Rocket v1.9.0 发布新增特性 & UX 改进

Rocket v1.9.0 发布了，Rocket （也叫 rkt）是 CoreOS 推出的一款容器引擎，和 Docker 类似，帮助开发者打包应用和依赖包到可移植容器中，简化搭环境等部署工作。Rocket 和 Docker 不同的地方在于，Rocket 没有 Docker 那些为企业用户提供的“友好功能”，比如云服务加速工具、集群系统等。反过来说，Rocket 想做的，是一个更纯粹的业界标准。

新增特性 & UX 改进：

rkt/run: added –set-env-file switch and priorities for environments (#2816). –set-env-file gets an environment variables file path in the format “VAR=VALUE\n…”.
run: add –cap-retain and –cap-remove (#2771).
store: print more information on rm as non-root (#2805).
Documentation/vagrant: use rkt binary for getting started (#2808).
docs: New file in documentation – instruction for new developers in rkt (#2639).
stage0/trust: change error message if prefix/root flag missing (#2661).

Bugs 修复：

rkt/uuid: fix match when uuid is an empty string (#2807).
rkt/api_service: fix fly pods (#2799).
api/client_example: fix panic if pod has no apps (#2766). Fixes the concern expressed in#2763 (comment)
api_service: wait until a pod regs with machined (#2788).

其他改进：

stage1: update coreos image to 1068.0.0 (#2821).
KVM: Update LKVM patch to mount with mmap mode (#2795).
stage1: always write /etc/machine-id (#2440). Prepare rkt for systemd-v230 in stage1.
stage1/prepare-app: always adjust /etc/hostname (#2761).