k8s - WEB终端（gotty）
搭建K8S私有云之后，我们需要在私有云上提供一种能力，让研发可以直接登录容器，参看容器或者应用程序当前的状态。研发人员不可直接登录宿主主机，登录宿主主机属于危险操作。
WEB终端的话，推荐使用gotty: github 地址： https://github.com/yudai/gotty
一、环境说明：
centos7
K8S: 1.8
gotty:1.0.1
二、gotty参数说明 ：
--address value, -a value IP address to listen (default: "0.0.0.0") [$GOTTY_ADDRESS]
--port value, -p value Port number to liten (default: "8080") [$GOTTY_PORT]
--permit-write, -w Permit clients to write to the TTY (BE CAREFUL) [$GOTTY_PERMIT_WRITE]
--credential value, -c value Credential for Basic Authentication (ex: user:pass, default disabled) [$GOTTY_CREDENTIAL]
--random-url, -r Add a random string to the URL [$GOTTY_RANDOM_URL]
--random-url-length value Random URL length (default: 8) [$GOTTY_RANDOM_URL_LENGTH]
--tls, -t Enable TLS/SSL [$GOTTY_TLS]
--tls-crt value TLS/SSL certificate file path (default: "~/.gotty.crt") [$GOTTY_TLS_CRT]
--tls-key value TLS/SSL key file path (default: "~/.gotty.key") [$GOTTY_TLS_KEY]
--tls-ca-crt value TLS/SSL CA certificate file for client certifications (default: "~/.gotty.ca.crt") [$GOTTY_TLS_CA_CRT]
--index value Custom index.html file [$GOTTY_INDEX]
--title-format value Title format of browser window (default: "{{ .command }}@{{ .hostname }}") [$GOTTY_TITLE_FORMAT]
--reconnect Enable reconnection [$GOTTY_RECONNECT]
--reconnect-time value Time to reconnect (default: 10) [$GOTTY_RECONNECT_TIME]
--max-connection value Maximum connection to gotty (default: 0) [$GOTTY_MAX_CONNECTION]
--once Accept only one client and exit on disconnection [$GOTTY_ONCE]
--timeout value Timeout seconds for waiting a client(0 to disable) (default: 0) [$GOTTY_TIMEOUT]
--permit-arguments Permit clients to send command line arguments in URL (e.g. http://example.com:8080/?arg=AAA&arg=BBB) [$GOTTY_PERMIT_ARGUMENTS]
--width value Static width of the screen, 0(default) means dynamically resize (default: 0) [$GOTTY_WIDTH]
--height value Static height of the screen, 0(default) means dynamically resize (default: 0) [$GOTTY_HEIGHT]
--ws-origin value A regular expression that matches origin URLs to be accepted by WebSocket. No cross origin requests are acceptable by default [$GOTTY_WS_ORIGIN]
--term value Terminal name to use on the browser, one of xterm or hterm. (default: "xterm") [$GOTTY_TERM]
--close-signal value Signal sent to the command process when gotty close it (default: SIGHUP) (default: 1) [$GOTTY_CLOSE_SIGNAL]
--close-timeout value Time in seconds to force kill process after client is disconnected (default: -1) (default: -1) [$GOTTY_CLOSE_TIMEOUT]
--config value Config file path (default: "~/.gotty") [$GOTTY_CONFIG]
--version, -v print the version三、启动gotty ：
./gotty -w --permit-arguments docker exec -ti 或者 ./gotty -w -p 8081 --permit-arguments kubectl exec -ti &浏览器直接传入容器的ID和进入容器需要执行的命令（/bin/bash）
http://172.172.241.180:8080/?arg=6f&arg=%2fbin%2fbash
其他：使用浏览器频繁进入容器之后，容器内部会产生大量/bin/bash进程，这个需要注意一下，一般是不推荐直接进入容器的。