fix(logs): resolve time ranges using client local time zone for logs commands

internal/cli/logs/time.go

@@ -0,0 +1,72 @@
+package logs
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// TimeRange resolves log filters that could be RFC 3339, timestamp, or relative duration to UTC timestamps.
+// Dates without a timezone use now's location. Relative durations are computed from now.
+func TimeRange(since, until string, now time.Time) (string, string, error) {
+	var err error
+	since, err = timestamp(since, now)
+	if err != nil {
+		return "", "", fmt.Errorf("invalid --since value: %w", err)
+	}
+	until, err = timestamp(until, now)
+	if err != nil {
+		return "", "", fmt.Errorf("invalid --until value: %w", err)
+	}
+
+	return since, until, nil
+}
+
+func timestamp(value string, now time.Time) (string, error) {
+	if value == "" {
+		return "", nil
+	}
+	// A bare zero is the Unix epoch, matching Docker's log filters.
+	if duration, err := time.ParseDuration(value); value != "0" && err == nil {
+		return now.Add(-duration).UTC().Format(time.RFC3339Nano), nil
+	}
+
+	// Keep Docker's supported date layouts, but use the location's offset at the requested date.
+	for _, layout := range []string{
+		time.RFC3339Nano,
+		"2006-01-02T15:04Z07:00",
+		"2006-01-02T15Z07:00",
+		"2006-01-02Z07:00",
+		"2006-01-02T15:04:05.999999999",
+		"2006-01-02T15:04",
+		"2006-01-02T15",
+		"2006-01-02",
+	} {
+		if t, err := time.ParseInLocation(layout, value, now.Location()); err == nil {
+			return t.UTC().Format(time.RFC3339Nano), nil
+		}
+	}
+
+	seconds, fraction, hasFraction := strings.Cut(value, ".")
+	sec, err := strconv.ParseInt(seconds, 10, 64)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse '%s' as a time or duration", value)
+	}
+
+	var nsec int64
+	if hasFraction {
+		if len(fraction) == 0 || len(fraction) > 9 || strings.ContainsAny(fraction, "+-") {
+			return "", fmt.Errorf("invalid Unix timestamp fraction in '%s'", value)
+		}
+		nsec, err = strconv.ParseInt(fraction+strings.Repeat("0", 9-len(fraction)), 10, 64)
+		if err != nil {
+			return "", fmt.Errorf("invalid Unix timestamp fraction in '%s': %w", value, err)
+		}
+	}
+	t := time.Unix(sec, nsec).UTC()
+	if t.Year() < 0 || t.Year() > 9999 {
+		return "", fmt.Errorf("Unix timestamp '%s' is outside the RFC 3339 date range", value)
+	}
+	return t.Format(time.RFC3339Nano), nil
+}