Singularity Container Instances Service¶
From Singularity version 2.4 onwards, you can cleanly, reliably, and safely run services in a container.
For the example here, we will start nginx service inside the container instance. First, we will need to put the command that we want to run in a script.:
%startscript
service nginx start
Start the Instance¶
With the %startscript included in the singularity nginx.simg image. We can start the nginx service with:
[command] [image] [name of instance]
$ singularity instance.start nginx.img web
Check the Running Instance¶
After start up the service instance, you can check which instances are running using:
$ singularity instance.list
INSTANCE NAME PID CONTAINER IMAGE
web 790 /home/mibauer/nginx.img
Multiple instances from the same image can be started as well.
Mount Host Folder (Bind Mount)¶
For example, if you wish to capture the output of the web1 container instance which is placed at /output/ inside the container you could do:
$ singularity instance.start -B output/dir/outside/:/output/ nginx.img web1
Connect to the Running Instance¶
$ singularity instance.stop web1