colored labels output for logcli (#2470)

* colored labels output for logcli

* add period to all cli description

cmd/logcli/main.go

@@ -25,7 +25,6 @@ var (
 	statistics = app.Flag("stats", "Show query statistics").Default("false").Bool()
 	outputMode = app.Flag("output", "Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.").Default("default").Short('o').Enum("default", "raw", "jsonl")
 	timezone   = app.Flag("timezone", "Specify the timezone to use when formatting output timestamps [Local, UTC]").Default("Local").Short('z').Enum("Local", "UTC")
-
 	cpuProfile = app.Flag("cpuprofile", "Specify the location for writing a CPU profile.").Default("").String()
 	memProfile = app.Flag("memprofile", "Specify the location for writing a memory profile.").Default("").String()
 
@@ -119,8 +118,9 @@ func main() {
 		}
 
 		outputOptions := &output.LogOutputOptions{
-			Timezone: location,
-			NoLabels: rangeQuery.NoLabels,
+			Timezone:      location,
+			NoLabels:      rangeQuery.NoLabels,
+			ColoredOutput: rangeQuery.ColoredOutput,
 		}
 
 		out, err := output.NewLogOutput(*outputMode, outputOptions)
@@ -140,8 +140,9 @@ func main() {
 		}
 
 		outputOptions := &output.LogOutputOptions{
-			Timezone: location,
-			NoLabels: instantQuery.NoLabels,
+			Timezone:      location,
+			NoLabels:      instantQuery.NoLabels,
+			ColoredOutput: instantQuery.ColoredOutput,
 		}
 
 		out, err := output.NewLogOutput(*outputMode, outputOptions)
@@ -280,6 +281,7 @@ func newQuery(instant bool, cmd *kingpin.CmdClause) *query.Query {
 	cmd.Flag("include-label", "Include labels given the provided key during output.").StringsVar(&q.ShowLabelsKey)
 	cmd.Flag("labels-length", "Set a fixed padding to labels").Default("0").IntVar(&q.FixedLabelsLen)
 	cmd.Flag("store-config", "Execute the current query using a configured storage from a given Loki configuration file.").Default("").StringVar(&q.LocalConfig)
+	cmd.Flag("colored-output", "Show ouput with colored labels").Default("false").BoolVar(&q.ColoredOutput)
 
 	return q
 }

docs/sources/getting-started/logcli.md

@@ -80,10 +80,10 @@ A command-line for loki.
 Flags:
       --help             Show context-sensitive help (also try --help-long and --help-man).
       --version          Show application version.
-  -q, --quiet            Suppress query metadata
-      --stats            Show query statistics
+  -q, --quiet            Suppress query metadata.
+      --stats            Show query statistics.
   -o, --output=default   Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.
-  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC]
+  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC].
       --cpuprofile=""    Specify the location for writing a CPU profile.
       --memprofile=""    Specify the location for writing a memory profile.
       --addr="http://localhost:3100"
@@ -164,10 +164,10 @@ instead.
 Flags:
       --help               Show context-sensitive help (also try --help-long and --help-man).
       --version            Show application version.
-  -q, --quiet              Suppress query metadata
-      --stats              Show query statistics
+  -q, --quiet              Suppress query metadata.
+      --stats              Show query statistics.
   -o, --output=default     Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.
-  -z, --timezone=Local     Specify the timezone to use when formatting output timestamps [Local, UTC]
+  -z, --timezone=Local     Specify the timezone to use when formatting output timestamps [Local, UTC].
       --cpuprofile=""      Specify the location for writing a CPU profile.
       --memprofile=""      Specify the location for writing a memory profile.
       --addr="http://localhost:3100"
@@ -182,22 +182,23 @@ Flags:
                            bypassing an auth gateway.
       --limit=30           Limit on number of entries to print.
       --since=1h           Lookback window.
-      --from=FROM          Start looking for logs at this absolute time (inclusive)
-      --to=TO              Stop looking for logs at this absolute time (exclusive)
+      --from=FROM          Start looking for logs at this absolute time (inclusive).
+      --to=TO              Stop looking for logs at this absolute time (exclusive).
       --step=STEP          Query resolution step width, for metric queries. Evaluate the query at the specified step over the time
                            range.
       --interval=INTERVAL  Query interval, for log queries. Return entries at the specified interval, ignoring those between.
-                           **This parameter is experimental, please see Issue 1779**
+                           **This parameter is experimental, please see Issue 1779**.
       --forward            Scan forwards through logs.
-      --no-labels          Do not print any labels
+      --no-labels          Do not print any labels.
       --exclude-label=EXCLUDE-LABEL ...
                            Exclude labels given the provided key during output.
       --include-label=INCLUDE-LABEL ...
                            Include labels given the provided key during output.
-      --labels-length=0    Set a fixed padding to labels
+      --labels-length=0    Set a fixed padding to labels.
       --store-config=""    Execute the current query using a configured storage from a given Loki configuration file.
-  -t, --tail               Tail the logs
-      --delay-for=0        Delay in tailing by number of seconds to accumulate logs for re-ordering
+  -t, --tail               Tail the logs.
+      --delay-for=0        Delay in tailing by number of seconds to accumulate logs for re-ordering.
+      --colored-output     Show ouput with colored labels.
 
