Part 3 - Pocket Configuration

1. Download Snapshot

Rather than synchronizing your Pocket node from block zero (which could take weeks), you can use a snapshot.

Instead of synchronizing your node from block zero, which could take weeks, you can use a snapshot. A snapshot of the Pocket blockchain is taken every 12 hours and can be downloaded using the instructions on the Pocket Snapshots Repository page.

The snapshots are updated every 12 hours. Check the last update time of the README.md file in the GitHub repo to know when the last snapshot was taken, and it's best to download one that's just a few hours old.

Downloading a snapshot will likely take a few hours, so we’re going to use the screen command so that the download can run in the background, allowing you to perform other tasks.

To download the most recent snapshot:

Create a screen instance:
```
screen
```
Press Enter to get back to a prompt.
Change into the .pocket directory.
```
cd ~/.pocket
```
Create a directory named data and change into it:
```
mkdir data && cd data
```

Download the latest snapshot using the following command:

wget -qO- https://snapshot.nodes.pokt.network/latest.tar.gz | tar xvfz -

While the snapshot is downloading, press Ctrl-A and then d to let the process run in the background and be returned to a prompt.

To return to your screen instance to see how things are going:

screen -r

You can also check on the status of the download by watching your disk usage:

df -h

Once your download is completed, make the pocket user the owner of the data directory:

sudo chown -R pocket ~/.pocket/data

And when you’re done with your screen instance, you can exit out of it:

exit

2. Create a Pocket wallet account

Pocket nodes work with a Pocket wallet account, which handles sending and receiving transactions from the node. You can make a new account with the Pocket CLI tool we just installed, or use one you already have. We'll make a new account for this guide.

Creating an account

To create an account, run the following command:

pocket accounts create

You’ll be asked to set a passphrase for the account. You can use any passphrase you like but for security reasons, it’s best to use a passphrase that is at least 12 characters long, preferably longer.

If you already have a Pocket account that you’d like to use to run the node, you can import it here. Upload the JSON file associated with your account to the server and run the following command:

pocket accounts import-armored <armoredJSONFile>

You will be prompted for the decryption passphrase of the file, and then for a new encryption passphrase to store in the keybase.

Listing accounts

After you’ve created the account you can use the pocket accounts list command to confirm that the account was added successfully.

pocket accounts list

Setting the validator address

Next, set the account as the one the node will use with the following command:

pocket accounts set-validator [YOUR_ACCOUNT_ADDRESS]

Confirm the validator address

Finally, you can confirm that the validator address was set correctly by running the following command:

 pocket accounts get-validator

Create `config.json`

The Pocket core software uses a config file to store configuration details. By default the config file is located at ~/.pocket/config/config.json. In this step we’ll look at how to create a new config file.

To create a new config file:

Run the following command, which will create the default config.json file, add the seeds, set port 8081 to 8082, and increase the RPC timeout value:

export SEEDS=$(curl -s https://raw.githubusercontent.com/pokt-network/pocket-seeds/main/mainnet.txt \
| tr '\n' ',' \
| sed 's/,*$//')
pocket util print-configs \
| jq --arg seeds "$SEEDS" '.tendermint_config.P2P.Seeds = $seeds' \
| jq '.pocket_config.rpc_timeout = 15000' \
| jq '.pocket_config.rpc_port = "8082"' \
| jq '.pocket_config.remote_cli_url = "http://localhost:8082"' \
| jq . > ~/.pocket/config/config.json

This code above includes a long command! Make sure you’ve copied it completely.

Verify the config.json file setting by viewing the contents of the file:

Command Response

cat ~/.pocket/config/config.json

3. Create `chains.json`

Pocket nodes relay transactions to other blockchains. So, you’ll need to configure the chains your node can relay to. For this guide, we’ll just be setting up our node to relay to the Pocket mainnet blockchain, essentially through itself.

To maximize your rewards, you’ll want to relay to other chains. We’ll cover that in more detail later but here is a list of other blockchains you could relay to.

Generating a `chains.json` file with the CLI

You can use the Pocket CLI to generate a chains.json file for your node by running the following command:

pocket util generate-chains

This will prompt you for the following information:

Enter the ID of the Pocket Network RelayChain ID:
```
0001
```
Enter the URL of the local network identifier.
```
http://127.0.0.1:8082/
```
When you’re prompted to add another chain, enter n for now.

