docker之封装镜像之nginx容器化3

本节：学会如何自己封装一个完整的镜像，将nginx容器化并且优化该镜像
容器启动后，宿主机能上网，容器也能上网。

基础的镜像的选取，通过docker查找拉取

[root@docker1 yum.repos.d]# docker search rhel7

STARS是下载量
前面带有名字的都不是官方镜像，有可能有问题。

[root@docker1 yum.repos.d]# docker search centos

这个是官方镜像

为了选择自己想要的版本，去docker官方仓库查看

https://hub.docker.com/

nginx容器化

首先要清除前面测试的镜像
^以什么开头

[root@docker1 docker]# docker rmi `docker images | grep ^test | awk '{print $1":"$2}'`

在本地先下载一个系统的镜像
-i指定导入的系统镜像,加个bash进去交互。

[root@docker1 docker]# docker load -i rhel7.tar 
e1f5733f050b: Loading layer [==================================================>]  147.1MB/147.1MB
[root@docker1 docker]# docker run -it --name demo rhel7:latest bash

版本是7.0的

bash-4.2# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 7.0 (Maipo)

现在容器里面里面安装Nginx，寻找需要什么资源后，在宿主机Dockerfile里面写相关资源提交镜像后，Nginx便容器化了。
容器中：
修改yum仓库

bash-4.2# cd /etc/yum.repos.d/
bash-4.2# vi rhel7.repo            
bash-4.2# cat rhel7.repo 
[dvd]
name = rhel7
baseurl = http://172.25.138.250/westos
gpgcheck=0
enabled =1 

[root@docker1 docker]# ls
Dockerfile  index.html  nginx-1.18.0.tar.gz  rhel7.tar
[root@docker1 docker]# tar zxf nginx-1.18.0.tar.gz 
[root@docker1 docker]# docker container cp nginx-1.18.0 demo:/
[root@docker1 docker]# docker container attach demo 
bash-4.2# ls
bin   dev  home  lib64	mnt	      nginx-1.18.0.tar.gz  proc  run   srv  tmp  var
boot  etc  lib	 media	nginx-1.18.0  opt		   root  sbin  sys  usr

nginx编译需要的包

bash-4.2# yum install gcc pcre-devel openssl-devel
Error: libselinux conflicts with fakesystemd-1-14.el7.x86_64

openssl与centos依赖性冲突了，所以就不装openssl

7.0升级到7.6
Rpmdb损坏了，要升级索引数据库。

bash-4.2# yum install gcc pcre-devel -y
Rpmdb checksum is invalid: dCDPT(pkg checksums): glibc-devel.x86_64 0:2.17-260.el7 - u

bash-4.2# rpmdb --rebuilddb

bash-4.2# cd nginx-1.18.0/
bash-4.2# ls
CHANGES  CHANGES.ru  LICENSE  README  auto  conf  configure  contrib  html  man  src
bash-4.2# ./configure --prefix=/usr/local/nginx 

报错：缺少了zlib的库，这个库如果安装openssl便自动安装进去了

./configure: error: the HTTP gzip module requires the zlib library.
You can either disable the module by using --without-http_gzip_module
option, or install the zlib library into the system, or build the zlib library
statically from the source with nginx by using --with-zlib=<path> option.

编译成功

bash-4.2# ./configure --prefix=/usr/local/nginx

在宿主机里面：

/usr/local/nginx/html是nginx的默认发布目录
/usr/local/nginx/sbin/nginx运行nginx
查看一下nginx官方如何启动Nginx

[root@docker1 docker]# docker search nginx
nginx                             Official build of Nginx.                        16202               [OK]  

每次拉取都是镜像的最新版，详细看inspect，大概看history

[root@docker1 docker]# docker pull nginx
[root@docker1 docker]# docker inspect nginx:latest 

自己写必须绝对路径而不是Nginx就行
Dockerfile写法：

[root@docker1 docker]# vim Dockerfile 
[root@docker1 docker]# cat Dockerfile 
FROM rhel7
EXPOSE 80
VOLUME ["/usr/local/nginx/html"]
COPY dvd.repo /etc/yum.repos.d/dvd.repo
RUN rpmdb --rebuilddb
RUN yum install -y gcc pcre-devel zlib-devel 
ADD nginx-1.18.0.tar.gz /mnt
WORKDIR /mnt/nginx-1.18.0
RUN ./configure --prefix=/usr/local/nginx
RUN make
RUN make install
CMD ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]

[root@docker1 docker]# docker build -t webserver:v1 .
Step 10/12 : RUN make
 ---> Running in 1871c9076c77
/bin/sh: make: command not found

所以需要修改一下Dockerfile
不要动上面好的部分,你在yum gcc那块添加的话，后面执行便不能用cache了，而且还可能改错。

FROM rhel7
EXPOSE 80
VOLUME ["/usr/local/nginx/html"]
COPY dvd.repo /etc/yum.repos.d/dvd.repo
RUN rpmdb --rebuilddb
RUN yum install -y gcc pcre-devel zlib-devel 
ADD nginx-1.18.0.tar.gz /mnt
WORKDIR /mnt/nginx-1.18.0
RUN ./configure --prefix=/usr/local/nginx
RUN yum install make -y
RUN make
RUN make install
CMD ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]

继续安装

[root@docker1 docker]# docker build -t webserver:v1 .
Successfully tagged webserver:v1

[root@docker1 docker]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
webserver           v1                  bdd2829a42e3        31 seconds ago      346MB

可以删掉之前做实验的容器了

[root@docker1 docker]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                        PORTS               NAMES
1871c9076c77        644179a9b6e3        "/bin/sh -c make"   6 minutes ago       Exited (127) 6 minutes ago                        modest_buck
7aaa2d2b53da        rhel7:latest        "bash"              43 hours ago        Exited (130) 16 minutes ago                       demo
[root@docker1 docker]# docker rm 1871c9076c77 7aaa2d2b53da

启动nginx的镜像

[root@docker1 docker]# docker run -d --name nginx webserver:v1
[root@docker1 docker]# docker inspect nginx
                    "IPAddress": "172.17.0.2",
                "Source": "/var/lib/docker/volumes/70f0dede14b7c1978edb38eb49534509f1fcc205e750bb365254b75677b76005/_data",

发布失败，因为在inspect查到mount里面的宿主机挂载点覆盖点我们的卷了

[root@docker1 docker]# curl 172.17.0.2
<html>
<head><title>403 Forbidden</title></head>
<body>
<center><h1>403 Forbidden</h1></center>
<hr><center>nginx/1.18.0</center>
</body>
</html>

重新测试：

[root@docker1 docker]# cd /var/lib/docker/volumes/70f0dede14b7c1978edb38eb49534509f1fcc205e750bb365254b75677b76005/_data
[root@docker1 _data]# vim index.html
[root@docker1 _data]# cat index.html 
www.yan.org
[root@docker1 _data]# curl 172.17.0.2
www.yan.org

Nginx容器化成功