goroslib is a library in pure Go that allows to build clients (nodes) for the Robot Operating System (ROS).
The Robot Operating System (ROS) is a project that provides a specification to make multiple programs communicate with each other over time, exchanging structured data with topics, services, actions and parameters. It was conceived to link sensors, algorithms and actuators in unmanned ground vehicles (UGVs) and robots, but it is not bounded to the robot world and can be used anywhere there's the need of building streams of data (for example in video processing).
Features:
- Subscribe and publish to topics, with TCP or UDP
- Provide and call services
- Provide and call actions and simple actions
- Get and set parameters
- Get infos about other nodes, topics, services
- Use namespaces and relative topics
- Use a time API to synchronize execution with a real or simulated clock
- Support IPv6 (only stateful addresses, since stateless are not supported by the ROS master)
- Compilation of
.msgfiles is not necessary, message definitions are extracted from code - Compile or cross-compile ROS nodes for all Golang supported OSs (Linux, Windows, Mac OS X) and architectures
- Examples provided for every feature, comprehensive test suite, continuous integration
-
Install Go ≥ 1.14.
-
Create an empty folder, open a terminal in it and initialize the Go modules system:
go mod init main -
Download one of the example files and place it in the folder:
-
Compile and run (a ROS master must be already running in the background)
go run name-of-the-go-file.go
https://pkg.go.dev/github.com/aler9/goroslib#pkg-index
The official project provides libraries to write nodes in C++ and Python, but they require the download of over 1GB of data and work only with a fixed buildchain. This library allows to write lightweight nodes that can be built with the standard Go compiler, do not need any runtime library and have a size of some megabytes. Another advantage lies in the possibility of compiling nodes for all the Golang supported operating systems (Linux, Windows, Mac OS X, etc) and architectures.
rosgo is currently unmaintained; furthermore, it requires compilation of .msg files, doesn't support UDP, doesn't support actions, doesn't support simulated clocks.
Current and missing features are described in the FEATURES document.
This library already provides most of the standard messages, services and actions in the folder pkg/msgs:
| package | documentation | repository |
|---|---|---|
| ackermann_msgs | link | link |
| actionlib | link | link |
| actionlib_msgs | link | link |
| audio_common_msgs | link | link |
| control_msgs | link | link |
| diagnostic_msgs | link | link |
| geometry_msgs | link | link |
| nav_msgs | link | link |
| rosgraph_msgs | link | link |
| sensor_msgs | link | link |
| shape_msgs | link | link |
| sound_play | link | link |
| std_msgs | link | link |
| std_srvs | link | link |
| stereo_msgs | link | link |
| trajectory_msgs | link | link |
| velodyne_msgs | link | link |
| vision_msgs | link | link |
| visualization_msgs | link | link |
To define custom messages, the standard ROS C++/Python libraries require .msg files in this format:
bool field1
int32 field2
This library doesn't require any .msg file, it is enough to write Go structures in this format:
import (
"github.com/aler9/goroslib/pkg/msgs"
)
type MessageName struct {
msg.Package `ros:"my_package"`
Field1 bool
Field2 int32
}The type of a field can be one of the following:
-
one of the primitive field types:
- bool
- int8
- uint8
- int16
- uint16
- int32
- uint32
- int64
- uint64
- float32
- float64
- string
- time.Time
- time.Duration
-
another standard or custom message
The name of a field must be in CamelCase, and is converted to snake_case when interacting with C++/Python nodes. If this conversion is not possible, the tag rosname can be used to override the field name:
type MessageName struct {
msg.Package `ros:"my_package"`
Field bool `rosname:"FIELD"`
}Services in this format:
uint32 input
---
uint32 output
Are equivalent to Go structures in this format:
type ServiceNameReq struct {
Input uint32
}
type ServiceNameRes struct {
Output uint32
}
type ServiceName struct {
msg.Package `ros:"my_package"`
ServiceNameReq
ServiceNameRes
}Actions in this format:
uint32 goal
---
uint32 result
---
uint32 feedback
Are equivalent to Go structures in this format:
type ActionNameGoal struct {
Goal uint32
}
type ActionNameResult struct {
Result uint32
}
type ActionNameFeedback struct {
Feedback uint32
}
type ActionName struct {
msg.Package `ros:"my_package"`
ActionNameGoal
ActionNameResult
ActionNameFeedback
}A command-line utility is provided to convert existing .msg files into their equivalent Go structures:
go get github.com/aler9/goroslib/cmd/msg-import
msg-import --rospackage=my_package mymessage.msg > mymessage.go
Another one is provided to convert existing .srv files into their equivalent Go structures:
go get github.com/aler9/goroslib/cmd/srv-import
srv-import --rospackage=my_package myservice.srv > myservice.go
Another one is provided to convert existing .action files into their equivalent Go structures:
go get github.com/aler9/goroslib/cmd/action-import
action-import --rospackage=my_package myaction.action > myaction.go
There's a field Namespace in the Node configuration:
goroslib.NewNode(goroslib.NodeConf{
Namespace: "/mynamespace",
Name: "goroslib",
MasterAddress: "127.0.0.1:11311",
})The default namespace is / (global namespace).
To compile a node for another OS, it's enough to follow the standard Golang procedure to cross-compile, that consists in setting the GOOS and GOARCH environment variables according to the target machine. For instance, to build a node for Windows from another OS, run:
GOOS=windows GOARCH=amd64 go build -o node.exe name-of-source-file.go
If you want to hack the library and test the results, unit tests can be launched with:
make test
(v1) ROS Documentation
- Conventions
- APIs
- Protocols
Other Go libraries
Other non-Go libraries
- (v1) [cpp] https://github.com/ros/ros_comm/tree/melodic-devel/clients/roscpp/src/libros (https://docs.ros.org/melodic/api/roscpp/html/classros_1_1NodeHandle.html)
- (v1) [python] https://docs.ros.org/melodic/api/rosnode/html/
- (v1) [c] https://github.com/ros-industrial/cros
- (v2) [misc] https://fkromer.github.io/awesome-ros2/
Conventions