本文的運行環境爲Centos 7.3,Docker與Kubernetes的安裝方式見kubeadm安裝kubernetes V1.11.1 集羣
最近在整理Docker和Kubernetes中的日誌與相關配置,在嘗試通過/etc/docker/daemon.json
配置Docker的log-driver
參數,遇到了Docker無法啓動的錯誤。
配置信息如下
{ "log-driver": "json-file", "log-opts": { "max-size": "1m", "max-file": "5" } }
錯誤提示如下
[root@devops-101 ~]# journalctl -amu docker -- Logs begin at Thu 2018-08-30 08:28:53 CST, end at Thu 2018-08-30 08:47:53 CST. -- Aug 30 08:29:07 devops-101 systemd[1]: Starting Docker Application Container Engine... Aug 30 08:29:08 devops-101 dockerd-current[1102]: 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-dri Aug 30 08:29:08 devops-101 systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE Aug 30 08:29:08 devops-101 systemd[1]: Failed to start Docker Application Container Engine.
這個含義應該是Docker啓動的時候傳入了命令行參數,同時也指定了配置文件,兩個配置發生了衝突。那麼就查看一下Docker服務啓動文件。
[root@devops-101 ~]# vim /usr/lib/systemd/system/docker.service [Service] Type=notify NotifyAccess=all 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 \ $REGISTRIES
可以看到啓動的時候會從/etc/sysconfig/docker
中獲取環境變量。
繼續查看這個配置文件。
[root@devops-101 ~]# vim /etc/sysconfig/docker # /etc/sysconfig/docker # Modify these options if you want to change the way the docker daemon runs OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false' if [ -z "${DOCKER_CERT_PATH}" ]; then DOCKER_CERT_PATH=/etc/docker fi
可以看到參數中默認了--log-driver=journald
,把這一段刪掉就可以了。重啓之後,就可以在/var/log/containers
下看到容器產生的日誌文件了。
[root@devops-101 containers]# pwd /var/log/containers [root@devops-101 containers]# ls coredns-78fcdf6894-52gp9_kube-system_coredns-6eea955dfaad8027b9382a9911817057c917e3187dee41502dcd687d8de18729.log coredns-78fcdf6894-mkvqn_kube-system_coredns-16ed56195ca55c613dec218cfd57c647f8bbe0341b38c446210db98d6ab78f3c.log etcd-devops-101_kube-system_etcd-42717aa4eda15817f05f35b68f84306ab83fd3f397426c2c9b47d71ebf61942b.log kube-apiserver-devops-101_kube-system_kube-apiserver-0df17d68a3b1742e9e34620b759b4617f1949bbe2d826b03216419b6994db42c.log kube-controller-manager-devops-101_kube-system_kube-controller-manager-ee1743e4a4c0114da1cfb32bd78f4f7a576bfc021aacd943e92d2e09cb41116d.log kube-flannel-ds-7sgps_kube-system_install-cni-92ce6121a1a5456752f502c07ae324676e0d1297261dad266b385a5e6522852c.log kube-flannel-ds-7sgps_kube-system_kube-flannel-e6eb715062314f175d9fbaa52323f93eeffbb9fa16eed95797c9950884f68b73.log kube-proxy-79gws_kube-system_kube-proxy-8ce96b3b403d0f7231ca6a004bfec162a093f85ea940867264f50530846d3e0a.log kube-scheduler-devops-101_kube-system_kube-scheduler-c7ce974eedbc3119320e729310e1b905f65df84dbe46624918dfc33628d9a864.log