Preinstall: Allow to extend default list (#96402)

conf/defaults.ini

@@ -1756,7 +1756,8 @@ hide_angular_deprecation =
 # Comma separated list of plugin ids for which environment variables should be forwarded. Used only when feature flag pluginsSkipHostEnvVars is enabled.
 forward_host_env_vars =
 # Comma separated list of plugin ids to install as part of the startup process.
-preinstall = grafana-lokiexplore-app
+# By default, the following plugins will be preinstalled: "grafana-lokiexplore-app"
+preinstall =
 # Controls whether preinstall plugins asynchronously (in the background) or synchronously (blocking). Useful when preinstalled plugins are used with provisioning.
 preinstall_async = true
 # Disables preinstall feature. It has the same effect as setting preinstall to an empty list.

pkg/setting/setting_plugins.go

@@ -26,6 +26,13 @@ func extractPluginSettings(sections []*ini.Section) PluginSettings {
 	return psMap
 }
 
+var (
+	defaultPreinstallPlugins = map[string]InstallPlugin{
+		// Default preinstalled plugins
+		"grafana-lokiexplore-app": {"grafana-lokiexplore-app", ""},
+	}
+)
+
 func (cfg *Cfg) readPluginSettings(iniFile *ini.File) error {
 	pluginsSection := iniFile.Section("plugins")
 
@@ -42,15 +49,27 @@ func (cfg *Cfg) readPluginSettings(iniFile *ini.File) error {
 	disablePreinstall := pluginsSection.Key("preinstall_disabled").MustBool(false)
 	if !disablePreinstall {
 		rawInstallPlugins := util.SplitString(pluginsSection.Key("preinstall").MustString(""))
-		cfg.PreinstallPlugins = make([]InstallPlugin, len(rawInstallPlugins))
-		for i, plugin := range rawInstallPlugins {
+		preinstallPlugins := make(map[string]InstallPlugin)
+		// Add the default preinstalled plugins
+		for _, plugin := range defaultPreinstallPlugins {
+			preinstallPlugins[plugin.ID] = plugin
+		}
+		// Add the plugins defined in the configuration
+		for _, plugin := range rawInstallPlugins {
 			parts := strings.Split(plugin, "@")
 			id := parts[0]
 			v := ""
 			if len(parts) == 2 {
 				v = parts[1]
 			}
-			cfg.PreinstallPlugins[i] = InstallPlugin{id, v}
+			preinstallPlugins[id] = InstallPlugin{id, v}
+		}
+		// Remove from the list the plugins that have been disabled
+		for _, disabledPlugin := range cfg.DisablePlugins {
+			delete(preinstallPlugins, disabledPlugin)
+		}
+		for _, plugin := range preinstallPlugins {
+			cfg.PreinstallPlugins = append(cfg.PreinstallPlugins, plugin)
 		}
 		cfg.PreinstallPluginsAsync = pluginsSection.Key("preinstall_async").MustBool(true)
 	}

pkg/setting/setting_plugins_test.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -95,4 +96,89 @@ func Test_readPluginSettings(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("when plugins.preinstall is defined", func(t *testing.T) {
+		defaultPreinstallPluginsList := make([]InstallPlugin, 0, len(defaultPreinstallPlugins))
+		defaultPreinstallPluginsIDs := []string{}
+		for _, p := range defaultPreinstallPlugins {
+			defaultPreinstallPluginsList = append(defaultPreinstallPluginsList, p)
+			defaultPreinstallPluginsIDs = append(defaultPreinstallPluginsIDs, p.ID)
+		}
+		tests := []struct {
+			name              string
+			rawInput          string
+			disablePreinstall bool
+			expected          []InstallPlugin
+			disableAsync      bool
+			disablePlugins    string
+		}{
+			{
+				name:     "should add the default preinstalled plugin",
+				rawInput: "",
+				expected: defaultPreinstallPluginsList,
+			},
+			{
+				name:     "should add the default preinstalled plugin and the one defined",
+				rawInput: "plugin1",
+				expected: append(defaultPreinstallPluginsList, InstallPlugin{"plugin1", ""}),
+			},
+			{
+				name:     "should add the default preinstalled plugin and the one defined with version",
+				rawInput: "plugin1@1.0.0",
+				expected: append(defaultPreinstallPluginsList, InstallPlugin{"plugin1", "1.0.0"}),
+			},
+			{
+				name:           "it should remove the disabled plugin",
+				rawInput:       "plugin1",
+				disablePlugins: "plugin1",
+				expected:       defaultPreinstallPluginsList,
+			},
+			{
+				name:           "it should remove default plugins",
+				rawInput:       "",
+				disablePlugins: strings.Join(defaultPreinstallPluginsIDs, ","),
+				expected:       nil,
+			},
+			{
+				name:              "should ignore input when preinstall is disabled",
+				rawInput:          "plugin1",
+				disablePreinstall: true,
+				expected:          nil,
+			},
+			{
+				name:         "should mark preinstall as sync",
+				rawInput:     "plugin1",
+				disableAsync: true,
+				expected:     append(defaultPreinstallPluginsList, InstallPlugin{"plugin1", ""}),
+			},
+		}
+		for _, tc := range tests {
+			t.Run(tc.name, func(t *testing.T) {
+				cfg := NewCfg()
+				sec, err := cfg.Raw.NewSection("plugins")
+				require.NoError(t, err)
+				_, err = sec.NewKey("preinstall", tc.rawInput)
+				require.NoError(t, err)
+				if tc.disablePreinstall {
+					_, err = sec.NewKey("preinstall_disabled", "true")
+					require.NoError(t, err)
+				}
+				if tc.disableAsync {
+					_, err = sec.NewKey("preinstall_async", "false")
+					require.NoError(t, err)
+				}
+				if tc.disablePlugins != "" {
+					_, err = sec.NewKey("disable_plugins", tc.disablePlugins)
+					require.NoError(t, err)
+				}
+
+				err = cfg.readPluginSettings(cfg.Raw)
+				require.NoError(t, err)
+				assert.ElementsMatch(t, cfg.PreinstallPlugins, tc.expected)
+				if tc.disableAsync {
+					require.Equal(t, cfg.PreinstallPluginsAsync, false)
+				}
+			})
+		}
+	})
 }