# Systemd

{% hint style="warning" %}
 This document assumes `/home/ubuntu` is the server user home directory, make sure to change it to fit the directory of your choice.
{% endhint %}

Prerequisites:

* Install [Git](https://www.atlassian.com/git/tutorials/install-git?linuxc#linux) to clone the zen-oracle repository
* Install [mono-devel](http://www.mono-project.com/download). If you choose to install via a package manager, add Mono's own repository first.
* Install the Headless Node and import a funded account
* Cron **(Optional)**
* Install [MongoDB](https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/)

## Oracle Service File 

#### `Save it in path: /etc/systemd/system/zen-oracle.service`

```bash
[Unit]
Description=Oracle
After=network.target

[Service]
Type=simple
EnvironmentFile=/home/ubuntu/services/scripts/env
WorkingDirectory=/home/ubuntu/services/zen-oracle/src/Oracle/bin/Release
ExecStart=/usr/bin/mono /home/ubuntu/services/zen-oracle/src/Oracle/bin/Release/zen-oracle.exe s
Restart=on-failure

[Install]
WantedBy=multi-user.target
```

## Oracle Service

1. Get the oracle service (from GitLab)

   ```bash
    mkdir /home/ubuntu/services
    cd /home/ubuntu/services
    git clone https://gitlab.com/zenprotocol/zen-oracle.git
   ```
2. Build the oracle service

   ```bash
    cd /home/ubuntu/services/zen-oracle
    ./paket restore
    msbuild src/zen-oracle.sln /p:Configuration=Release
   ```
3. Create `/etc/systemd/system/zen-oracle.service` service file as mentioned above
4. Put all the environment variables assignments in the file `/home/ubuntu/services/scripts/env`
5. Follow node deployment instructions and be sure to have the zen-node service enabled
6. Enable Zen-Oracle

   ```bash
   sudo systemctl enable zen-oracle
   ```
7. Start MongoDB

   ```bash
    sudo systemctl start mongodb
   ```
8. Start Zen-Oracle Server

   ```bash
   sudo systemctl start zen-oracle
   ```

## Execution Scripts

1. Make sure all the environment variables are provided and correct
   * zen\_path : path of the oracle committer
   * zen\_wallet\_password: password of the F# wallet
   * zen\_node\_uri: uri of the node
   * oracle\_api: `uri:port` api port for oracle requests

## Cron job

* In order to commit at a precise time we suggest to use a script in a cron job to take care of the commitment.