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Docker Swarm mode 指令教學 | docker service

MacauYeah・2023-08-22

之前一直都討論Image 的打包形式，現在聊聊部署上線時的一些指令。 Docker Service swarm mode 主要通過quot;docker servicequot; 指令去產生一堆可以在不同節點上運行的container。為了更加形象地講，我把container稱為Image的分身。 docker service create跟docker container run的感覺很像，兩者都可以指定image # swarm mode $ docker swarm init $ docker service create name nginx_s nginx # container mode $ docker container run d name nginx_c nginx 兩者的差別在於docker service 可以指定多少個分身，可以隨時加減數目，而且如果你有多過一台機器，分身就會在不同的機器上遊走。而docker container就是只對本機有操作，也不會散播到其他機器。 # swarm mode $ docker service create replicas=2 name nginx_s nginx $ docker service ls ID NAME MODE REPLICAS IMAGE PORTS uro4rwy6nelh nginx_s replicated 22 nginxlatest $ docker service update replicas=5 nginx_s $ docker service ls ID NAME MODE REPLICAS IMAGE PORTS uro4rwy6nelh nginx_s replicated 55 nginxlatest # container mode $ docker container run d name nginx_c1 nginx $ docker container run d name nginx_c2 nginx $ docker container run d name nginx_c3 nginx $ docker container run d name nginx_c4 nginx $ docker container run d name nginx_c5 nginx $ docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES c45771f06612 nginx quot;dockerentrypoint.hellip;quot; 7 seconds ago Up 6 seconds 80tcp nginx_c5 a587a718da3a nginx quot;dockerentrypoint.hellip;quot; 9 seconds ago Up 9 seconds 80tcp nginx_c4 079f206f8645 nginx quot;dockerentrypoint.hellip;quot; 9 seconds ago Up 9 seconds 80tcp nginx_c3 e10dc525fd22 nginx quot;dockerentrypoint.hellip;quot; 10 seconds ago Up 9 seconds 80tcp nginx_c2 dcaa2b4bb3de nginx quot;dockerentrypoint.hellip;quot; 10 seconds ago Up 9 seconds 80tcp nginx_c1 在建立網段時也差不多，service需要的是overlay network，而container用一般network就可以。 # swarm mode $ docker network create driver overlay nginx_s_gateway $ docker service update networkadd name=nginx_s_gateway,alias=gateway nginx_s $ docker service ps nginx_s ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS fxqtheyvr914 nginx_s.1 nginxlatest dockertest Running Running 33 seconds ago u0pvj1leoizw _ nginx_s.1 nginxlatest dockertest Shutdown Shutdown 33 seconds ago q7arumjlxduv nginx_s.2 nginxlatest dockertest Running Running 36 seconds ago kurlwqfmopbg _ nginx_s.2 nginxlatest dockertest Shutdown Shutdown 37 seconds ago zd0zlkhxafv0 nginx_s.3 nginxlatest dockertest Running Running 40 seconds ago 3kapr00fs6pt _ nginx_s.3 nginxlatest dockertest Shutdown Shutdown 40 seconds ago 5o4afd3whygo nginx_s.4 nginxlatest dockertest Running Running 35 seconds ago oxocropolbo8 _ nginx_s.4 nginxlatest dockertest Shutdown Shutdown 35 seconds ago x5y94jf3ok51 nginx_s.5 nginxlatest dockertest Running Running 38 seconds ago cgld3au0w1i9 _ nginx_s.5 nginxlatest dockertest Shutdown Shutdown 39 seconds ago # container mode $ docker network create nginx_c_gateway $ docker network connect alias gateway nginx_c_gateway nginx_c1 $ docker network connect alias gateway nginx_c_gateway nginx_c2 $ docker network connect alias gateway nginx_c_gateway nginx_c3 $ docker network connect alias gateway nginx_c_gateway nginx_c4 $ docker network connect alias gateway nginx_c_gateway nginx_c5 不過比較大的差異是service會停了原有的分身，重開新的分身去加入網段。所以上面的docker service ps nginx_s執行結果，就有一半是停掉的。類似地，docker service也不能單獨地停掉分身，頂多只能調整replicas=NUMBER，來控制分身數量。而單機則可以經過docker container stop來暫停分身。