By default the chains.json file will be created in ~/.pocket/config. You can use the --datadir flag to create the chains.json file in an alternate location. For example: pocket util generate-chains --datadir "/mnt/data/.pocket".

4. Create `genesis.json`

Now that we have a chains.json file set up, so we can move on to test our node.

When you start a Pocket node for the first time, it will need to find other nodes (peers) to connect with. To do that we use a file named genesis.json with details about peers the node should connect to get on the network.

To create a JSON file with the genesis information:

Change to the .pocket/config directory:
```
cd ~/.pocket/config
```

Use the following command to get the genesis.json file from GitHub:

wget https://raw.githubusercontent.com/pokt-network/pocket-network-genesis/master/mainnet/genesis.json genesis.json

5. Set open file limits

Ubuntu and other UNIX-like systems have a ulimit shell command that’s used to set resource limits for users. One of the limits that can be set is the number of open files a user is allowed to have. Pocket nodes will have a lot of files open at times, so we’ll want to increase the default ulimit for the pocket user account.

Increasing the ulimit

Before increasing the ulimit, you can check the current ulimit with the following command:
```
ulimit -n
```
Increase the ulimit to 16384. The -Sn option is for setting the soft limit on the number of open files:
```
ulimit -Sn 16384
```
Check the new ulimit to confirm that it was set correctly. The -n option is for getting the limit for just the number of open files:
```
ulimit -n
```

Permanent settings

Using the above method for setting the ulimit only keeps the change in effect for the current session. To permanently set the ulimit, you can do the following:

Open the /etc/security/limits.conf file.
```
sudo nano /etc/security/limits.conf
```

Add the following line to the bottom of the file:

pocket           soft    nofile          16384

Save the file with Ctrl+O and then Enter.
Exit nano with Ctrl+X.

After permanently setting the ulimit, the next thing we’ll do is download a snapshot of the Pocket blockchain.

6. Configure systemd

Next, we’ll configure the Pocket service using systemd, a Linux service manager. This will enable the Pocket node to run and restart even when we’re not logged in.

Creating a systemd service in Linux

To setup a systemd service for Pocket, do the following:

Open nano and create a new file called pocket.service:
```
sudo nano /etc/systemd/system/pocket.service
```

Add the following lines to the file:

[Unit]
Description=Pocket service
After=network.target mnt-data.mount
Wants=network-online.target systemd-networkd-wait-online.service

[Service]
User=pocket
Group=sudo
ExecStart=/home/pocket/go/bin/pocket start
ExecStop=/home/pocket/go/bin/pocket stop

[Install]
WantedBy=default.target

Make sure the User is set to the user that will run the Pocket service.
Make sure the ExecStart and ExecStop paths are set to the path for the Pocket binary.
Save the file with Ctrl+O and then return.
Exit nano with Ctrl+X.
Reload the service files to include the pocket service:
```
sudo systemctl daemon-reload
```
Start the pocket service:
```
sudo systemctl start pocket.service
```
Verify the service is running:
CommandResponse
```
sudo systemctl status pocket.service
```
Stop the pocket service:
```
sudo systemctl stop pocket.service
```
Verify the service is stopped:
```
sudo systemctl status pocket.service
```
Set the service to start on boot:
```
sudo systemctl enable pocket.service
```

Verify the service is set to start on boot:

CommandResponse

sudo systemctl list-unit-files --type=service | grep pocket.service

Start the pocket service:
```
sudo systemctl start pocket.service
```

Other systemctl commands

Restart the Pocket service:
```
sudo systemctl restart pocket.service
```
Prevent the service from starting on boot:
```
sudo systemctl disable pocket.service
```
View mounted volumes:
```
sudo systemctl list-units --type=mount
```

Viewing the logs

View the logs for the Pocket service:
```
sudo journalctl -u pocket.service
```
View just the last 100 lines of the logs (equivalent to the tail -f command):
```
sudo journalctl -u pocket.service -n 100 --no-pager
```

Finding Errors

You can use grep to find errors in the logs.

sudo journalctl -u pocket.service | grep -i error

In case you skipped the step above while the snapshot was downloading, once your download is completed, make the pocket user the owner of the data directory:

sudo chown -R pocket ~/.pocket/data