## 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 18.04 server installed, typically installed in a virtual environment such a Virtual Box and are able to SSH into your Ubuntu installation for convenience.
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First upgrade the installed packages to the latest versions, to remove any security warnings.

`sudo apt-get update`


`sudo apt-get upgrade`

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#### Installing the tools and components

Now we install some essential tools.

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

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Now install python and related tools.

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

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

`sudo apt-get install -y postgresql postgresql-contrib libpq-dev postgis postgresql-10-postgis-2.4`

and additional geo-spatial tools

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

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Now clone the colouring london codebase.

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

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

`NODE_VERSION=v8.11.3`

`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`

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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`

You can check the updated variables as follows

`echo $PATH`

`echo $NODEJS_HOME`

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#### Configuring Postgres

Now we configure postgres. First ensure postgres is running.

`service postgresql start`

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Ensure the `en_US` locale exists.

`sudo locale-gen en_US.UTF-8`

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Configure the database to listen on network connection.

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

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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`

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Restart postgres to pick up config changes.

`service postgresql restart`

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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>';"`

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

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

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Create the necessary postgres extensions.

`psql -d <colorlondondb> -c "create extension postgis;"`

`psql -d <colorlondondb> -c "create extension pgcrypto;"`

`psql -d <colorlondondb> -c "create extension pg_trgm;"`

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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 <colorlondondb>  < $migration; done;`

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#### 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`


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#### 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-v8.11.3/bin/`

`export PATH=$NODEJS_HOME:​$PATH`

`npm install -g npm@next`

`exit`


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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`


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#### Running the application

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

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


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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.

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Finally to quit the application type `Ctrl-C`.