linux alpine 用dockerfile创建的ssh镜像

- 日理万妓 2021-07-28 23:16 431阅读 0赞

### 1、下载alpine镜像 ###

[root@docker43 ~]# docker pull alpine
    Using default tag: latest
    Trying to pull repository docker.io/library/alpine ...
    latest: Pulling from docker.io/library/alpine
    4fe2ade4980c: Pull complete
    Digest: sha256:621c2f39f8133acb8e64023a94dbdf0d5ca81896102b9e57c0dc184cadaf5528
    Status: Downloaded newer image for docker.io/alpine:latest
    [root@docker43 ~]# docker images
    REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
    docker.io/alpine    latest              196d12cf6ab1        3 weeks ago         4.41 MB

### 2、编写dockerfile ###

2.1.创建一个工作目录

[root@docker43 ~]# cd /opt/
    [root@docker43 opt]# mkdir alpine_ssh && cd alpine_ssh && touch Dockerfile
    
    [root@docker43 alpine_ssh]# ll
    总用量 4
    -rw-r--r-- 1 root root 654 10月  3 23:21 Dockerfile

2.2.编写Dockerfile

# 指定创建的基础镜像
    FROM alpine
    
    # 作者描述信息
    MAINTAINER alpine_sshd (zhujingzhi@123.com)
    
    # 替换阿里云的源
    RUN echo "http://mirrors.aliyun.com/alpine/latest-stable/main/" > /etc/apk/repositories
    RUN echo "http://mirrors.aliyun.com/alpine/latest-stable/community/" >> /etc/apk/repositories
    
    # 同步时间
    
    # 更新源、安装openssh 并修改配置文件和生成key 并且同步时间
    RUN apk update && \
        apk add --no-cache openssh-server tzdata && \
        cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && \
        sed -i "s/#PermitRootLogin.*/PermitRootLogin yes/g" /etc/ssh/sshd_config && \
        ssh-keygen -t rsa -P "" -f /etc/ssh/ssh_host_rsa_key && \
        ssh-keygen -t ecdsa -P "" -f /etc/ssh/ssh_host_ecdsa_key && \
        ssh-keygen -t ed25519 -P "" -f /etc/ssh/ssh_host_ed25519_key && \
        echo "root:admin" | chpasswd
    
    # 开放22端口
    EXPOSE 22
    
    # 执行ssh启动命令
    CMD ["/usr/sbin/sshd", "-D"]

2.3.创建镜像

# 在dockerfile所在的目录下
    [root@docker43 alpine_ssh]# pwd
    /opt/alpine_ssh
    [root@docker43 alpine_ssh]# docker build -t alpine:sshd .

### 3、创建容器测试 ###

创建容器

[root@docker43 alpine_ssh]# docker run -itd -p 10022:22 --name alpine_ssh_v1 alpine:sshd
    [root@docker43 alpine_ssh]# docker ps
    CONTAINER ID        IMAGE               COMMAND               CREATED             STATUS              PORTS                   NAMES
    b353f5f3b703        alpine:sshd         "/usr/sbin/sshd -D"   17 minutes ago      Up 17 minutes       0.0.0.0:10022->22/tcp   alpine_ssh_v1

测试

### 4、问题总结 ###

这些都是我在手动测试的时候遇见的，已经在写Dockerfile的时候加进去了处理方法

[root@docker43 alpine_ssh]# ssh root@127.0.0.1 -p10022
    root@127.0.0.1's password:
    Welcome to Alpine!
    The Alpine Wiki contains a large amount of how-to guides and general
    information about administrating Alpine systems.
    See <http://wiki.alpinelinux.org>.
    You can setup the system with the command: setup-alpine
    You may change this message by editing /etc/motd.
    b353f5f3b703:~#1. apk add --no-cache openssh-server   # 安装openssh的问题
    
    / # apk add --no-cache openssh-server
    fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/main/x86_64/APKINDEX.tar.gz
    fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/community/x86_64/APKINDEX.tar.gz
    (1/3) Installing openssh-keygen (7.7_p1-r2)
    ERROR: openssh-keygen-7.7_p1-r2: package mentioned in index not found (try 'apk update')
    (2/3) Installing openssh-server-common (7.7_p1-r2)
    (3/3) Installing openssh-server (7.7_p1-r2)
    ERROR: openssh-server-7.7_p1-r2: package mentioned in index not found (try 'apk update')
    2 errors; 4 MiB in 14 packages
    
    原因是：提示源没有这个openssh的包
    
    解决方式：
    在dockerfile中改为国内的源
    http://mirrors.aliyun.com/alpine/latest-stable/main/
    http://mirrors.aliyun.com/alpine/latest-stable/community/
    
    创建容器文件修改
    [root@docker43 ~]# docker run -it alpine
    / # vi /etc/apk/repositories
    http://mirrors.aliyun.com/alpine/latest-stable/main/
    http://mirrors.aliyun.com/alpine/latest-stable/community/
                                                         
    #http://dl-cdn.alpinelinux.org/alpine/v3.8/main    
    #http://dl-cdn.alpinelinux.org/alpine/v3.8/community
    
    # 注释或者删除原来的默认源，添加阿里云的源，然后执行apk update，在进行安装就OK了
    
    
    2、ssh 启动问题
    / # /etc/init.d/sshd start
    /bin/sh: /etc/init.d/sshd: not found
    
    这样的方式不能启动，需要安装一个alpine的管理工具
    apk add --no-cache openrc
    / # /etc/init.d/sshd start
     * WARNING: sshd is already starting
     所以使用 /usr/sbin/sshd -D 方式启动。但是又出现如下错误
     / # /usr/sbin/sshd -D
    Could not load host key: /etc/ssh/ssh_host_rsa_key
    Could not load host key: /etc/ssh/ssh_host_ecdsa_key
    Could not load host key: /etc/ssh/ssh_host_ed25519_key
    sshd: no hostkeys available -- exiting.
    解决方式：
    ssh-keygen -t rsa -P "" -f /etc/ssh/ssh_host_rsa_key
    ssh-keygen -t ecdsa -P "" -f /etc/ssh/ssh_host_ecdsa_key
    ssh-keygen -t ed25519 -P "" -f /etc/ssh/ssh_host_ed25519_key
    
    再次启动
    / # /usr/sbin/sshd -D
    
    启动成功
    
    
    3、创建容器后的网络问题
    [root@docker43 opt]# docker run -it alpine
    WARNING: IPv4 forwarding is disabled. Networking will not work.
    
    解决方式：
    [root@docker43 ~]# vim /etc/sysctl.conf
    net.ipv4.ip_forward=1    # 添加这一行
    
    [root@docker43 ~]# docker run -it alpine
    / #