(一) Docker基础知识
Docker：它是一个开源的软件项目，在Linux操作系统上，docker提供了一个额外的软件抽象层及操作系统层虚拟化的自动管理机制。
物理机环境部署应用过程：
a.安装系统
b.依赖环境
c.Java – jdk jre
d.NodeJS – Node
e.PHP – PHP
f.应用程序
g.加一个物理机—> 提高并发量
虚拟机环境部署应用过程：
KVM Xen
a.把一个物理机虚拟机虚拟成多个机器
b.把依赖环境打成一个系统的模板
容器化环境部署应用过程：
Docker
a.镜像基础
b.依赖环境的镜像
c.Java – Java基础的基础镜像
d.PHP – PHP基础的基础镜像
e.根据基础镜像 – 放入自己的代码或者包
f.生产一个新镜像
g.程序镜像
h.镜像 – 按层存储
i. 启动时间特别，秒级启动
A – Java JDK1.8
a.jar
B – Java -> JDK1.8
b.jar
容器：把自己的应用程序，根据某个依赖的基础镜像，生成一个应用程序镜像
应用程序镜像，可以运行在任何部署了Docker环境的机器上。
(二) Docker基本命令
查看Docker版本
# docker version
Client: Docker Engine - Community
Version: 19.03.4
API version: 1.40
Go version: go1.12.10
Git commit: 9013bf583a
Built: Fri Oct 18 15:52:22 2019
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 19.03.4
API version: 1.40 (minimum version 1.12)
Go version: go1.12.10
Git commit: 9013bf583a
Built: Fri Oct 18 15:50:54 2019
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.2.6
GitCommit: 894b81a4b802e4eb2a91d1ce216b8817763c29fb
runc:
Version: 1.0.0-rc8
GitCommit: 425e105d5a03fabd737a126ad93d62a9eeede87f
docker-init:
Version: 0.18.0
GitCommit: fec3683
Docker详细信息
# docker info
Client:
Debug Mode: false
Server:
Containers: 8
Running: 4
Paused: 0
Stopped: 4
Images: 8
Server Version: 19.03.4
Storage Driver: overlay2
# aufs、overlay brtfs
Backing Filesystem: xfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
# json-file: 存在本地
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 894b81a4b802e4eb2a91d1ce216b8817763c29fb
runc version: 425e105d5a03fabd737a126ad93d62a9eeede87f
init version: fec3683
Security Options:
seccomp
Profile: default
Kernel Version: 4.18.0-80.el8.x86_64
Operating System: CentOS Linux 8 (Core)
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 1.764GiB
Name: k8s-master01
ID: PRWL:PVRE:U7JQ:LNM6:SNLN:4QDV:URQA:MWQF:XXCE:VOT3:53GL:ECC6
Docker Root Dir: /var/lib/docker
# 可以更改的，ssd的硬盘。最后使用一个单独的磁盘进行挂载
Debug Mode: false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
#生产环境一定要True
搜索镜像：
# docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 6054 [OK]
ansible/centos7-ansible Ansible on Centos7 130 [OK]
consol/centos-xfce-vnc Centos container with "headless" VNC session… 116 [OK]
jdeathe/centos-ssh OpenSSH / Supervisor / EPEL/IUS/SCL Repos - … 114 [OK]
centos/systemd systemd enabled base container. 84 [OK]
centos/mysql-57-centos7 MySQL 5.7 SQL database server 77
imagine10255/centos6-lnmp-php56 centos6-lnmp-php56 58 [OK]
tutum/centos Simple CentOS docker image with SSH access 47
centos/postgresql-96-centos7 PostgreSQL is an advanced Object-Relational … 45
kinogmt/centos-ssh CentOS with SSH 29 [OK]
pivotaldata/centos-gpdb-dev CentOS image for GPDB development. Tag names… 12
guyton/centos6 From official centos6 container with full up… 10 [OK]
drecom/centos-ruby centos ruby 6 [OK]
centos/tools Docker image that has systems administration… 6 [OK]
pivotaldata/centos Base centos, freshened up a little with a Do… 4
pivotaldata/centos-gcc-toolchain CentOS with a toolchain, but unaffiliated wi… 3
pivotaldata/centos-mingw Using the mingw toolchain to cross-compile t… 3
darksheer/centos Base Centos Image -- Updated hourly 3 [OK]
miko2u/centos6 CentOS6 日本語環境 2 [OK]
blacklabelops/centos CentOS Base Image! Built and Updates Daily! 1 [OK]
mcnaughton/centos-base centos base image 1 [OK]
indigo/centos-maven Vanilla CentOS 7 with Oracle Java Developmen… 1 [OK]
pivotaldata/centos6.8-dev CentosOS 6.8 image for GPDB development 0
smartentry/centos centos with smartentry 0 [OK]
pivotaldata/centos7-dev CentosOS 7 image for GPDB development 0
# docker search nginx
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
nginx Official build of Nginx. 13358 [OK]
Docker拉取镜像：
拉取一个镜像到本地：
