colouring-montreal/docs/setup-dev-environment.md

Setting up a local development environment

This document is intended to guide you through setting up a local development environment for Colouring London. This guide assumes you already have Ubuntu 20.04 server installed, typically installed in a virtual environment such a Virtual Box and are able to SSH into your Ubuntu installation for convenience.

First upgrade the installed packages to the latest versions, to remove any security warnings.

sudo apt-get update
sudo apt-get upgrade

Installing the tools and components

Now we install some essential tools.

sudo apt-get install -y build-essential git vim-nox wget curl

Now install python and related tools.

sudo apt-get install -y python3 python3-pip python3-dev python3-venv

Next install postgres and postgis to enable support for geographical objects.

sudo apt-get install -y postgresql postgresql-contrib libpq-dev postgis postgresql-12-postgis-3

and additional geo-spatial tools

sudo apt-get install -y gdal-bin libspatialindex-dev libgeos-dev libproj-dev

Now clone the colouring london codebase.

git clone https://github.com/colouring-london/colouring-london.git

Now install Node. It is helpful to define some local variables.

export NODE_VERSION=v16.13.2
export DISTRO=linux-x64
wget -nc https://nodejs.org/dist/$NODE_VERSION/node-$NODE_VERSION-$DISTRO.tar.xz
sudo mkdir /usr/local/lib/node
sudo tar xf node-$NODE_VERSION-$DISTRO.tar.xz -C /usr/local/lib/node
sudo mv /usr/local/lib/node/node-$NODE_VERSION-$DISTRO /usr/local/lib/node/node-$NODE_VERSION
rm node-$NODE_VERSION-$DISTRO.tar.xz

Now add the Node installation to the path and export this to your bash profile.

cat >> ~/.profile <<EOF
export NODEJS_HOME=/usr/local/lib/node/node-$NODE_VERSION/bin
export PATH=\$NODEJS_HOME:\$PATH
EOF

Then run source to make sure node and npm are on your path:

source ~/.profile

You can check the updated variables as follows

echo $PATH
echo $NODEJS_HOME

Configuring Postgres

Now we configure postgres. First ensure postgres is running.

service postgresql start

Ensure the en_US locale exists.

sudo locale-gen en_US.UTF-8

Configure the database to listen on network connection.

sudo sed -i "s/#\?listen_address.*/listen_addresses '*'/" /etc/postgresql/10/main/postgresql.conf

Allow authenticated connections from any IP (so includes the host).

echo "host all all all md5" | sudo tee --append /etc/postgresql/10/main/pg_hba.conf > /dev/null

Restart postgres to pick up config changes.

service postgresql restart

Create a superuser role for this user (<username>) if it does not already exist. The password <pgpassword> is arbitrary and probably should not be your Ubuntu login password.

sudo -u postgres psql -c "SELECT 1 FROM pg_user WHERE usename = '<username>';" | grep -q 1 || sudo -u postgres psql -c "CREATE ROLE <username> SUPERUSER LOGIN PASSWORD '<pgpassword>';"

Create a colouring london database if none exists. The name (<colouringlondondb>) is arbitrary.

sudo -u postgres psql -c "SELECT 1 FROM pg_database WHERE datname = '<colouringlondondb>';" | grep -q 1 || sudo -u postgres createdb -E UTF8 -T template0 --locale=en_US.utf8 -O <username> <colouringlondondb>

To test the app user's connection to the database, you could run psql interactively:

psql -d <colouringlondondb> -U <username> -h localhost

Create the necessary postgres extensions.

psql -d <colouringlondondb> -c "create extension postgis;"
psql -d <colouringlondondb> -c "create extension pgcrypto;"
psql -d <colouringlondondb> -c "create extension pg_trgm;"

Now run all 'up' migrations to create tables, data types, indexes etc. The .sql scripts to do this are located in the migrations folder of your local repository.

ls ./colouring-london/migrations/*.up.sql 2>/dev/null | while read -r migration; do psql -d <colouringlondondb> < $migration; done;

Setting up Python

Now set up a virtual environment for python. In the following example we have named the virtual environment colouringlondon but it can have any name.

pyvenv colouringlondon

Activate the virtual environment so we can install python packages into it.

source colouringlondon/bin/activate

Install python pip package manager and related tools.

pip install --upgrade pip
pip install --upgrade setuptools wheel

Now install the required python packages. This relies on the requirements.txt file located in the etl folder of your local repository.

pip install -r ./colouring-london/etl/requirements.txt

Setting up Node

Now upgrade the npm package manager to the most recent release with global privileges. This needs to be performed as root user, so it is necessary to export the node variables to the root user profile. Don't forget to exit from root at the end.

sudo su root
export NODEJS_HOME=/usr/local/lib/node/node-v16.13.2/bin/
export PATH=$NODEJS_HOME:$PATH
npm install -g npm@latest
exit

Now install the required Node packages. This needs to done from the app directory of your local repository, so that it can read from the package.json file.

cd ./colouring-london/app && npm install

Running the application

Now we are ready to run the application. The APP_COOKIE_SECRET is arbitrary.

PGPASSWORD=<pgpassword> PGDATABASE=<colouringlondondb> PGUSER=<username> PGHOST=localhost PGPORT=5432 APP_COOKIE_SECRET=123456 npm start

If you a running Ubuntu in a virtual environment you will need to configure networking to forward ports from the guest to the host. For Virtual Box the following was configured under NAT port forwarding.

Name	Protocol	Host Port	Guest Port
app	TCP	8080	3000
app_dev	TCP	3001	3001
ssh	TCP	4022	22

The site can then be viewed on http://localhost:8080. The app_dev mapping is used in development by Razzle which rebuilds and serves client side assets on the fly.

Finally to quit the application type Ctrl-C.