Kong API Gateway Installation Guide for beginners

In this post, we will discuss about the uses of API Gateways and the installation of open source KONG API Gateway.

API Gateways provides security and control over the access by sitting in-front of any number of API services. KONG, Tyk, API Umbrella, Ambassador, Gravitee.io etc., are some of the API Gateways currently available in the market. These Gateways provides services like Authentication, rate-limiting, analysis, logging etc., to your API endpoints.

  Flowchart diagram to illustrate the API Gateway usage

Why choosing KONG over other gateways? Because, it is most straightforward of the choices above and the community is very much alive.

The latest version of the Kong 0.14.x comes with the support of various platforms. click here to choose. We proceed further with Installing Kong on Ubuntu platform.

Installing kong on Ubuntu

Installation of deb file

1. download the debian file here.
2. After downloading at the file location, do the following.

$ sudo apt-get update
$ sudo apt-get install openssl libpcre3 procps perl
$ sudo dpkg -i kong-community-edition-0.14.1.zesty.all.deb

Database setup

Now, we have to setup database. Kong supports PostgreSQL and cassandra

Lets setup PostgreSQL for KONG with user, database name and its password.

$ sudo apt-get install postgresql postgresql-contrib

Switch over to the postgres account on your server which created at the time of installation procedure by typing:

$ sudo -i -u postgres

Type psql to access a Postgres prompt and \q to exit the prompt.

Setup USER, DATABASE with password

postgres=# CREATE USER kong; CREATE DATABASE kong OWNER kong;

postgres=# ALTER USER kong WITH PASSWORD 'password you set';

Update Kong configuration and run migrations

Generally the Kong configuration path will be at /etc/kong/kong.conf.default

$ sudo cp /etc/kong/kong.conf.default /etc/kong/kong.conf

run the migrations job before the start

$ sudo kong migrations up -c /etc/kong/kong.conf
Error: missing password, required for connect
Run with — v (verbose) or — vv (debug) for more details

The above error might encounter if you don’t update the Kong configuration file. For this, you have to do the following steps.

$ sudo nano /etc/kong/kong.conf
and paste the below lines
pg_user = kong
pg_password = password you set
pg_database = kong

Running Kong migrations

$ sudo kong migrations up -c /etc/kong/kong.conf

If this throws an error Error: [postgres error] could not retrieve current migrations: [postgres error] ERROR: function to_regclass(unknown) does not exist (8) , check the PostgreSQL version here.

$ sudo service postgresql status

Kong requires PostgreSQL 9.5 or later. Upgrade the older version here.

If you upgrade to PostgreSQL 9.5 or later, then you don’t have to setup the database, user and password. If you install, you should setup again.

Start Kong

$ sudo kong start -c /etc/kong/kong.conf

Stop Kong

$ sudo kong stop #to stop the Kong

Final step to make sure the installation and setup process succeeded is:

$ curl -i http://localhost:8001/ or http://localhost:8001/ in the browser

   Welcome to Kong

That’s the end of Kong setup.