From e4bd01e0c706fedca7e2584322d3e458569f40a4 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
Date: Thu, 24 Jun 2021 22:50:24 +0200
Subject: [PATCH] Exclude read-timeout from being an error (#9429)

---
 plugins/inputs/dovecot/dovecot.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/plugins/inputs/dovecot/dovecot.go b/plugins/inputs/dovecot/dovecot.go
index ab5067534..fbc3b7905 100644
--- a/plugins/inputs/dovecot/dovecot.go
+++ b/plugins/inputs/dovecot/dovecot.go
@@ -93,7 +93,7 @@ func (d *Dovecot) gatherServer(addr string, acc telegraf.Accumulator, qtype stri
 
 	c, err := net.DialTimeout(proto, addr, defaultTimeout)
 	if err != nil {
-		return fmt.Errorf("enable to connect to dovecot server '%s': %s", addr, err)
+		return fmt.Errorf("unable to connect to dovecot server '%s': %s", addr, err)
 	}
 	defer c.Close()
 
@@ -113,7 +113,12 @@ func (d *Dovecot) gatherServer(addr string, acc telegraf.Accumulator, qtype stri
 	}
 	var buf bytes.Buffer
 	if _, err := io.Copy(&buf, c); err != nil {
-		return fmt.Errorf("copying message failed for dovecot server '%s': %s", addr, err)
+		// We need to accept the timeout here as reading from the connection will only terminate on EOF
+		// or on a timeout to happen. As EOF for TCP connections will only be sent on connection closing,
+		// the only way to get the whole message is to wait for the timeout to happen.
+		if nerr, ok := err.(net.Error); !ok || !nerr.Timeout() {
+			return fmt.Errorf("copying message failed for dovecot server '%s': %s", addr, err)
+		}
 	}
 
 	var host string