Install the Amazon IoT Greengrass Core software

To uninstall the Amazon IoT Greengrass core software and preserve configuration information

• Run the following command to remove the Amazon IoT Greengrass core software packages and preserve configuration information in the /greengrass folder.

  sudo apt remove aws-iot-greengrass-core aws-iot-greengrass-keyring

To uninstall the Amazon IoT Greengrass core software and remove configuration information

1. Run the following command to remove the Amazon IoT Greengrass core software packages and remove configuration information from the /greengrass folder.

   sudo apt purge aws-iot-greengrass-core aws-iot-greengrass-keyring

2. Remove the Amazon IoT Greengrass core software repository from your sources list. For more information, see Remove the Amazon IoT Greengrass core software repository sources.

To remove the APT repository from the sources list

• Run the following commands to remove the Amazon IoT Greengrass core software repository from the sources list.

  sudo rm /etc/apt/sources.list.d/greengrass.list
  sudo apt update

1. Install the core18 snap by running the following command in your device's terminal:

   sudo snap install core18

   The core18 snap is a base snap that provides a runtime environment with commonly used libraries. This snap is built from Ubuntu 18.04 LTS.

2. Upgrade snapd by running the following command:

   sudo snap install --channel=edge snapd; sudo snap refresh --channel=edge snapd

3. Run the snap list command to check if you have the Amazon IoT Greengrass snap installed.

   The following example response shows that snapd is installed, but aws-iot-greengrass isn't.

   Name              Version               Rev    Tracking         Publisher   Notes
   amazon-ssm-agent  3.0.161.0             2996   latest/stable/…  aws✓        classic
   core              16-2.48               10444  latest/stable    canonical✓  core
   core18            20200929              1932   latest/stable    canonical✓  base
   lxd               4.0.4                 18150  4.0/stable/…     canonical✓  -
   snapd             2.48+git548.g929ccfb  10526  latest/edge      canonical✓  snapd

4. Choose one of the following options to install Amazon IoT Greengrass snap 1.11.x.

   • To install the Amazon IoT Greengrass snap, run the following command:

     sudo snap install aws-iot-greengrass

     Example response:

     aws-iot-greengrass 1.11.5 from Amazon Web Services (aws) installed

   • To migrate from an earlier version to v1.11.x or update to the latest available patch version, run the following command:

     sudo snap refresh --channel=1.11.x aws-iot-greengrass

   Like other snaps, the Amazon IoT Greengrass snap uses channels to manage minor versions. Snaps are automatically updated to the latest available version of the current channel. For examples, if you specify --channel=1.11.x, your Amazon IoT Greengrass snap is updated to v1.11.5.

   You can run the snap info aws-iot-greengrass command to get the list of available channels for Amazon IoT Greengrass.

5. To access specific resources that your Lambda functions need, you can connect to additional interfaces.

   Run the following command to get the list of Amazon IoT Greengrass snap supported interfaces:

   snap connections aws-iot-greengrass

   Example response:

   Interface                Plug                                                Slot                 Notes
   camera                   aws-iot-greengrass:camera                           -                    -
   dvb                      aws-iot-greengrass:dvb                              -                    -
   gpio                     aws-iot-greengrass:gpio                             -                    -
   gpio-memory-control      aws-iot-greengrass:gpio-memory-control              -                    -
   greengrass-support       aws-iot-greengrass:greengrass-support-no-container  :greengrass-support  -
   hardware-observe         aws-iot-greengrass:hardware-observe                 :hardware-observe    manual
   hardware-random-control  aws-iot-greengrass:hardware-random-control          -                    -
   home                     aws-iot-greengrass:home-for-greengrassd             -                    -
   home                     aws-iot-greengrass:home-for-hooks                   :home                manual
   hugepages-control        aws-iot-greengrass:hugepages-control                :hugepages-control   manual
   i2c                      aws-iot-greengrass:i2c                              -                    -
   iio                      aws-iot-greengrass:iio                              -                    -
   joystick                 aws-iot-greengrass:joystick                         -                    -
   log-observe              aws-iot-greengrass:log-observe                      :log-observe         manual
   mount-observe            aws-iot-greengrass:mount-observe                    :mount-observe       manual
   network                  aws-iot-greengrass:network                          :network             -
   network-bind             aws-iot-greengrass:network-bind                     :network-bind        -
   network-control          aws-iot-greengrass:network-control                  :network-control     -
   opengl                   aws-iot-greengrass:opengl                           :opengl              -
   optical-drive            aws-iot-greengrass:optical-drive                    :optical-drive       -
   process-control          aws-iot-greengrass:process-control                  :process-control     -
   raw-usb                  aws-iot-greengrass:raw-usb                          -                    -
   removable-media          aws-iot-greengrass:removable-media                  -                    -
   serial-port              aws-iot-greengrass:serial-port                      -                    -
   spi                      aws-iot-greengrass:spi                              -                    -
   system-observe           aws-iot-greengrass:system-observe                   :system-observe      -

   If you see a hyphen (-) in the Slot column, the corresponding interface isn't connected.

