====== ScanServJS ======

At first i tried to make **saned** work, the great network extension to Sane scan tool for Linux. Unfortunately it turns out that the scanner i own (a MFD HP Laser printer/scanner) cannot be shared with saned over the network because the HP provided driver does not allow it. Frankly it seems more an oversight / bug than anything else, but still that's an issue, because i do not want to install HP drivers on all my computers just for scanning.

Luckly, [[https://github.com/sbs20/scanservjs|ScanServJS]] is very nice, simple and powerful WEB GUI to the sane backend which works wonders and can be self-hosted on your home server.

===== Prerequisites =====

ScanServJs require, of course, sane-backends package to be installed and your scanners to be configured to work locally on the server. I will not cover those steps here, i assume your scanner is already properly configured and can scan with the **saned** user on the server.

You must install **nodejs** and the **deb2targz** packages, because ScanServJS is deployed as a DEB package and requires NodeJS to run.

So, if you don't already have them:
<code bash>
emerge -vp app-arch/deb2targz nodejs
</code>

Also, you might want to install **tesseract** to enable OCR functionalities.


===== Installation =====

You will need to alter a little bit the content of the DEB package, because it's better to install it on **/opt/scanservjs** rather than having it mess with your **/usr** and **/var** system folders, so as root:
<code bash>
mkdir /opt/scanservjs
chown saned:scanner /opt/scanservjs
</code>

And then now, as user **saned**:
<code bash>
sudo -u saned bash
cd /opt/scanservjs
wget https://github.com/sbs20/scanservjs/releases/ << get here latest deb file for your server >>
deb2targz scanservjs_X.Y.Z-1_all.deb
tar xvf scanservjs_X.Y.Z-1_all.tar.xz
cd usr/lib/scanservjs
</code>

Now, since the DEB package assumes it's installed on **/usr** you need to recreate two symlinks:
<code bash>
 rm config 
ln -s /opt/scanservjs/etc/scanservjs config
 rm data 
ln -s /opt/scanservjs/var/lib/scanservjs data
</code>

Now move the default config file from **/opt/scanservjs/etc/scanservjs/config.default.js** to **/opt/scanservjs/etc/scanservjs/config.local.js** and edit to resemble the following (adapt where needed):
<file - config.local.js>
const options = { paths: ['/opt/scanservjs/usr/lib/scanservjs'] };
    config.host = '127.0.0.1';
    config.port = 7781;
    config.scanimage = '/usr/sbin/scanimage';
    config.convert = '/usr/bin/convert';
... [ omissis ] ...
</file>

And that's it! 

===== NGINX configuration =====

I choose to install ScanServJS as a sub-path of my **home.mydomain.com**, so this is the relative NGINX config file:
<file - scanner.conf>

location = /scanner {
        return 301 https://$host/scanner/;
}

# Interfaccia Web stmapante HP
location /scanner/ {
        proxy_pass http://10.70.43.1:7781/;
}
</file>

For more details, see [[selfhost:nginx|The Reverse Proxy concept]]

And restart your NGINX service.


===== Start and Autostart =====

Since i use OpenRC, just drop the following **/etc/init.d/scanservjs**:
<file - scanservjs>
#!/sbin/openrc-run
# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

description="SCan from web interface"
pidfile="/run/scanservjs.pid"
command_background=true
command="node /opt/scanservjs/usr/lib/scanservjs/server/server.js "
command_args=""
command_user="saned:scanner"

depend() {
        need net
}

start_pre()
{
        cd /opt/scanservjs/usr/lib/scanservjs
        export NODE_ENV=production
}
</file>

make it executable and add it to the default runlevel:
<code bash>
chmod +x /etc/init.d/scanservjs
rc-update add /etc/init.d/scanservjs default
 /etc/init.d/scanservjs start
</code>


===== Update =====

Get new DEB, replace files, restart!