AWS Greengrass - Developer Guide

1 AWS GreengrassDeveloper GuideAWS Greengrass Developer GuideAWS Greengrass : Developer GuideCopyright 2018 Amazon Web Services, Inc. and/or its affiliates. All rights 's trademarks and trade dress may not be used in connection with any product or service that is not Amazon's, in any mannerthat is likely to cause confusion among customers, or in any manner that disparages or discredits Amazon. All other trademarks notowned by Amazon are the property of their respective owners, who may or may not be affiliated with, connected to, or sponsored Greengrass Developer GuideTable of ContentsWhat Is AWS Greengrass ? .. 1 AWS Greengrass Core Software .. 2 AWS Greengrass Core Versions .. 2 AWS Greengrass Groups .. 4 Devices in AWS Greengrass .. 6 Supported Platforms and Requirements .. 12We Want to Hear from You .. 16 AWS Greengrass Core .. 2 AWS Greengrass Core Configuration File.

2 17 Write Directory .. 23 MQTT Message Queue .. 25 Start Greengrass on System Boot .. 28 Getting Started with AWS Greengrass .. 30 Requirements .. 30 Create an AWS Account .. 31 Module 1: Environment Setup for Greengrass .. 31 Setting Up a Raspberry Pi .. 31 Setting Up an Amazon EC2 Instance .. 37 Setting Up Other Devices .. 40 Module 2: Installing the Greengrass Core Software .. 44 Configure AWS Greengrass on AWS IoT .. 44 Start AWS Greengrass on the Core Device .. 49 Module 3 (Part 1): Lambda Functions on AWS Greengrass .. 52 Create and Package a Lambda Function .. 52 Configure the Lambda Function for AWS Greengrass .. 58 Deploy Cloud Configurations to a Core Device .. 63 Verify the Lambda Function Is Running on the Device .. 64 Module 3 (Part 2): Lambda Functions on AWS Greengrass .. 67 Create and Package the Lambda Function .. 67 Configure Long-Lived Lambda Functions for AWS Greengrass .

3 69 Test Long-Lived Lambda Functions .. 70 Test On-Demand Lambda Functions .. 75 Module 4: Interacting with Devices in an AWS Greengrass Group .. 78 Create AWS IoT Devices in an AWS Greengrass Group .. 79 Configure Subscriptions .. 83 Install the AWS IoT Device SDK for Python .. 84 Test Communications .. 88 Module 5: Interacting with Device Shadows .. 92 Configure Devices and Subscriptions .. 93 Download Required Files .. 95 Test Communications (Device Syncs Disabled) .. 96 Test Communications (Device Syncs Enabled) .. 97 Module 6: Accessing AWS Cloud Services .. 99 Configure IAM Roles .. 100 Create and Configure the Lambda Function .. 104 Configure Subscriptions .. 109 Test Communications .. 112 OTA Updates of AWS Greengrass Core Software .. 115 Greengrass OTA Agent .. 116 Integration with Init 118 OTA Self-Update with Managed Respawn .. 119 AWS Greengrass Core Update with Managed Respawn.

4 119 OTA Agent Self-Update .. 119iiiAWS Greengrass Developer GuideGreengrass Core Software Update .. 120 Reset Deployments .. 121 Run Local Lambda Functions .. 123 Migrating Cloud-Based Lambda Functions .. 124 Function Aliases and Versions .. 124 Group-Specific Configuration .. 125 Communication Flows .. 125 MQTT Messages .. 126 Other Communication Flows .. 126 Lifecycle Configuration .. 126 Lambda Executables .. 127 Create a Lambda Executable .. 128 Access Local Resources with Lambda Functions .. 130 Supported Resource Types .. 130 Requirements .. 131 Volume Resources Under the /proc Directory .. 131 Group Owner File Access Permission .. 131 See 132 Using the 132 Create Local Resources .. 132 Create the Greengrass Function .. 133 Add the Lambda Function to the Group .. 134 Troubleshooting .. 136 Using the 136 Prerequisites .. 137 Create a Lambda Function Deployment Package.

5 137 Create and Publish a Lambda Function .. 139 Add the Lambda Function to the Group .. 143 Add a Local Resource to the Group .. 146 Add Subscriptions to the Group .. 148 Deploy the Group .. 150 Test Local Resource Access .. 151 Perform Machine Learning Inference .. 155 How AWS Greengrass ML Inference Works .. 155 Machine Learning Resources .. 156 Supported Model Sources .. 156 Requirements .. 158 Precompiled Libraries for ML Frameworks .. 158 MXNet Versioning .. 158 TensorFlow Model-Serving Limitations on Raspberry Pi .. 158 How to Configure Machine Learning Inference .. 159 Prerequisites .. 159 Configure the Raspberry Pi .. 160 Install the MXNet Framework .. 160 Create a Model Package .. 162 Create and Publish a Lambda Function .. 162 Add the Lambda Function to the Group .. 167 Add Resources to the Group .. 169 Add a Subscription to the Group .. 172 Deploy the Group .. 173 Test the App.

