How to: Run a Grin node on Google Cloud for free

Contents

• Introduction
• Google Cloud Set up
• Provisioning an instance
• Building
• Syncing a floonet (testnet) Grin node
• Syncing a mainnet Grin node
• Connection to Google Grin node from local wallet
• Future work

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Introduction

Thanks to Google Cloud's Always Free program, it's possible to create an instance on Cloud Compute that runs a full Grin node, 24/7, without it costing you anything. This is a cheap (free!) and fool-proof way to get a node up and running since it:

• Is not dependent on the compatibility of your computer or OS;
• Does not require you to open up ports on your network;
• Starts you off from a clean instance; and
• Allows you to follow instructions that are replicable.

The only requirement is that you are willing to sign up for a Google Cloud account and that you have a valid credit or debit card (which will not be charged).

NOTE: This is for testing purposes only. The node is free to run, but if you make mistakes in the configuration you may incur charges. Make sure you monitor your account and billing status regularly whilst running your instance to avoid any unpleasant surprises.

Google Cloud Set up

1. Visit http://cloud.google.com and set up an account as an individual. This will require a debit or credit card, they do a $1 reserve charge on your card to ensure it's valid. As part of signing up you also get $300 in free trial credit to spend within 12 months.
2. In order to qualify for Always Free you need to have an upgraded account. So ensure you upgrade. Note that this means that you will start to be charged automatically if your spend beyond the $300 in free trial credit. As you will not exceed the Always Free limits here, this point is moot, but keep it in mind for any other projects you use this account for.
3. Launch a Cloud Shell console from your browser, or install the Google Cloud SDK to run Cloud Shell from your local terminal.

Provisioning an instance

From the cloud shell, run the following command to create grin-node1, an always free-compatible instance running Linux Debian 10:

gcloud beta compute instances create grin-node1 --zone=us-east1-b --machine-type=f1-micro --tags=grin-node --image=debian-10-buster-v20191210 --image-project=debian-cloud --boot-disk-size=30GB --boot-disk-type=pd-standard --boot-disk-device-name=grin-disk1

Building

Your newly created grin-node1 should now be visible in your list of Cloud Compute Instances. From there, open an SSH session in your browser by clicking the SSH button, or SSH to the instance through your own terminal.

As always, first update your system:

sudo apt-get update

Install some tools:

• git
• pkg-config
• nano, a simple text editor
• tmux, which will allow you to run multiple terminal sessions and keep your node running on your instance once you disconnect remotely. See gentle intro and cheatsheet.

 sudo apt-get install git nano tmux pkg-config

You can now enter a tmux session by tmux and at any time you can close down your connection by CTRL+b and then d as in detach, and then return to it later by tmux a as in attach.

Next install all dependencies:

• clang
• cmake
• ncurse
• zlibs
• openssl
• tor

sudo apt-get install clang cmake libncurses5-dev libncursesw5-dev zlib1g-dev libssl-dev tor

Install rust:

curl https://sh.rustup.rs -sSf | sh; source $HOME/.cargo/env

Clone grin and build a release version

git clone https://github.com/mimblewimble/grin.git
cd grin
git checkout current/4.0.x
cargo build --release

Building takes ~90 minutes on the grin-node1 instance. Slow, but it's free. Good time for a coffee break. Alternatively, you can skip the build process by downloading the latest Grin binary from here.

Clone grin-wallet and build a release version

cd ~
git clone https://github.com/mimblewimble/grin-wallet.git
cd grin-wallet
cargo build --release

Building takes ~60 minutes on the grin-node1 instance. Slow, but it's free. Good time for a coffee break. Alternatively, you can skip the build process by downloading the latest Grin binary from here.

Syncing a floonet (testnet) Grin node

When the build has completed, create a new tmux session and launch your Grin node in it:

tmux new -s floo
cd target/release
./grin --floonet

The node should automatically connect to peers and begin syncing. This might also take a while, so you might want to go for another break.

Once completed, the node should be at the same block height as https://floonet.grinscan.net/. We can now detach from the tmux session running the node by pressing ctrl+b, then d. This will allow us to continue interfacing with the gcloud instance command line, with the node running in the background. If you want to check in on the node at a later time, you can attach back into it's tmux session with tmux a -t floo

Syncing a mainnet Grin node

To sync and use a mainnet grin node, perform the above steps with the following modifications:

• omit the --floonet flag when running ./grin
• substitute floo with main when navigating directories and managing tmux sessions
• open up your node's p2p port so it can receive inbound connections

gcloud compute firewall-rules create main-p2p-port --direction=INGRESS --action=ALLOW --rules=tcp:3414 --target-tags=grin-node

Connecting to Google Grin node from local wallet

This will allow you to use your wallet quickly and easily without the need to wait for your local node to sync! Follow instructions for setting up a Grin node as above. Once built and synched continue below.

To enable external api calls to your Grin node, edit your ~/.grin/main/grin-server.toml configuration file on your Google instance:

• set api_http_addr to 0.0.0.0:3413 and host to 0.0.0.0:

api_http_addr = "0.0.0.0:3413"

host = "0.0.0.0"

• open up your node's api port so it can receive inbound connections

gcloud compute firewall-rules create main-api-port --direction=INGRESS --action=ALLOW --rules=tcp:3413 --target-tags=grin-node

• your ~/.grin/main/grin-server.toml file on your Google instance will have an api_secret_path field (ex: ~/.grin/main/.api_secret unless changed.) Copy the value in the file and save this for later as you will need to provide this to your local wallet.
• on your local machine, create a new file for storing the api secret from the previous step (ex: ~/.grin/main/.remote_api_secret, but can be any location). Save file with key value copied in previous step.
• now update your local wallet configuration file: set node_api_secret_path to the path of the file created in the previous step (ex: ~/.grin/main/.remote_api_secret) and update check_node_api_http_addr with IP address of your Google instance:

api_secret_path = "~/.grin/main/.remote_api_secret"

check_node_api_http_addr = "http://{YourGoogleCloudIP}:3413"

• Restart your node to update configuration changes. Once started, you can run wallet commands which will use your new external node. No need to start your local node and wait for synchronization on each start!

./grin-wallet info
Password:

____ Wallet Summary Info - Account 'default' as of height 235438 ____

 Confirmed Total                  | 0.000000000
 Awaiting Confirmation (< 10)     | 0.000000000
 Awaiting Finalization            | 0.000000000
 Locked by previous transaction   | 0.000000000
 -------------------------------- | -------------
 Currently Spendable              | 0.000000000

Command 'info' completed successfully

Future work

• Updating your node
• Connecting to Grin-Pool