Fix line delimited JSON response

For GET /events, line delimit JSON.
Fixes #7047

Signed-off-by: Jessica Frazelle <jfrazelle@users.noreply.github.com>

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jfrazelle@users.noreply.github.com> (github: )

integration-cli/docker_api_events_test.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestGetEventsLineDelim(t *testing.T) {
+	name := "testimageevents"
+	defer deleteImages(name)
+	_, err := buildImage(name,
+		`FROM scratch
+        MAINTAINER "docker"`,
+		true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := deleteImages(name); err != nil {
+		t.Fatal(err)
+	}
+
+	endpoint := fmt.Sprintf("/events?since=1&until=%d", time.Now().Unix())
+	body, err := sockRequest("GET", endpoint)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	linesRead := 0
+	scanner := bufio.NewScanner(bytes.NewReader(body))
+	for scanner.Scan() && linesRead < 2 {
+		line := scanner.Bytes()
+		if len(line) == 0 {
+			continue
+		}
+
+		// make sure line delimited json
+		res := make(map[string]interface{})
+		if err := json.Unmarshal(line, &res); err != nil {
+			t.Fatalf("Unmarshaling the line as JSON failed: %v", err)
+		}
+
+		linesRead++
+	}
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("Scanner failed: %v", err)
+	}
+
+	if linesRead < 2 {
+		t.Fatalf("Only %d lines were read from the stream", linesRead)
+	}
+
+	logDone("events - test the api response is line delimited json")
+}