Pulumi to create ACR and ACR Task to purge image automatically

AcrTask.cs

using Pulumi.AzureNative.ContainerRegistry;
using Pulumi.AzureNative.ContainerRegistry.Inputs;

var opt = new CustomResourceOptions { Parent = this };
var cmd = "acr purge --filter 'samples/devimage1:.*' --filter 'samples/devimage2:.*' --ago 0d --untagged --dry-run";

var acr = new Registry("nanika", new RegistryArgs
{
    RegistryName = "nantoka",
    Sku = new SkuArgs
    {
        Name = SkuName.Basic,
    },
    AdminUserEnabled = true, // 無効推奨。だが、ContainerApp で必要: https://azure.github.io/PSRule.Rules.Azure/en/rules/Azure.ACR.AdminUser/
    ResourceGroupName = "foo-group",
    Location = "japaneast",
}, opt);

_ = new Pulumi.AzureNative.ContainerRegistry.Task("nanika-task", new TaskArgs
{
  TaskName = "purgeTask",
  AgentConfiguration = new AgentPropertiesArgs
  {
    Cpu = 2,
  },
  Platform = new PlatformPropertiesArgs
  {
    Architecture = Architecture.Amd64,
    Os = OS.Linux,
  },
  Step = new EncodedTaskStepArgs
  {
    EncodedTaskContent = ToEncodedTaskString(cmd),
    Type = "EncodedTask",
  },
  Status = TaskStatus.Enabled,
  Timeout = 3600,
  Trigger = new TriggerPropertiesArgs
  {
    BaseImageTrigger = new BaseImageTriggerArgs
    {
      BaseImageTriggerType = BaseImageTriggerType.Runtime,
      Name = "defaultBaseimageTriggerName",
      Status = TriggerStatus.Enabled,
      UpdateTriggerPayloadType = UpdateTriggerPayloadType.Default,
    },
    TimerTriggers = new [] {
        new TimerTriggerArgs
        {
          Name = "t1",
          Schedule = "0 0 * * *", // UTCベース
          Status = TriggerStatus.Enabled,
        },
    }
  },
  RegistryName = acr.Name,
  ResourceGroupName = "foo-group",
  Location = "japaneast",
}, opt);


private static string ToEncodedTaskString(string cmd)
{
    const string format = @"version: v1.1.0
steps:
- cmd: {0}
disableWorkingDirectoryOverride: true
timeout: 3600";
    var step = string.Format(format, cmd);
    return Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(step));
}