我们知道容器是一个打包了应用和相关依赖的盒子,那怎么去操控这个盒子呢? 这一篇我通过一个简单的aspnetcore程序来加深对盒子的理解,使用之前先
安装一下Docker的环境。
一:Docker的安装
官方下载地址:https://docs.docker.com/install/linux/docker-ce/centos/ ,跟着文档执行完下面2个大步骤即可。
2. INSTALL DOCKER CEsudo yum install docker-ce docker-ce-cli containerd.io
二:新建asp.net core 网站
docker已经有了,接下来新建一个website,采用vs默认的mvc模板即可,有了网站之后新建一个Dockerfile文件,内容如下,目的就是为了制作镜像,
关于dockerfile的更多内容我会放到后面的文章中去说,本篇关注点在容器上。FROM microsoft/dotnet:2.2-aspnetcore-runtime LABEL hxc@qq.com RUN mkdir/data COPY ./ /data WORKDIR/data EXPOSE80CMD ["dotnet","WebNotebook.dll" ]
然后点击vs的发布功能,把发布后的内容通过ftp push 到虚拟机中/data/publish文件夹下,具体内容如下:[root@localhost publish]/# lsappsettings.Development.json web.config WebNotebook.pdb WebNotebook.Views.pdb appsettings.json WebNotebook.deps.json WebNotebook.runtimeconfig.json wwwroot Dockerfile WebNotebook.dll WebNotebook.Views.dll [root@localhost publish]/#
接下来通过 docker build 的方式构建出webnotebook的镜像。[root@localhost publish]/# docker build -f ./Dockerfile -t huangxincheng/webnodebook:v1 . Sending build context to Docker daemon4.201MB Step1/7 : FROM microsoft/dotnet:2.2-aspnetcore-runtime2.2-aspnetcore-runtime: Pulling from microsoft/dotnet 6ae821421a7d: Already exists 8a3a416e6dac: Already exists ed82f21723d8: Already exists 4f77997e649d: Already exists Digest: sha256:988829fbff8cde8b431d045d2dd2e3ea54d69abf5c61c69794c523535ce382e7 Status: Downloaded newer imagefor microsoft/dotnet:2.2-aspnetcore-runtime--->dad26d192ae6 Step2/7: MAINTAINER hxc@qq.com---> Running in89b9a2c5bec6 Removing intermediate container 89b9a2c5bec6--->2d6c5ecba6d2 Step3/7 : RUN mkdir /data---> Running in08e8d316c3da Removing intermediate container 08e8d316c3da--->7d28be2a2bc1 Step4/7 : COPY ./ /data--->9f603790a8a2 Step5/7 : WORKDIR /data---> Running in85fbed40b4f7 Removing intermediate container 85fbed40b4f7--->8c18eaadc85b Step6/7 : EXPOSE 80 ---> Running in0eaa5046ee1d Removing intermediate container 0eaa5046ee1d--->9b6ee99c1875 Step7/7 : CMD [ "dotnet","WebNotebook.dll"]---> Running in7c0d2fa1eb46 Removing intermediate container 7c0d2fa1eb46---> 513950255443Successfully built513950255443Successfully tagged huangxincheng/webnodebook:v1
最后可以通过 docker images 查看一下镜像是否构建成功,从下图中可以看到,当前有一个我的应用镜像,还有一个runtime镜像。[root@localhost publish]/# docker images REPOSITORY TAG IMAGE ID CREATED SIZE huangxincheng/webnodebook v1 513950255443 38seconds ago 264MB microsoft/dotnet 2.2-aspnetcore-runtime dad26d192ae6 4 days ago 260MB
三:容器操作
通常启动容器的方式有两种,第一种为docker create, 还有一种是docker run,更多的情况我们使用docker run 方式,比如下面的命令。[root@localhost publish]/# docker run --name webnotebook -d huangxincheng/webnodebook:v1 51ded69fce15fb912ab167c4dea26535a17b0f2147a5571aaa411a974ab95b11
《1》 --name: 这个就是给你当前运行的容器取一个名字,如果不取的话就采用系统给你的默认名字。
《2》 -d: 表示脱离shell终端采用deamon形式的后台运行,在生产环境中必须要这么处理,没毛病吧。
《3》 huangxincheng/webnodebook:v1 : huangxincheng表示仓库名,当然你也可以不需要这个。webnodebook 表示镜像名, v1表示镜像的版本。
容器运行成功后,会返回一个容器的标识码,这里要注意的是,如果镜像在本地不存在,docker 默认会到官方的 hub.docker.com上进行拉取。
