docker network基础
前面介紹了nginx與php兩個容器間是如何進行通信的:
[root@docker ~]# docker run -d --name=php -v /www:/usr/local/nginx/html php [root@docker ~]# docker run -d --name=nginx --link=php:php -v /www:/usr/local/nginx/html -p 81:80 nginx [root@docker ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 58280fe851f9 nginx "/usr/local/nginx/..." 15 seconds ago Up 14 seconds 0.0.0.0:81->80/tcp nginx 9ea150c35587 php "/usr/local/php/sb..." 36 seconds ago Up 35 seconds 9000/tcp php通過容器間的選項--link指定容器名稱進行不同容器間的通信(--link container_name或者將container_name取一個別名)
現在使用另外一種方式替代--link來達到容器間的通信:docker network
查看local的網絡信息:
[root@docker ~]# docker network ls NETWORK ID NAME DRIVER SCOPE 5133ec415c3c bridge bridge local f359ca4e2d39 host host local 8d68673c045c none null local現在創建一個網絡名為my_net且driver為bridge的網絡:(默認創建的就是bridge)
[root@docker ~]# docker network create my_net 67e29f0e4a77c79144efc337a081a889188b5b8e289968f22be6e4ddd9b80610 [root@docker ~]# docker network ls NETWORK ID NAME DRIVER SCOPE 5133ec415c3c bridge bridge local f359ca4e2d39 host host local 67e29f0e4a77 my_net bridge local 8d68673c045c none null local利用--network啟動容器提供服務:
[root@docker ~]# docker run -d --name=php --network my_net --network-alias php -v /www:/usr/local/nginx/html php 6b493cbe8207dee4cb4d5945cfce305dba96914083bd7f46841b0b42376bcb99 [root@docker ~]# docker run -d --name=nginx --network my_net --network-alias nginx -v /www:/usr/local/nginx/html -p 80:80 nginx 5ab220196b52bb768bef508433f0b920eecee70c3ee47880ebc5e2a74b5ee254通過選項--network-alias將取名的my_net起了一個別名
[root@docker ~]# docker exec -it nginx ping php PING php (172.18.0.2) 56(84) bytes of data. 64 bytes from php.my_net (172.18.0.2): icmp_seq=1 ttl=64 time=0.079 ms 64 bytes from php.my_net (172.18.0.2): icmp_seq=2 ttl=64 time=0.090 ms這里為啥能夠ping通過php這個容器呢,因為這兩個容器在同一個網絡m'y_net內,而nginx里面ping的php是容器名(這里管理的是容器級別)
由于能夠ping通php,所以在nginx中配置的:
server {listen 80;root /usr/local/nginx/html;index index.htm index.html index.php;location ~ \.php$ {root /usr/local/nginx/html;fastcgi_pass php:9000;fastcgi_index index.php;fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;include fastcgi_params;} }所以配置文件中的php不會導致nginx啟動失敗,通過network的driver bridge實現了容器間的訪問
?
上面在容器啟動的時候使用的是選項--network,而在compose的配置文件中則是networks,現在通過配置文件來進行闡述該參數的作用:
[root@docker lnmp]# cat lnmp.yml version: '3' services:nginx:image: nginxcontainer_name: lnmp-nginxdepends_on:- phpports:- "80:80"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"php:image: phpcontainer_name: lnmp-phpexpose: - "9000"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"networks:net1:driver: bridge由上述文件中可以知道networks定義了一個名稱為net1的網絡,由于networks是top-level(頂層級別,所以需要在頂層設置),而在創建的網絡時候需要指定driver(單一網絡使用bridge,swarm集群使用overlay),而且driver內容不能省略,在nginx和php兩個service中使用了同一網絡net1,現在將服務啟動:
[root@docker lnmp]# docker-compose -f lnmp.yml up 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可以看出在啟動服務的時候創建了服務級別的網絡lnmp_net1
[root@docker lnmp]# docker network ls NETWORK ID NAME DRIVER SCOPE 5133ec415c3c bridge bridge local f359ca4e2d39 host host local 29d798852b52 lnmp_net1 bridge local 67e29f0e4a77 my_net bridge local 8d68673c045c none null local服務nginx和php在網絡lnmp_net1實現了互聯通信
[root@docker lnmp]# docker-compose -f lnmp.yml exec nginx ping php PING php (172.19.0.2) 56(84) bytes of data. 64 bytes from lnmp-php.lnmp_net1 (172.19.0.2): icmp_seq=1 ttl=64 time=0.060 ms在nginx服務中能夠訪問php的服務,在compose編排中級別的訪問是對service級別的訪問,所以在nginx服務配置文件中對應的php能夠實現,不會導致nginx啟動失敗
及在compose的配置文件設置并對應的是service級別,當使用參數links也是配置的php服務,使得nginx服務能夠ping通php服務并實現訪問通信
[root@docker lnmp]# cat lnmp.yml version: '3' services:nginx:image: nginxcontainer_name: lnmp-nginxdepends_on:- phpports:- "80:80"links:- php:phpvolumes:- "/www:/usr/local/nginx/html"php:image: phpcontainer_name: lnmp-phpexpose: - "9000"volumes:- "/www:/usr/local/nginx/html"將networks參數改為了links參數,使得兩個服務能夠繼續互聯訪問
[root@docker lnmp]# docker-compose -f lnmp.yml up Creating network "lnmp_default" with the default driver Creating lnmp-php ... Creating lnmp-php ... done Creating lnmp-nginx ... Creating lnmp-nginx ... done Attaching to lnmp-php, lnmp-nginx而且啟動的時候創建的默認的網絡
[root@docker lnmp]# docker-compose -f lnmp.yml exec nginx ping php PING php (172.19.0.2) 56(84) bytes of data. 64 bytes from lnmp-php.lnmp_default (172.19.0.2): icmp_seq=1 ttl=64 time=0.091 ms 64 bytes from lnmp-php.lnmp_default (172.19.0.2): icmp_seq=2 ttl=64 time=0.107 ms--links也是能夠使得服務間進行訪問的
?
