Introduction

An example Cumulocity IoT microservice written in go (golang) to add simple endpoints to running go-c8y-cli commands

The project uses the unofficial github.com/reubenmiller/go-c8y Cumulocity client modules.

Getting Started

Dev container

This project includes a VScode dev container definition to make it easier to install of the project requirements and provide a normalized development environment.

The ~/.cumulocity folder (created by go-c8y-cli) is mounted from your host OS into your dev container so that all of your existing sessions will be available inside the dev container environment.

Starting the app locally

1. Clone the project

   git clone https://github.com/reubenmiller/go-c8y-cli-microservice.git
   cd go-c8y-cli-microservice

2. Open the project in VScode

   code .

3. When prompted by VScode, rebuild/reopen the project in the dev container. Be patient, it needs to build a docker image.

   If you do not want to open the project in a dev container, then you must install go-task using the following procedure:

   env GOBIN="$(pwd)/bin" go install github.com/go-task/task/v3/cmd/task@latest
   export PATH=$(cd bin && pwd):$PATH
   
   # alternative you can call the locally installed task version using:
   bin/task init
   bin/task build:microservice
   bin/task deploy:microservice

4. Activate/Create a Cumulocity session pointing to the Cumulocity instance you want to develop against

   set-session

5. Run the init task to create a dummy microservice placeholder and initialize the .env file containing the microservice's bootstrap credentials

   task init
   

6. Start the application via debugger (F5)

Known Issues

• Ctrl-c does not work to kill the application. You will have to manually stop the process by either killing your console, or the process itself.

Build

Build the Cumulocity microservice zip file by executing

task build:microservice

Notes

• It is assumed that the user running the command is able to run docker commands without using sudo. If your user does not have the correct permissions, then you may have some success using the following

  sudo -E task build:microservice
  

Deploy

task deploy:microservice

Testing the endpoints manually

go-c8y-cli can be used to check the microservice's endpoints either when running locally or when hosted in Cumulocity IoT.

When the microservice locally, you will need to add --host http://localhost:8000 to the command.

Check prometheus endpoint

c8y api /prometheus --host http://localhost:8000

Upload a file to import

# Run a test command
echo -e "1111\n22222" > input.list
c8y api POST "/commands/importevents/async" --host http://localhost:8000 --force --file "./input.list"

# Run a test command
echo -e "1111\n22222" > input.list
c8y api POST "/service/go-c8y-cli-microservice/commands/importevents/sync" --force --file "./input.list"

sudo docker run -it --env-file=.env go-c8y-cli-microservice:0.0.2 bash

Execute command

Execute a custom command. Note only creating data is supported

c8y api POST "/service/go-c8y-cli-microservice/commands/execute/sync" --data "command=c8y devices list | c8y events create --text 'Example event' --type 'c8y_CliExample'"