在 Windows Server 2019 上安装 dapr ，安装成功后有一段提示文字

Ensure that Docker Desktop is set to Linux containers mode when you run Dapr in self hosted mode.

开始时没注意到这个提示，然后安装 docker engine

Install-Module -Name DockerMsftProvider -Repository PSGallery -Force
Install-Package -Name docker -ProviderName DockerMsftProvider

接着运行 dapr init ，报下面的错误

docker: no matching manifest for windows/amd64 10.0.17763 in the manifest list entries.

查找资料后得知 docker engine 默认是 Windows container 模式，解决上面的错误需要切换到 Linux container 模式，这时才注意到安装 dapr 时的提示。

通过 docker desktop 切换到 Linux container 模式，但 docker engine 总是启动失败，报错如下：

The Virtual Machine Management Service failed to start the virtual machine 'DockerDesktopVM' because one of the Hyper-V components is not running

折腾一阵，没有解决，后来通过 Run Docker Containers on Windows Server 2019 知道原来需要安装 preview 版 Docker EE。

通过下面的一系列 powershell 命令安装 preview 版 Docker EE 之后，支持 Linux container 模式终于成功启动。

Install-Module -Name DockerMsftProvider -Repository PSGallery -Force

Uninstall-Package -Name docker -ProviderName DockerMSFTProvider
Install-Module DockerProvider
Install-Package Docker -ProviderName DockerProvider -RequiredVersion preview
Restart-Computer -Force
[Environment]::SetEnvironmentVariable("LCOW_SUPPORTED", "1", "Machine")
Restart-Service docker

但是运行 dapr init 出现新的错误

docker: failed to register layer: failed to start service utility VM (applydiff 88e57cc977280a42ef93829fad29a6ffbe1be1320278764f77575546056c1800): container 88e57cc977280a42ef93829fad29a6ffbe1be1320278764f77575546056c1800_svm encountered an error during CreateContainer: failure in a Windows system call: The virtual machine could not be started because a required feature is not installed. (0xc0370102) extra info: {"SystemType":"container","Name":"88e57cc977280a42ef93829fad29a6ffbe1be1320278764f77575546056c1800_svm","Layers":null,"HvPartition":true,"HvRuntime":{"ImagePath":"C:\Program Files\Linux Containers","LinuxInitrdFile":"initrd.img","LinuxKernelFile":"bootx64.efi"},"ContainerType":"linux","TerminateOnLastHandleClosed":true}.

运行 ubuntu 容器也是同样的错误

docker run -it --rm ubuntu /bin/bash

又折腾一阵，通过 Azure VM Docker CreateContainer Error (0xc0370102) 知道原来需要云服务器支持 Nested Virtualization，看来当前使用的百度云服务器不支持。

换到阿里云试试，阿里云提供了专门的“Windows Server 2019 with Container 数据中心版”镜像，用这个镜像也未能成功运行 Linux container。