停泊机组的服务与集装箱的区别 [英] Difference between service and container in docker compose

问题描述

我正在通过docker撰写的 volumes_from 选项。显然，您可以从容器或服务导入卷。从码头组成文件是：

I was going through volumes_from option in docker compose. Apparently you can import a volumes from either a container or a service. From the docker compose documentation it is:

volumes_from

从其他服务或容器安装所有卷，可选地
指定只读访问（ro）或读写（rw）。

Mount all of the volumes from another service or container, optionally specifying read-only access(ro) or read-write(rw).

volumes_from:
 - service_name
 - service_name:ro
 - container:container_name
 - container:container_name:rw

注意：容器：...格式仅支持版本2
文件格式。在版本1中，您可以使用容器名称，而不使用
：

Note: The container:... formats are only supported in the version 2 file format. In version 1, you can use container names without marking them as such:

- service_name
- service_name:ro
- container_name
- container_name:rw

$ b $我很困惑，这里容器和服务有什么区别？

I am confused here what is the difference between containers and services here?

推荐答案

服务和容器是相关的是不同的东西。

Services and container are related but both are different things.

服务可以由一个或多个容器运行。
使用 docker 可以处理容器，并且使用 docker-compose 可以处理服务。

A service can be run by one or multiple containers. With docker you can handle containers and with docker-compose you can handle services.

例如：

让我们说我们有这个 docker-compose.yml file：

Let's say that we have this docker-compose.yml file:

web:
  image: example/my_web_app:latest
  expose:
    - 80
  links:
    - db 

db:
  image: postgres:latest

此撰写文件定义了两个服务， web 和 db 。

This compose file defines two services, web and db.

当您运行 docker-compise up 时，假设项目目录为 test1 然后撰写将启动2个名为 myapp_db_1 和 myapp_web_1 的容器。

When you run docker-compose up, Asuming that the project directory is test1 then compose will start 2 containers named myapp_db_1 and myapp_web_1.

$ docker ps -a
CONTAINER ID   IMAGE        COMMAND          ...      NAMES
1c1683e871dc   test1_web    "nginx -g"       ...      test1_web_1
a41360558f96   test1_db     "postgres -d"    ...      test1_db_1

所以，在这一点上，您有两个服务，每个服务有1个容器。

So, in this point you have 2 services and 1 container for each.

但是，您可以扩展名为 web 使用5个容器。

But you could scale the service named web to use 5 containers.

$ docker-compose scale web=5
Creating and starting 2 ... done
Creating and starting 3 ... done
Creating and starting 4 ... done
Creating and starting 5 ... done

在这一点上，您有2个服务和6个容器

In this point you have 2 services and 6 containers

$ docker ps -a  
CONTAINER ID   IMAGE        COMMAND         ...      NAMES
1bf4c939263f   test1_web    "nginx -g"      ...      test1_web_3
d3033964a44b   test1_web    "nginx -g"      ...      test1_web_4
649bbda4d0b0   test1_web    "nginx -g"      ...      test1_web_5
a265ea406727   test1_web    "nginx -g"      ...      test1_web_2
1c1683e871dc   test1_web    "nginx -g"      ...      test1_web_1
a41360558f96   test1_db     "postgres -d'   ...      test1_db_1

此外，使用docker-compose，您可以针对一个或多个服务运行子命令。

Additionally, with docker-compose you can run subcommand against one or more services.

$docker-compose stop web

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