ElectrumX on a RaspiBlitz

This is a rough overview, the guide is work in progress.

Tested environments:

X86_64 Xeon E5 with 32GB RAM and SSD storage - first sync time: 2d 16h 07m
Raspberry Pi4 8GB 64bit RaspberryOS with SSD is ~6.5 days

Issue: https://github.com/rootzoll/raspiblitz/issues/1130

Prepare the system and directories

Requires txindex=1 for Bitcoin Core

# create a dedicated user
sudo adduser --disabled-password --gecos "" electrumx
cd /home/electrumx

sudo -u electrumx git clone https://github.com/spesmilo/electrumx.git
cd electrumx

# installation
# dependencies
sudo -u electrumx pip install aiohttp pylru
# from: https://github.com/spesmilo/electrumx/blob/master/contrib/raspberrypi3/install_electrumx.sh
sudo apt-get install -y \
  python3-pip \
  build-essential \
  libc6-dev \
  libncurses5-dev \
  libncursesw5-dev \
  libreadline6-dev/stable \
  libreadline6/stable \
  libleveldb-dev
sudo pip3 install plyvel

# places the binaries in /home/electrumx/.local/bin/
sudo -u electrumx pip3 install .

# alternative install method (places the binaries in /usr/local/bin):
# sudo -u electrumx python3 setup.py build
# sudo python3 setup.py install

# create the database directory in /mnt/hdd/app-storage (on the disk)
sudo mkdir -p /mnt/hdd/app-storage/electrumx/db
sudo chown -R electrumx:electrumx /mnt/hdd/app-storage/electrumx

# create a symlink to /home/electrumx/.electrumx
sudo ln -s /mnt/hdd/app-storage/electrumx /home/electrumx/.electrumx
sudo chown -R electrumx:electrumx /home/electrumx/.electrumx

Create a config file

https://electrumx-spesmilo.readthedocs.io/en/latest/environment.html
Can paste the this as a block to create the config file, but fill in the PASSWORD_B (Bitcoin Core RPC password):
```
PASSWORD_B="your-password-here"
```
``` echo “
DB_DIRECTORY=/home/electrumx/.electrumx/db DAEMON_URL=http://raspibolt:${PASSWORD_B}@127.0.0.1 COIN=Bitcoin

SERVICES = tcp://:50010,rpc:// PEER_DISCOVERY = off COST_SOFT_LIMIT = 0 COST_HARD_LIMIT = 0

NET=mainnet CACHE_MB=1200

SERVICES = tcp://:50010,ssl://:50011,rpc://

SSL_CERTFILE=/home/electrumx/.electrumx/certfile.crt

SSL_KEYFILE=/home/electrumx/.electrumx/keyfile.key

BANNER_FILE=/home/electrumx/.electrumx/banner

DONATION_ADDRESS=your-donation-address

” | sudo -u electrumx tee /home/electrumx/.electrumx/electrumx.conf

* the ports 50010 and 50011 are used to not interfere with a possible Electrs instance
* edit afterwards with `sudo nano /home/electrumx/.electrumx/electrumx.conf`

## Create a systemd service  
* <https://github.com/spesmilo/electrumx/blob/master/contrib/systemd/electrumx.service>
* Can paste this as a block to create the electrumx.service file:

echo “
[Unit] Description=Electrumx After=network.target bitcoind.service

[Service] EnvironmentFile=/home/electrumx/.electrumx/electrumx.conf ExecStart=/home/electrumx/.local/bin/electrumx_server User=electrumx LimitNOFILE=8192 TimeoutStopSec=30min

[Install] WantedBy=multi-user.target “ | sudo tee /etc/systemd/system/electrumx.service

## Start
* depending on the available RAM it is a good idea to keep at least 10GB swap:  
  <https://www.digitalocean.com/community/tutorials/how-to-add-swap-space-on-debian-10>
  can consider ZRAM: 
  <https://haydenjames.io/raspberry-pi-performance-add-zram-kernel-parameters/>
  <https://github.com/rootzoll/raspiblitz/issues/2905>

sudo systemctl enable electrumx sudo systemctl start electrumx


## Monitor

sudo journalctl -fu electrumx sudo systemctl status electrumx


## Remove the electrumx user and installation (not the database)

sudo systemctl disable electrumx sudo systemctl stop electrumx sudo userdel -rf electrumx

to remove the database directory:

sudo rm -rf /mnt/hdd/app-storage/electrumx

```

Set SSL

https://electrumx-spesmilo.readthedocs.io/en/latest/HOWTO.html#creating-a-self-signed-ssl-certificate