本文介紹compose配置文件參數的使用,熟練編寫compose文件php
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: /root/docker_demo/nginx/ ports: - "80:80" links: - php:php volumes: - "/www:/usr/local/nginx/html" php: image: php expose: - "9000" volumes: - "/www:/usr/local/nginx/html"
上面的一個例子version表明版本html
什麼版本的docker-compose對應什麼版本的docker:node
services就是compose中定義的服務,compose管理的是project、service、container,project若是沒有指定就是默認的lnmp.yml文件的lnmpmysql
nginx、php就是屬於services的子集欄,定義了兩個servicenginx
nginx服務中有各類參數:web
build:和docker中的build構建同樣,後面的路徑指向Dockerfile的位置:redis
[root@docker lnmp]# ll /root/docker_demo/nginx/ total 832 -rw-r--r--. 1 root root 1133 Nov 6 13:40 Dockerfile -rw-r--r--. 1 root root 1033 Nov 6 10:17 fastcgi_params -rw-r--r--. 1 root root 833473 Nov 6 09:35 nginx-1.8.1.tar.gz -rw-r--r--. 1 root root 776 Nov 6 10:16 nginx.conf -rw-r--r--. 1 root root 341 Nov 6 16:43 www.conf
ports參數就是docker在docker run啓動容器時-p選項的意思差很少,映射到本機host,前者的端口是本機host,後面是container_portsql
links參數也是docker run在啓動容器時--link選項的意思差很少,用於與容器間的互聯訪問,php:php,前者php是定義的service名稱,後者的php是給它定義了一個別名docker
volumes:與docker run在啓動容器時-v選項的意思差很少,用於host與container之間的映射掛載,前者是host_mount_dir,後面是container中的目錄數據庫
volumes: # Just specify a path and let the Engine create a volume - /var/lib/mysql # Specify an absolute path mapping - /opt/data:/var/lib/mysql # Path on the host, relative to the Compose file - ./cache:/tmp/cache # User-relative path - ~/configs:/etc/configs/:ro # Named volume - datavolume:/var/lib/mysql
在下面的php這個service中:
image:表明的就是使用的docker images中的某個鏡像名稱去開啓container(默認tag爲latest),若是本地沒有鏡像將會進行pull
image: redis image: ubuntu:14.04 image: tutum/influxdb image: example-registry.com:4000/postgresql image: a4bc65fd
有了上面的第一個簡單的compose yml文件,因而進行啓動container:
[root@docker lnmp]# docker-compose -f lnmp.yaml up --build
因爲我這裏進行了配置文件的修改,因此再也不單獨的up,而是up --build(If you change a service’s Dockerfile or the contents of its build directory, run docker-compose build to rebuild it.)
單獨的docker-compose -f lnmp.yaml build只會進行build而不會進行啓動容器,以後還需進行docker-compose -f lnmp.yaml up
build: /root/docker_demo/nginx/,build參數這裏能夠指定解決路徑也能夠以compose的項目路徑的相對路徑進行指定
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile
build參數的子集也能夠根據Dockerfile構建的context來進行build
在build子集中還有args的使用,配合Dockerfile中的ARG結合使用
[root@docker nginx]# cat Dockerfile FROM centos_init:v2 MAINTAINER json_hc@163.com ARG buildno RUN echo "Build number: $buildno"
上面的Dockerfile中定義了build,可是並無賦值,RUN執行打印這個值,而在compose的yml中:
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: buildno: 2
定義了buildno的值,因而在docker-compose執行構建時使用了這個值,下面是過程
若是僅僅在yml文件中定義了args變量,而沒有在Dockerfile中定義相同的變量,將會報錯:
[Warning] One or more build-args [foo] were not consumed.
