Patch wireguard-go for low memory pods

Patch wireguard-go to workaround ongoing issue related to pods
with low memory limits OOMing due to wireguard-go buffer/gc issues.

Related to WireGuard/wireguard-go#69

Author: logan2211

Dockerfile

@@ -12,9 +12,12 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/* /var/log/* && \
     mkdir ${PREFIX}
 
+ADD wg-buffers.patch /
+
 RUN git clone https://git.zx2c4.com/wireguard-go && \
     cd wireguard-go && \
     git checkout $wg_go_tag && \
+    git apply /wg-buffers.patch && \
     make && \
     make install
 

wg-buffers.patch

@@ -0,0 +1,11 @@
+diff --git a/device/queueconstants_default.go b/device/queueconstants_default.go
+index b061185..d15780c 100644
+--- a/device/queueconstants_default.go
++++ b/device/queueconstants_default.go
+@@ -15,5 +15,5 @@ const (
+ 	QueueInboundSize           = 1024
+ 	QueueHandshakeSize         = 1024
+ 	MaxSegmentSize             = (1 << 16) - 1 // largest possible UDP datagram
+-	PreallocatedBuffersPerPool = 0             // Disable and allow for infinite memory growth
++	PreallocatedBuffersPerPool = 4096
+ )