Summary

The datadog-firehose-nozzle is a CF component which forwards metrics from the Loggregator Firehose to Datadog

Configure CloudFoundry UAA for Firehose Nozzle

The datadog firehose nozzle requires a UAA user who is authorized to access the loggregator firehose. You can add a user by editing your CloudFoundry manifest to include the details about this user under the properties.uaa.clients section. For example to add a user datadog-firehose-nozzle:

properties:
  uaa:
    clients:
      datadog-firehose-nozzle:
        access-token-validity: 1209600
        authorized-grant-types: authorization_code,client_credentials,refresh_token
        override: true
        secret: <password>
        scope: openid,oauth.approvals,doppler.firehose
        authorities: oauth.login,doppler.firehose

Running

The datadog nozzle uses a configuration file to obtain the firehose URL, datadog API key and other configuration parameters. The firehose and the datadog servers both require authentication -- the firehose requires a valid username/password and datadog requires a valid API key.

You can start the firehose nozzle by executing:

go run main.go -config config/datadog-firehose-nozzle.json"

Batching

The configuration file specifies the interval at which the nozzle will flush metrics to datadog. By default this is set to 15 seconds.

slowConsumerAlert

For the most part, the datadog-firehose-nozzle forwards metrics from the loggregator firehose to datadog without too much processing. A notable exception is the datadog.nozzle.slowConsumerAlert metric. The metric is a binary value (0 or 1) indicating whether or not the nozzle is forwarding metrics to datadog at the same rate that it is receiving them from the firehose: 0 means the the nozzle is keeping up with the firehose, and 1 means that the nozzle is falling behind.

The nozzle determines the value of datadog.nozzle.slowConsumerAlert with the following rules:

1. When the nozzle receives a TruncatingBuffer.DroppedMessages metric, it publishes the value 1. The metric indicates that Doppler determined that the client (in this case, the nozzle) could not consume messages as quickly as the firehose was sending them, so it dropped messages from its queue of messages to send.

2. When the nozzle receives a websocket Close frame with status 1008, it publishes the value 1. Traffic Controller pings clients to determine if the connections are still alive. If it does not receive a Pong response before the KeepAlive deadline, it decides that the connection is too slow (or even dead) and sends the Close frame.

3. Otherwise, the nozzle publishes 0.

Tests

You need ginkgo to run the tests. The tests can be executed by:

ginkgo -r

Deploying

Bosh

There is a bosh release that will configure, start and monitor the datadog nozzle: https://github.com/cloudfoundry-incubator/datadog-firehose-nozzle-release

Lattice

There is a docker image which can be used to deploy the datadog nozzle to lattice. If you are running lattice locally with Vagrant, you can use the following command line to start the nozzle:

ltc create datadog-nozzle cloudfoundry/datadog-nozzle-lattice \
  -e NOZZLE_DATADOGAPIKEY=<API KEY> \
  -e NOZZLE_METRICPREFIX=<METRIC PREFIX>  --no-monitor

The API KEY is your datadog API key used to publish metrics. The METRIC PREFIX gets prepended to all metric names going through the nozzle.

The docker image runs the nozzle with the config provided in lattice/lattice-datadog-firehose-nozzle.json. If you are not running lattice locally you will have to also configure the traffic controller URL

ltc create datadog-nozzle cloudfoundry/datadog-nozzle-lattice \
  -e NOZZLE_DATADOGAPIKEY=<API KEY> \
  -e NOZZLE_METRICPREFIX=<METRIC PREFIX> \
  -e NOZZLE_TRAFFICCONTROLLERURL=<TRAFFICONTROLLER URL>

Any of the configuration parameters can be overloaded by using environment variables. The following parameters are supported

Environment variable	Description
NOZZLE_UAAURL	UAA URL which the nozzle uses to get an authentication token for the firehose
NOZZLE_USERNAME	User who has access to the firehose
NOZZLE_PASSWORD	Password for the user
NOZZLE_TRAFFICCONTROLLERURL	Loggregator's traffic controller URL
NOZZLE_FIREHOSESUBSCRIPTIONID	Subscription ID used when connecting to the firehose. Nozzles with the same subscription ID get a proportional share of the firehose
NOZZLE_DATADOGURL	The Datadog API URL
NOZZLE_DATADOGAPIKEY	The API key used when publishing metrics to datadog
NOZZLE_METRICPREFIX	The metric prefix is prepended to all metrics flowing through the nozzle
NOZZLE_DEPLOYMENT	The deployment name for the nozzle. Used for tagging metrics internal to the nozzle
NOZZLE_FLUSHDURATIONSECONDS	Number of seconds to buffer data before publishing to Datadog
NOZZLE_INSECURESSLSKIPVERIFY	If true, allows insecure connections to the UAA and the Trafficcontroller
NOZZLE_DISABLEACCESSCONTROL	If true, disables authentication with the UAA. Used in lattice deployments

CI

The concourse pipeline for the datadog nozzle is present here