ARG在Dockerfile中的用法:
ARG <name>[=<default value>] 設置變量命令,ARG命令定義了一個變量,在docker build建立鏡像的時候,使用 --build-arg <varname>=<value>來指定參數
ARG user1
ARG buildno
或者定義默認值
ARG user1=someuser
ARG buildno=1
ARG只是在build構建過程當中使用,構建完成後,變量將會消失和ENV有着明顯的區別
而在compose的yml文件中args的定義:
build: context: . args: buildno: 1 password: secret build: context: . args: - buildno=1 - password=secret
上面兩種方式均可以
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: - buildno=2
command參數,覆蓋容器內默認的命令
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: - buildno=2 command: ["/usr/local/nginx/sbin/nginx"]
這裏定義command的命令,而Dockerfile中的nginx的啓動命令:
CMD ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]
因此在[root@docker lnmp]# docker-compose -f lnmp.yaml up --build
構建並啓動時並不會成功:
能夠明顯的看到command定義的命令替換掉了Dockerfile中的CMD命令
container_name:自定義容器名
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: - buildno=2 container_name: lnmp-nginx
能夠看見nginx服務的容器名已經改成lnmp-nginx了
depends_on:定義服務間的依賴關係
好比數據庫db,必須在web啓動以前進行啓動,也就是說web啓動依賴db的啓動
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: - buildno=2 container_name: lnmp-nginx depends_on: - db ports: - "80:80" links: - php:php volumes: - "/www:/usr/local/nginx/html" php: image: php expose: - "9000" volumes: - "/www:/usr/local/nginx/html" db: image: mysql ports: - "3306:3306" environment: MYSQL_ROOT_PASSWORD: redhat MYSQL_DATABASE: wordpress MYSQL_USER: wordpress MYSQL_PASSWORD: wordpress
能夠看出nginx服務是最後啓動容器的,因爲nginx依賴db,而php與nginx有link,因此nginx最後啓動
dns:設置dns
dns: 8.8.8.8 dns: - 8.8.8.8 - 9.9.9.9
能夠設置是一個單一值,也能夠是一個列表
dns_search:自定義搜索域:
dns_search: example.com dns_search: - dc1.example.com - dc2.example.com
能夠設置爲單一值,也能夠是一個列表
entrypoint:覆蓋Dockerfile中的entrypoint,用法同Dockerfile中的用法
[root@docker lnmp]# cat lnmp.yaml version: '3' services: nginx: build: context: /root/docker_demo/nginx/ dockerfile: /root/docker_demo/nginx/Dockerfile args: - buildno=2 container_name: lnmp-nginx entrypoint: ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]
[root@docker lnmp]# docker-compose -f lnmp.yaml ps Name Command State Ports ---------------------------------------------------------------------------- lnmp-nginx /usr/local/nginx/sbin/ngin ... Up 0.0.0.0:80->80/tcp lnmp_db_1 docker-entrypoint.sh mysqld Up 0.0.0.0:3306->3306/tcp lnmp_php_1 /usr/local/php/sbin/php-fpm Up 9000/tcp
env_file:將定義的變量編寫在文件中,而後在yml文件中進行添加
env_file: .env env_file: - ./common.env - ./apps/web.env - /opt/secrets.env
建立env_file文件mysql_env.txt:
[root@docker lnmp]# ll total 16 -rw-r--r--. 1 root root 477 Nov 9 17:00 docker-compose.yml.bak -rw-r--r--. 1 root root 550 Nov 10 15:45 lnmp.yaml -rw-r--r--. 1 root root 271 Nov 10 10:26 lnmp.yaml.bak -rw-r--r--. 1 root root 98 Nov 10 15:46 mysql_env.txt
查看定義的變量:
[root@docker lnmp]# cat mysql_env.txt MYSQL_ROOT_PASSWORD=redhat MYSQL_DATABASE=wordpress MYSQL_USER=wordpress MYSQL_PASSWORD=wordpress
變量的定義格式爲這樣
而後進行docker-compose:
[root@docker lnmp]# docker-compose -f lnmp.yaml up --build
進入到db服務中進行驗證變量是否建立成功:
[root@docker nginx]# docker-compose -f /root/compose_project/lnmp/lnmp.yaml exec db sh # mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.20 MySQL Community Server (GPL) Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | wordpress | +--------------------+ 5 rows in set (0.00 sec) mysql>
能夠看見MySQL的root密碼已經設置,也建立了數據庫wordpress等等
environment:添加環境變量,能夠是一個字典也能夠是數組
