Step 4: Git Repository

We now set up the Git repository and a specific post-receive script that makes it easy for experimenters to deploy experiments on the server.

Directories

First we will create two directories: oTree will contain the live oTree project. oTree.git will be the repository that experimenters can push their experiments to. After creating the directories, we initialize an empty Git repository in the latter.

mkdir /home/otree/oTree
mkdir /home/otree/oTree.git
cd /home/otree/oTree.git
git init --bare
cd ~

Post-Receive Script

Experimenters can push their oTree experiments to the Git repository we have just created. Now we set up a script that is executed after every push to the repository. It will take care of the following steps:

• wipe the current virtual environment
• re-create the virtual environment
• install current versions of all required packages
• attempt to migrate the existing database if migrations are specified by the experimenter
• reset the database in all other cases
• restart the web server

Edit oTree.git/hooks/post-receive with nano:

nano /home/otree/oTree.git/hooks/post-receive

Add the following script:

#!/bin/bash
GIT_WORK_TREE="/home/otree/oTree"
VENV_DIR="/home/otree/venv_otree"
export GIT_WORK_TREE
git checkout -f

if [[ -d "$VENV_DIR" ]]; then
    echo "[log] - Cleaning virtualenv"
    rm -rf $VENV_DIR
    echo "[log] - Finished creating virtualenv"
fi

# recreate venv
echo "[log] - create venv"
python3.6 -m venv $VENV_DIR

# activate
echo "[log] - activate venv"
echo $VENV_DIR
source $VENV_DIR/bin/activate
source /home/otree/.otree_env

# install requirements
echo "[log] - install requirements"
pip install -U pip
pip install -r $GIT_WORK_TREE/requirements.txt

echo "[log] - Staring DB migration"
cd $GIT_WORK_TREE
if [[ -d "$GIT_WORK_TREE/otree_core_migrations" ]]
    then
        echo "[log] - detected migrations in otree project dir"
        echo "[log] - attempting migrations"
        otree migrate
        echo "[log] - migrations done"
    else
        echo "[log] - no migrations defined"
        echo "[log] - resetting db"
        otree resetdb --noinput
        echo "[log] - database reset"
fi

cd ..
echo "[log] - Finished DB migration "

echo "[log] - restart services"
sudo /usr/sbin/service supervisor restart

Finally, we make the script executable:

chmod +x /home/otree/oTree.git/hooks/post-receive

Continue with step 5.