cloudwatch_logger

Overview

The cloudwatch_logger node enables logs generated in a ROS system to get sent to AWS CloudWatch Logs. Out of the box, this node provides the ability to subscribe to the /rosout_agg (rosout aggregated) topic, which all logs using the ROS logging framework will be published to, and sends logs to the AWS CloudWatch Logs service. Logs can be sent to AWS CloudWatch Logs selectively based on log severity. The cloudwatch_logger node can also subscribe to other topics if logs are not sent to /rosout_agg, and it is able to unsubscribe to the rosout_agg topic for getting logs.

The cloudwatch_logger node wraps the aws-sdk-c++ in a ROS service API.

Amazon CloudWatch Logs Summary: AWS CloudWatch Logs can monitor applications and systems using log data. You can create alarms in CloudWatch and receive notifications of particular API activity as captured by CloudTrail and use the notification to perform troubleshooting. By default, logs are kept indefinitely and never expire. You can adjust the retention policy for each log group, keeping the indefinite retention, or choosing a retention periods between 10 years and one day. AWS CloudWatch Logs stores your log data in highly durable storage.

Keywords: ROS Application logs, System logs, AWS CloudWatch Logs service

License

The source code is released under an Apache 2.0.

Author: AWS RoboMaker
Affiliation: Amazon Web Services (AWS)

RoboMaker cloud extensions rely on third-party software licensed under open-source licenses and are provided for demonstration purposes only. Incorporation or use of RoboMaker cloud extensions in connection with your production workloads or commercial product(s) or devices may affect your legal rights or obligations under the applicable open-source licenses. License information for this repository can be found here. AWS does not provide support for this cloud extension. You are solely responsible for how you configure, deploy, and maintain this cloud extension in your workloads or commercial product(s) or devices.

Supported ROS Distributions

Kinetic
Melodic

Installation

AWS Credentials

You will need to create an AWS Account and configure the credentials to be able to communicate with AWS services. You may find AWS Configuration and Credential Files helpful.

This node will require the following AWS account IAM role permissions:

logs:PutLogEvents
logs:DescribeLogGroups
logs:DescribeLogStreams
logs:CreateLogStream
logs:CreateLogGroup

Building from Source

To build from source you'll need to create a new workspace, clone and checkout the latest release branch of this repository, install all the dependencies, and compile. If you need the latest development features you can clone from the master branch instead of the latest release branch. While we guarantee the release branches are stable, the master should be considered to have an unstable build due to ongoing development.

Create a ROS workspace and a source directory
```
  mkdir -p ~/ros-workspace/src
```

Clone the package into the source directory .

  cd ~/ros-workspace/src
  git clone https://github.com/aws-robotics/cloudwatchlogs-ros1.git -b release-latest

Install dependencies

  cd ~/ros-workspace 
  sudo apt-get update && rosdep update
  rosdep install --from-paths src --ignore-src -r -y

Note: If building the master branch instead of a release branch you may need to also checkout and build the master branches of the packages this package depends on.

Build the packages

cd ~/ros-workspace && colcon build

Configure ROS library Path

source ~/ros-workspace/install/setup.bash

Build and run the unit tests

colcon test --packages-select cloudwatch_logger && colcon test-result --all

Launch Files

An example launch file called sample_application.launch is provided.

Usage

Run the node

With launch file using parameters in .yaml format (example provided)
- ROS: roslaunch cloudwatch_logger sample_application.launch
Without launch file using default values
- ROS: rosrun cloudwatch_logger cloudwatch_logger

Send a test log message

rostopic pub -1 /rosout rosgraph_msgs/Log '{header: auto, level: 2, name: test_log, msg: test_cloudwatch_logger, function: test_logs, line: 1}'

Verify that the test log message was successfully sent to CloudWatch Logs

Go to your AWS account
Find CloudWatch and click into CloudWatch
On the upper right corner, change region to Oregon if you launched the node using the launch file, or change to N. Virginia if you launched the node without using the launch file
Select Logs from the left-hand side menu
With launch file: The name of the log group should be robot_application_name and the log stream should be device name
Without launch file: The name of the log group should be ros_log_group and the log stream should be ros_log_stream

Configuration File and Parameters

An example configuration file called sample_configuration.yaml is provided. When the parameters are absent in the ROS parameter server, default values are used, thus all parameters are optional. See table below for details.

Parameter Name	Description	Type	Allowed Values	Default
sub_to_rosout	Whether to subscribe to rosout_agg topic	bool	true/false	true
publish_frequency	Log publishing frequency in seconds	double	number	5.0
log_group_name	AWS CloudWatch log group name	std::string	'string' note: Log group names must be unique within a region foran AWS account	ros_log_group
log_stream_name	AWS CloudWatch log stream name	std::string	'string' note: The : (colon) and * (asterisk) characters are not allowed	ros_log_stream
topics	A list of topics to get logs from (excluding `rosout_agg`)	std::vectorstd::string	['string', 'string', 'string']	`[]`
min_log_verbosity	The minimum log severity for sending logs selectively to AWS CloudWatch Logs, log messages with a severity lower than `min_log_verbosity` will be ignored	std::string	DEBUG/INFO/WARN/ERROR/FATAL	DEBUG
publish_topic_names	Whether or not to include topic name information in the log messsages that are uploaded to AWS CloudWatch Logs	bool	true/false	true
storage_directory	The location where all offline metrics will be stored	string	string	~/.ros/cwlogs/
storage_limit	The maximum size of all offline storage files in KB. Once this limit is reached offline logs will start to be deleted oldest first.	int	number	1048576
delete_stale_data	Whether or not to delete log batch data that are over 14 days old, which are rejected by AWS PutLogEvents.	bool	true/false	false
aws_client_configuration	AWS region configuration	std::string	region: "us-west-2"/"us-east-1"/"us-east-2"/etc.	region: us-west-2

Advanced Configuration Parameters

Most users won't need to touch these parameters, they are useful if you want fine grained control over how your logs are stored offline and uploaded to CloudWatch.

Parameter Name	Description	Type	Default
batch_max_queue_size	The maximum number logs to add to the CloudWatch upload queue before they start to be written to disk	int	1024
batch_trigger_publish_size	Only publish logs to CloudWatch when there are this many items in the queue. When this is set the publishing of logs on a constant timer is disabled. This must be smaller than batch_max_queue_size. Logs uploaded from offline storage are not affected by this.	int	unset
file_max_queue_size	The max number of batches in the queue, each of size file_upload_batch_size, when reading and uploading from offline storage files	int	5
file_upload_batch_size	The size of each batch of logs in the queue, when reading and uploading from offline storage files	int	50
file_prefix	A prefix to add to each offline storage file so they're easier to identify later	string	cwlog
file_extension	The extension for all offline storage files	string	.log
maximum_file_size	The maximum size each offline storage file in KB	int	1024
stream_max_queue_size	The maximum number of batches in the queue to stream to CloudWatch. If this queue is full subsequent batches of logs will be written to disk.	int	3

Node