AC UserManual

Home directory

Once you have your PIC account you are able to access the UI's machines:

ssh {user}@ui.pic.es

and you are you are logged in to your "home":

/nfs/pic.es/user/{initial_user}/{user}

This directory is basically though for storing your software. It is backup and has 10GiB of capacity.

Storage

Massive storage

Each project has a massive storage space accessible at the following path:

/pnfs/pic.es/data/astro/{project} (see projects_url for more details)

which has only read permissions for the project's users.

Inside the directory there are two different paths corresponding to two different back-ends:

Tape

/pnfs/pic.es/data/astro/{project}/tape

As its name suggests, the data in the tape path is stored in magnetic tapes, and is critical, such as raw data or very difficult data to obtain or to get. The size of each file is usually large, from 1-2GB to 100-200GB, due to technical reasons (they are usually iso or tar.bz2 files). Data in tapes is not very often accessed. It is necessary a previous step when accessing data in tapes, which is the pre-stage. This step is the action of reading the magnetic tape and put the data into a buffer. Once the data is in the buffer one can access the data as it was in a disk. After some time, the data is removed from the buffer. In case the data in tape has to be available for long time get in touch with the contant person of the project.

Disk

/pnfs/pic.es/data/astro/{project}/disk

Disk data is usually the data being currently used by the project, and it is being very often accessed. The size of the files is not important here.

Scratch

Each user has a scratch space at the following path:

/nfs/astro/{user}

This space is thought as a sandbox. When the project decides some data from any scratch space is important enough for the whole collaboration, the contact person for each project will move the data into the /pnfs storage.

Take note that all data older than 6 months may be erased at any time without prior notice.

Any location not included in the former paths is not allowed and its contents erased on sight.

Working with Python environments (any machine except Big Data platform)

1.1 Usually environments are all saved in the same directory (e.g. ~/env). In case it is not created:

mkdir ~/env/

1.2 Create a new environment:

cd  ~/env/
virtualenv {env_name}

1.3 Activate environment:

. ~/env/{env_name}/bin/activate

1.4 Update pip command (only for the first time):

pip install -U pip

1.5 Install any package you need (in case you have any problem with some package, please contact us) 1.5.1 e.g. jupyter notebooks:

pip install jupyter[notebook]

1.5.2 e.g numpy:

pip install numpy

Download code and git rules

These are the git rules for developers at PIC.

The methodology written below is a try to help the code development of the team and they are thought for non-experts git users.

It has been compiled from the official git documentation, which we strongly recommend to look at (at least the first three chapters):

Git documentation

And from this git branch model:

A successful Git branching model

We assume you already have a PIC account and you have already created a python virtual environment

Codes are hosted at https://gitlab.pic.es.

1. Download the code (first you need to have permissions to do it)

1.1. Access ui:

ssh {user}@ui.pic.es

1.2 Usually software is stored in the same directory:

mkdir ~/src/

1.2 Create a directory in which you are going to develop your codes, e.g:

mkdir -p ~/{src}/{software_project_name}

1.3 Copy the code from the gitlab repository in the created directory:

cd ~/src/{software_project_name}
git clone https://gitlab01.pic.es/{software_project_name}/{pipeline}.git

1.4 Activate your environment

. ~/env/{env_name}/bin/activate

1.5 Locate the `setup.py` file of the project (usually in the main software directory), and deploit the code:

cd  ~/src/{software_project_name}
pip install -e .

2. Create your own branch

Every project has two main protected branches: master and develop. Protected means you, as a standard developer, will not have permissions to write on them. Therefore in order to develop your features in the code you need to create your own branch that will always come from the develop branch.

2.1 Enter in the project directory:

cd {pipeline}

2.2 Create the branch:

git checkout -b feature_branch_name origin/develop

3. Modify the code

3.1 Day Tip:

Everyday you sit in your computer and want to modify the code, in order not to be outdated in the changes made in the develop branch, you should do:

3.1.1 Download any modification in the code

git fetch

3.1.2 Incorporate changes in the develop branch into your feature_branch_name branch

git rebase origin/develop

(Hopefully there will be no conflicts if all developers are working in independent branches. If this is not the case and you have doubts after reading the references given in point 5 below, please call us before meshing it up!)

3.2 See the changes you have done

git status

3.3 Add changes

git add changed_files

3.4 Commit changes

git commit -m "message describing the modifications"

4. Finish the new feature

Once you finish to develop, debug and test the new feature you send us an email.

We immediately will send you back another one saying that your feature has been integrated into the develop branch.

Note that your branch will be deleted.

5. Incorporate changes and start a new feature again

In order to start with a new feature you need to incorporate the changes we just did (integrate the feature into develop) and create another new branch:

git fetch

git checkout -b anoter_feature_branch_name origin/develop