現在通過案例講解參數external_links的作用:external_links類似于links針對的也是service級別,但是external_links對應的是外部的service而不是同一compose配置文件中的service
[root@docker lnmp]# cat lnmp.yml version: '3' services:nginx:image: nginxcontainer_name: lnmp-nginxdepends_on:- phpports:- "80:80"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"external_links:- php1:phpphp:image: phpcontainer_name: lnmp-phpexpose: - "9000"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"networks:net1:driver: bridge上面可以看見external_links配置了php1的服務,并且將php1的服務也取別名為了php,然后編寫另一個compose配置文件,并配置服務名為php1的服務:
[root@docker lnmp]# cat php1.yml version: '3' services:php1:image: phpcontainer_name: lnmp-php1expose: - "9000"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"networks:net1:driver: bridge結合兩個compose配置文件,可以知道有nginx、php、php1的服務,并且php1的服務也有php的別名,現在依次開啟php1,和nginx與php:
[root@docker lnmp]# docker-compose -f php1.yml up Creating network "lnmp_net1" with driver "bridge" Creating lnmp-php1 ... Creating lnmp-php1 ... done Attaching to lnmp-php1 [root@docker lnmp]# docker-compose -f lnmp.yml up --build WARNING: Found orphan containers (lnmp-php1) for this project. If you removed or renamed this service in your compose file, you can run this command with the --remove-orphans flag to clean it up. Creating lnmp-php ... Creating lnmp-php ... done Creating lnmp-nginx ... Creating lnmp-nginx ... done Attaching to lnmp-php, lnmp-nginx查看啟動的容器狀態:
[root@docker www]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a089cd261279 nginx "/usr/local/nginx/..." 25 seconds ago Up 25 seconds 0.0.0.0:80->80/tcp lnmp-nginx 4ff4bf7c1bf9 php "/usr/local/php/sb..." 25 seconds ago Up 25 seconds 9000/tcp lnmp-php 4e39cdf62bf1 php "/usr/local/php/sb..." 51 seconds ago Up 51 seconds 9000/tcp lnmp-php1現在將nginx一起的php的這個服務停止掉,看下nginx服務是否將會被停止:
[root@docker lnmp]# docker-compose -f lnmp.yml stop php Stopping lnmp-php ... done而在nginx這里的輸出如下:
lnmp-php exited with code 0 [root@docker www]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a089cd261279 nginx "/usr/local/nginx/..." 2 minutes ago Up 2 minutes 0.0.0.0:80->80/tcp lnmp-nginx 4ff4bf7c1bf9 php "/usr/local/php/sb..." 2 minutes ago Exited (0) 52 seconds ago lnmp-php而php服務對應的容器lnmp-php也停止了,但是nginx的服務卻沒有停止,為什么呢?那是因為php1的服務并沒有停止,而php1的服務也是別名php服務的,而external_links就是實現這種情況的
使一個compose中的服務能與另一個compose中的服務能夠互聯通信,compose就是service級別的實現,配置文件中對應的都是service級別,而不是容器名
而在另一個compose中也必須定義與之相同的網絡名稱,也就是說配置external_links時,兩者服務間的網絡名稱必須一致,不然依舊不能進行互相訪問
當使用了external_links時,必須啟動另一個compose的service,如果僅僅啟動的是包含此函數的compose那么service將會啟動報錯
[root@docker lnmp]# cat lnmp.yml_external_links version: '3' services:nginx:image: nginxcontainer_name: lnmp-nginxdepends_on:- phpports:- "80:80"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"external_links:- php1:phpphp:image: phpcontainer_name: lnmp-phpexpose: - "9000"networks:- "net1"volumes:- "/www:/usr/local/nginx/html"networks:net1:driver: bridge [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 lnmp-nginx | nginx: [emerg] host not found in upstream "php" in /usr/local/nginx/conf/vhost/www.conf:7 lnmp-nginx exited with code 1參數external_links連接的外部php服務并沒有啟動,所以nginx還是啟動報錯
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