From b5d71ea77998ceb3681e56511408eebe8449e774 Mon Sep 17 00:00:00 2001
From: "R.B. Boyer" <public@richardboyer.net>
Date: Fri, 1 Feb 2019 09:21:54 -0600
Subject: [PATCH] testutil: redirect some test agent logs to testing.T.Logf
 (#5304)

When tests fail, only the logs for the failing run are dumped to the
console which helps in diagnosis. This is easily added to other test
scenarios as they come up.
---
 agent/consul/server_test.go |  1 +
 testutil/testlog.go         | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 testutil/testlog.go

diff --git a/agent/consul/server_test.go b/agent/consul/server_test.go
index de5396270..d89db2619 100644
--- a/agent/consul/server_test.go
+++ b/agent/consul/server_test.go
@@ -43,6 +43,7 @@ func testServerConfig(t *testing.T) (string, *Config) {
 	config.Bootstrap = true
 	config.Datacenter = "dc1"
 	config.DataDir = dir
+	config.LogOutput = testutil.TestWriter(t)
 
 	// bind the rpc server to a random port. config.RPCAdvertise will be
 	// set to the listen address unless it was set in the configuration.
diff --git a/testutil/testlog.go b/testutil/testlog.go
new file mode 100644
index 000000000..de603729b
--- /dev/null
+++ b/testutil/testlog.go
@@ -0,0 +1,30 @@
+package testutil
+
+import (
+	"io"
+	"log"
+	"strings"
+	"testing"
+)
+
+func TestLogger(t testing.TB) *log.Logger {
+	return log.New(&testWriter{t}, "test: ", log.LstdFlags)
+}
+
+func TestLoggerWithName(t testing.TB, name string) *log.Logger {
+	return log.New(&testWriter{t}, "test["+name+"]: ", log.LstdFlags)
+}
+
+func TestWriter(t testing.TB) io.Writer {
+	return &testWriter{t}
+}
+
+type testWriter struct {
+	t testing.TB
+}
+
+func (tw *testWriter) Write(p []byte) (n int, err error) {
+	tw.t.Helper()
+	tw.t.Log(strings.TrimSpace(string(p)))
+	return len(p), nil
+}