Print peer address

README.md

@@ -364,7 +364,7 @@ pipe-to-`jq` use.
 ### Output
 
 Default: human-readable table with space-separated thousands (`18 432`).
-`--json`: one JSON object per target (NDJSON for `stream`).
+`--json`: a single JSON array (one object per target) for `topn` and `trend`; NDJSON for `stream` (unbounded).
 
 `stream` reconnects automatically on error (5 s backoff). All other subcommands exit immediately
 with a non-zero code on gRPC error.

cmd/aggregator/server.go

@@ -8,6 +8,7 @@ import (
 	pb "git.ipng.ch/ipng/nginx-logtail/proto/logtailpb"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/status"
 )
 
@@ -64,15 +65,23 @@ func (srv *Server) ListTargets(_ context.Context, _ *pb.ListTargetsRequest) (*pb
 	return resp, nil
 }
 
+func peerAddr(ctx context.Context) string {
+	if p, ok := peer.FromContext(ctx); ok {
+		return p.Addr.String()
+	}
+	return "unknown"
+}
+
 func (srv *Server) StreamSnapshots(_ *pb.SnapshotRequest, stream grpc.ServerStreamingServer[pb.Snapshot]) error {
 	ch := srv.cache.Subscribe()
 	defer srv.cache.Unsubscribe(ch)
 
-	log.Printf("server: new StreamSnapshots subscriber")
+	addr := peerAddr(stream.Context())
+	log.Printf("server: new StreamSnapshots subscriber from %s", addr)
 	for {
 		select {
 		case <-stream.Context().Done():
-			log.Printf("server: StreamSnapshots subscriber disconnected")
+			log.Printf("server: StreamSnapshots subscriber disconnected: %s", addr)
 			return nil
 		case snap, ok := <-ch:
 			if !ok {

cmd/cli/cmd_topn.go

@@ -33,6 +33,10 @@ func runTopN(args []string) {
 
 	results := fanOutTopN(sf.targets, filter, grp, *n, win)
 
+	if sf.jsonOut {
+		printTopNJSONArray(results)
+		return
+	}
 	for _, r := range results {
 		if hdr := targetHeader(r.target, r.resp.GetSource(), len(sf.targets)); hdr != "" {
 			fmt.Println(hdr)
@@ -41,11 +45,7 @@ func runTopN(args []string) {
 			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
 			continue
 		}
-		if sf.jsonOut {
-			printTopNJSON(r)
-		} else {
-			printTopNTable(r)
-		}
+		printTopNTable(r)
 		if len(sf.targets) > 1 {
 			fmt.Println()
 		}
@@ -99,7 +99,7 @@ func printTopNTable(r topNResult) {
 	printTable(os.Stdout, rows)
 }
 
-func printTopNJSON(r topNResult) {
+func printTopNJSONArray(results []topNResult) {
 	type entry struct {
 		Label string `json:"label"`
 		Count int64  `json:"count"`
@@ -109,14 +109,22 @@ func printTopNJSON(r topNResult) {
 		Target  string  `json:"target"`
 		Entries []entry `json:"entries"`
 	}
-	o := out{
-		Source:  r.resp.Source,
-		Target:  r.target,
-		Entries: make([]entry, len(r.resp.Entries)),
+	rows := make([]out, 0, len(results))
+	for _, r := range results {
+		if r.err != nil {
+			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
+			continue
+		}
+		o := out{
+			Source:  r.resp.Source,
+			Target:  r.target,
+			Entries: make([]entry, len(r.resp.Entries)),
+		}
+		for i, e := range r.resp.Entries {
+			o.Entries[i] = entry{Label: e.Label, Count: e.Count}
+		}
+		rows = append(rows, o)
 	}
-	for i, e := range r.resp.Entries {
-		o.Entries[i] = entry{Label: e.Label, Count: e.Count}
-	}
-	b, _ := json.Marshal(o)
+	b, _ := json.Marshal(rows)
 	fmt.Println(string(b))
 }

cmd/cli/cmd_trend.go

@@ -30,6 +30,10 @@ func runTrend(args []string) {
 
 	results := fanOutTrend(sf.targets, filter, win)
 
+	if sf.jsonOut {
+		printTrendJSONArray(results)
+		return
+	}
 	for _, r := range results {
 		if hdr := targetHeader(r.target, r.resp.GetSource(), len(sf.targets)); hdr != "" {
 			fmt.Println(hdr)
@@ -38,11 +42,7 @@ func runTrend(args []string) {
 			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
 			continue
 		}
-		if sf.jsonOut {
-			printTrendJSON(r)
-		} else {
-			printTrendTable(r)
-		}
+		printTrendTable(r)
 		if len(sf.targets) > 1 {
 			fmt.Println()
 		}
@@ -90,7 +90,7 @@ func printTrendTable(r trendResult) {
 	printTable(os.Stdout, rows)
 }
 
