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 && microk8sInfo.HasInstallDate() {
+				cmd.PrintErrln("Error: microk8s snap is installed. Please remove it using the following command and try again:\n\n  sudo snap remove microk8s")
+				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/go.mod

@@ -5,7 +5,7 @@ go 1.22.6
 require (
 	dario.cat/mergo v1.0.0
 	github.com/canonical/go-dqlite v1.22.0
-	github.com/canonical/k8s-snap-api v1.0.12
+	github.com/canonical/k8s-snap-api v1.0.13
 	github.com/canonical/lxd v0.0.0-20240822122218-e7b2a7a83230
 	github.com/canonical/microcluster/v3 v3.0.0-20240827143335-f7a4d3984970
 	github.com/go-logr/logr v1.4.2

src/k8s/go.sum

@@ -99,8 +99,8 @@ github.com/bugsnag/panicwrap v0.0.0-20151223152923-e2c28503fcd0 h1:nvj0OLI3YqYXe
 github.com/bugsnag/panicwrap v0.0.0-20151223152923-e2c28503fcd0/go.mod h1:D/8v3kj0zr8ZAKg1AQ6crr+5VwKN5eIywRkfhyM/+dE=
 github.com/canonical/go-dqlite v1.22.0 h1:DuJmfcREl4gkQJyvZzjl2GHFZROhbPyfdjDRQXpkOyw=
 github.com/canonical/go-dqlite v1.22.0/go.mod h1:Uvy943N8R4CFUAs59A1NVaziWY9nJ686lScY7ywurfg=
-github.com/canonical/k8s-snap-api v1.0.12 h1:ofS2+JRlPMnpWgHLmnE4QEUqWv9Dgrmsv3hrjI0O4zQ=
-github.com/canonical/k8s-snap-api v1.0.12/go.mod h1:LDPoIYCeYnfgOFrwVPJ/4edGU264w7BB7g0GsVi36AY=
+github.com/canonical/k8s-snap-api v1.0.13 h1:Z+IW6Knvycu+DrkmH+9qB1UNyYiHfL+rFvT9DtSO2+g=
+github.com/canonical/k8s-snap-api v1.0.13/go.mod h1:LDPoIYCeYnfgOFrwVPJ/4edGU264w7BB7g0GsVi36AY=
 github.com/canonical/lxd v0.0.0-20240822122218-e7b2a7a83230 h1:YOqZ+/14OPZ+/TOXpRHIX3KLT0C+wZVpewKIwlGUmW0=
 github.com/canonical/lxd v0.0.0-20240822122218-e7b2a7a83230/go.mod h1:YVGI7HStOKsV+cMyXWnJ7RaMPaeWtrkxyIPvGWbgACc=
 github.com/canonical/microcluster/v3 v3.0.0-20240827143335-f7a4d3984970 h1:UrnpglbXELlxtufdk6DGDytu2JzyzuS3WTsOwPrkQLI=

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

@@ -0,0 +1,41 @@
+package snapd
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"time"
+)
+
+type SnapInfoResult struct {
+	InstallDate time.Time `json:"install-date"`
+}
+
+type SnapInfoResponse struct {
+	StatusCode int            `json:"status-code"`
+	Result     SnapInfoResult `json:"result"`
+}
+
+func (c *Client) GetSnapInfo(snap string) (*SnapInfoResponse, 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 SnapInfoResponse
+	if err := json.Unmarshal(resBody, &snapInfoResponse); err != nil {
+		return nil, fmt.Errorf("client: could not unmarshal response body: %w", err)
+	}
+
+	return &snapInfoResponse, nil
+}
+
+func (s SnapInfoResponse) HasInstallDate() bool {
+	return !s.Result.InstallDate.IsZero()
+}

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()