启用的 systemd 单元不会在启动时启动

Question

systemd-unit我的系统上有一个已启用。问题是，重新启动后它不会重新启动。它依赖于其他两个按预期启动的服务。

该服务是已知的、启用的和死的：

[centos@ansible-kube-4 ~]$ sudo systemctl status flanneld
flanneld.service - Flanneld overlay address etcd agent
   Loaded: loaded (/usr/lib/systemd/system/flanneld.service; enabled)
   Active: inactive (dead)

单元文件：

[centos@ansible-kube-4 ~]$ cat /usr/lib/systemd/system/flanneld.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=etcd.service

[Service]
Type=notify
Restart=always
RestartSec=3

EnvironmentFile=/etc/sysconfig/flanneld
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/flanneld -etcd-endpoints=${FLANNEL_ETCD} -etcd-prefix=${FLANNEL_ETCD_KEY} $FLANNEL_OPTIONS
ExecStartPost=/usr/libexec/flannel/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker

[Install]
WantedBy=multi-user.target

更新 1

dmesg 的输出：

$ dmesg | grep systemd
[    1.312165] systemd[1]: systemd 208 running in system mode. (+PAM +LIBWRAP +AUDIT +SELINUX +IMA +SYSVINIT +LIBCRYPTSETUP +GCRYPT +ACL +XZ)
[    1.317238] systemd[1]: Detected virtualization 'kvm'.
[    1.319597] systemd[1]: Running in initial RAM disk.
[    1.323489] systemd[1]: No hostname configured.
[    1.324874] systemd[1]: Set hostname to <localhost>.
[    1.327570] systemd[1]: Initializing machine ID from KVM UUID.
[    1.389047] systemd[1]: Expecting device dev-disk-by\x2duuid-a78bb152\x2de525\x2d4f0e\x2d961a\x2dbf6147ac7d3e.device...
[    1.394577] systemd[1]: Starting -.slice.
[    1.396820] systemd[1]: Created slice -.slice.
[    1.397990] systemd[1]: Starting System Slice.
[    1.400212] systemd[1]: Created slice System Slice.
[    1.401503] systemd[1]: Starting Slices.
[    1.403556] systemd[1]: Reached target Slices.
[    1.404756] systemd[1]: Starting Timers.
[    1.406834] systemd[1]: Reached target Timers.
[    1.408042] systemd[1]: Starting Dispatch Password Requests to Console Directory Watch.
[    1.410065] systemd[1]: Started Dispatch Password Requests to Console Directory Watch.
[    1.413402] systemd[1]: Starting Paths.
[    1.415399] systemd[1]: Reached target Paths.
[    1.416574] systemd[1]: Starting Journal Socket.
[    1.418894] systemd[1]: Listening on Journal Socket.
[    1.420242] systemd[1]: Started dracut ask for additional cmdline parameters.
[    1.422150] systemd[1]: Starting dracut cmdline hook...
[    1.424870] systemd[1]: Started Load Kernel Modules.
[    1.426124] systemd[1]: Starting Journal Service...
[    1.429731] systemd[1]: Started Journal Service.
[    1.692884] systemd-udevd[213]: starting version 208
[    2.621300] systemd-journald[90]: Received SIGTERM
[    2.968711] systemd[1]: Successfully loaded SELinux policy in 274.569ms.
[    3.023076] systemd[1]: Relabelled /dev and /run in 20.031ms.
[    3.365195] systemd-udevd[382]: starting version 208
[    3.482910] systemd-journald[377]: Received request to flush runtime journal from PID 1

更新 2

的输出chkconfig：

sudo chkconfig

Note: This output shows SysV services only and does not include native
      systemd services. SysV configuration data might be overridden by native
      systemd configuration.

      If you want to list systemd services use 'systemctl list-unit-files'.
      To see services enabled on particular target use
      'systemctl list-dependencies [target]'.

netconsole      0:off   1:off   2:off   3:off   4:off   5:off   6:off
network         0:off   1:off   2:on    3:on    4:on    5:on    6:off

的输出systemctl list-dependencies flanneld：

flanneld.service
??system.slice
??basic.target
  ??microcode.service
  ??rhel-autorelabel-mark.service
  ??rhel-autorelabel.service
  ??rhel-configure.service
  ??rhel-dmesg.service
  ??rhel-loadmodules.service
  ??paths.target
  ??slices.target
  ? ??-.slice
  ? ??system.slice
  ??sockets.target
  ? ??dbus.socket
  ? ??rpcbind.socket
  ? ??systemd-initctl.socket
  ? ??systemd-journald.socket
  ? ??systemd-shutdownd.socket
  ? ??systemd-udevd-control.socket
  ? ??systemd-udevd-kernel.socket
  ??sysinit.target
  ? ??dev-hugepages.mount
  ? ??dev-mqueue.mount
  ? ??kmod-static-nodes.service
  ? ??proc-sys-fs-binfmt_misc.automount
  ? ??sys-fs-fuse-connections.mount
  ? ??sys-kernel-config.mount
  ? ??sys-kernel-debug.mount
  ? ??systemd-ask-password-console.path
  ? ??systemd-binfmt.service
  ? ??systemd-journal-flush.service
  ? ??systemd-journald.service
  ? ??systemd-modules-load.service
  ? ??systemd-random-seed.service
  ? ??systemd-sysctl.service
  ? ??systemd-tmpfiles-setup-dev.service
  ? ??systemd-tmpfiles-setup.service
  ? ??systemd-udev-trigger.service
  ? ??systemd-udevd.service
  ? ??systemd-update-utmp.service
  ? ??systemd-vconsole-setup.service
  ? ??cryptsetup.target
  ? ??local-fs.target
  ? ? ??-.mount
  ? ? ??rhel-import-state.service
  ? ? ??rhel-readonly.service
  ? ? ??systemd-fsck-root.service
  ? ? ??systemd-remount-fs.service
  ? ??swap.target
  ??timers.target
    ??systemd-tmpfiles-clean.timer

Answer 1

单元文件被修改：

前：

[Install]
RequiredBy=docker.service

后：

[Install]
WantedBy=multi-user.target

在那次修改之后，我没有重新启用该单元。原来这是 systemd 重新配置所需要的：

$ sudo systemctl reenable flanneld
rm '/etc/systemd/system/docker.service.requires/flanneld.service'
ln -s '/usr/lib/systemd/system/flanneld.service' '/etc/systemd/system/multi-user.target.wants/flanneld.service'

Answer 2

我在您的配置中没有发现该服务应该在启动时启动的证据。systemd允许通过两种方式启用服务，使其在启动时启动：

chkconfig flanneld on

或者：

systemctl enable flanneld

实际上，第一个是调用第二个的遗留方式，我不确定chkconfig默认情况下是否安装了该软件包，但您可以使用apt-get或安装它yum。