我有点困惑的是 Docker 容器内部lsof -i没有产生任何输出。
示例（来自容器内部的所有命令/输出）：
[1] root@ec016481cf5f:/# lsof -i
[1] root@ec016481cf5f:/# netstat -tulpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp6 0 0 :::22 :::* LISTEN -
另请注意 是如何不显示 PID 或程序名称的netstat。fuser也给出了一些令人困惑的输出，并且也无法精确定位 PID。
任何人都可以阐明这一点吗？
- 我怎样才能替代
lsof -i（以查看进程名称还有！） - 为什么输出
netstat也残破了？
注意：容器运行时使用"ExecDriver": "native-0.1"，即 Docker 自己的执行层，而不是 LXC。
[1] root@ec016481cf5f:/# fuser -a4n tcp 22
Cannot stat file /proc/1/fd/0: Permission denied
Cannot stat file /proc/1/fd/1: Permission denied
Cannot stat file /proc/1/fd/2: Permission denied
Cannot stat file /proc/1/fd/3: Permission denied
Cannot stat file /proc/1/fd/255: Permission denied
Cannot stat file /proc/6377/fd/0: Permission denied
Cannot stat file /proc/6377/fd/1: Permission denied
Cannot stat file /proc/6377/fd/2: Permission denied
Cannot stat file /proc/6377/fd/3: Permission denied
Cannot stat file /proc/6377/fd/4: Permission denied
22/tcp:
（我并不痴迷于Permission denied，因为那是数字。令我困惑的是 后面的空 PID 列表22/tcp。）
# lsof|awk '$1 ~ /^sshd/ && $3 ~ /root/ {print}'
sshd 6377 root cwd unknown /proc/6377/cwd (readlink: Permission denied)
sshd 6377 root rtd unknown /proc/6377/root (readlink: Permission denied)
sshd 6377 root txt unknown /proc/6377/exe (readlink: Permission denied)
sshd 6377 root 0 unknown /proc/6377/fd/0 (readlink: Permission denied)
sshd 6377 root 1 unknown /proc/6377/fd/1 (readlink: Permission denied)
sshd 6377 root 2 unknown /proc/6377/fd/2 (readlink: Permission denied)
sshd 6377 root 3 unknown /proc/6377/fd/3 (readlink: Permission denied)
sshd 6377 root 4 unknown /proc/6377/fd/4 (readlink: Permission denied)
sshd 6442 root cwd unknown /proc/6442/cwd (readlink: Permission denied)
sshd 6442 root rtd unknown /proc/6442/root (readlink: Permission denied)
sshd 6442 root txt unknown /proc/6442/exe (readlink: Permission denied)
sshd 6442 root 0 unknown /proc/6442/fd/0 (readlink: Permission denied)
sshd 6442 root 1 unknown /proc/6442/fd/1 (readlink: Permission denied)
sshd 6442 root 2 unknown /proc/6442/fd/2 (readlink: Permission denied)
sshd 6442 root 3 unknown /proc/6442/fd/3 (readlink: Permission denied)
sshd 6442 root 4 unknown /proc/6442/fd/4 (readlink: Permission denied)
sshd 6442 root 5 unknown /proc/6442/fd/5 (readlink: Permission denied)
连接的用户还有一些输出，也被正确识别，但仅此而已。显然不可能辨别某个lsof -i“对象”的类型（仅限于互联网套接字）。
答案1
（注意：问题中不清楚询问者如何进入 docker 容器。我是假设 docker exec -it CONTAINER bash被使用了。）
centos:7我在使用基于docker 版本的docker 镜像时遇到了这个问题1.9.0，为了克服这个问题，我只是运行：
docker exec --privileged -it CONTAINER bash
请注意包含--privileged.
我对需要这样做的原因的天真理解：似乎 docker 努力让容器更加“安全”，因为记录在这里。
答案2
哈哈，剧情越来越丰富了。如果有人有更好的答案，请写下来，如果可以接受，我会接受。但这是明显的原因。我是多么疏忽，忽略了日志文件主持人:
Jun 12 01:29:46 hostmachine kernel: [140235.718807] audit_printk_skb: 183 callbacks suppressed
Jun 12 01:29:46 hostmachine kernel: [140235.718810] type=1400 audit(1402536586.521:477): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="trace" denied_mask="trace" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.718860] type=1400 audit(1402536586.521:478): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.718886] type=1400 audit(1402536586.521:479): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.718899] type=1400 audit(1402536586.521:480): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.718921] type=1400 audit(1402536586.521:481): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.718954] type=1400 audit(1402536586.521:482): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.719001] type=1400 audit(1402536586.521:483): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.719043] type=1400 audit(1402536586.521:484): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.719086] type=1400 audit(1402536586.521:485): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
Jun 12 01:29:46 hostmachine kernel: [140235.719126] type=1400 audit(1402536586.521:486): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3782 comm="lsof" requested_mask="read" denied_mask="read" peer="docker-default"
因此，apparmor 似乎是罪魁祸首，尽管我必须弄清楚如何说服它允许这样做而不损害主机/容器的安全性，或者看看它是否可能在不损害安全性的情况下实现。
答案3
另一种可能性，这次有更细粒度的安全设置：向 docker 容器授予 SYS_PTRACE 权限：
docker run --cap-add=SYS_PTRACE ...
答案4
我也发现了这个问题。我禁用apparmor后问题就消失了docker：
$ sudo aa-complain <docker apparmor profile name, "docker-default" on ubuntu>