Kong is a scalable, open source API Platform (also known as an API Gateway or API Middleware). Kong was originally built by Kong Inc. (formerly known as Mashape) to secure, manage, and extend over 15,000 Microservices for its API Marketplace, which generates billions of requests per month.
Under active development, Kong is now used in production at hundreds of organizations from startups, to large enterprises and governments including: The New York Times, Expedia, Healthcare.gov, The Guardian, Condè Nast, The University of Auckland, Ferrari, Rakuten, Cisco, SkyScanner, Yahoo! Japan, Giphy and so on.
Kong's official documentation can be found at docs.konghq.com.
Kong 1.1 added the capability to run Kong without a database, using only in-memory storage for entities: we call this DB-less mode. When running Kong DB-less, the configuration of entities is done in a second configuration file, in YAML or JSON, using declarative configuration.
$ docker run -d --name kong \
-e "KONG_DATABASE=off" \
-e "KONG_PROXY_ACCESS_LOG=/dev/stdout" \
-e "KONG_ADMIN_ACCESS_LOG=/dev/stdout" \
-e "KONG_PROXY_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_LISTEN=0.0.0.0:8001, 0.0.0.0:8444 ssl" \
-p 8000:8000 \
-p 8443:8443 \
-p 8001:8001 \
-p 8444:8444 \
%%IMAGE%%
Generate a skeleton configuration file to get you started
$ docker exec -it kong kong config init /home/kong/kong.yml
$ docker exec -it kong cat /home/kong/kong.yml >> kong.yml
Load a declarative configuration into a running Kong node via its Admin API using HTTPie
$ http :8001/config config=@kong.yml
Note: Not all Kong plugins are compatible with DB-less mode, since some of them by design require a central database coordination and/or dynamic creation of entities, see the doc for details at DB-less and Declarative Configuration
You can either use the official Cassandra/PostgreSQL containers, or use your own.
It's up to you to decide which datastore between Cassandra or PostgreSQL you want to use, since Kong supports both.
Start a Cassandra container by executing:
$ docker run -d --name kong-database \
-p 9042:9042 \
cassandra:3
Start a PostgreSQL container by executing:
$ docker run -d --name kong-database \
-p 5432:5432 \
-e "POSTGRES_USER=kong" \
-e "POSTGRES_DB=kong" \
-e "POSTGRES_PASSWORD=kong" \
postgres:9.6
Run the database migrations with an ephemeral Kong container:
$ docker run --rm \
--link kong-database:kong-database \
-e "KONG_DATABASE=postgres" \
-e "KONG_PG_HOST=kong-database" \
-e "KONG_PG_USER=kong" \
-e "KONG_PG_PASSWORD=kong" \
-e "KONG_CASSANDRA_CONTACT_POINTS=kong-database" \
%%IMAGE%% kong migrations bootstrap
In the above example, both Cassandra and PostgreSQL are configured, but you should update the KONG_DATABASE
environment variable with either cassandra
or postgres
.
Note for Kong < 0.15: with Kong versions below 0.15 (up to 0.14), use the up
sub-command instead of bootstrap
. Also note that with Kong < 0.15, migrations should never be run concurrently; only one Kong node should be performing migrations at a time. This limitation is lifted for Kong 0.15, 1.0, and above.
Once the database has been started and prepared, we can start a Kong container and link it to the database container, and configuring the KONG_DATABASE
environment variable with either cassandra
or postgres
depending on which database you decided to use:
$ docker run -d --name kong \
--link kong-database:kong-database \
-e "KONG_DATABASE=postgres" \
-e "KONG_PG_HOST=kong-database" \
-e "KONG_PG_PASSWORD=kong" \
-e "KONG_CASSANDRA_CONTACT_POINTS=kong-database" \
-e "KONG_PROXY_ACCESS_LOG=/dev/stdout" \
-e "KONG_ADMIN_ACCESS_LOG=/dev/stdout" \
-e "KONG_PROXY_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_LISTEN=0.0.0.0:8001, 0.0.0.0:8444 ssl" \
-p 8000:8000 \
-p 8443:8443 \
-p 8001:8001 \
-p 8444:8444 \
%%IMAGE%%
If everything went well, and if you created your container with the default ports, Kong should be listening on your host's 8000
(Proxy), 8443
(Proxy SSL), 8001
(Admin API) and 8444
(Admin API SSL) ports.
You can read the docs at docs.konghq.com to learn more about Kong.
You can override any property of the Kong configuration file with environment variables. Just prepend any Kong configuration property with the KONG_
prefix, for example:
$ docker run -d --name kong \
-e "KONG_DATABASE=postgres" \
-e "KONG_PG_HOST=kong-database" \
-e "KONG_LOG_LEVEL=info" \
-e "KONG_CUSTOM_PLUGINS=helloworld" \
-e "KONG_PG_HOST=1.1.1.1" \
-e "KONG_ADMIN_LISTEN=0.0.0.0:8001, 0.0.0.0:8444 ssl" \
-p 8000:8000 \
-p 8443:8443 \
-p 8001:8001 \
-p 8444:8444 \
%%IMAGE%%
If you change your custom configuration, reload Kong (without downtime) by running:
$ docker exec -it kong kong reload
This will run the kong reload
command in your container.
Among the many deployment options available, Kong also offers a Kubernetes Ingress Controller ready to use in your K8s environment.