从2015年3月份将Docker升级到v1.10.3，已经在生产环境中使用了近一年的时间。从整体上看，该版本还是比较稳定的，虽然没有出现过重大问题，但是，也发现了一些小的不足。随着Docker的快速发展，被其一些新的特性所吸引，所有决定将Docker进行一次大的升级，直接升级到最新版的v1.13.0。
Issues or shortages in Docker v1.10.3
- Very slow when push or pull multiple images at the same time
- Containers will stop when daemon shuts down
Motivation to update Docker from v1.10.3 to v1.13.0
- Keep containers running when daemon shuts down
- Support for live reloading daemon configuration through systemd
- Configurable
maxUploadConcurrencyandmaxDownloadConcurrencyto speed up image pushing and pulling speed - Key features in each Docker release
- Performance is greatly improved (Performance comparation between Docker v1.13.0 and v1.10.3)
Steps to update Docker
- Get docker-engine-1.13.0-1.el7.centos.x86_64.rpm and docker-engine-selinux-1.13.0-1.el7.centos.noarch.rpm from Docker Stable Repository.
- Download aliyun yum repo and place it in folder /etc/yum.repo.d/
- Create Docker Daemon config file: /etc/docker/daemon.json
{ "disable-legacy-registry": true, "max-concurrent-downloads": 10, "max-concurrent-uploads": 20, "log-level": "warn", "log-opts": { "max-size": "2m", "max-file": "5" }, "storage-driver": "devicemapper", "storage-opts": [ "dm.fs=xfs", "dm.thinpooldev=/dev/mapper/docker--vg-docker--pool", "dm.use_deferred_removal=true", "dm.use_deferred_deletion=true" ], "insecure-registries": ["https://registry.robin.com"], "live-restore": true } - Run update script
#!/bin/bash
set -ex
# Stop docker & kubelet
systemctl stop docker
systemctl stop kubelet
# Wait docker & kubelet to stop
sleep 20
# Use aliyun yum repo for dependencies
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
mv CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo
yum makecache
# Uninstall the old Docker
rpm -e --nodeps docker-1.10.3-10.el7.centos.x86_64 docker-selinux-1.10.3-10.el7.centos.x86_64
# Install the new Docker
yum install -y docker-engine-selinux-1.13.0-1.el7.centos.noarch.rpm docker-engine-1.13.0-1.el7.centos.x86_64.rpm
# Create the Daemon config file
cp daemon.json /etc/docker/
# Start docker
systemctl daemon-reload
systemctl start docker
Troubleshootings
- Lack of dependencies
Use aliyun yum repo.
$ mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
$ wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
$ yum makecache
- Kubernetes-1.12 and kubernetes-node-1.12 are uninstalled while uninstalling old Docker 1.10.3
Kubernetes 1.12 on CentOS 7.1 depends docker.x86_64. Kubernetes-1.12 and kubernetes-node-1.12 are uninstalled when uninstall docker 1.10.3 by the command yum erase -y docker docker-selinux. At the same time, the uninstalled kubernetes-1.12 and kubernetes-node-1.12 can not be reinstalled after docker-engine-1.13.0-1.el7.centos.x86_64.rpm is installed, as they depend on docker.x86_64, not docker-engine.x86_64.
Use command rpm -e --nodeps docker-1.10.3-10.el7.centos.x86_64 to uninstall Docker instead of yum erase -y docker.
- Can not reload daemon configuration through systemd
Use daemon.json instead of config files such as docker, docker-storage and docker-network under /etc/sysconfig/ for Docker daemon options. daemon.json is the recommended configuration in Docker 1.13.
- The default storage driver is changed from Device mapper to OverlayFS
Overlay requires the kernel 3.18+, and has known limitations with inode exhaustion and commit performance. The overlay2 driver addresses this limitation, but requires the kernel 4.0+.
- No effect on Docker daemon after change /usr/lib/systemd/system/docker.service
Run systemctl daemon-reload to flush changes before start Docker.