6 175 Next Steps .. 178 Configuring an NVIDIA Jetson TX2 .. 178 Greengrass Discovery RESTful API .. 179 Request .. 179 Response .. 179ivAWS Greengrass Developer 179 Example Discover Response Documents .. 180 Greengrass OPC-UA .. 182 Architectural Overview .. 182 Set Up a Test OPC-UA Server .. 183 Make sure your Greengrass Group is ready .. 183 Use Greengrass OPC-UA to Interact with your OPC-UA Server .. 184 Verify that your Lambda function is receiving OPC-UA Publishes and posting them onto Greengrass .. 186 Next Steps .. 186 AWS Greengrass Security .. 187 Configuring Greengrass Security .. 188 Device Connection Workflow .. 188 Greengrass Messaging Workflow .. 188 MQTT Core Server Certificate Rotation .. 189 AWS Greengrass Cipher Suites .. 191 CloudWatch Logs .. 191 File System Logs .. 191 Default Logging 192 Configure Logging for AWS Greengrass .. 192 Configure Logging (Console).

7 192 Configure Logging (API) .. 193 Configuration 194 Logging 195 Transactions per Second .. 195 Memory .. 195 Clock Skew .. 195 Disk 195 Log 195 Troubleshooting AWS Greengrass Applications .. 196 Troubleshooting with Logs .. 199 Troubleshooting Storage Issues .. 202 Troubleshooting Messages .. 203 Troubleshooting Shadow Synchronization Timeout Issues .. 203 Document History .. 207 Earlier 207vAWS Greengrass Developer GuideWhat Is AWS Greengrass ?AWS Greengrass is software that extends AWS Cloud capabilities to local devices, making it possiblefor those devices to collect and analyze data closer to the source of information, while also securelycommunicating with each other on local networks. More specifically, developers who use AWSG reengrass can author serverless code (AWS Lambda functions) in the cloud and conveniently deploy itto devices for local execution of following diagram shows the basic architecture of AWS Greengrass makes it possible for customers to use Lambda functions to build IoT devices andapplication logic.

8 Specifically, AWS Greengrass provides cloud-based management of applications thatcan be deployed for local execution. Locally deployed Lambda functions are triggered by local events,messages from the cloud, or other AWS Greengrass , devices securely communicate on a local network and exchange messages witheach other without having to connect to the cloud. AWS Greengrass provides a local pub/sub messagemanager that can intelligently buffer messages if connectivity is lost so that inbound and outboundmessages to the cloud are Greengrass protects user data: Through the secure authentication and authorization of devices. Through secure connectivity in the local network. Between local devices and the security credentials function in a group until they are revoked, even if connectivity to the cloud isdisrupted, so that the devices can continue to securely communicate Greengrass provides secure, over-the-air software updates of Lambda Greengrass consists of: Software distributions AWS Greengrass core software AWS Greengrass core SDK1 AWS Greengrass Developer GuideAWS Greengrass Core Software Cloud service AWS Greengrass API Features Lambda runtime Shadows implementation Message manager Group management Discovery service Over-the-air update agent Local resource access Machine learning inferenceAWS Greengrass Core SoftwareThe AWS Greengrass core software provides the following functionality: Allows deployment and execution of local applications created using Lambda functions and managedthrough the deployment API.

9 Enables local messaging between devices over a secure network using a managed subscription schemethrough the MQTT protocol. Ensures secure connections between devices and the cloud using device authentication andauthorization. Provides secure, over-the-air software updates of user-defined Lambda AWS Greengrass core software consists of: A message manager that routes messages between devices, Lambda functions, and AWS IoT. A Lambda runtime that runs user-defined Lambda functions. An implementation of the Device Shadow service that provides a local copy of shadows, whichrepresent your devices. Shadows can be configured to sync with the cloud. A deployment agent that is notified of new or updated AWS Greengrass group configuration. When anew or updated configuration is detected, the deployment agent downloads the configuration dataand restarts the AWS Greengrass Greengrass core instances are configured through AWS Greengrass APIs that create and updateAWS Greengrass group definitions stored in the Greengrass Core VersionsThe following tabs describe what's new and changed in AWS Greengrass core software features: Lambda executables that run binary code on the Greengrass core.

10 Use the new AWS GreengrassCore SDK for C to write Lambda executables in C and C++. For more information, see the sectioncalled Lambda Executables (p. 127).2 AWS Greengrass Developer GuideAWS Greengrass Core Versions Optional local storage message cache that can persist across restarts. You can configure thestorage settings for MQTT messages that are queued for processing. For more information, see thesection called MQTT Message Queue (p. 25). Configurable maximum reconnect retry interval for when the core device is disconnected. Formore information, see the mqttMaxConnectionRetryInterval property in the section called AWS Greengrass Core Configuration File (p. 17). Local resource access to the host /proc directory. For more information, see Access Local Resourceswith Lambda Functions (p. 130). Configurable write directory. The AWS Greengrass core software can be deployed to read-only andread-write locations.