Docker修改配置log-driver参数后无法启动

概述

因环境需要对docker日志文件大小进行限制，对/etc/docker/daemon.json文件进行编辑后遇到无法启动docker问题。

配置内容

[root@localhost ~]# cat /etc/docker/daemon.json
{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  }
}

报错内容

这个含义应该是Docker启动的时候传入了命令行参数，同时也指定了配置文件，两个配置发生了冲突。那么就查看一下Docker服务启动文件。

[root@localhost ~]# systemctl status docker -l
11月 05 11:00:02 localhost.localdomain dockerd-current[9833]: unable to configure the Docker daemon with file /etc/docker/daemon.json: the following directives are specified both as a flag and in the configuration file: log-driver: (from flag: journald, from file: json-file)

排查步骤

查看Docker服务配置文件

可以看到启动的时候会从/etc/sysconfig/docker中获取环境变量。

[root@localhost ~]# cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target
Wants=docker-storage-setup.service
Requires=docker-cleanup.timer

[Service]
Type=notify
NotifyAccess=main
EnvironmentFile=-/run/containers/registries.conf
EnvironmentFile=-/etc/sysconfig/docker
EnvironmentFile=-/etc/sysconfig/docker-storage
EnvironmentFile=-/etc/sysconfig/docker-network
Environment=GOTRACEBACK=crash
Environment=DOCKER_HTTP_HOST_COMPAT=1
Environment=PATH=/usr/libexec/docker:/usr/bin:/usr/sbin
ExecStart=/usr/bin/dockerd-current \
          --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current \
          --default-runtime=docker-runc \
          --exec-opt native.cgroupdriver=systemd \
          --userland-proxy-path=/usr/libexec/docker/docker-proxy-current \
          --init-path=/usr/libexec/docker/docker-init-current \
          --seccomp-profile=/etc/docker/seccomp.json \
          $OPTIONS \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $ADD_REGISTRY \
          $BLOCK_REGISTRY \
          $INSECURE_REGISTRY \
      $REGISTRIES
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=1048576
LimitNPROC=1048576
LimitCORE=infinity
TimeoutStartSec=0
Restart=on-abnormal
KillMode=process

[Install]
WantedBy=multi-user.target

可以看到参数中默认了--log-driver=journald，把这一段删掉就可以了。

[root@localhost ~]# cat /etc/sysconfig/docker
# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; then
    DOCKER_CERT_PATH=/etc/docker
fi

# Do not add registries in this file anymore. Use /etc/containers/registries.conf
# instead. For more information reference the registries.conf(5) man page.

# Location used for temporary files, such as those created by
# docker load and build operations. Default is /var/lib/docker/tmp
# Can be overriden by setting the following environment variable.
# DOCKER_TMPDIR=/var/tmp

# Controls the /etc/cron.daily/docker-logrotate cron job status.
# To disable, uncomment the line below.
# LOGROTATE=false

# docker-latest daemon can be used by starting the docker-latest unitfile.
# To use docker-latest client, uncomment below lines
#DOCKERBINARY=/usr/bin/docker-latest
#DOCKERDBINARY=/usr/bin/dockerd-latest
#DOCKER_CONTAINERD_BINARY=/usr/bin/docker-containerd-latest
#DOCKER_CONTAINERD_SHIM_BINARY=/usr/bin/docker-containerd-shim-latest
[root@localhost ~]# sed -i 's/\(^OPTIONS.*\)--log-driver=journald \(.*\)/\1\2/g' /etc/sysconfig/docker
[root@localhost ~]# systemctl restart docker

重启后服务正常无报错。

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