yaml"
+	rkeDataDirDefault          = "/var/lib/rancher/rke2"
+	rkeKubectl                 = "/bin/kubectl"
 	elementalAgentPlanDir      = "/var/lib/elemental/agent/applied/"
 	rancherAgentPlanDirDefault = "/var/lib/rancher/agent/applied/"
 	rancherAgentConf           = "/etc/rancher/agent/config.yaml"
@@ -56,6 +59,10 @@ const (
 	systemOEMDir               = "/system/oem"
 )
 
+type RKEConfig struct {
+	DataDir string `json:"data-dir,omitempty" yaml:"data-dir,omitempty"`
+}
+
 func getServices() []string {
 	return []string{
 		"elemental-system-agent",
@@ -553,14 +560,53 @@ func getKubectl() (string, error) {
 		log.Infof("Found k3s kubectl at %s", k3sKubectl)
 		return k3sKubectl, nil
 	}
-	if existsNoWarn(rkeKubectl) {
-		log.Infof("Found rke kubectl at %s", rkeKubectl)
-		return rkeKubectl, nil
+	rkeKubectlPath := getRKEKubectlPath()
+	if existsNoWarn(rkeKubectlPath) {
+		log.Infof("Found rke kubectl at %s", rkeKubectlPath)
+		return rkeKubectlPath, nil
 	}
 
 	return "", errors.New("Cant find kubectl")
 }
 
+// getRKEKubectlPath tries to locate the RKE2 installed kubectl, parsing the RKE2 config.
+// Note that this config has .yaml extension but is a JSON file.
+// We try to parse both.
+// See: https://github.com/rancher/rancher/issues/45865
+func getRKEKubectlPath() string {
+	if existsNoWarn(rkeConfigPath) {
+		log.Infof("Found RKE config: %s", rkeConfigPath)
+		rkeConfigBytes, err := os.ReadFile(rkeConfigPath)
+		if err != nil {
+			log.Errorf("Could not read file '%s': %s", rkeConfigPath, err.Error())
+			return filepath.Join(rkeDataDirDefault, rkeKubectl)
+		}
+		rkeConfig := RKEConfig{}
+		err = json.Unmarshal(rkeConfigBytes, &rkeConfig)
+		if err != nil {
+			log.Errorf("Could not unmarshal JSON '%s': %s", rkeConfigPath, err.Error())
+		}
+		if len(rkeConfig.DataDir) > 0 {
+			kubectlPath := filepath.Join(rkeConfig.DataDir, rkeKubectl)
+			log.Infof("Determined kubectl location: %s", kubectlPath)
+			return kubectlPath
+		}
+		// If JSON didn't work, try YAML
+		err = yaml.Unmarshal(rkeConfigBytes, &rkeConfig)
+		if err != nil {
+			log.Errorf("Could not unmarshal YAML '%s': %s", rkeConfigPath, err.Error())
+		}
+		if len(rkeConfig.DataDir) > 0 {
+			kubectlPath := filepath.Join(rkeConfig.DataDir, rkeKubectl)
+			log.Infof("Determined kubectl location: %s", kubectlPath)
+			return kubectlPath
+		}
+	}
+	return filepath.Join(rkeDataDirDefault, rkeKubectl)
+}
+
+// getSystemAgentAppliedDir tries to locate the Rancher System Agent applied plans dir,
+// parsing the system agent config.
 func getSystemAgentAppliedDir(systemAgentConfigPath string) string {
 	if existsNoWarn(systemAgentConfigPath) {
 		log.Infof("Found Rancher System Agent config: %s", systemAgentConfigPath)