shankarlaldhakar/noaa

NOAA is a client library to consume metric and log messages from Doppler.

#NOAA

noaa is a client library to consume metric and log messages from Doppler.

##Get the Code

This Go project is designed to be imported into $GOPATH, rather than being cloned into any working directory. There are two ways to do this.

• The easiest way with with go get. This will import the project, along with all dependencies, into your $ GOPATH.

  $ echo $GOPATH
  /Users/myuser/go
  
  $ go get github.com/cloudfoundry/noaa
  
  $ ls ~/go/src/github.com/cloudfoundry/
  noaa/         sonde-go/
  

• You can also manually clone the repo into your $GOPATH, but you then have to manually import dependencies.

  $ echo $GOPATH
  /Users/myuser/go
  
  $ cd /Users/myuser/go/src/github.com/cloudfoundry
  $ git clone git@github.com:cloudfoundry/noaa.git
  $ cd noaa
  $ go get ./...
  

Updates

Reconnecting to Traffic Controller

noaa has recently updated its reconnect strategy from trying to reconnect five times in quick succession to a back-off strategy. The back-off strategy can be configured by setting the SetMinRetryDelay() and the SetMaxRetryDelay().

During reconnection, noaa will wait initially at the MinRetryDelay interval and double until it reaches MaxRetryDelay where it will try reconnecting indefinitely at the MaxRetryDelay interval.

This behavior will affect functions like consumer.Firehose(), consumer.Stream() and consumer.TailingLogs().

Sample Applications

Prerequisites

In order to use the sample applications below, you will have to export the following environment variables:

• CF_ACCESS_TOKEN - You can get this value by executing ($ cf oauth-token). Example:

export CF_ACCESS_TOKEN="bearer eyJhbGciOiJSUzI1NiJ9.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.mAaOJthCotW763lf9fysygqdES_Mz1KFQ3HneKbwY4VJx-ARuxxiLh8l_8Srx7NJBwGlyEtfYOCBcIdvyeDCiQ0wT78Zw7ZJYFjnJ5-ZkDy5NbMqHbImDFkHRnPzKFjJHip39jyjAZpkFcrZ8_pUD8XxZraqJ4zEf6LFdAHKFBM"

• DOPPLER_ADDR - It is based on your environment. Example:

export DOPPLER_ADDR="wss://doppler.10.244.0.34.xip.io:4443"

Application logs

The samples/app_logs/main.go application streams logs for a particular app. The following environment variable needs to be set:

• APP_GUID - You can get this value from running $ cf app APP --guid. Example:

export APP_GUID=55fdb274-d6c9-4b8c-9b1f-9b7e7f3a346c

Then you can run the sample app like this:

go build -o bin/app_logs samples/app_logs/main.go
bin/app_logs

Logs and metrics firehose

The samples/firehose/main.go application streams metrics data and logs for all apps.

You can run the firehose sample app like this:

go build -o bin/firehose samples/firehose/main.go
bin/firehose

Multiple subscribers may connect to the firehose endpoint, each with a unique subscription_id (configurable in main.go). Each subscriber (in practice, a pool of clients with a common subscription_id) receives the entire stream. For each subscription_id, all data will be distributed evenly among that subscriber's client pool.

Container metrics

The samples/container_metrics/consumer/main.go application streams container metrics for the specified appId.

You can run the container metrics sample app like this:

go build -o bin/container_metrics samples/container_metrics/consumer/main.go
bin/container_metrics

For more information to setup a test environment in order to pull container metrics look at the README.md in the container_metrics sample.

##Development

Use go get -d -v -t ./... && ginkgo --race --randomizeAllSpecs --failOnPending --skipMeasurements --cover to run the tests.