Setting up a Raspberry Pi

Download and install an SD card formatter such as SD Memory Card Formatter. 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.

Download the Raspbian Buster operating system as a zip file.

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.

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.

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.

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

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:

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

On your Raspberry Pi, run the following command in the terminal:

hostname -I

This returns the IP address of your Raspberry Pi.

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:

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

If a PuTTY security alert is displayed, choose Yes.

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

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

To improve security on the Pi device, enable hardlink and softlink (symlink) 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.

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. You might need to use the sudo command to edit as root (for example, sudo nano cmdline.txt).

   cgroup_enable=memory cgroup_memory=1

3. Now reboot the Pi.

   sudo reboot

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

Optional. Install the Java 8 runtime, which is required by stream manager. This tutorial doesn't use stream manager, but it does use the Default Group creation workflow that enables stream manager by default. Use the following commands to install the Java 8 runtime on the core device, or disable stream manager before you deploy your group. Instructions for disabling stream manager are provided in Module 3.

sudo apt install openjdk-8-jdk

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-GGCv1.11.x
cd greengrass-dependency-checker-GGCv1.11.x
wget https://github.com/aws-samples/aws-greengrass-samples/raw/master/greengrass-dependency-checker-GGCv1.11.x.zip
unzip greengrass-dependency-checker-GGCv1.11.x.zip
cd greengrass-dependency-checker-GGCv1.11.x
sudo modprobe configs
sudo ./check_ggc_dependencies | more

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

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