# multiple fylrs in one Linux

Our default recommended fylr Installation has one fylr directly listening to port 443/80 for http(s). If you want multiple fylrs you need to direct web traffic to the correct one. We present one example here with Apache webserver used as reverse proxy.

{% hint style="info" %}
This increases the risk to run into resource and performance issues (except for small fylr instances with few traffic on a big server).
{% endhint %}

To somewhat reduce performance issues, only one indexer and only one PostgreSQL is used for all fylrs in this example.

## Prerequisites

* install [docker](https://docs.docker.com/engine/install/#server)
* install [certbot](https://certbot.eff.org/)\
  e.g. for Debian 12:\
  `apt install -y snapd`

  log out and back in again, to ensure snap’s paths are updated correctly\
  `snap install snapd`\
  `apt-get remove certbot`\
  `snap install --classic certbot`\
  `type -a certbot || ln -s /snap/bin/certbot /usr/local/bin/`
* install Apache 2\
  e.g. for Debian 12: `apt-get install -y apache2 ; a2enmod ssl rewrite proxy_http`

## Prepare Linux for fylr

We assume `bash` and Debian 12 in our examples.

```
mkdir /srv/fylr ; cd /srv/fylr
echo "vm.max_map_count=262144" >> /etc/sysctl.d/99-memory_for_indexer.conf
sysctl -p /etc/sysctl.d/99-memory_for_indexer.conf
mkdir -p postgres indexer sqlbackups
chown  999 postgres sqlbackups
chown 1000 indexer
swapoff -a; free -h
```

## Download all and configure common services

Use the following `docker-compose.yml` as a starting point:

```
curl https://raw.githubusercontent.com/programmfabrik/fylr-gitbook/main/_assets/multi/docker-compose.yml -o docker-compose.yml
```

Replace all strings that have `EXAMPLE` in it. E.g. with vim: `vim docker-compose.yml`

Download all software and start the indexer and SQL database service:

```
docker compose pull
docker compose up -d postgresql opensearch
```

## For each fylr instance

Do all the rest of the instructions for the first fylr instance. Then repeat all of it for the second.

Choose unique names and ports and put them into bash variables. Use the same as you used in `docker-compose.yml`.

```
DIR=fylr-EXAMPLE1     # directory name below /srv/fylr/
SERVICE=fylr-EXAMPLE1 # name in docker-compose.yml
DOMAIN=EXAMPLE1.COM
PORT=81
DB=EXAMPLE1
DBUSER=EXAMPLE1
```

#### Configure the reverse proxy:

```
cd /etc/apache2/sites-enabled
cat >>../sites-available/$DOMAIN.conf<<EOF
<VirtualHost *:80>
    ServerName $DOMAIN
    ServerAdmin administratoren@programmfabrik.de
    ProxyPreserveHost On
    ProxyPass / http://127.0.0.1:$PORT/ upgrade=websocket
    ProxyPassReverse / http://127.0.0.1:$PORT/ upgrade=websocket
</VirtualHost>
EOF
ln -s ../sites-available/$DOMAIN.conf .
apache2ctl -t && systemctl restart apache2
certbot --apache --agree-tos -d $DOMAIN # -m emailadress
```

... certbot in the last command will configure the https part of the reverse proxy in Apache.

#### Configure fylr:

```
cd /srv/fylr
mkdir -p $DIR/config/fylr $DIR/assets $DIR/migration $DIR/backups
chown 1000 $DIR/assets $DIR/backups $DIR/migration
curl https://raw.githubusercontent.com/programmfabrik/fylr-gitbook/main/_assets/multi/fylr.yml -o $DIR/config/fylr/fylr.yml
vi $DIR/config/fylr/fylr.yml  # replace string with EXAMPLE
```

Replace all strings in `fylr.yml` that have `EXAMPLE` in it. E.g. with vim:\
`vim $DIR/config/fylr/fylr.yml`

#### Create SQL database:

```
PSQL="docker compose exec postgresql psql -U fylr"
$PSQL -c 'CREATE DATABASE "'$DB'";'

$PSQL -c "CREATE USER $DBUSER WITH LOGIN ENCRYPTED PASSWORD '$DBUSER';"

$PSQL -c 'GRANT ALL PRIVILEGES ON DATABASE '$DB' TO '$DBUSER';'

$PSQL -c 'ALTER DATABASE '$DB' OWNER TO '$DBUSER';'
```

#### Start this fylr instance:

```
docker compose up -d $SERVICE
```

Repeat for each additional fylr instance the whole part from "For each fylr instance" to here.

## Remarks

A maintain script and cron job, as in the [default recommended installation](/for-system-administrators/installation/linux-docker-compose.md), are not provided by us, as we do not have sufficient experience with this multi-fylr-setup. Use the recommended installation instead, when possible.


---

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