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Controller interface

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Pierre Lasorak edited this page Jun 5, 2024 · 7 revisions

This page provides an entry point to the way the drunc server should be interfaced.

This document refers to the Controller in particular. Its proto file can be found here

Messages

Remember that all the messages sent to and received from the controller follow the drunc schema described here. All the messages described here will end up in some form or another in the data fields of the Request and Response after being Anyfied.

Status

This message encodes the status (and FSM status) of a controller or DAQ application. It has the form:

message Status {
  string name = 1;
  string state = 2;
  string sub_state = 3;
  bool   in_error = 4;
  bool   included = 5;
}

Most of the fields should be self-explanatory. The state refers to the FSM state. There is another (secondary) FSM that encodes transitions themselves. Generally, if the endpoint is not transitioning, you should get state = substate or substate = idle for a DAQ application, otherwise, you will get substate of the form preparing-configure etc.

ChildrenStatus

This message is a list of the above Status, and encodes the statuses of the children of the controller. Schema is:

message ChildrenStatus {
  repeated Status children_status = 1;
}

Argument

This message is for describing a generic FSM argument. It has the form:

message Argument {
  enum Presence{
    MANDATORY = 0;
    OPTIONAL = 1;
  }
  enum Type {
    INT = 0;
    FLOAT = 1;
    STRING = 2;
    BOOL = 3;
  }
  string name = 1;
  Presence presence = 2;
  Type type = 3;
  optional google.protobuf.Any default_value = 4;
  repeated google.protobuf.Any choices = 5;
  string help = 6;
}

Where:

  • name is the name of the arguments
  • presence is encoded in an enum defined in the Argument schema.
  • type is the data type. Note that the only supported data types are the ones listed here.
  • default_value is the default value that the argument will take (required if presence=optional)
  • choices are the eventual choices that the argument can take
  • help is some string for help.

FSMCommandDescription

have the form:

message FSMCommandDescription {
  string name = 1;
  repeated string data_type = 2;
  string help = 3;
  string return_type = 4;
  repeated Argument arguments = 5;
}

Where:

  • name is the name of the FSM command (such as conf, enable_triggers, etc.)
  • data_type is what is needed to run the command (it's always FSMCommand - described later)
  • help some explanatory text of the command (never really filled but would be nice to have at some point)
  • return_type is what is returned by the command (it's always FSMCommandResponse - described later)
  • arguments is a list of the arguments in Argument format that are needed to execute the command.

FSMCommandsDescription

Is a list of available FSM commands described above:

message FSMCommandsDescription {
  string type = 1;
  string name = 2;
  optional string session = 3;
  repeated FSMCommandDescription commands = 4;
}

Everything can be ignored except commands which is a list of the command accessible now. TODO: Needs cleanup

FSMCommand

Have the format:

message FSMCommand{
  string command_name = 1;
  map<string, google.protobuf.Any> arguments = 2;
  repeated string children_nodes = 3;
  optional string data = 4; // unfortunately, this is just some plain old json data introduced by the fsm interfaces
}

where:

  • command_name is the name of the command one wants to execute (such as conf, enable_triggers, etc.)
  • arguments is a map of argument names to their values. Their value must be one of the 4:
  • children_nodes is used to address the command to one or more children. If one wants to send a command to a specific list of children they can be specified as a list here. If no list is specified, the controller will send the FSM command to all the children.
  • data is the internal drunc message that gets derived from the FSMInterfaces. The user should not fill this out manually.

FSMResponseFlag

Is a simple enum to understand if the command was successful or not:

enum FSMResponseFlag {
  FSM_EXECUTED_SUCCESSFULLY = 0;
  FSM_FAILED = 1;
  FSM_INVALID_TRANSITION = 2;
  FSM_NOT_EXECUTED_EXCLUDED = 3;
}

FSMCommandResponse

The format is described in here:

message FSMCommandResponse{
  FSMResponseFlag flag = 1;
  string command_name = 2;
  google.protobuf.Any data = 3;
}

where:

  • flag is a simple enum describing the FSM command's successful execution or not
  • command_name is the command that was executed.
  • data is the returned data for the FSM transition (which can be safely ignored for now, since it's not used)

Endpoints

Each RPC call is described here.

describe

... is already described in here.

describe_fsm

One can ask the controller to specifically describe its FSM. The controller will answer with data of the format FSMCommandsDescription. This message will contain a list of FSMCommandDescription. These commands can contain a list of Arguments that need to be specified for some transitions.

execute_fsm_command

FSM commands can be sent to the controller by using the RPC endpoint execute_fsm_command:

  • input: FSMCommand
  • output: FSMCommandResponse
  • interruption/exceptions:
    • The sender is not in control of the controller
    • The arguments in the input data are not of correct type
    • The mandatory arguments were not specified

get_status

  • input: None
  • output: Status message
  • interruption/exceptions:
    • None hopefully

get_children_status

ls

  • input: None
  • output: PlainTextVector containing all a list of the controller's children
  • interruption/exceptions:
    • None hopefully

exclude

Excluded nodes won't be passed FSM commands. This command excludes the controller and all its descendants.

  • input: None (TODO should be a list of children to exclude)
  • output: PlainText of the form: "<controller_name> excluded"
  • interruption/exceptions:
    • The sender is not in control of the controller
    • The controller is already excluded

include

Excluded nodes won't be passed FSM commands. This command includes the controller and all its descendants.

  • input: None (TODO should be a list of children to include)
  • output: PlainText of the form: "<controller_name> included"
  • interruption/exceptions:
    • The sender is not in control of the controller
    • The controller is already included

take_control

Takes control of a controller and it's children

  • input: None (TODO should be a list of children to take control of)
  • output: PlainText of the form: "<user_name> took control"
  • interruption/exceptions:
    • Someone is already in control of the controller (including the same user name)

surrender_control

Surrenders control of a controller and it's children

  • input: None (TODO should be a list of children to surrender the control of)
  • output: PlainText of the form: "<user_name> surrendered control"
  • interruption/exceptions:
    • The sender is not in control of the controller

who_is_in_charge

Says who is controlling the controller

  • input: None
  • output: PlainText of the form: "<user_name>"
  • interruption/exceptions:
    • None hopefully.
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