vpnkit process is using huge amount of RAM

[busesorin94]

After upgrading to Docker 18.03.0-ce, vpnkit process is eating all of the available RAM memory. After a time, docker eventually crashed and 20gb of RAM were freed.

Steps to reproduce the issue:

1. Have docker running for more than 12 hours with a stack having 7 services

Describe the results you received:
20GB of RAM memory used by vpnkit process.

Additional information you deem important (e.g. issue happens only occasionally):

Output of docker version:

Client:
 Version:       18.03.0-ce
 API version:   1.37
 Go version:    go1.9.4
 Git commit:    0520e24
 Built: Wed Mar 21 23:06:28 2018
 OS/Arch:       windows/amd64
 Experimental:  false
 Orchestrator:  swarm

Server:
 Engine:
  Version:      18.03.0-ce
  API version:  1.37 (minimum version 1.12)
  Go version:   go1.9.4
  Git commit:   0520e24
  Built:        Wed Mar 21 23:14:32 2018
  OS/Arch:      linux/amd64
  Experimental: true

Output of docker info:

Containers: 6
 Running: 6
 Paused: 0
 Stopped: 0
Images: 16
Server Version: 18.03.0-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: active
 NodeID: hdy2opx8cdnws1ebjepp3n4u7
 Is Manager: true
 ClusterID: zv7es0rl1fj0wnqwsgzxuzfkz
 Managers: 1
 Nodes: 1
 Orchestration:
  Task History Retention Limit: 5
 Raft:
  Snapshot Interval: 10000
  Number of Old Snapshots to Retain: 0
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
  Force Rotate: 0
 Autolock Managers: false
 Root Rotation In Progress: false
 Node Address: 192.168.65.3
 Manager Addresses:
  192.168.65.3:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: cfd04396dc68220d1cecbe686a6cc3aa5ce3667c
runc version: 4fc53a81fb7c994640722ac585fa9ca548971871
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.9.87-linuxkit-aufs
Operating System: Docker for Windows
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 1.934GiB
Name: linuxkit-00155d824325
ID: 76CE:XROS:4BJH:AIBV:MWWS:Z63Q:I6PB:2D5M:3SXE:U35B:VLMV:O7SQ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 35
 Goroutines: 188
 System Time: 2018-03-28T06:31:10.0568562Z
 EventsListeners: 1
Registry: https://index.docker.io/v1/
Labels:
Experimental: true
Insecure Registries:
 172.24.142.121:5003
 127.0.0.0/8
Live Restore Enabled: false

Additional environment details (AWS, VirtualBox, physical, etc.):
Docker diagnostic: B2827FA8-932B-4EA0-9468-DD999596955F/2018-03-28_09-25-27

[AkihiroSuda]

dupe: moby/vpnkit#371