Not Mandatory

In this post I detail the steps needed to enable fan control, install electrs Electrum personal server, and install and configure nginx to provide an SSL proxy for the electrs server, to make it easy to use with the Electrum client software.

enable the case fan using Active Thermal Service, follow github instruction
install c language and git (if not already installed)
```
sudo apt install clang git
```

install rust tools per rust-lang.org/tools/install instructions

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
source $HOME/.cargo/env

clone and build the electrs project

git clone https://github.com/romanz/electrs.git
cd electrs
cargo build --release

add a new electrs system user and make it part of bitcoin group

sudo adduser --system --home /var/lib/electrs --ingroup bitcoin electrs

create a new LVM logical volume for electrs data, I allocate 40% of bitcoin volume size which is needed during indexing, but can lowered later after the indexes are compacted if I need the space back.
```
sudo lvcreate -n electrs -L 200g rockpro64
```

format my new electrs logical volume, identify it's UUID and mount it via fstab

sudo mkfs.ext4 /dev/rockpro64/electrs
sudo blkid
sudo vi /etc/fstab

add line to /etc/fstab:

UUID=<THE UUID OF MY NEW LOGICAL PARTITION> /var/lib/electrs ext4 errors=remount-ro 0 1

sudo mount -a
sudo chown electrs:bitcoin /var/lib/electrs
sudo chmod -R o-rwx /var/lib/electrs
sudo chmod u+rxw /var/lib/electrs
sudo chmod g+x /var/lib/electrs

copy electrs binary to /var/lib/electrs

sudo mkdir /var/lib/electrs/bin
sudo chown electrs:bitcoin /var/lib/electrs/bin
sudo cp target/release/electrs /var/lib/electrs/bin
sudo chown electrs:bitcoin /var/lib/electrs/bin/electrs

create systemd startup file for electrs

sudo vi /usr/lib/systemd/system/electrs.service

and add below content to file

[Unit]
Description=Electrs
After=bitcoind.service

[Service]
WorkingDirectory=/var/lib/electrs
ExecStart=/var/lib/electrs/bin/electrs -vvv --db-dir ./db --index-batch-size=10 --jsonrpc-import --cookie-file /var/lib/bitcoind/.cookie --daemon-dir /var/lib/bitcoind --electrum-rpc-addr="127.0.0.1:50001"
User=electrs
Group=bitcoin
Type=simple
KillMode=process
TimeoutSec=60
Restart=always
RestartSec=60

[Install]
WantedBy=multi-user.target

edit the bitcoind service to enable the rpc server, restart bitcoind

sudo vi /usr/lib/systemd/system/bitcoind.service

add -server=1 to the ExecStart line

sudo systemctl daemon-reload
sudo systemctl restart bitcoind

update the permission for bitcoind .cookie file so electrs can use it to connect to the bitcoind rpc api

sudo chmod -R g+r /var/lib/bitcoind/
sudo chmod g+x /var/lib/bitcoind
sudo chmod g+x /var/lib/bitcoind/blocks /var/lib/bitcoind/chainstate /var/lib/bitcoind/database

create /run/electrs directory, reload systemd services and start the electrs daemon
```
sudo mkdir /run/electrs
sudo chown electrs:bitcoin /run/electrs
sudo systemctl daemon-reload
sudo syste:qqmctl start electrs
```
At this point electrs will start indexing, this took almost 24 hours on my system.
install nginx
```
sudo apt install nginx
```

create a new nginx cert

sudo mkdir /etc/nginx/ssl
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/nginx/ssl/nginx.key -out /etc/nginx/ssl/nginx.crt

add the below block to the nginx config file

sudo vi /etc/nginx/nginx.conf

stream {
        upstream electrs {
                server 127.0.0.1:50001;
        }

        server {
                listen 50002 ssl;
                proxy_pass electrs;

                ssl_certificate /etc/nginx/ssl/nginx.crt;
                ssl_certificate_key /etc/nginx/ssl/nginx.key;
                ssl_session_cache shared:SSL:1m;
                ssl_session_timeout 4h;
                ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
                ssl_prefer_server_ciphers on;
        }
}

unlink the nginx default site in the sites-active directory and restart nginx
```
sudo rm /etc/nginx/sites-enabled/default
sudo systemctl restart nginx
```

Done! I now have an electrum server at https://localhost:50001 that I can use as a back end to an electrum client, or any other service that uses the electrum server apis to browse the bitcoin block chain.