AWS IoT Greengrass
Developer Guide

Setting Up a Raspberry Pi

If you are setting up a Raspberry Pi for the first time, you must follow all of these steps. Otherwise, you can skip to step 9. However, we recommend that you re-image your Raspberry Pi with the operating system as recommended in step 2.

  1. Download and install an SD card formatter such as SD Memory Card Formatter or PiBakery. Insert the SD card into your computer. Start the program and choose the drive where you have inserted your SD card. You can perform a quick format of the SD card.

  2. Download the Raspbian Stretch operating system as a .zip file.

  3. Using an SD card-writing tool (such as Etcher), follow the tool's instructions to flash the downloaded zip file onto the SD card. Because the operating system image is large, this step might take some time. Eject your SD card from your computer, and insert the microSD card into your Raspberry Pi.

  4. For the first boot, we recommend that you connect the Raspberry Pi to a monitor (through HDMI), a keyboard, and a mouse. Next, connect your Pi to a micro USB power source and the Raspbian operating system should start up.

  5. You might want to configure the Pi's keyboard layout before you continue. To do so, choose the Raspberry icon in the upper-right, choose Preferences and then choose Mouse and Keyboard Settings. Next, on the Keyboard tab, choose Keyboard Layout, and then choose an appropriate keyboard variant.

  6. Next, connect your Raspberry Pi to the internet through a Wi-Fi network or an Ethernet cable.

    Note

    Connect your Raspberry Pi to the same network that your computer is connected to, and be sure that both your computer and Raspberry Pi have internet access before you continue. If you're in a work environment or behind a firewall, you might need to connect your Pi and your computer to the guest network to get both devices on the same network. However, this approach might disconnect your computer from local network resources, such as your intranet. One solution is to connect the Pi to the guest Wi-Fi network and to connect your computer to the guest Wi-Fi network and your local network through an Ethernet cable. In this configuration, your computer should be able to connect to the Raspberry Pi through the guest Wi-Fi network and your local network resources through the Ethernet cable.

  7. You must set up SSH on your Pi to remotely connect to it. On your Raspberry Pi, open a terminal window and run the following command:

    sudo raspi-config

    You should see the following:

    
                            Raspberry Pi Software Configuration Tool (raspi-config)
                                screenshot.

    Scroll down and choose Interfacing Options and then choose P2 SSH. When prompted, choose Yes. (Use the Tab key followed by Enter). SSH should now be enabled. Choose OK. Use the Tab key to choose Finish and then press Enter. If the Raspberry Pi doesn't reboot automatically, run the following command:

    sudo reboot
  8. On your Raspberry Pi, run the following command in the terminal:

    hostname -I

    This returns the IP address of your Raspberry Pi.

    Note

    For the following, if you receive an ECDSA key fingerprint message (Are you sure you want to continue connecting (yes/no)?), enter yes. The default password for the Raspberry Pi is raspberry.

    If you are using macOS, open a terminal window and enter the following:

    ssh pi@IP-address

    IP-address is the IP address of your Raspberry Pi that you obtained by using the hostname -I command.

    If you are using Windows, you need to install and configure PuTTY. Expand Connection, choose Data, and make sure that Prompt is selected:

    
                            PuTTY window with Prompt selected.

    Next, choose Session, enter the IP address of the Raspberry Pi, and then choose Open using default settings.

    
                            PuTTY window with IP address in the "Host Name (or IP address)"
                                field.

    If a PuTTY security alert is displayed, choose Yes.

    The default Raspberry Pi login and password are pi and raspberry, respectively.

    
                            Initial PuTTY terminal window.

    Note

    If your computer is connected to a remote network using VPN, you might have difficulty connecting from the computer to the Raspberry Pi using SSH.

  9. You are now ready to set up the Raspberry Pi for AWS IoT Greengrass. First, run the following commands from a local Raspberry Pi terminal window or an SSH terminal window:

    sudo adduser --system ggc_user sudo addgroup --system ggc_group
  10. To improve security on the Pi device, enable hardlink and softlink protection on the operating system at startup.

    1. Navigate to the 98-rpi.conf file.

      cd /etc/sysctl.d ls

      Note

      If you don't see the 98-rpi.conf file, follow the instructions in the README.sysctl file.

    2. Use a text editor (such as Leafpad, GNU nano, or vi) to add the following two lines to the end of the file. You might need to use the sudo command to edit as root (for example, sudo nano 98-rpi.conf).

      fs.protected_hardlinks = 1 fs.protected_symlinks = 1
    3. Reboot the Pi.

      sudo reboot

      After about a minute, connect to the Pi using SSH and then run the following command to confirm the change:

      sudo sysctl -a 2> /dev/null | grep fs.protected

      You should see fs.protected_hardlinks = 1 and fs.protected_symlinks = 1.

  11. Edit your command line boot file to enable and mount memory cgroups. This allows AWS IoT Greengrass to set the memory limit for Lambda functions. Cgroups are also required to run AWS IoT Greengrass in the default containerization mode.

    1. Navigate to your boot directory.

      cd /boot/
    2. Use a text editor to open cmdline.txt. Append the following to the end of the existing line, not as a new line.

      cgroup_enable=memory cgroup_memory=1
    3. Now reboot the Pi.

      sudo reboot

    Your Raspberry Pi should now be ready for AWS IoT Greengrass.

  12. To make sure that you have all required dependencies, download and run the Greengrass dependency checker from the AWS IoT Greengrass Samples repository on GitHub. These commands unzip and run the dependency checker script in the Downloads directory.

    cd /home/pi/Downloads mkdir greengrass-dependency-checker-GGCv1.9.x cd greengrass-dependency-checker-GGCv1.9.x wget https://github.com/aws-samples/aws-greengrass-samples/raw/master/greengrass-dependency-checker-GGCv1.9.x.zip unzip greengrass-dependency-checker-GGCv1.9.x.zip cd greengrass-dependency-checker-GGCv1.9.x sudo modprobe configs sudo ./check_ggc_dependencies | more

    Where more appears, press the Spacebar key to display another screen of text.

    Important

    This tutorial requires Python 2.7. The check_ggc_dependencies script might produce warnings about the missing optional Node.js and Java prerequisites. You can ignore these warnings.

    For information about the modprobe command, run man modprobe in the terminal.

Your Raspberry Pi configuration is complete. Continue to Module 2: Installing the AWS IoT Greengrass Core Software.