 Args:
   <query>  eg '{foo="bar",baz=~".*blip"} |~ ".*error.*"'
@@ -210,10 +211,10 @@ Find values for a given label.
 Flags:
       --help             Show context-sensitive help (also try --help-long and --help-man).
       --version          Show application version.
-  -q, --quiet            Suppress query metadata
-      --stats            Show query statistics
+  -q, --quiet            Suppress query metadata.
+      --stats            Show query statistics.
   -o, --output=default   Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.
-  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC]
+  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC].
       --cpuprofile=""    Specify the location for writing a CPU profile.
       --memprofile=""    Specify the location for writing a memory profile.
       --addr="http://localhost:3100"
@@ -227,8 +228,8 @@ Flags:
       --org-id=""        adds X-Scope-OrgID to API requests for representing tenant ID. Useful for requesting tenant data when
                          bypassing an auth gateway.
       --since=1h         Lookback window.
-      --from=FROM        Start looking for labels at this absolute time (inclusive)
-      --to=TO            Stop looking for labels at this absolute time (exclusive)
+      --from=FROM        Start looking for labels at this absolute time (inclusive).
+      --to=TO            Stop looking for labels at this absolute time (exclusive).
 
 Args:
   [<label>]  The name of the label.
@@ -241,10 +242,10 @@ Run series query.
 Flags:
       --help             Show context-sensitive help (also try --help-long and --help-man).
       --version          Show application version.
-  -q, --quiet            Suppress query metadata
-      --stats            Show query statistics
+  -q, --quiet            Suppress query metadata.
+      --stats            Show query statistics.
   -o, --output=default   Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.
-  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC]
+  -z, --timezone=Local   Specify the timezone to use when formatting output timestamps [Local, UTC].
       --cpuprofile=""    Specify the location for writing a CPU profile.
       --memprofile=""    Specify the location for writing a memory profile.
       --addr="http://localhost:3100"
@@ -258,8 +259,8 @@ Flags:
       --org-id=""        adds X-Scope-OrgID to API requests for representing tenant ID. Useful for requesting tenant data when
                          bypassing an auth gateway.
       --since=1h         Lookback window.
-      --from=FROM        Start looking for logs at this absolute time (inclusive)
-      --to=TO            Stop looking for logs at this absolute time (exclusive)
+      --from=FROM        Start looking for logs at this absolute time (inclusive).
+      --to=TO            Stop looking for logs at this absolute time (exclusive).
       --match=MATCH ...  eg '{foo="bar",baz=~".*blip"}'
 
 ```

pkg/logcli/output/default.go

@@ -24,6 +24,11 @@ func (o *DefaultOutput) Format(ts time.Time, lbls loghttp.LabelSet, maxLabelsLen
 		return fmt.Sprintf("%s %s", color.BlueString(timestamp), line)
 	}
 
+	if o.options.ColoredOutput {
+		labelsColor := getColor(lbls.String()).SprintFunc()
+		return fmt.Sprintf("%s %s %s", color.BlueString(timestamp), labelsColor(padLabel(lbls, maxLabelsLen)), line)
