Referencing Other Environment Variables in Systemd : <p>Is is possible to reference other environment variables when setting new ones in systemd?</p>

<pre><code>[Service]
EnvironmentFile=/etc/environment
Environment=HOSTNAME=$COREOS_PRIVATE_IPV4
Environment=IP=$COREOS_PRIVATE_IPV4
Environment=FELIX_FELIXHOSTNAME=$COREOS_PRIVATE_IPV4
</code></pre>

<p>The above code does not seem to be working.</p>
