Check if Microk8s is installed

src/k8s/cmd/k8s/k8s_bootstrap.go

@@ -13,6 +13,7 @@ import (
 
 	apiv1 "github.com/canonical/k8s-snap-api/api/v1"
 	cmdutil "github.com/canonical/k8s/cmd/util"
+	"github.com/canonical/k8s/pkg/client/snapd"
 	"github.com/canonical/k8s/pkg/config"
 	"github.com/canonical/k8s/pkg/k8sd/features"
 	"github.com/canonical/k8s/pkg/utils"
@@ -47,6 +48,24 @@ func newBootstrapCmd(env cmdutil.ExecutionEnvironment) *cobra.Command {
 		Long:   "Generate certificates, configure service arguments and start the Kubernetes services.",
 		PreRun: chainPreRunHooks(hookRequireRoot(env), hookInitializeFormatter(env, &opts.outputFormat), hookCheckLXD()),
 		Run: func(cmd *cobra.Command, args []string) {
+			snapdClient, err := snapd.NewClient()
+			if err != nil {
+				cmd.PrintErrln("Error: failed to create snapd client: %w", err)
+				env.Exit(1)
+				return
+			}
+			microk8sInfo, err := snapdClient.GetSnapInfo("microk8s")
+			if err != nil {
+				cmd.PrintErrln("Error: failed to check if microk8s is installed: %w", err)
+				env.Exit(1)
+				return
+			}
+			if microk8sInfo.StatusCode == 200 {
+				cmd.PrintErrln("Error: microk8s snap is installed, please remove it and try again.")
+				env.Exit(1)
+				return
+			}
+
 			if opts.interactive && opts.configFile != "" {
 				cmd.PrintErrln("Error: --interactive and --file flags cannot be set at the same time.")
 				env.Exit(1)

src/k8s/pkg/client/snapd/snap_info.go

@@ -0,0 +1,31 @@
+package snapd
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type snapdSnapInfoResponse struct {
+	StatusCode int `json:"status-code"`
+}
+
+func (c *Client) GetSnapInfo(snap string) (*snapdSnapInfoResponse, error) {
+	resp, err := c.client.Get(fmt.Sprintf("http://localhost/v2/snaps/%s", snap))
+	if err != nil {
+		return nil, fmt.Errorf("failed to get snapd snap info: %w", err)
+	}
+	defer resp.Body.Close()
+
+	resBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("client: could not read response body: %w", err)
+	}
+
+	var snapInfoResponse snapdSnapInfoResponse
+	if err := json.Unmarshal(resBody, &snapInfoResponse); err != nil {
+		return nil, fmt.Errorf("client: could not unmarshal response body: %w", err)
+	}
+
+	return &snapInfoResponse, nil
+}

tests/integration/tests/test_util/test_bootstrap.py

@@ -0,0 +1,16 @@
+#
+# Copyright 2024 Canonical, Ltd.
+#
+from typing import List
+
+import pytest
+from test_util import harness
+
+
+@pytest.mark.node_count(1)
+@pytest.mark.disable_k8s_bootstrapping()
+def test_microk8s_installed(instances: List[harness.Instance]):
+    instance = instances[0]
+    instance.exec("snap install microk8s --classic".split())
+    result = instance.exec("k8s bootstrap".split(), capture_output=True, check=False)
+    assert "Error: microk8s snap is installed" in result.stderr.decode()