4. Environment

Environment Setup for HNG Boilerplate Golang Web

Overview

This document outlines the environment setup required to run the HNG Boilerplate Golang Web application in both development (test) and production environments. It covers the necessary software, hardware, and configuration settings, including setting up Nginx as a reverse proxy.

Required Software

Go Programming Language

• Version: 1.19 or later
• Installation: Follow the official Go installation guide for your operating system.

PostgreSQL

• Version: 14 or later
• Installation: You can install PostgreSQL using the package manager of your choice:
  • Homebrew (MacOS):

    brew install postgresql

  • APT (Ubuntu):

    sudo apt-get update
    sudo apt-get install postgresql postgresql-contrib

  • YUM (CentOS):

    sudo yum install postgresql-server postgresql-contrib

Docker (Optional)

• Purpose: To run PostgreSQL instances in containers, simplifying setup and teardown.
• Installation: Follow the official Docker installation guide.

Git

• Version: Latest version recommended.
• Installation: Follow the official Git installation guide.

Nginx

• Version: Latest stable version.
• Installation: You can install Nginx using the package manager of your choice:
  • APT (Ubuntu):

    sudo apt-get update
    sudo apt-get install nginx

  • YUM (CentOS):

    sudo yum install nginx

PM2 (Process Manager)

• Purpose: To manage and monitor the Go application processes.
• Installation: Follow the official PM2 installation guide:

  npm install pm2@latest -g

Setting Up the Environment

PostgreSQL

PostgreSQL can be set up locally or using Docker for convenience.

Local Set Up

The script shown below is used to install and set up PostgreSQL:

#! /bin/bash

# Update package lists
sudo apt-get update

# Install PostgreSQL
sudo apt-get install -y postgresql postgresql-contrib

# Start & Enable PostgreSQL
sudo systemctl start postgresql
sudo systemctl enable postgresql

# Variables for credentials
DB_USER="postgres"
DB_PASSWORD="password"
DB_NAME="db_name"

# Check if the DB_USER is postgres and alter the password of this user else create a new user
if [ "$DB_USER" == "postgres" ]; then
  sudo -i -u postgres psql <<EOF
    ALTER USER postgres WITH PASSWORD '$DB_PASSWORD';
EOF
    echo "Password for 'postgres' user has been updated to '$DB_PASSWORD'."
else
    sudo -i -u postgres psql <<EOF
    -- Create a user named '$DB_USER' with password '$DB_PASSWORD'
    CREATE USER $DB_USER WITH PASSWORD '$DB_PASSWORD';
EOF
fi

# Create the database and grant the user access to it
sudo -i -u postgres psql <<EOF 
    -- Create a database named '$DB_NAME'
    CREATE DATABASE $DB_NAME;

    -- Grant all privileges on the database '$DB_NAME' to the user '$DB_USER'
    GRANT ALL PRIVILEGES ON DATABASE $DB_NAME TO $DB_USER;
EOF

# Modify pg_hba.conf to allow password authentication
PG_HBA_FILE=$(sudo -i -u postgres psql -t -P format=unaligned -c 'SHOW hba_file')
sudo sed -i "s/^local\s\+all\s\+all\s\+peer/local   all             all                                     md5/" $PG_HBA_FILE
sudo sed -i "s/^host\s\+all\s\+all\s\+127.0.0.1\/32\s\+ident/host    all             all             127.0.0.1\/32            md5/" $PG_HBA_FILE
sudo sed -i "s/^host\s\+all\s\+all\s\+::1\/128\s\+ident/host    all             all             ::1\/128                 md5/" $PG_HBA_FILE
sudo bash -c "echo 'host    all             all             0.0.0.0/0               md5' >> $PG_HBA_FILE"
sudo bash -c "echo 'host    all             all             ::/0                    md5' >> $PG_HBA_FILE"

# Modify postgresql.conf to listen on all addresses
POSTGRESQL_CONF=$(sudo -i -u postgres psql -t -P format=unaligned -c 'SHOW config_file')
sudo sed -i "s/^#listen_addresses = 'localhost'/listen_addresses = '*'/" $POSTGRESQL_CONF

# Restart PostgreSQL to apply changes
sudo systemctl restart postgresql

echo "PostgreSQL setup is complete. User '$DB_USER' with database '$DB_NAME' has been created. The user can connect using the password '$DB_PASSWORD'."