Changes between Initial Version and Version 1 of TipAndDoc/Linux/LXC/ArchLinux

Timestamp:

Apr 23, 2016 4:38:48 PM (9 years ago)

Author:

mitty

Comment:

--

TipAndDoc/Linux/LXC/ArchLinux

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+[[PageOutline]]
+
+ * [http://unix.stackexchange.com/questions/71527/arch-linux-pacman-does-not-work-when-chrooting grub2 - Arch linux : pacman does not work when chrooting - Unix & Linux Stack Exchange]
+ > Remember to {{{arch-chroot}}} and not simply {{{chroot}}} - that way {{{/proc}}} will be populated and pacman will function as expected.
+
+ * [http://bryanalves.github.io/2015/07/02/enabling-lxc-archlinux-with-systemd-networkd/ Enabling LXC on Archlinux with systemd-networkd – Bryan's Blah Blog]
+ > I’m on a laptop with wireless, so I can’t just create a bridge and give IPs to containers from an upstream DHCP server. I needed to do NAT and essentially simulate/replicate how docker networking works.
+
+ = DHCP =
+
+ == no valid interfaces found ==
+ * Arch Linux 4.4.5-1
+ * lxc 1:1.1.5-4
+ * dhcpcd 6.10.1-1
+
+ * # dhcpcd
+{{{
+dev: loaded udev
+no valid interfaces found
+no interfaces have a carrier
+forked to background, child pid 65
+}}}
+ * # dhcpcd eth0
+{{{
+DUID 00:01:00:01:1e:8a:6a:5e:ba:4a:37:94:4a:9d
+eth0: IAID 16:b6:47:44
+eth0: rebinding lease of 192.168.0.185
+eth0: NAK: address in use from 192.168.0.1
+eth0: message: address in use
+eth0: soliciting a DHCP lease
+eth0: soliciting an IPv6 router
+eth0: offered 192.168.0.172 from 192.168.0.1
+eth0: probing address 192.168.0.172/24
+eth0: leased 192.168.0.172 for 86400 seconds
+eth0: adding route to 192.168.0.0/24
+eth0: adding default route via 192.168.0.1
+forked to background, child pid 123
+}}}
+
+ * LXCコンテナ内で、udevdが起動しないことが原因の模様
+ * strace -f dhcpcd
+  * コンテナホスト(検証はKVMゲストで行った)
+{{{
+access("/run/udev/control", F_OK) = 0
+
+open("/sys/devices/virtual/net/lo/uevent", O_RDONLY|O_CLOEXEC) = 9
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+read(9, "INTERFACE=lo\nIFINDEX=1\n", 4096) = 23
+read(9, "", 4096)                 = 0
+read(9, "", 4096)                 = 0
+close(9)                          = 0
+open("/run/udev/data/n1", O_RDONLY|O_CLOEXEC) = 9
+
+open("/sys/devices/pci0000:00/0000:00:03.0/virtio0/net/ens3/uevent", O_RDONLY|O_CLOEXEC) = 9
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+read(9, "INTERFACE=ens3\nIFINDEX=2\n", 4096) = 25
+read(9, "", 4096)                 = 0
+read(9, "", 4096)                 = 0
+close(9)                          = 0
+open("/run/udev/data/n2", O_RDONLY|O_CLOEXEC) = 9
+}}}
+  * LXCコンテナ
+{{{
+access("/run/udev/control", F_OK) = -1 ENOENT (No such file or directory)
+
+open("/sys/devices/virtual/net/lo/uevent", O_RDONLY|O_CLOEXEC) = 9
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+read(9, "INTERFACE=lo\nIFINDEX=1\n", 4096) = 23
+read(9, "", 4096)                 = 0
+read(9, "", 4096)                 = 0
+close(9)                          = 0
+open("/run/udev/data/n1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
+
+open("/sys/devices/virtual/net/eth0/uevent", O_RDONLY|O_CLOEXEC) = 9
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+fstat(9, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
+read(9, "INTERFACE=eth0\nIFINDEX=6\n", 4096) = 25
+read(9, "", 4096)                 = 0
+read(9, "", 4096)                 = 0
