Docker（2）dockerfile的使用（创建镜像，网上拉取镜像）

1、创建镜像

FROM指定base镜像，本地不存在就会从远程仓库下载（有网就行）

[root@server1 docker]# pwd    #在干净的目录下创建dockerfile镜像文件
/mnt/docker                               #以u免运行时，有影响
[root@server1 docker]# vim dockerfile    
[root@server1 docker]# cat dockerfile     
FROM busybox
RUN echo testfile >file1
RUN echo testfile >file2


注意：dockerfile中写命令时，不能有多余的空格

创建镜像：

[root@server1 docker]# docker build -t busyboxecho .     #根据文件内容，创建镜像。
Sending build context to Docker daemon  2.048kB   #可以看到，在这里是创建了三层镜像
Step 1/3 : FROM busybox       第一层，本身具有的
 ---> 020584afccce
Step 2/3 : RUN echo testfile >file1        第二层
 ---> Running in 0de902502270
Removing intermediate container 0de902502270
 ---> 244f864d70e3
Step 3/3 : RUN echo testfile >file2         第三层
 ---> Running in 864ca57f5451
Removing intermediate container 864ca57f5451
 ---> 2887c30be242
Successfully built 2887c30be242
Successfully tagged busyboxecho:latest

 

查看本地开启的镜像

[root@server1 docker]# docker images       
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB

使用当前目录下的dockerfile创建镜象（path为‘ . ’）：
             busybox:镜像名； v1版本号

[root@server1 docker]# docker build -t busybox1.0:v1 .    
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM busybox
 ---> 020584afccce
Step 2/3 : RUN echo testfile >file1
 ---> Running in b59d6b7eddca
Removing intermediate container b59d6b7eddca
 ---> 35226fda4810
Step 3/3 : RUN echo testfile >file2
 ---> Running in 8e6aaa675e2a
Removing intermediate container 8e6aaa675e2a
 ---> 5b551bd01d32
Successfully built 5b551bd01d32
Successfully tagged busybox1.0:v1
[root@server1 docker]# docker images     #查看本地所有开着的镜像
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox1.0          v1                  5b551bd01d32        7 seconds ago       1.22MB
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB

docker history--查看镜像的构建过程

[root@server1 docker]# docker history busybox1.0:v1
IMAGE               CREATED             CREATED BY                                      SIZE             COMMENT
5b551bd01d32        2 minutes ago       /bin/sh -c echo testfile >file2                 9B                  
35226fda4810        2 minutes ago       /bin/sh -c echo testfile >file1                 9B                  
020584afccce        3 days ago          /bin/sh -c #(nop)  CMD ["sh"]                   0B                  
           3 days ago          /bin/sh -c #(nop) ADD file:1141b81e5149cc37c…   1.22MB

2、运行镜像

[root@server1 docker]# docker run -it busybox1.0:v1   #运行镜像，此时运行后产生的容器的名字是随机的，在这里是mystifying_darwin
                                                              #如果要自己取名字，采用名令 docker run -it --name busybox1.0:v1
/ # ls
bin    etc    file2  proc   sys    usr
dev    file1  home   root   tmp    var
/ # exit

显示所有的本地正在运行的镜像  docker ps

root@server1 docker]# docker ps   
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

显示所有的本地镜像   docker ps -a
 

[root@server1 docker]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
7cef13f36d74        busybox1.0:v1       "sh"                     36 seconds ago      Exited (0) 13 seconds ago                       mystifying_darwin
9044a6a4bd60        game2048            "/bin/sh -c 'sed -i …"   18 hours ago        Exited (137) 17 hours ago

创建镜像

[root@server1 docker]# cat dockerfile
FROM busybox
RUN echo testfile >file1
RUN echo testfile >file2
RUN echo testfile >file3

[root@server1 docker]# docker build -t busybox1.0:v2 .
Sending build context to Docker daemon  2.048kB
Step 1/4 : FROM busybox
 ---> 020584afccce
Step 2/4 : RUN echo testfile >file1
 ---> Using cache
 ---> 35226fda4810
Step 3/4 : RUN echo testfile >file2
 ---> Using cache
 ---> 5b551bd01d32
Step 4/4 : RUN echo testfile >file3
 ---> Running in c00f74a8c2cb
Removing intermediate container c00f74a8c2cb
 ---> 7b1844c4fa77
Successfully built 7b1844c4fa77
Successfully tagged busybox1.0:v2

[root@server1 docker]# docker images          查看镜像
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox1.0          v2                  7b1844c4fa77        34 seconds ago      1.22MB
busybox1.0          v1                  5b551bd01d32        6 minutes ago       1.22MB
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB

进入镜像
[root@server1 docker]# docker run -it busybox1.0:v2
/ # ls
bin    etc    file2  home   root   tmp    var
dev    file1  file3  proc   sys    usr
/ # echo 333 >yyz
/ # ls
bin    etc    file2  home   root   tmp    var
dev    file1  file3  proc   sys    usr    yyz
/ # echo yy >file1
/ # ls
bin    etc    file2  home   root   tmp    var
dev    file1  file3  proc   sys    usr    yyz

copy的用法：

删除dockerfile创建的镜像
[root@server1 docker]# docker rmi -f 7b1844c4fa77
Untagged: busybox1.0:v2
Deleted: sha256:7b1844c4fa779a3054263b9441d8009acb969aa416f145fb89281dbb94de417d

