docker-compose scale 命令不起作用

當我輸入命令

docker-compose up -d  --scale web=5 

顯示如下

Builds, (re)creates, starts, and attaches to containers for a service.

Unless they are already running, this command also starts any linked services.

The `docker-compose up` command aggregates the output of each container. When
the command exits, all containers are stopped. Running `docker-compose up -d`
starts the containers in the background and leaves them running.

沒有擴大服務。

作業系統是 openSUSE Leap。

輸出的剩餘部分是

If there are existing containers for a service, and the service's configuration
or image was changed after the container's creation, `docker-compose up` picks
up the changes by stopping and recreating the containers (preserving mounted
volumes). To prevent Compose from picking up changes, use the `--no-recreate`
flag.

If you want to force Compose to stop and recreate all containers, use the
`--force-recreate` flag.

Usage: up [options] [SERVICE . . . ]

Options:
   -d                              Detached mode: Run containers in the background,
                                   print new container names.
                                   Incompatible with --abort-on-container-exit.
   --no-color                  Produce monochrome output.
   --no-deps                   Don't start linked services.
   --force-recreate            Recreate containers even if their configuration
                                   and image haven't changed.
                                   Incompatible with --no-recreate.
   --no-recreate               If containers already exist, don't recreate them.
                                   Incompatible with --force-recreate.
   --no-build                  Don't build an image, even if it's missing.
   --build                         Build images before starting containers.
   --abort-on-container-exit   Stops all containers if any container was stopped.
                                   Incompatible with -d.
   -t, --timeout TIMEOUT       Use this timeout in seconds for container shutdown
                                   when attached or when containers are already
                                   running. (default: 10)
   --remove-orphans            Remove containers for services not
                                   defined in the Compose file

docker-compose 的版本是 1.8.1。

docker-compose.yml 文件是

   version: '2'

   services:

           web:
              image: nginx:alpine

           util:
              image: sixeyed/ubuntu-with-utils
              container_name: util
              command: ping web

該標誌直到 2017 年 5 月的 1.13.0 版本--scale才引入。1.8.1 版本相當過時（從2016 年 9 月開始），應該升級。

您可以從docker-compose github 發布頁面中提取最新版本。

該--scale標誌僅在新版本中有效。檢查 docker-compose 版本：

$ docker-compose -v

如果低於 1.24.0 版本，請安裝新版本。遵循這個：如何將 docker-compose 升級到最新版本

引用自：https://serverfault.com/questions/990909