既然你说容器启动了,那我怎么判别是否真的启动了呢? 这里你就可以用 docker ps命令鉴别。[root@localhost publish]/# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 51ded69fce15 huangxincheng/webnodebook:v1 "dotnet WebNotebook.…" 6 minutes ago Up 6 minutes 80/tcp webnotebook
从上图中可以看到,容器的ID为 51ded69fce15 ,而这个刚好是你docker run 返回的前12个字符,然后Status= Up 6 minutes ,说明容器是启动的没毛病。
容器启动了不代表我的webnotebook没问题,对吧,那接下来怎么去鉴别容器内的程序是否正常启动呢? 这里就可以用到下面两种方式。
《1》 docker top xxx 查看容器运行的进程。
xxx 就是你的容器名或者容器ID,如下图可以看到确实我的WebNoteBook的进程号是5323,说明是启动的。[root@localhost publish]/# docker top webnotebook UID PID PPID C STIME TTY TIME CMD root5323 5306 0 00:09 ? 00:00:01 dotnet WebNotebook.dll
《2》 直接在宿主机上通过ps -ef 查看指定的程序。
从下图中你也看到了,WebNotebook的PID果然是5323,说明启动了无疑。[root@localhost publish]/# ps -ef | grepdotnet root5323 5306 0 00:09 ? 00:00:01dotnet WebNotebook.dll root6235 3499 0 00:23 pts/1 00:00:00 grep --color=auto dotnet
既然容器和容器内程序都是启动的,那接下来我怎么访问这个webnotebook呢? 要想访问,你肯定是要知道这个容器的ip+port,不然怎么访问呢? 通常有
两种做法可以获取到容器的ip和port端口。
《1》 使用docker exec 直接进入容器内[root@localhost publish]/# docker exec -it webnotebook /bin/bash root@51ded69fce15:/data/# ifconfigbash:ifconfig: command not found root@51ded69fce15:/data/#
-it 表示给当前的容器分配一个终端,由于容器是ubuntu环境,为了精简并没有把ifconfig打包进来,所以你需要使用apt-get 安装一下net包即可。root@51ded69fce15:/data/# apt-get update && apt-get install net-tools -y Ign:1 http://cdn-fastly.deb.debian.org/debian stretch InRelease Get:3 http://cdn-fastly.deb.debian.org/debian stretch-updates InRelease [91.0 kB] Get:4 http://cdn-fastly.deb.debian.org/debian stretch Release [118 kB] Get:2 http://security-cdn.debian.org/debian-security stretch/updates InRelease [94.3 kB] Get:5 http://cdn-fastly.deb.debian.org/debian stretch-updates/main amd64 Packages [7748 B] Get:6 http://cdn-fastly.deb.debian.org/debian stretch Release.gpg [2434 B] Get:7 http://cdn-fastly.deb.debian.org/debian stretch/main amd64 Packages [7084 kB] Get:8 http://security-cdn.debian.org/debian-security stretch/updates/main amd64 Packages [474 kB] Fetched 7871 kB in 1min 52s (69.8 kB/s) Reading package lists... Done Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: net-tools0 upgraded, 1 newly installed, 0 to remove and 5not upgraded. Need to get248kB of archives. After this operation,963kB of additional disk space will be used. Get:1 http://cdn-fastly.deb.debian.org/debian stretch/main amd64 net-tools amd64 1.60+git20161116.90da8a0-1 [248 kB] Fetched 248 kB in 4s (56.4 kB/s) debconf: delaying package configuration, since apt-utils is not installed Selecting previously unselected package net-tools. (Reading database ...6953files and directories currently installed.) Preparing to unpack .../net-tools_1.60+git20161116.90da8a0-1_amd64.deb ... Unpacking net-tools (1.60+git20161116.90da8a0-1) ... Setting up net-tools (1.60+git20161116.90da8a0-1) ... root@51ded69fce15:/data/# ifconfigeth0: flags=4163