[root@server1 docker]# cat dockerfile
FROM busybox
COPY testfile /tmp
COPY ["hello","/tmp"]
[root@server1 docker]# vim testfile    
[root@server1 docker]# vim hello
[root@server1 docker]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB
[root@server1 docker]# docker build -t test:v1 .
Sending build context to Docker daemon  4.096kB
Step 1/3 : FROM busybox
 ---> 020584afccce
Step 2/3 : COPY testfile /tmp
 ---> 936f1a729bd5
Step 3/3 : COPY ["hello","/tmp"]
 ---> 4ce4f04be438
Successfully built 4ce4f04be438
Successfully tagged test:v1
[root@server1 docker]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
test                v1                  4ce4f04be438        5 seconds ago       1.22MB
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB
[root@server1 docker]# docker history test:v1
IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
4ce4f04be438        22 seconds ago      /bin/sh -c #(nop) COPY file:1b0cdc05878fe9c3…   9B                  
936f1a729bd5        22 seconds ago      /bin/sh -c #(nop) COPY file:8994bfe58384692d…   5B                  
020584afccce        3 days ago          /bin/sh -c #(nop)  CMD ["sh"]                   0B                  
           3 days ago          /bin/sh -c #(nop) ADD  
[root@server1 docker]# docker run -it --name vm1 test:v1
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # cd /tmp/
/tmp # ls
hello     testfile
/tmp # cat hello
hello~~~

ADD:用法和COPY类似，不同的是SRC可以是归档压缩文件，文件会自动解压到dest，也可以下载URL并且拷贝到镜像

eg：ADD html。tar /var/www
   ADD http://ip/html.tar /var/www

[root@server1 docker]# ls
dockerfile  hello  redis-5.0.3.tar.gz  testfile
[root@server1 docker]# vim dockerfile
[root@server1 docker]# cat dockerfile
FROM busybox
COPY testfile /tmp
ADD redis-5.0.3.tar.gz /tmp
[root@server1 docker]# docker build -t test:v1 .
Sending build context to Docker daemon  1.965MB
Step 1/3 : FROM busybox
 ---> 020584afccce
Step 2/3 : COPY testfile /tmp
 ---> 050d6ad30a3e
Step 3/3 : ADD redis-5.0.3.tar.gz /tmp
 ---> e24cd31530c4
Successfully built e24cd31530c4
Successfully tagged test:v1
[root@server1 docker]# docker run -it --name vm1 test:v1
docker: Error response from daemon: Conflict. The container name "/vm1" is already in use by container "6b0bf10240b41c8ef3db8ff572ac719b72149b3faaf5019c35198eab65751995". You have to remove (or rename) that container to be able to reuse that name.
See 'docker run --help'.
[root@server1 docker]# docker run -it --name yyz test:v1
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # cd /tmp
/tmp # ls
redis-5.0.3  testfile

编写Dockerfile构建镜像

(1)删除前面构建的镜像和容器
(2)从真机给server1传送一个镜像
[root@server1 ~]# ls
docker包  game2048.tar  python.tar  rhel7.tar

(3)导入镜像
[root@server1 ~]# docker load -i rhel7.tar
e1f5733f050b: Loading layer  147.1MB/147.1MB
[root@server1 ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              020584afccce        3 days ago          1.22MB
nginx               latest              540a289bab6c        11 days ago         126MB
game2048            latest              19299002fdbe        2 years ago         55.5MB
rhel7               latest              0a3eb3fde7fd        5 years ago         140MB

(4)编写Dockerfile

[root@server1 docker]# cat dockerfile
FROM rhel7     # 源镜像是rhel7，最好将名为rhel7的镜像放在本地
EXPOSE 80      # 定义端口为80
MAINTAINER [email protected]   #作者
COPY yum.repo /etc/yum.reos.d    #将本地的yum源文件复制到容器中的/etc/yum.repo.d/目录下  
RUN rpmdb --rebuilddb
# rpmdb 命令用于初始化和重建rpm数据库
# --rebuilddb：从已安装的包头文件，反向重建RPM数据库   
RUN yum install -y gcc pcre-devel zlib-devel make
ADD nginx-1.17.4.tar.gz /mnt
WORKDIR /mnt/nginx-1.17.4
RUN ./configure --prefix=/usr/local/nginx
RUN make
RUN make install
CMD ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]

(5)编写yum.repo(在当前目录下，也就是放置Dockerfile的目录中)
[root@server1 docker]# cat yum.repo
[rhel7.5]
baseurl=http://172.25.28.250/isos
gpgcheck=0
name=rhel7.5

Successfully built 95aa91dc32bc
Successfully tagged rhel7:v5

（6）封装镜像，并测试能否正常使用
[root@server1 docker]# docker build  -t rhel7:v1 .
如果出现以下错误，则在dockerfile文件里，执行安装make的命令

/bin/sh: make: command not found
The command '/bin/sh -c make' returned a non-zero code: 127

RUN yum install -y gcc pcre-devel zlib-devel make

Successfully built 95aa91dc32bc
Successfully tagged rhel7:v5
代表封装成功
(7)基于刚才封装的镜像运行一个容器

[root@server1 docker]# docker run -d --name vm rhel7:v5
e7416e35fadd416dc49c2bbda42c51919e6cc2ccf8279bbb0eba36006eed4d98

docker inspect vm   查看容器IP地址