+	}
+
 	return fmt.Sprintf("%s %s %s", color.BlueString(timestamp), color.RedString(padLabel(lbls, maxLabelsLen)), line)
 }
 

pkg/logcli/output/default_test.go

@@ -132,6 +132,49 @@ func TestDefaultOutput_FormatLabelsPadding(t *testing.T) {
 	}
 }
 
+func TestColorForLabels(t *testing.T) {
+	tests := map[string]struct {
+		labels      loghttp.LabelSet
+		otherLabels loghttp.LabelSet
+		expected    bool
+	}{
+
+		"different labels": {
+			loghttp.LabelSet(map[string]string{
+				"type": "test",
+				"app":  "loki",
+			}),
+			loghttp.LabelSet(map[string]string{
+				"type": "test",
+				"app":  "grafana-loki",
+			}),
+			false,
+		},
+		"same labels": {
+			loghttp.LabelSet(map[string]string{
+				"type": "test",
+				"app":  "loki",
+			}),
+			loghttp.LabelSet(map[string]string{
+				"type": "test",
+				"app":  "loki",
+			}),
+			true,
+		},
+	}
+
+	for testName, testData := range tests {
+		testData := testData
+
+		t.Run(testName, func(t *testing.T) {
+			t.Parallel()
+			labelsColor := getColor(testData.labels.String())
+			otherLablesColor := getColor(testData.otherLabels.String())
+			assert.Equal(t, testData.expected, labelsColor.Equals(otherLablesColor))
+		})
+	}
+}
+
 func findMaxLabelsLength(labelsList []loghttp.LabelSet) int {
 	maxLabelsLen := 0
 

pkg/logcli/output/output.go

@@ -2,11 +2,29 @@ package output
 
 import (
 	"fmt"
+	"hash/fnv"
 	"time"
 
+	"github.com/fatih/color"
+
 	"github.com/grafana/loki/pkg/loghttp"
 )
 
+// Blue color is excluded since we are already printing timestamp
+// in blue color
+var colorList = []*color.Color{
+	color.New(color.FgHiCyan),
+	color.New(color.FgCyan),
+	color.New(color.FgHiGreen),
+	color.New(color.FgGreen),
+	color.New(color.FgHiMagenta),
+	color.New(color.FgMagenta),
+	color.New(color.FgHiYellow),
+	color.New(color.FgYellow),
+	color.New(color.FgHiRed),
+	color.New(color.FgRed),
+}
+
 // LogOutput is the interface any output mode must implement
 type LogOutput interface {
 	Format(ts time.Time, lbls loghttp.LabelSet, maxLabelsLen int, line string) string
@@ -14,8 +32,9 @@ type LogOutput interface {
 
 // LogOutputOptions defines options supported by LogOutput
 type LogOutputOptions struct {
-	Timezone *time.Location
-	NoLabels bool
+	Timezone      *time.Location
+	NoLabels      bool
+	ColoredOutput bool
 }
 
 // NewLogOutput creates a log output based on the input mode and options
@@ -41,3 +60,11 @@ func NewLogOutput(mode string, options *LogOutputOptions) (LogOutput, error) {
 		return nil, fmt.Errorf("unknown log output mode '%s'", mode)
 	}
 }
+
+func getColor(labels string) *color.Color {
+	hash := fnv.New32()
+	hash.Write([]byte(labels))
+	id := hash.Sum32() % uint32(len(colorList))
+	color := colorList[id]
+	return color
+}

pkg/logcli/output/output_test.go

@@ -8,7 +8,7 @@ import (
 )
 
 func TestNewLogOutput(t *testing.T) {
-	options := &LogOutputOptions{time.UTC, false}
+	options := &LogOutputOptions{time.UTC, false, false}
 
 	out, err := NewLogOutput("default", options)
 	assert.NoError(t, err)

pkg/logcli/query/query.go

@@ -51,8 +51,8 @@ type Query struct {
 	IgnoreLabelsKey []string
 	ShowLabelsKey   []string
 	FixedLabelsLen  int
-
-	LocalConfig string
+	ColoredOutput   bool
+	LocalConfig     string
 }
 
 // DoQuery executes the query and prints out the results