Poke API

Poke API is a scheduler and an API which have to main goal to trigger agent using Apache Kafka.

Environment variables

Name	Description	Type
SCHEDULER_ENABLED	Enable the scheduler in order to send events in kafka	Boolean
SHARDING_ENABLED	Enable sharding, allows to start multiple instances with scheduling enabled	Boolean
SHARDING_NBSHARDS	Set the number of shards, must be a power of two	Number
APP_SECRET	Application secret	String
MACAROONS_SECRET	Macaroon secret	String
JAAS_PATH	Path to the .jaas file containing kafka credentials	String
POSTGRESQL_ADDON_URI	URI of the PostgreSQL database	URI
POSTGRESQL_ADDON_PORT	Port of the PostgreSQL database	Number
POSTGRESQL_ADDON_DB	Name of the PostgreSQL database	String
POSTGRESQL_ADDON_USER	User to use with the PostgreSQL database	String
POSTGRESQL_ADDON_PASSWORD	Password of the user to use with the PostgreSQL database	String
POSTGRESQL_ADDON_HOST	Host of the PostgreSQL database	String
WARP_PRODUCER	The UUID of the producer	UUID
WARP_SIP_HASH_APP	Hexadecimal key of the Warp 10 instance	Hex
WARP_SIP_HASH_TOKEN	Hexadecimal key of the Warp 10 instance	Hex
WARP_AES_TOKEN	Hexadecimal key of the Warp 10 instance	Hex
WARP_ENDPOINT	URL of the Warp 10 instance	URL
KAFKA_HOST	Host of the kafka instance with optionnaly a port	String
KAFKA_HTTPCHECKS_TOPIC	Topic of the HTTP checks	String
KAFKA_HTTPCHECKS_INTERVAL	Interval to treat message batching	String
KAFKA_SSLCHECKS_TOPIC	Topic of the SSL checks	String
KAFKA_SSLCHECKS_INTERVAL	Interval to treat message batching	String
KAFKA_DNSCHECKS_TOPIC	Topic of the DNS checks	String
KAFKA_DNSCHECKS_INTERVAL	Interval to treat message batching	String
KAFKA_ICMPCHECKS_TOPIC	Topic of the ICMP checks	String
KAFKA_ICMPCHECKS_INTERVAL	Interval to treat message batching	String
KAFKA_ENDPOINT	Kafka endpoint	String
KAFKA_WRITER_USER	Kafka user with writing permission	String
KAFKA_WRITER_PASSWORD	Password of the kafka permission	String
KAFKA_SECURITY_PROTOCOL	Kafka security protocol which can be PLAINTEXT, SASL_PLAINTEXT, SASL_SSL and SSL	String
ZOOKEEPER_SERVERS	Zookeeper connection string (e.g. 192.168.0.1:2181,192.168.0.2:2181,192.168.0.3:2181)	String

Usage

To use the Poke API you should fill the previous environment variables in order to start the application. This means you should have at least as dependencies:

• An instance of PostgreSQL
• An instance of Apache Kafka
• An instance of Warp 10

Once, all dependencies are up and running, you can compile the Poke API using the following command:

sbt stage

Now, you are ready to run it in production using the following command:

./target/universal/stage/bin/poke-api

Sharding

If you want to start multiples instances with the scheduler enabled, you must enable sharding.

Set SHARDING_ENABLED to true and SHARDING_NBSHARDS to a power of two.

The number of shards must be at least as big as the number of instances you want to start.

That being said, changing the number of shards is not trivial; you would have to either stop all scheduler instances or have checks being scheduled at least twice during the change.

It's better to choose a "big enough" number, in case you want to add more instances later.

Development

To contribute to the project you will need the same dependencies that for the usage. Furthermore, the project

To start the incremental compilation type the following commands:

$ sbt

[info] Loading settings from plugins.sbt,scaffold.sbt ...
[info] Loading project definition from poke-api/project
[info] Loading settings from build.sbt ...
[info] Loading project definition from .sbt/1.0/staging/49b31237ef85983ed75d/anorm-pg-entity/project
[info] Loading settings from build.sbt ...
[info] Set current project to poke-api (in build poke-api/)
[info] sbt server started at .sbt/1.0/server/e3a928848655bdf089a9/sock
[poke-api] $ ~compile
...
[success] Total time: 2 s, completed Mar 20, 2018 5:14:47 PM
1. Waiting for source changes... (press enter to interrupt)

So, now you are ready to contribute 😄.