From f0da64fb63c3b8976ac9bbcda87da399a0a3961e Mon Sep 17 00:00:00 2001
From: Sasha Klizhentas <klizhentas@gmail.com>
Date: Mon, 22 Jan 2018 12:25:11 -0800
Subject: [PATCH] UX and performance changes

* Do not log EOF errors, avoid polluting logs
* Trim space from tokens when reading from file
* Do not use dir based caching

The caching problem deserves a separate explanation.

Directory backend is not concurrent friendly - it has a
fundamental design flaw - multiple gorotuines writing to the
same file corrupt cache data.

This requires either redesign of the backend or switching
to boltdb backend for caching.

Boltdb backend uses transactions and is safe for concurrent
access. This PR changes local cache to use boltdb instead
of the dir backend that is now used only in tests.
---
 constants.go           | 5 +++++
 lib/auth/register.go   | 3 ++-
 lib/service/service.go | 6 ++++--
 lib/sshutils/server.go | 5 ++++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/constants.go b/constants.go
index a0040bf5a8810..989913da6b767 100644
--- a/constants.go
+++ b/constants.go
@@ -287,3 +287,8 @@ const (
 	// at expected interval
 	RemoteClusterStatusOnline = "online"
 )
+
+const (
+	// SharedDirMode is a mode for a directory shared with group
+	SharedDirMode = 0750
+)
diff --git a/lib/auth/register.go b/lib/auth/register.go
index 0fd12a33dde83..2f6ab5f98a4e9 100644
--- a/lib/auth/register.go
+++ b/lib/auth/register.go
@@ -148,7 +148,8 @@ func readToken(token string) (string, error) {
 	if err != nil {
 		return "", nil
 	}
-	return string(out), nil
+	// trim newlines as tokens in files tend to have newlines
+	return strings.TrimSpace(string(out)), nil
 }
 
 // PackedKeys is a collection of private key, SSH host certificate
diff --git a/lib/service/service.go b/lib/service/service.go
index 1b627391b267f..d1494a9927a47 100644
--- a/lib/service/service.go
+++ b/lib/service/service.go
@@ -639,9 +639,11 @@ func (process *TeleportProcess) newLocalCache(clt auth.ClientI, cacheName []stri
 	if !process.Config.CachePolicy.Enabled {
 		return clt, nil
 	}
-
 	path := filepath.Join(append([]string{process.Config.DataDir, "cache"}, cacheName...)...)
-	cacheBackend, err := dir.New(backend.Params{"path": path})
+	if err := os.MkdirAll(path, teleport.SharedDirMode); err != nil {
+		return nil, trace.ConvertSystemError(err)
+	}
+	cacheBackend, err := boltbk.New(backend.Params{"path": path})
 	if err != nil {
 		return nil, trace.Wrap(err)
 	}
diff --git a/lib/sshutils/server.go b/lib/sshutils/server.go
index ac0d73c5aa5c3..7555658cc49a8 100644
--- a/lib/sshutils/server.go
+++ b/lib/sshutils/server.go
@@ -467,7 +467,10 @@ func (c *connectionWrapper) Read(b []byte) (int, error) {
 	buff := make([]byte, MaxVersionStringBytes)
 	n, err := c.Conn.Read(buff)
 	if err != nil {
-		log.Error(err)
+		// EOF happens quite often, don't pollute the logs with EOF
+		if err != io.EOF {
+			log.Error(err)
+		}
 		return n, err
 	}
 	// chop off extra unused bytes at the end of the buffer: