TensorDock Marketplace VM

# Cloud-init ## Setting a cloud-init script To set a cloud-init script, click on the "Click for more advanced options" green link when deploying your virtual machine.

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This is the default cloudinit configuration we pass to the hypervisor: ```bash #cloud-config user: user password: [your defined password] chpasswd: {expire: False} ssh_pwauth: True package_update: True package_upgrade: False ``` The script that you provide simply gets appended to the end of this file. ## Examples ### Example 1: Preventing the automatic update of NVIDIA drivers {% hint style="info" %} NVIDIA drivers autoupdate on the first boot. Once this happens, they become unusable. By including this cloud-init script, you'll lock the NVIDIA driver versions so that they do not autoupdate {% endhint %} #### Objectives * Write a file using cloud-init `write_files` in base64 encoding that uses `apt-mark` to hold NVIDIA packages from being automatically updated * The file will have the following contents: \ `dpkg-query -W --showformat='${Package} ${Status}\n' | grep -v deinstall | awk '{ print $1 }' | grep -E 'nvidia.*-[0-9]+$' | xargs -r -L 1 apt-mark hold` * Run a file {% embed url="" %} This is the source of the script included {% endembed %} #### Process We'll set this as our cloud-init script: ```bash write_files: - encoding: b64 path: /home/user/tensordock_scripts/prevent_update.sh permissions: '0644' content: ZHBrZy1xdWVyeSAtVyAtLXNob3dmb3JtYXQ9JyR7UGFja2FnZX0gJHtTdGF0dXN9XG4nIHwgZ3JlcCAtdiBkZWluc3RhbGwgfCBhd2sgJ3sgcHJpbnQgJDEgfScgfCBncmVwIC1FICdudmlkaWEuKi1bMC05XSskJyB8IHhhcmdzIC1yIC1MIDEgc3VkbyBhcHQtbWFyayBob2xk owner: user:user runcmd: - bash /home/user/tensordock_scripts/prevent_update.sh ``` #### Debrief Explanation: * First, our server will write the new file, `prevent_update.sh`, in the user's new `tensordock_scripts` directory * Then, our server run this file, locking in our NVIDIA driver versions to prevent autoupdates

### Example 2: Hosting a website with Apache2 #### Objectives * Install a package through cloud-init `packages` * Write a file using cloud-init `write_files` in plaintext #### Process By default, the Apache2 webserver listens on port 80. As such, we'll first forward an external port into that internal port.

Because Apache listens on port 80, you'll want to forward an external port into that internal port

Then, we'll set this as our cloud-init script: ```bash packages: - apache2 write_files: - path: /var/www/html/index.html permissions: '0644' content: | TensorDock Marketplace VM

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owner: www-data:www-data ``` {% hint style="warning" %} Note the indentation of the custom HTML we've defined above! When writing files, we must append four (4) spaces in front of each text block. {% endhint %} #### Debrief Explanation: * First, our server will install the `apache2` package * Then, our server will overwrite the we create an index.html file with the custom HTML we've defined Now, let's try accessing our web server!

### Example 3: Hosting a simple Docker container #### Objectives * Host a simple Docker container through the Docker CLI {% hint style="success" %} TensorDock operating system templates come preinstalled with Docker {% endhint %} #### Process For networking, we forward an external port into an internal port in the virtual machine. Then, a Docker container forwards a virtual machine's port into its own internal network. By default, the NGINX webserver listens on port 80 within the Docker container, but we can have the Docker container listen on any port. As such, we'll first forward an external port (e.g. 20018) into itself.

We'll forward an external port into an internal port on the virtual machine

Then, we'll set this as our cloud-init script: ```bash write_files: - path: /home/user/cloudinit_website/index.html permissions: '0644' content: | TensorDock Marketplace VM

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owner: www-data:www-data runcmd: - docker run -d --restart unless-stopped --stop-timeout 300 -v /home/user/cloudinit_website:/usr/share/nginx/html:ro -p 20018:80 --name default_container nginx ``` {% hint style="warning" %} Note that we have our Docker container listen on port 20018 because we forwarded external port 20018 into the virtual machine on port 20018 {% endhint %} #### Debrief Explanation: * First, our server will write a file to a new directory containing our custom HTML * Then, our server will run a Docker container that passes through the directory of our HTML page into the NGINX contiainer * When users access the external port 20018, our hypervisor forwards that to the virtual machine's port 20018, and then Docker forwards that to the NGINX container on port 80 Now, let's try accessing our web server!