vendor/github.com/docker/docker/integration-cli/fixtures/credentialspecs/valid.json

{
    "CmsPlugins":  [
                       "ActiveDirectory"
                   ],
    "DomainJoinConfig":  {
                             "Sid":  "S-1-5-21-4288985-3632099173-1864715694",
                             "MachineAccountName":  "MusicStoreAcct",
                             "Guid":  "3705d4c3-0b80-42a9-ad97-ebc1801c74b9",
                             "DnsTreeName":  "hyperv.local",
                             "DnsName":  "hyperv.local",
                             "NetBiosName":  "hyperv"
                         },
    "ActiveDirectoryConfig":  {
                                  "GroupManagedServiceAccounts":  [
                                                                      {
                                                                          "Name":  "MusicStoreAcct",
                                                                          "Scope":  "hyperv.local"
                                                                      },
                                                                      {
                                                                          "Name":  "MusicStoreAcct",
                                                                          "Scope":  "hyperv"
                                                                      }
                                                                  ]
                              }
}