# Computing Info: FLEUR Hands-on 2022
[Link to this page](https://iffmd.fz-juelich.de/s/Diafl-tYK)
To participate in the hands-on sessions we prepared a tutorial that will enable you to gain experience with FLEUR calculations. We offer two options to access this tutorial:
1. You might use docker or podman on your own computer.
Using this option has the following implications:
- You need to install docker/podman on your own computers. We are not able to assist you with this process but for many operating systems it is a rather simple process. You might want to check https://www.docker.com/products/docker-desktop or https://podman.io/getting-started/installation. For the purpose of this tutorial, either docker or podman can be used. We will use the term docker in the following, but the instructions apply to podman as well. If you use linux it is probably best to use the docker/podman provided by your distribution.
- You will run the tutorial using the small script provided below. You can work any-time on this using your own powerful hardware. You will have the tutorial available after the workshop as well.
2. You can also a free web-service with the tutorial with the mybinder.org webservice. Just use the following link for this service: [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/git/http%3A%2F%2Fiffgit.fz-juelich.de%2Ffleur%2Ffleur_tutorial_container/master?labpath=Welcome.ipynb)
This has the following disadvantages:
- The resources in the containers run on mybinder.org are limited.
- You depend on the availablity of the mybinder.org service.
## Start a tutorial
In all cases please be aware that the tutorial files in the image are ***not in persistent storage***. Hence, you will get a clean image if you restart (or more negativ: you will have to start again after restarting). In the image you start using our script you have a local directory from the host mounted into the container.
- If you want to use a local docker/podman install, please use the [small shell-script we provide here](https://www.flapw.de/future.sh). Please download the script and execute it with ```bash fleur_tutorial.sh```. If you experience problems with the script finding your docker/podman executable, please do ``` DOCKER=path_to_your_docker bash future.sh```.
- Alternatively, (i.e. if you run on windows without a proper shell): start the container on your command line with:
``` docker run -p 8888:8888 judft/future:noAiiDA ``` or ``` podman run -p 8888:8888 judft/future:noAiiDA ```.
You will see some output including a link like ```http://127.0.0.1:8888.....```. Open this link in your browser and start. If you do this you might want to call ```docker pull judft/future:noAiiDA``` each morning to ensure you use the most recent version. For the AiiDA tutorial you need a special image `judft/future:AiiDA` which you should however only use if you are studying this part of the tutorial.
### Trouble shooting hints
- Please ensure that your docker works. E.g. you could try a simple ```docker run -it busybox```. You should get a termial in this container. Stop it with CTRL+d.
- On some linux installations you might have to run docker and the script with ```sudo```.
- If the script writes out dots (```......```) for some time it is probable that something went wrong, e.g., you could have missing permissions for running docker or the used socket is blocked by another (instance) of a docker image. If you observe something like this please have a look at the ```log``` file the script writes out to get a hint on whether something went wrong. You may check whether other images are running with ```docker ps``` and terminate them with the command ```docker kill <CONTAINER ID>```, where ```CONTAINER ID>``` is the container ID. For other issues it may be a good idea to search for the error message in the ```log```file in the internet. For example, to fix the permission issue [this Stack Overflow discussion](https://stackoverflow.com/questions/48957195/how-to-fix-docker-got-permission-denied-issue) may help.