Busybox

最后修改: 2019-11-11

有的时候在集群中的Pod出现问题需要定位的时候，得要能够深入“内部”去具体看看，当然直接进入到Pod的内部也是可以的，不过更多的时候还是要验证下所在Pod是不是网络不通，是不是其他原因导致的和集群之间通讯"失联"

那么这个时候就可以运行一个Busybox的Pod，它是一个很小，但是大多数功能都比较全的系统镜像，其在Kubernetes中的yaml如下所示：

apiVersion: v1
kind: Pod 
metadata:
  name: busybox
  namespace: default
spec:
  containers:
    # 这里推荐使用这个版本，最新的版本貌似有BUG
    - name: busybox
      image: busybox:1.28.4
      imagePullPolicy: IfNotPresent
      command:
        - sleep
        - "3600"
  restartPolicy: Always

然后执行 kubectl apply -f pod.yml,如下：

[root@dot-pure ~]# kubectl get pods busybox 
NAME      READY   STATUS    RESTARTS   AGE
busybox   1/1     Running   0          37s

接下来可以验证下这个容器镜像：

[root@dot-pure ~]# kubectl exec busybox -it sh
/ # nslookup fanruan.com
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      fanruan.com
Address 1: 115.28.1xx.xxx

如果你部署了busybox，但是不清楚里面有啥命令，可以查看 帮助文档

备注：

当前有效的命令可以速查：

[, [[, acpid, addgroup, adduser, adjtimex, ar, arp, arping, ash,
        awk, basename, beep, blkid, brctl, bunzip2, bzcat, bzip2, cal, cat,
        catv, chat, chattr, chgrp, chmod, chown, chpasswd, chpst, chroot,
        chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond, crontab,
        cryptpw, cut, date, dc, dd, deallocvt, delgroup, deluser, depmod,
        devmem, df, dhcprelay, diff, dirname, dmesg, dnsd, dnsdomainname,
        dos2unix, dpkg, du, dumpkmap, dumpleases, echo, ed, egrep, eject,
        env, envdir, envuidgid, expand, expr, fakeidentd, false, fbset,
        fbsplash, fdflush, fdformat, fdisk, fgrep, find, findfs, flash_lock,
        flash_unlock, fold, free, freeramdisk, fsck, fsck.minix, fsync,
        ftpd, ftpget, ftpput, fuser, getopt, getty, grep, gunzip, gzip, hd,
        hdparm, head, hexdump, hostid, hostname, httpd, hush, hwclock, id,
        ifconfig, ifdown, ifenslave, ifplugd, ifup, inetd, init, inotifyd,
        insmod, install, ionice, ip, ipaddr, ipcalc, ipcrm, ipcs, iplink,
        iproute, iprule, iptunnel, kbd_mode, kill, killall, killall5, klogd,
        last, length, less, linux32, linux64, linuxrc, ln, loadfont,
        loadkmap, logger, login, logname, logread, losetup, lpd, lpq, lpr,
        ls, lsattr, lsmod, lzmacat, lzop, lzopcat, makemime, man, md5sum,
        mdev, mesg, microcom, mkdir, mkdosfs, mkfifo, mkfs.minix, mkfs.vfat,
        mknod, mkpasswd, mkswap, mktemp, modprobe, more, mount, mountpoint,
        mt, mv, nameif, nc, netstat, nice, nmeter, nohup, nslookup, od,
        openvt, passwd, patch, pgrep, pidof, ping, ping6, pipe_progress,
        pivot_root, pkill, popmaildir, printenv, printf, ps, pscan, pwd,
        raidautorun, rdate, rdev, readlink, readprofile, realpath,
        reformime, renice, reset, resize, rm, rmdir, rmmod, route, rpm,
        rpm2cpio, rtcwake, run-parts, runlevel, runsv, runsvdir, rx, script,
        scriptreplay, sed, sendmail, seq, setarch, setconsole, setfont,
        setkeycodes, setlogcons, setsid, setuidgid, sh, sha1sum, sha256sum,
        sha512sum, showkey, slattach, sleep, softlimit, sort, split,
        start-stop-daemon, stat, strings, stty, su, sulogin, sum, sv,
        svlogd, swapoff, swapon, switch_root, sync, sysctl, syslogd, tac,
        tail, tar, taskset, tcpsvd, tee, telnet, telnetd, test, tftp, tftpd,
        time, timeout, top, touch, tr, traceroute, true, tty, ttysize,
        udhcpc, udhcpd, udpsvd, umount, uname, uncompress, unexpand, uniq,
        unix2dos, unlzma, unlzop, unzip, uptime, usleep, uudecode, uuencode,
        vconfig, vi, vlock, volname, watch, watchdog, wc, wget, which, who,
        whoami, xargs, yes, zcat, zcip