一、软件版本:
要想稳定地、顺畅地使用Rancher部署K8S,软件版本需求为:
Ubuntu 16.04.3 LTS(内核4.4.0以上)
Docker 1.12.3
K8S v1.6.6
Rancher v1.6.5
二、问题1:为什么不用最新版的Docker?
自从2017年3月以后,Docker每个月都会推出一个Edge版本,比如17.04.x,17.05.x等,三个月会推出一个稳定版本,比如17.03.x,17.06.x,17.09.x等。软件研发都是需要投入人员和时间的,Rancher和K8S这样的大项目来说,不可能每一个Docker小版本都支持,支持稳定的版本是一个不错的选择。
三、问题2:为什么只能用docker 1.12.3? 1.12.6也不行吗?
目前Rancher是支持稳定的Docker版本的,比如Docker 1.12.3、1.13.x、17.03.x-ce、17.06.x-ce等。但要想使用Rancher部署K8S,就需要考虑到K8S的软件依赖情况。Rancher官方网站文档显示,目前K8S v1.6.6版暂时只能使用Docker 1.12.3版本。K8S在github上的官方变更日志显示:“Docker 1.12.6已经验证的,但并不全部支持overlay2 driver驱动”,因此只有使用Docker 1.12.3版本。
K8S在github上的官方变更日志相关信息:
Node Components
Drop the support for docker 1.9.x. Docker versions 1.10.3, 1.11.2, 1.12.6 have been validated.
External Dependency Version Information
Continuous integration builds have used the following versions of external dependencies, however, this is not a strong recommendation and users should consult an appropriate installation or upgrade guide before deciding what versions of etcd, docker or rkt to use.
Docker versions 1.10.3, 1.11.2, 1.12.6 have been validated
Docker versions 1.10.3, 1.11.2, 1.12.6 have been validated
Docker versions 1.10.3, 1.11.2, 1.12.6 have been validated
Docker version 1.12.6 known issues
overlay2 driver not fully supported
overlay2 driver not fully supported
overlay2 driver not fully supported
live-restore not fully supported
no shared pid namespace support
Docker version 1.11.2 known issues
Kernel crash with Aufs storage driver on Debian Jessie (#27885) which can be identified by the node problem detector
Leaked File descriptors (#275)
Additional memory overhead per container (#21737)
Docker 1.10.3 contains backports provided by RedHat for known issues
Support for Docker version 1.9.x has been removed
rkt version 1.23.0+
known issues with the rkt runtime are listed in the Getting Started Guide
etcd version 3.0.17
参考链接:
Rancher 支持的Docker版本
http://rancher.com/docs/rancher/v1.6/en/hosts/#supported-docker-versions
Kubernetes版本更新日志
https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md#external-dependency-version-information
Rancher 在线培训视频回放-K8s离线加速部署
http://mp.weixin.qq.com/s?__biz=MzIyMTUwMDMyOQ==&mid=2247486407&idx=1&sn=6c61cc32290c57e1cad9482d97eca3e7&chksm=e83a8d01df4d0417935d069138e2ce5ca8b1dbbd97c50fa057407e68be4a82ec26ff80f4b98b&mpshare=1&scene=23&srcid=0826jqcI818KHAjZtPAx5vwN#rd