dockerfile构建docker镜像

1、dockerfile构建nginx镜像，准备nginx.repo文件

[root@localhost dockerfile]# cat nginx.repo
[nginx]
name = nginx repo
baseurl = http://nginx.org/packages/centos/7/$basearch/
enabled = 1
gpgcheck = 0
[root@localhost dockerfile]# 

2、编写dockerfile文件

[root@localhost dockerfile]# cat dockerfile
FROM centos:centos7
MAINTAINER MichselHo
COPY nginx.repo /etc/yum.repos.d/
RUN yum install -y nginx
EXPOSE 80
CMD ["nginx","-g","daemon off;"]
[root@localhost dockerfile]# 

3、要确保这两个文件在同一个目录下

[root@localhost dockerfile]# ls
dockerfile  nginx.repo

4、通过docker build构建镜像

[root@localhost dockerfile]# docker build -t nginx:v3 .
[+] Building 23.3s (8/8) FINISHED
 => [internal] load build definition from dockerfile                                                                                          1.0s
 => => transferring dockerfile: 242B                                                                                                          0.0s
 => [internal] load .dockerignore                                                                                                             0.7s
 => => transferring context: 2B                                                                                                               0.0s
 => [internal] load metadata for docker.io/library/centos:centos7                                                                            19.1s
 => [internal] load build context                                                                                                             0.5s
 => => transferring context: 91B                                                                                                              0.0s
 => [1/3] FROM docker.io/library/centos:centos7@sha256:be65f488b7764ad3638f236b7b515b3678369a5124c47b8d32916d6487418ea4                       0.0s
 => CACHED [2/3] COPY nginx.repo /etc/yum.repos.d/                                                                                            0.0s
 => CACHED [3/3] RUN yum install -y nginx                                                                                                     0.0s
 => exporting to image                                                                                                                        0.2s
 => => exporting layers                                                                                                                       0.0s
 => => writing image sha256:14be8875682a93dda41826c2c4f95b60a338ea0d4e9dad2aa993130784c3f370                                                  0.1s
 => => naming to docker.io/library/nginx:v3                                                                                                   0.1s
[root@localhost dockerfile]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED       SIZE
mysql        8.0       041315a16183   11 days ago   565MB
nginx        v3        14be8875682a   2 weeks ago   426MB
[root@localhost dockerfile]#