environment: RACK_ENV: development SHOW: 'true' SESSION_SECRET: environment: - RACK_ENV=development - SHOW=true - SESSION_SECRET
db: image: mysql ports: - "3306:3306" environment: - MYSQL_ROOT_PASSWORD=redhat - MYSQL_DATABASE=wordpress - MYSQL_USER=wordpress - MYSQL_PASSWORD=wordpress
定義完成後進行構建並啓動後,進行驗證:
[root@docker nginx]# docker-compose -f /root/compose_project/lnmp/lnmp.yaml exec db sh # mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.20 MySQL Community Server (GPL) Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | wordpress | +--------------------+ 5 rows in set (0.00 sec) mysql>
expose:暴露container的端口,可是並無映射到host主機上,用法相似於Dockerfile中的EXPOSE
php: image: php expose: - "9000" volumes: - "/www:/usr/local/nginx/html"
external_links:
external_links: - redis_1 - project_db_1:mysql - project_db_1:postgresql
連接到 docker-compose.yml 外部的容器,甚至 並不是 Compose
管理的容器。參數格式跟 links
相似。
這個參數下篇文章有介紹
extra_hosts:添加hostname映射,相似於docker cli下面的--add-host
extra_hosts: - "www.hcstart.com:192.168.101.14"
而後將這個compose file進行up:
[root@docker lnmp]# docker-compose -f lnmp.yml up --build Creating network "lnmp_net1" with driver "bridge" Creating lnmp-php ... Creating lnmp-php ... done Creating lnmp-nginx ... Creating lnmp-nginx ... done Attaching to lnmp-php, lnmp-nginx
[root@docker lnmp]# docker-compose -f lnmp.yml exec nginx cat /etc/hosts 127.0.0.1 localhost ::1 localhost ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters 192.168.101.14 www.hcstart.com 172.19.0.3 35cc14084be9
上面的/etc/hosts就能夠看見剛剛加入的www.hctsrat.com映射了
healthcheck:配置一個檢查去測試服務中的容器是否運行正常
[root@docker lnmp]# cat lnmp.yml|grep health -A 4 healthcheck: test: ["CMD", "curl", "-f", "http://localhost"] interval: 1m30s timeout: 10s retries: 3
查看healthcheck的狀態輸出:
[root@docker lnmp]# docker inspect lnmp-nginx
"Health": { "Status": "healthy", "FailingStreak": 0, "Log": [ { "Start": "2017-10-27T03:52:37.921723965-04:00", "End": "2017-10-27T03:52:38.021941235-04:00", "ExitCode": 0, "Output": " % Total % Received % Xferd Average Speed Time Time Time Current\n Dload Upload Total Spent Left Speed\n\r 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0<h1>hello nginx and php</h1>\n\r100 29 100 29 0 0 5741 0 --:--:-- --:--:-- --:--:-- 7250\n" },
healthcheck中選項的詳解:https://docs.docker.com/engine/reference/builder/#healthcheck
labels:添加元數據到container中,查看現有容器的labels:
[root@docker lnmp]# docker inspect -f {{.Config.Labels}} lnmp-nginx map[com.docker.compose.oneoff:False com.docker.compose.service:nginx com.docker.compose.version:1.17.0 license:GPLv2 vendor:CentOS build-date:20170911 com.docker.compose.config-hash:edaa6c6d8f12639e28cb4bcdffda4961ef5a90f076e9017b204dacda56525e5b com.docker.compose.container-number:1 com.docker.compose.project:lnmp name:CentOS Base Image]
logging:爲服務配置記錄日誌
[root@docker lnmp]# cat lnmp.yml|grep logging -A 4 logging: driver: "json-file" options: max-size: "2000k" max-file: "10"
logging支持不少driver,而每個driver對應的options都不同:
[root@docker lnmp]# docker inspect -f {{.HostConfig.LogConfig}} lnmp-nginx {json-file map[max-file:10 max-size:2000k]}
[root@docker lnmp]# docker info |grep 'Logging Driver' Logging Driver: json-file
更多其餘的driver查看:https://docs.docker.com/engine/admin/logging/overview/
sysctls:在容器中設置內核參數
sysctls: net.core.somaxconn: 1024 net.ipv4.tcp_syncookies: 0 sysctls: - net.core.somaxconn=1024 - net.ipv4.tcp_syncookies=0