nomad-firehose

nomad-firehose

nomad-firehose is a tool meant to enable teams to quickly build logic around nomad task events without hooking into Nomad API.

Running

The project has build artifacts for Linux, Darwin and Windows in the GitHub releases tab.

A Docker container is also provided at seatgeek/nomad-firehose

Requirements

• Go 1.8

Building

To build a binary, run the following

# get this repo
go get github.com/seatgeek/nomad-firehose

# go to the repo directory
cd $GOPATH/src/github.com/seatgeek/nomad-firehose

# build the `nomad-firehose` binary
make build

This will create a nomad-firehose binary in your $GOPATH/bin directory.

Configuration

Any NOMAD_* env that the native nomad CLI tool supports are supported by this tool.

Any CONSUL_* env that the native consul CLI tool supports are supported by this tool.

The most basic requirement is export NOMAD_ADDR=http://<ip>:4646 and export CONSUL_HTTP_ADDR=<ip>:8500.

Consul

nomad-firehose will use Consul to maintain leader-ship and store last event time processed (saved on quit or every 10s).

This mean you can run more than 1 process of each firehose, and only one will actually do any work.

Saving the last event time mean that restarting the process won't firehose all old changes to your sink, reducing duplicated events.

The Consul lock is maintained in KV at nomad-firehose/${type}.lock and the last event time is stored in KV at nomad-firehose/${type}.value.

Consul ACL Token Permissions

If the Consul cluster being used is running ACLs, the following ACL policy will allow the required access:

key "nomad-firehose" {
  policy = "write"
}
session "" {
  policy = "write"
}

Usage

The nomad-firehose binary has several helper subcommands.

The sink type is configured using $SINK_TYPE environment variable. Valid values are:

• amqp
• kinesis
• nsq
• redis
• stdout

The amqp sink is configured using $SINK_AMQP_CONNECTION (amqp://guest:guest@127.0.0.1:5672/), $SINK_AMQP_EXCHANGE and $SINK_AMQP_ROUTING_KEY, $SINK_AMQP_WORKERS (default: 1) environment variables.

The kinesis sink is configured using $SINK_KINESIS_STREAM_NAME and $SINK_KINESIS_PARTITION_KEY environment variables.

The nsq sink is configured using $SINK_NSQ_ADDR and $SINK_NSQ_TOPIC_NAME environment variables.

The redis sink is configured using $SINK_REDIS_URL (redis://[user]:[password]@127.0.0.1[:5672]/0) and $SINK_REDIS_KEY environment variables.

The kafka sink is configured using $SINK_KAFKA_BROKERS (kafka1:9092,kafka2:9092,kafka3:9092), and $SINK_KAFKA_TOPIC environment variables.

The stdout sink does not have any configuration, it will simply output the JSON to stdout for debugging.

allocations

nomad-firehose allocations will monitor all allocation changes in the Nomad cluster and emit each task state as a new firehose event to the configured sink.

The allocation output is different from the default API response, as the tool will emit an event per new TaskStates, rather than all the previous events.

{
    "Name": "job.task[0]",
    "AllocationID": "1ef2eba2-00e4-3828-96d4-8e58b1447aaf",
    "DesiredStatus": "run",
    "DesiredDescription": "",
    "ClientStatus": "running",
    "ClientDescription": "",
    "JobID": "logrotate",
    "GroupName": "cron",
    "TaskName": "logrotate",
    "EvalID": "bf926150-ed30-6c13-c597-34d7a3165fdc",
    "TaskState": "running",
    "TaskFailed": false,
    "TaskStartedAt": "2017-06-30T19:58:28.325895579Z",
    "TaskFinishedAt": "0001-01-01T00:00:00Z",
    "TaskEvent": {
        "Type": "Task Setup",
        "Time": 1498852707712617200,
        "FailsTask": false,
        "RestartReason": "",
        "SetupError": "",
        "DriverError": "",
        "DriverMessage": "",
        "ExitCode": 0,
        "Signal": 0,
        "Message": "Building Task Directory",
        "KillReason": "",
        "KillTimeout": 0,
        "KillError": "",
        "StartDelay": 0,
        "DownloadError": "",
        "ValidationError": "",
        "DiskLimit": 0,
        "DiskSize": 0,
        "FailedSibling": "",
        "VaultError": "",
        "TaskSignalReason": "",
        "TaskSignal": ""
    }
}

nodes

nomad-firehose nodes will monitor all node changes in the Nomad cluster and emit a firehose event per change to the configured sink.

The output will be equal to the Nomad Node API structure

evaluations

nomad-firehose evaluations will monitor all evaluation changes in the Nomad cluster and emit a firehose event per change to the configured sink.

The output will be equal to the Nomad Evaluation API structure

jobs

nomad-firehose jobs will monitor all job changes in the Nomad cluster and emit a firehose event per change to the configured sink.

The output will be equal to the full Nomad Job API structure

deployments

nomad-firehose deployments will monitor all deployment changes in the Nomad cluster and emit a firehose event per change to the configured sink.

The output will be equal to the full Nomad Deployment API structure