feat(ui): allow setting default value for UI darkTheme option

docs/CONFIGURATION.md

@@ -770,6 +770,7 @@ ui:
   refresh: duration
   hideFiltersWhenIdle: bool
   colorTitlebar: bool
+  darkTheme: bool
   minimalGroupWidth: integer
   alertsPerGroup: integer
   collapseGroups: string
@@ -781,6 +782,8 @@ ui:
   user inactivity
 - `colorTitlebar` - if enabled alert group title bar color will be set to follow
   alerts in that group
+- `darkTheme` - if enabled dark mode will be enabled.
+  Note: dark mode is *experimental* and might be buggy.
 - `minimalGroupWidth` - minimal width (in pixels) for each alert group rendered
   on the grid. This value is used to calculate the number of columns rendered on
   the grid.
@@ -799,6 +802,7 @@ ui:
   refresh: 30s
   hideFiltersWhenIdle: true
   colorTitlebar: false
+  darkTheme: false
   minimalGroupWidth: 420
   alertsPerGroup: 5
   collapseGroups: collapsedOnMobile

internal/config/config.go

@@ -96,6 +96,7 @@ func init() {
 	pflag.Duration("ui.refresh", time.Second*30, "UI refresh interval")
 	pflag.Bool("ui.hideFiltersWhenIdle", true, "Hide the filters bar when idle")
 	pflag.Bool("ui.colorTitlebar", false, "Color alert group titlebar based on alert state")
+	pflag.Bool("ui.darkTheme", false, "Enable dark theme")
 	pflag.Int("ui.minimalGroupWidth", 420, "Minimal width for each alert group on the grid")
 	pflag.Int("ui.alertsPerGroup", 5, "Default number of alerts to show for each alert group")
 	pflag.String("ui.collapseGroups", "collapsedOnMobile", "Default state for alert groups")
@@ -186,6 +187,7 @@ func (config *configSchema) Read() {
 	config.UI.Refresh = v.GetDuration("ui.refresh")
 	config.UI.HideFiltersWhenIdle = v.GetBool("ui.hideFiltersWhenIdle")
 	config.UI.ColorTitlebar = v.GetBool("ui.colorTitlebar")
+	config.UI.DarkTheme = v.GetBool("ui.darkTheme")
 	config.UI.MinimalGroupWidth = v.GetInt("ui.minimalGroupWidth")
 	config.UI.AlertsPerGroup = v.GetInt("ui.alertsPerGroup")
 	config.UI.CollapseGroups = v.GetString("ui.collapseGroups")

internal/config/config_test.go

@@ -136,6 +136,7 @@ ui:
   refresh: 30s
   hideFiltersWhenIdle: true
   colorTitlebar: false
+  darkTheme: false
   minimalGroupWidth: 420
   alertsPerGroup: 5
   collapseGroups: collapsedOnMobile

internal/config/models.go

@@ -112,6 +112,7 @@ type configSchema struct {
 		Refresh             time.Duration
 		HideFiltersWhenIdle bool   `yaml:"hideFiltersWhenIdle" mapstructure:"hideFiltersWhenIdle"`
 		ColorTitlebar       bool   `yaml:"colorTitlebar" mapstructure:"colorTitlebar"`
+		DarkTheme           bool   `yaml:"darkTheme" mapstructure:"darkTheme"`
 		MinimalGroupWidth   int    `yaml:"minimalGroupWidth" mapstructure:"minimalGroupWidth"`
 		AlertsPerGroup      int    `yaml:"alertsPerGroup" mapstructure:"alertsPerGroup"`
 		CollapseGroups      string `yaml:"collapseGroups" mapstructure:"collapseGroups"`