当你安装完net包后,通过ifconfig你就可以看到 172.17.0.2 这个ip地址了,然后通过netstat 来查看webnotebook的端口号。root@51ded69fce15:/data/# netstat -tlnp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp60 0 :::80 :::/* LISTEN 1/dotnet root@51ded69fce15:/data/#
《2》 使用 docker inspect 查看容器各方面的底层信息。
[root@localhost ~]/# docker inspect webnotebook [ ..."NetworkSettings": {"Bridge": "","SandboxID": "cc8d9e678ef1137d992f3c8d019d81300c2b5f379bc8b746b08fe233d06ffb02","HairpinMode": false,"LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"Ports": {"80/tcp": null},"SandboxKey": "/var/run/docker/netns/cc8d9e678ef1","SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"EndpointID": "e37e565a26af790ce156dc957beab5182cd136215d61b655be26e5c31362b4ae","Gateway": "172.17.0.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","MacAddress": "02:42:ac:11:00:02","Networks": {"bridge": {"IPAMConfig": null,"Links": null,"Aliases": null,"NetworkID": "d234a2cc0ff52b802e846d12530e41d886ec780f2344cf601f022ff1c434afe4","EndpointID": "e37e565a26af790ce156dc957beab5182cd136215d61b655be26e5c31362b4ae","Gateway": "172.17.0.1","IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"MacAddress": "02:42:ac:11:00:02","DriverOpts": null} } } ... ]
从NetworkSettings节点中,你可以找到一个"IPAddress": "172.17.0.2" 的信息,这个ip就是你的容器IP,很简单吧,而且从"Ports": { "80/tcp": null } 上
你也看到,当前暴露的是80端口。
容器和程序都启动起来了,不代表程序运行就正常,为了保险起见,还是要看一下程序打印到终端的一些操作日志,这样我才放心一些不是吗? 那现在
我可以通过 docker logs xxx 来查看指定容器的日志输出,从下面可以看到,一点问题都没有。[root@localhost ~]/# docker logs webnotebook warn: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[35] No XML encryptor configured. Key {8199b0ea-afae-4586-8e6d-aae75aa91db2} may be persisted to storage inunencrypted form. Hosting environment: Production Content root path:/data Now listening on: http://[::]:80 Application started. Press Ctrl+C to shut down.
容器运行这一块基本上就是这样了,由于项目不断的迭代升级,你的旧版本程序的容器就该停止了,接下来你有 docker stop 和 docker kill 两种方式,
两者的区别在于,前者是给你的程序 sigterm信号,后者是sigkill信号,如果不明白两者的区别,可以看我的这篇博文:
https://www.cnblogs.com/huangxincheng/p/9576795.html[root@localhost ~]/# docker stop webnotebook webnotebook [root@localhost~]/# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 51ded69fce15 huangxincheng/webnodebook:v1 "dotnet WebNotebook.…" 35 minutes ago Exited (0) 2seconds ago webnotebook [root@localhost~]/#
可以看到,当我执行了stop之后再 ps -a 发现,当前的容器已经退出了,然后你可以通过 docker start 重启,再用 docker kill 关闭。[root@localhost ~]/# docker start webnotebook webnotebook [root@localhost~]/# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 51ded69fce15 huangxincheng/webnodebook:v1 "dotnet WebNotebook.…" 37 minutes ago Up 2 seconds 80/tcp webnotebook [root@localhost~]/# docker killwebnotebook webnotebook [root@localhost~]/# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 51ded69fce15 huangxincheng/webnodebook:v1 "dotnet WebNotebook.…" 37 minutes ago Exited (137) 1second ago webnotebook [root@localhost~]/#
既然ip+port都知道了,接下来网站你就可以访问啦。访问之前确保你的容器是start状态哦( docker webnotebook start )。
好了,本篇就说到这里,希望对你有帮助。