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Nasrul Hazim Bin Mohamad
Nasrul Hazim Bin Mohamad

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Setup Kong in Almalinux 9

#kong #api #apigateway #almalinux

Today I will share with you how you can setup Kong Gateway 3.5 with PostgreSQL 16, both in Almalinux 9.

PostgreSQL 9

We going to start with PostgreSQL 16. The steps required as following:

  1. Install PostgreSQL 16
  2. Initialise PostgreSQL 16
  3. Add port 5432 into public zone
  4. Allow remote access to PostgreSQL 16.
  5. Enable and start the service.
  6. Create kong database, user and password.

I have the following script which I place it in user's home - ~/install-postgresql.

#!/bin/bash echo "🚀 Downloading PostgreSQL 16..." sudo dnf update -y sudo dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-9-x86_64/pgdg-redhat-repo-latest.noarch.rpm echo "🚀 Installing PostgreSQL 16..." sudo dnf install -y postgresql16 postgresql16-server echo "🚀 Initialise DB for PostgreSQL 16..." /usr/pgsql-16/bin/postgresql-16-setup initdb echo "🚀 Configuring PostgreSQL 16 firewall..." sudo firewall-cmd --zone=public --permanent --add-port=5432/tcp sudo firewall-cmd --reload echo "🚀 Configuring ph_hba.conf..." echo "host all all 0.0.0.0/0 md5" >>/var/lib/pgsql/16/data/pg_hba.conf echo "🚀 Configuring postgresql.conf..." echo "listen_addresses = '*'" >>/var/lib/pgsql/16/data/postgresql.conf echo "🚀 Enabling PostgreSQL 16 at startup..." sudo systemctl enable postgresql-16 echo "🚀 Starting the PostgreSQL 16 service..." sudo systemctl start postgresql-16 echo "🚀 Configuring kong database, user and password..." POSTGRES_PASSWORD=$(echo $RANDOM | md5sum | head -c 20) DB_EXISTS=$(sudo su - postgres -c "psql -lqt" | cut -d \| -f 1 | grep -w kong | wc -l) || true if [[ $DB_EXISTS == 0 ]]; then sudo su - postgres -c "psql -c \"CREATE USER kong WITH PASSWORD '$POSTGRES_PASSWORD';\" > /dev/null" sudo su - postgres -c "psql -c \"CREATE DATABASE kong OWNER kong\" > /dev/null" echo POSTGRES_PASSWORD > kong-database.pass fi
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Run the following command to start the installation and configuration:

cd ~ chmod +x install-postgresql . ./install-postgresql
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Copy the password in kong-database.pass and we will use it in the Kong configuration.

Kong Gateway

For Almalinux, we can use RHEL installer.

I have download it and place it in ~/installers/ directory - assuming you are in user's directory.

Then I have config/ directory which stored the kong configuration as following:

# Port port_maps = 80:8000,443:8443 proxy_listen = 0.0.0.0:80 reuseport backlog=16384, 0.0.0.0:443 http2 ssl reuseport backlog=16384 admin_listen = 127.0.0.1:8001 reuseport backlog=16384, 127.0.0.1:8444 http2 ssl reuseport backlog=16384 # admin_listen = 0.0.0.0:8001 admin_gui_listen = 0.0.0.0:8002 headers = latency_tokens nginx_http_client_max_body_size = 100m nginx_http_client_body_buffer_size = 100m # DATASTORE database = postgres pg_host = kong-db-node pg_port = 5432 pg_timeout = 5000 pg_user = kong pg_password = pg_database = kong pg_schema = public
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Then I have the following script to install and setup Kong.

#!/bin/bash # Parse command line arguments while [[ $# -gt 0 ]]; do key="$1" case $key in -k|--kong-ip) KONG_DB_IP="$2" shift # past argument shift # past value ;; *) # unknown option echo "Unknown option: $1" return ;; esac done # Check if required arguments are provided if [ -z "$KONG_DB_IP" ]; then echo "Error: Please provide Kong Database IP Address." return fi echo "🚀 Installing Kong..." yum install "$(dirname "$0")/installers/kong-3.5.0.el8.x86_64.rpm" -y echo "🚀 Enabling at startup..." systemctl enable kong echo "🚀 Setup hostname..." echo "$KONG_DB_IP kong-db-node" >> /etc/hosts echo "🚀 Backup Configuration..." cp /etc/kong/kong.conf /etc/kong/kong.conf.default echo "🚀 Configuring..." cp "$(dirname "$0")/config/kong.conf" /etc/kong/kong.conf echo "🚀 Disable Proxy on localhost..." echo "export no_proxy=localhost,127.0.0.1" >> /etc/environment echo "⚠️ You need to update the kong database credential located in /etc/kong/kong.conf" echo "⚠️ Then you are good to go to start the kong service"
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Then you can the script:

cd ~/ chmod +x install-kong . ./install-kong <database-ip>
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Then open up the /etc/kong/kong.conf and update the password for kong database based on step in PostgreSQL 16 installation.

Once you are done, run the following command:

kong migrations bootstrap kong kong migrations up && kong migrations finish
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Update the firewall rules:

sudo firewall-cmd --zone=public --permanent --add-port=443/tcp sudo firewall-cmd --zone=public --permanent --add-port=80/tcp sudo firewall-cmd --zone=public --permanent --add-port=8000/tcp sudo firewall-cmd --zone=public --permanent --add-port=8001/tcp sudo firewall-cmd --zone=public --permanent --add-port=8002/tcp sudo firewall-cmd --reload
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Then start the kong service:

systemctl start kong
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Now you can test your Kong:

curl -i -X GET --url http://localhost:8001/services
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And open Kong Manager at http://localhost:8002.

It is advisable that Kong Manager only be access from limited IP address and exposing to the internet.

Photo by Rodion Kutsaiev on Unsplash

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