ulimit -n is too low in arm docker

[HarrisChu]

docker run -it --rm centos:7 /bin/bash -c 'ulimit -n'

# arm
1024

# x86
1048576

we should change the ulimit conf in docker file

[Shinji-IkariG]

I just realized that this is running the official Centos Docker image, so the ulimit defaults for different platforms are not determined by Nebula. Since this problem will affect the performance of Nebula on the arm platform, I will further locate the cause of the difference and find a solution

[Shinji-IkariG]

The difference comes from the difference in the configuration of the host machine. You can define the ulimit value in the container by modifying the systemd configuration of dockerd or modifying docker/dameon.json default-ulimit (https://docs.docker.com/engine/reference/commandline/ run/#set-ulimits-in-container---ulimit)