There are several ways to clone a repository from github. Similar from other providers, such as bitbucket, gitlab, etc.

https://git-scm.com/book/en/v2/Git-on-the-Server-The-Protocols

Mostly, we use 

- http
- ssh

### Sample clone commands: 
The clone command with protocol `https`

```
git clone https://github.com/kubernetes/kubernetes.git
```

 The clone command with protocol `ssh+git`

```
git clone git@github.com:kubernetes/kubernetes.git
```

### Work with ssh config 
So I have to set ssh config (`~/ssh/config`) with `ProxyCommand` properly, git clone start working with proxy. 

Install `corkscrew` or other proxy tool first. 

#### no need set username and proxy for your proxy

set ssh config
```
Host github.com
    Hostname github.com
    ServerAliveInterval 55
    ForwardAgent yes
    ProxyCommand /usr/bin/corkscrew <replace_with_your_company_proxy_server> <3128> %h %p
```
#### need username and password for your proxy

```
cat ~/.ssh/myauth
proxyUsername:proxyPassword
```
set ssh config
```
Host github.com
    Hostname github.com
    ServerAliveInterval 55
    ForwardAgent yes
    ProxyCommand /usr/bin/corkscrew <replace_with_your_company_proxy_server> <3128> %h %p ~/.ssh/myauth
```

### Work with http/https 

update ~/.gitconfig

```
[http]
[http "https://github.com"]
	proxy = http://proxyUsername:proxyPassword@proxy.server.com:port
	sslVerify = false
```

`sslVerify` setting is not necessary. 

### Notes: 
**If you only need access github by the way of `ssh+git`, you needn't set any proxy in `~/.gitconfig` and run `git config --global http.proxy ...` and similar commands at all**