+close(9)                          = 0
+open("/run/udev/data/n6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
+write(2, "no valid interfaces found", 25) = 25
+write(2, "\n", 1)                 = 1
+
+write(1, "no interfaces have a carrier\n", 29) = 29
+}}}
+   * [root@test /]# systemctl status systemd-udevd
+{{{
+● systemd-udevd.service - udev Kernel Device Manager
+   Loaded: loaded (/usr/lib/systemd/system/systemd-udevd.service; static; vendor preset: disabled)
+   Active: inactive (dead)
+Condition: start condition failed at Sat 2016-04-02 08:30:59 UTC; 5h 9min ago
+           ConditionPathIsReadWrite=/sys was not met
+     Docs: man:systemd-udevd.service(8)
+           man:udev(7)
+}}}
+ * arch:Linux_Containers#Systemd_considerations_.28required.29
+  * 上記を参考にsystemdの設定を行ったが効果なし
+
+ * arch:dhcpcd#dhcpcd_and_systemd_network_interfaces
+ > {{{dhcpcd.service}}} can be [arch:Enabled] without specifying an interface. This may, however, create a race condition at boot with ''systemd-udevd'' trying to apply a predictable network interface name:
+ > {{{
+ > error changing net interface name wlan0 to wlp4s0: Device or resource busy" 
+ > }}}
+ > To avoid it, enable dhcpcd per interface it should bind to as described in [arch:dhcpcd#Running]. The downside of the template unit is, however, that it does not support hot-plugging of a wired connection and will fail if the network cable is not connected. To work-around the failure, see [arch:dhcpcd#Timeout_delay].
+ とのことなので、いずれにせよ{{{dhcpcd.service}}}を使用しないのがよさそう
+
+ * 古い情報
+  * [http://blog.oddbit.com/2013/02/01/dhcpcd-under-lxc/ Odd Bits] {{{dhcpcd[492]: eth0: if_init: Read-only file system}}}
+
+ == Dependency failed for dhcpcd on eth0. ==
+ * # systemctl start dhcpcd@eth0
+{{{
+A dependency job for dhcpcd@eth0.service failed. See 'journalctl -xe' for details.
+}}}
+ * # journalctl -xe
+{{{
+Apr 10 20:00:56 test3 systemd[1]: Starting of sys-subsystem-net-devices-eth0.device not supported.
+-- Subject: Unit sys-subsystem-net-devices-eth0.device has failed
+-- Defined-By: systemd
+-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
+--
+-- Unit sys-subsystem-net-devices-eth0.device has failed.
+--
+-- The result is unsupported.
+Apr 10 20:00:56 test3 systemd[1]: Dependency failed for dhcpcd on eth0.
+-- Subject: Unit dhcpcd@eth0.service has failed
+-- Defined-By: systemd
+-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
+--
+-- Unit dhcpcd@eth0.service has failed.
+--
+-- The result is dependency.
+Apr 10 20:00:56 test3 systemd[1]: dhcpcd@eth0.service: Job dhcpcd@eth0.service/start failed with result 'dependency'.
+}}}
+
+ * /usr/lib/systemd/system/dhcpcd@.service
+{{{
+[Unit]
+Description=dhcpcd on %I
+Wants=network.target
+Before=network.target
+BindsTo=sys-subsystem-net-devices-%i.device
+After=sys-subsystem-net-devices-%i.device
+
+[Service]
+Type=forking
+PIDFile=/run/dhcpcd-%I.pid
+ExecStart=/usr/bin/dhcpcd -q -w %I
+ExecStop=/usr/bin/dhcpcd -x %I
+
+[Install]
+WantedBy=multi-user.target
+}}}
+  * {{{BindsTo=}}}, {{{After=}}}の行を削除することで対応可能
+
+ * see also
+  * [https://bbs.archlinux.org/viewtopic.php?id=164753 Netctl doesn't work in LXC (Linux containers) due to udev dependency / Networking, Server, and Protection / Arch Linux Forums]
+  * [https://bugs.archlinux.org/task/35715 FS#35715 : (netctl) fails to start network inside Linux Container]