# docker pull alpine:latest
latest: Pulling from library/alpine
df20fa9351a1: Already exists
Digest: sha256:185518070891758909c9f839cf4ca393ee977ac378609f700f60a771a2dfe321
Status: Downloaded newer image for alpine:latest
docker.io/library/alpine:latest
提交一个镜像到仓库：
# docker login
# docker tag calico/pod2daemon-flexvol:v3.11.1 dotbalo/pod2daemon-flexvol:v3.11.1
# docker push dotbalo/pod2daemon-flexvol:v3.11.1
Docker run：启动一个镜像
--前台启动
# docker run -ti centos:8 bash
[root@55eb31fec62e /]# whoami
root
-- 后台启动
# docker run -d centos:8 bash
# docker ps -a
查看容器日志：
# docker logs -l docker-ID
# cd /var/lib/docker/containers/
查看正在运行的容器
# docker ps
# docker ps -a
# docker ps -q
进入容器
# docker exec -ti docker-ID sh/bash
# kubectl exec -ti pod-id – sh/bash
拷贝文件
# docker cp docker-ID:/var/log/testfile ./
# docker cp ./testfile docker-ID:/var/log/
删除容器
# docker rm docker-ID
# docker rm ‘docker ps -aq’
删除镜像
# docker rmi
查看镜像
# docker image
启动/停止容器
# docker start/stop
创新镜像
# docker build
查看历史
# docker history
提交变更的镜像
# docker commit
(三) Dockerfile语法基础
FROM：继承基础镜像
MAINTAINER：镜像制作作者信息
RUN：用来执行shell命令
EXPOSE：暴露端口号
CMD：启动容器默认的命令
ENTRYPIOINT：启动容器真正执行的命令
VOLUME：创建挂载点
ENV：配置环境变量
ADD：复制文件到容器
COPY：复制文件到容器
WORKDIR：设置容器的工作目录
USER：容器使用的用户
CMD和ENTRYPIOINT 必须要有一个
CMD可以被覆盖，如果有ENTRYPIOINT的话，CMD就是ENTRYPIOINT的参数。
ENTRYPIOINT – 》 COMMAND
CMD –》 arg
例1：
LABEL maintainer="test dockerfile"
LABEL test=dockerfile
RUN useradd dot
RUN mkdir /opt/dot
CMD [ "sh", "-c", "echo 1"]
#RUN useradd dot && /opt/dot
例2：
FROM centos:8
LABEL maintainer="test dockerfile"
LABEL test=dockerfile
ENV test_env1 env1
ENV test_env2 env2
RUN useradd dot
RUN mkdir /opt/dot
#ENTRYPOINT ["echo"]
ENV env1=test1 env2=test2
ADD ./index.tar.gz /opt/
COPY ./index.tar.gz /opt/dot/
WORKDIR /opt/dot
USER 1000
CMD pwd ; ls
#RUN useradd dot && /opt/dot
(四) 制作Docker镜像及多阶段制作镜像
制作小镜像：
一定不要使用centos镜像
Alpine，busybox，scratch，Debian
Glibc： node:slim python:slim net
使用多阶段构建：
编译操作和生成最终镜像的操作
# build step
FROM golang:1.14.4-alpine as builder
WORKDIR /opt
COPY main.go /opt
RUN go build /opt/main.go
CMD "./main"
# create real app image
FROM alpine:3.8
COPY --from=builder /opt/main /
CMD "./opt/main"
FROM php:7.1.22-fpm-alpine
RUN apk add --no-cache binutils freetype libpng libjpeg-turbo freetype-dev libpng-dev libjpeg-turbo-dev libc6-compat libxml2 libxml2-dev libmcrypt libmcrypt-dev libc-dev icu-dev gettext-dev openssl-dev bzip2-dev
RUN docker-php-ext-install pdo pdo_mysql mcrypt zip gd pcntl opcache bcmath
#RUN docker-php-ext-install gettext
RUN docker-php-ext-install mysqli
#RUN apk add --no-cache php7-sysvsem php7-pdo_dblib php7-sockets php-soap php7-xmlrpc
##RUN apk add --no-cache php7-sysvsem php7-pdo_dblib php7-sockets php-soap php7-xmlrpc
##RUN apk add --no-cache freetds-dev
##RUN docker-php-ext-install pdo_dblib
#RUN docker-php-ext-install soap
#RUN docker-php-ext-install sockets
#RUN docker-php-ext-install sysvsem
#RUN docker-php-ext-install xmlrpc
#RUN apk add --no-cache freetds-dev
#RUN docker-php-ext-install pdo_dblib
#RUN docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/
#RUN docker-php-ext-install -j$(nproc) gd
#FROM php:7.1.22-fpm-alpine
#COPY --from=0 /usr/local/lib/php/extensions/no-debug-non-zts-20160303 /usr/local/lib/php/extensions/no-debug-non-zts-20160303
#RUN apk add --no-cache freetds-dev php7-sysvsem php7-pdo_dblib php7-sockets php-soap php7-xmlrpc binutils freetype libpng libjpeg-turbo freetype-dev libpng-dev libjpeg-turbo-dev libc6-compat libxml2 libxml2-dev libmcrypt libmcrypt-dev libc-dev icu-dev gettext-dev openssl-dev bzip2-dev && cd /usr/local/lib/php/extensions/no-debug-non-zts-20160303 && docker-php-ext-enable *.so && rm -rf /var/cache/apk/*
网友评论