如果有人已经将hg server的image做好了，那么我还要自己作吗？答案是拿来用吧。
一、安装
用hg为关键词搜索，得出以下结果：
$ docker search hgNAMEDESCRIPTIONSTARSOFFICIAL AUTOMATEDhgomez/gatling1[OK]v7soft/hgdns0[OK]hg8496/gridvis-service0[OK]hgomez/di-centos6-myjenkins-lts0[OK]jrandall/hgi-project0[OK]hgomez/di-centos6-myartifactory0[OK]hgomez/di-centos6-myjenkins0[OK]hgomez/di-centos6-mynexus0[OK]hgomez/di-centos6-myarchiva0[OK]hg8496/piwigo0[OK]hg8496/apache0[OK]hgomez/di-centos6-mygitblit0[OK]hgomez/di-centos6-mygitbucket0[OK]jyotisingh/ubuntu-hg0hg8496/dokuwiki0[OK]hg8496/owncloud0[OK]misshie/ucsc-blat-hg190[OK]ussie/hg-execadds mercurial to ubuntu:14.04.0misshie/ucsc-blat-hg380[OK]hg8496/gridvis-pc0[OK]Test. Automated builds for this repo are b… 0[OK]hg8496/rsync0[OK]secondbit/hgbundler0uotbw/hgamer3dDocker image for hgamer3d, see 0hgomez/di-centos6-base0[OK]hgweb貌似不错的选择，在github上的主页是https://github.com/amclain/docker-hgweb 。
将其pull下来，在漫长的等待中我也在思考着如何启动它。
主页上提供了它的Dockerfile，通过它我们就可以了解这个image是如果构造的。先来说说什么是Dockerfile。
二、Dockerfile
它是用户创建自定义镜像的文件。它通常分为四部分：基础镜像信息，维护者信息，镜像操作指令和容器启动时的指令。
#基础系统信息，基于ubuntu 14.04构建的FROM ubuntu:14.04MAINTAINER Alex McLain <alex@alexmclain.com>RUN apt-get -qq update#安装apache、hg、php5RUN apt-get -y install apache2 apache2-utils curl mercurial php5 php5-cli php5-mcrypt# TODO: Remove#是的，vim确实很大，不安装为好RUN apt-get -y install vimRUN echo "colorscheme delek" > ~/.vimrc# Configure hgwebADD hg/add.php /etc/default/hgweb/hg/ADD hg/hgweb.config /etc/default/hgweb/hg/ADD hg/hgweb.cgi /etc/default/hgweb/hg/ADD hg/hgusers /etc/default/hgweb/hg/# Configure ApacheADD apache/hg.conf /etc/default/hgweb/apache/RUN rm /etc/apache2/sites-enabled/*RUN a2enmod rewrite && a2enmod cgiADD load-default-scripts /bin/RUN chmod u+x /bin/load-default-scripts#创建一个挂载点，本机或其他容器可以将其挂载。启动时用-v参数进行挂载VOLUME /var/hgVOLUME /etc/apache2/sites-available#暴露的端口号，启动时要通过-p参数指定EXPOSE 80#启动时执行的命令CMD load-default-scripts && service apache2 start && /bin/bash三、启动
有了上述的背景，我们知道启动时要做两件事：指定端口号、挂载本地目录。
比如还是使用端口号80，那么只需用 -p 80:80即可。
比如本机目录hg-repos用来做hg repo的放置目录，只需 -v /home/linc/hg-repos:/var/hg/repos 挂载即可。
另外，，我们还要将其启动在后台（Daemonized），加上-d参数。
完整启动命令如下：
docker run -idt -p 80:80 -v /home/linc/hg-repos:/var/hg/repos amclain/hgweb四、与后台容器交互
1.attach方法
docker 自带attach命令，但此命令的不方便之处在于，多个窗口（同时attach此容器）会同步显示操作，并且当一个窗口exit时，所有窗口都会退出，后台运行的容器也停止了。
$ docker psCONTAINER IDIMAGECOMMANDCREATEDSTATUSPORTSNAMESb22cc1880b7aamclain/hgweb:latest"/bin/sh -c ‘load-de 3 hours agoUp 3 hours0.0.0.0:80->80/tcphigh_almeida $ docker attach b22cc1880b7aroot@b22cc1880b7a:/# 2.nsenter
此工具需要从源码安装：
$ cd /tmp; curl https://www.kernel.org/pub/linux/utils/util-linux/v2.24/util-linux-2.24.tar.gz | tar -zxf-; cd util-linux-2.24;$ ./configure –without-ncurses$ make nsenter && sudo cp nsenter /usr/local/bin直接用nsenter命令交互很繁琐，然后有人写了配置文件放到bashrc中，就可以方便的使用了。#dockerexport DOCKER_HOST=tcp://localhost:4243alias docker-pid="sudo docker inspect –format ‘{{.State.Pid}}’"alias docker-ip="sudo docker inspect –format ‘{{ .NetworkSettings.IPAddress }}’"#the implementation refs from https://github.com/jpetazzo/nsenter/blob/master/docker-enterfunction docker-enter() {if [ -e $(dirname "$0")/nsenter ]; then# with boot2docker, nsenter is not in the PATH but it is in the same folderNSENTER=$(dirname "$0")/nsenterelseNSENTER=nsenterfi[ -z "$NSENTER" ] && echo "WARN Cannot find nsenter" && returnif [ -z "$1" ]; thenecho "Usage: `basename "$0"` CONTAINER [COMMAND [ARG]…]"echo ""echo "Enters the Docker CONTAINER and executes the specified COMMAND."echo "If COMMAND is not specified, runs an interactive shell in CONTAINER."elsePID=$(sudo docker inspect –format "{{.State.Pid}}" "$1")if [ -z "$PID" ]; thenecho "WARN Cannot find the given container"returnfishiftOPTS="–target $PID –mount –uts –ipc –net –pid"if [ -z "$1" ]; then# No command given.# Use su to clear all host environment variables except for TERM,# initialize the environment variables HOME, SHELL, USER, LOGNAME, PATH,# and start a login shell.#sudo $NSENTER "$OPTS" su – rootsudo $NSENTER –target $PID –mount –uts –ipc –net –pid su – rootelse# Use env to clear all host environment variables.sudo $NSENTER –target $PID –mount –uts –ipc –net –pid env -i $@fifi}其中有两个alias和一个function，使用docker-enter会很容易于容器交互并没有attach中的副作用。如下：$ docker psCONTAINER IDIMAGECOMMANDCREATEDSTATUSPORTSNAMESbeb178cd9335amclain/hgweb:latest"/bin/sh -c ‘load-de 11 seconds agoUp 10 seconds0.0.0.0:80->80/tcpstoic_yonath$ docker-enter beb178cd9335root@beb178cd9335:~# lsroot@beb178cd9335:~# pwd/root五、快速启动hg-server天有泪，烛有泪，天泪有声，烛泪有形，
