examples

README

CN-infra examples

The examples folder contains several executable examples (built from their respective main.go files) used to illustrate the cn-infra functionality. While most of the examples show a very simple use case, they still need to connect to ETCD and/or Kafka. Therefore, you need to have running instances of Etcd and Kafka to which the examples can connect.

Examples with the suffix _lib demonstrate the usage of CN-Infra APIs in generic Go programs. You can simply import the CN-Infra library where the API is declared into your program and starting using the API.

Examples with the suffix _plugin demonstrate the usage of CN-Infra APIs within the context of plugins. Plugins are the basic building blocks of any given CN-Infra application. The CNB-Infra plugin framework provides plugin initialization and graceful shutdown and supports uniform dependency injection mechanism to manage dependencies between plugins.

Current examples:

• cassandra lib shows how to use the Cassandra data broker API to access the Cassandra database,
• datasync plugin showcases the data synchronization APIs of the datasync package on an example plugin,
• etcdv3 lib shows how to use the ETCD data broker API to write data into ETCD and catch this change as an event by the watcher,
• flags plugin registers flags and shows their runtime values in an example plugin,
• kafka lib shows how to use the Kafka messaging library on set of individual tools (producer, sync and async consumer),
• kafka plugin (non-clustered) contains a simple plugin which registers a Kafka consumer and sends a test notification,
• kafka plugin (clustered) contains a simple plugin which registers a Kafka consumer watching on specific partition/offset and sends a test notification to partition in Kafka cluster
• logs lib shows how to use the logger library and switch between the log levels,
• logs plugin showcases how to ue the logger library in a simple plugin,
• redis lib contains several examples that use the Redis data broker API,
• model show how to define a custom data model using Protocol Buffers and how to integrate it into the application,
• simple-agent showcases an approach how a set of plugins can be turned into an application.

How to run an example

1. Start ETCD server on localhost

sudo docker run -p 2379:2379 --name etcd --rm \
quay.io/coreos/etcd:v3.0.16 /usr/local/bin/etcd \
-advertise-client-urls http://0.0.0.0:2379 \
-listen-client-urls http://0.0.0.0:2379

2. Start Kafka

sudo docker run -p 2181:2181 -p 9092:9092 --name kafka --rm \
 --env ADVERTISED_HOST=172.17.0.1 --env ADVERTISED_PORT=9092 spotify/kafka

3. Start the desired example

Each example can be started now from its directory.

go run main.go  \
--etcdv3-config=/opt/vnf-agent/dev/etcd.conf \
--kafka-config=/opt/vnf-agent/dev/kafka.conf

Documentation

Overview

Package examples contains examples that demonstrate the usage of various cn-infra components.