6. Follow Installing the Amazon IoT Greengrass Core software to create an Amazon IoT thing, a Greengrass group, security resources that enable secure communications with Amazon IoT, and the Amazon IoT Greengrass Core software configuration file. The configuration file, config.json, contains configuration specific to your Greengrass core, such as the location of certificate files and the Amazon IoT device data endpoint.

   Note

   If you downloaded the file to a different device, follow this step to transfer the files to the Amazon IoT Greengrass core device.

7. For the Amazon IoT Greengrass snap, make sure that you update the config.json file, as shown in the following:

   • Replace each instance of certificateId with the certificate ID in the name of the certificate and key files.

   • If you downloaded a different Amazon root CA certificate than Amazon Root CA 1, replace each instance of AmazonRootCA1.pem with the name of the Amazon root CA file.

   {
     ...
     "crypto" : {
       "principals" : {
         "SecretsManager" : {
           "privateKeyPath" : "file:///snap/aws-iot-greengrass/current/greengrass/certs/certificateId-private.pem.keyy"
         },
         "IoTCertificate" : {
           "privateKeyPath" : "file:///snap/aws-iot-greengrass/current/greengrass/certs/certificateId-private.pem.key",
           "certificatePath" : "file:///snap/aws-iot-greengrass/current/greengrass/certs/certificateId-certificate.pem.crt"
         }
       },
       "caPath" : "file:///snap/aws-iot-greengrass/current/greengrass/certs/AmazonRootCA1.pem"
     },
     "writeDirectory": "/var/snap/aws-iot-greengrass/current/ggc-write-directory",
     "pidFileDirectory": "/var/snap/aws-iot-greengrass/current/pidFileDirectory"
   }

8. Run the following command to add your Amazon IoT Greengrass certificate and configuration files:

   sudo snap set aws-iot-greengrass gg-certs=/home/ubuntu/my-certs

1. Run the following command to start the Amazon IoT Greengrass daemon:

   sudo snap start aws-iot-greengrass

   Example response:

   Started.

   Note

   If you get an error, you can use the snap run command for a detailed error message. For more troubleshooting information, see error: cannot perform the following tasks: - Run service command "start" for services ["greengrassd"] of snap "aws-iot-greengrass" ([start snap.aws-iot-greengrass.greengrassd.service] failed with exit status 1: Job for snap.aws-iot-greengrass.greengrassd.service failed because the control process exited with error code. See "systemctl status snap.aws-iot-greengrass.greengrassd.service" and "journalctl -xe" for details.).

2. Run the following command to confirm that the daemon is running:

   snap services aws-iot-greengrass.greengrassd

   Example response:

   Service                         Startup   Current  Notes
   aws-iot-greengrass.greengrassd  disabled  active   -

3. Follow Module 3 (part 1): Lambda functions on Amazon IoT Greengrass to create and deploy a Hello World Lambda function. However, before you deploy the Lambda function, complete the next step.

4. Make sure that your Lambda function run as the snap_daemon user and in the no container mode. To update the settings of your Greengrass group, do the following in the Amazon IoT Greengrass console:

   1. Sign in to the Amazon IoT Greengrass console.

   2. In the Amazon IoT console navigation pane, under Manage, expand Greengrass devices, and then choose Groups (V1).

   3. Under Greengrass groups, choose the target group.

   4. On the group configuration page, in the navigation pane, choose the Lambda functions tab.

   5. Under Default Lambda function runtime environment, choose Edit, and do the following:

      1. For Default system user and group, choose Another user ID/group ID, and then enter 584788 for both System user ID (number) and System group ID (number).

      2. For Default Lambda function containerization, choose No container.

      3. Choose Save.

To archive the current installation and install a new version

1. Download the Amazon IoT Greengrass Core software installation package that you want to upgrade to.

2. Copy the package to the destination core device. For instructions that show how to transfer files, see this step.

   Note

   You copy your current certificates, keys, and configuration file to the new installation later.

   Run the commands in the following steps in your core device terminal.

3. Make sure that the Greengrass daemon is stopped on the core device.

   1. To check whether the daemon is running:

      ps aux | grep -E 'greengrass.*daemon'

      If the output contains a root entry for /greengrass/ggc/packages/ggc-version/bin/daemon, then the daemon is running.

      Note

      This procedure is written with the assumption that the Amazon IoT Greengrass Core software is installed in the /greengrass directory.

   2. To stop the daemon:

      cd /greengrass/ggc/core/
      sudo ./greengrassd stop

4. Move the current Greengrass root directory to a different directory.

   sudo mv /greengrass /greengrass_backup

5. Untar the new software on the core device. Replace the os-architecture and version placeholders in the command.

   sudo tar –zxvf greengrass-os-architecture-version.tar.gz –C /

6. Copy the archived certificates, keys, and configuration file to the new installation.

   sudo cp /greengrass_backup/certs/* /greengrass/certs
   sudo cp /greengrass_backup/config/* /greengrass/config

7. Start the daemon:

   cd /greengrass/ggc/core/
   sudo ./greengrassd start

To restore the archived installation

1. Stop the daemon.

2. Delete the new /greengrass directory.

3. Move the /greengrass_backup directory back to /greengrass.

4. Start the daemon.