-func printTrendJSON(r trendResult) {
+func printTrendJSONArray(results []trendResult) {
 	type point struct {
 		Ts    int64 `json:"ts"`
 		Count int64 `json:"count"`
@@ -100,14 +100,22 @@ func printTrendJSON(r trendResult) {
 		Target string  `json:"target"`
 		Points []point `json:"points"`
 	}
-	o := out{
-		Source: r.resp.Source,
-		Target: r.target,
-		Points: make([]point, len(r.resp.Points)),
+	rows := make([]out, 0, len(results))
+	for _, r := range results {
+		if r.err != nil {
+			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
+			continue
+		}
+		o := out{
+			Source: r.resp.Source,
+			Target: r.target,
+			Points: make([]point, len(r.resp.Points)),
+		}
+		for i, p := range r.resp.Points {
+			o.Points[i] = point{Ts: p.TimestampUnix, Count: p.Count}
+		}
+		rows = append(rows, o)
 	}
-	for i, p := range r.resp.Points {
-		o.Points[i] = point{Ts: p.TimestampUnix, Count: p.Count}
-	}
-	b, _ := json.Marshal(o)
+	b, _ := json.Marshal(rows)
 	fmt.Println(string(b))
 }

cmd/collector/server.go

@@ -8,6 +8,7 @@ import (
 	pb "git.ipng.ch/ipng/nginx-logtail/proto/logtailpb"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/status"
 )
 
@@ -62,15 +63,23 @@ func (srv *Server) ListTargets(_ context.Context, _ *pb.ListTargetsRequest) (*pb
 	}, nil
 }
 
+func peerAddr(ctx context.Context) string {
+	if p, ok := peer.FromContext(ctx); ok {
+		return p.Addr.String()
+	}
+	return "unknown"
+}
+
 func (srv *Server) StreamSnapshots(req *pb.SnapshotRequest, stream grpc.ServerStreamingServer[pb.Snapshot]) error {
 	ch := srv.store.Subscribe()
 	defer srv.store.Unsubscribe(ch)
 
-	log.Printf("server: new StreamSnapshots subscriber from %v", stream.Context().Value("peer"))
+	addr := peerAddr(stream.Context())
+	log.Printf("server: new StreamSnapshots subscriber from %s", addr)
 	for {
 		select {
 		case <-stream.Context().Done():
-			log.Printf("server: StreamSnapshots subscriber disconnected")
+			log.Printf("server: StreamSnapshots subscriber disconnected: %s", addr)
 			return nil
 		case snap, ok := <-ch:
 			if !ok {

docs/USERGUIDE.md

@@ -394,9 +394,9 @@ RANK  COUNT    LABEL
    1  18 432   example.com
 ```
 
-**JSON** (`--json`) — one object per target, suitable for `jq`:
+**JSON** (`--json`) — a single JSON array with one object per target, suitable for `jq`:
 ```json
-{"source":"agg-prod","target":"agg:9091","entries":[{"label":"example.com","count":18432},...]}
+[{"source":"agg-prod","target":"agg:9091","entries":[{"label":"example.com","count":18432},...]}]
 ```
 
 **`stream` JSON** — one object per snapshot received (NDJSON), runs until interrupted:
@@ -438,7 +438,7 @@ logtail-cli topn --target agg:9091 --window 1m --group-by prefix --status 429 --
 
 # Same query, pipe to jq for scripting
 logtail-cli topn --target agg:9091 --window 1m --group-by prefix --status 429 --n 20 \
-  --json | jq '.entries[0]'
+  --json | jq '.[0].entries[0]'
 
 # Which website has the most errors (4xx or 5xx) over the last 24h?
 logtail-cli topn --target agg:9091 --window 24h --group-by website --status '>=400'
@@ -462,7 +462,7 @@ logtail-cli topn --target nginx1:9090,nginx2:9090 --window 5m
 logtail-cli topn --target nginx3:9090,agg:9091 --window 5m --group-by prefix
 
 # Trend of total traffic over 6h (for a quick sparkline in the terminal)
-logtail-cli trend --target agg:9091 --window 6h --json | jq '[.points[] | .count]'
+logtail-cli trend --target agg:9091 --window 6h --json | jq '.[0].points | [.[].count]'
 
 # Watch live merged snapshots from the aggregator
 logtail-cli stream --target agg:9091