SimonSimCity / apm-nodejs-http-client

A low-level Node.js HTTP client for communicating with the Elastic APM intake API

elastic-apm-http-client

A low-level HTTP client for communicating with the Elastic APM intake API version 2. For support for version 1, use version 5.x of this module.

This module is meant for building other modules that needs to communicate with Elastic APM.

If you are looking to use Elastic APM in your app or website, you'd most likely want to check out the official Elastic APM agent for Node.js instead.

Installation

npm install elastic-apm-http-client --save

Example Usage

const Client = require('elastic-apm-http-client')

const client = new Client({
  serviceName: 'My App',
  agentName: 'my-nodejs-agent',
  agentVersion: require('./package.json').version,
  userAgent: 'My Custom Elastic APM Agent'
})

const span = {
  name: 'SELECT FROM users',
  duration: 42,
  start: 0,
  type: 'db.mysql.query'
}

client.sendSpan(span)

API

new Client(options)

Construct a new client object. Data given to the client will be converted to ndjson, compressed using gzip, and streamed to the APM Server.

Arguments:

• options - An object containing config options (see below)

Data sent to the APM Server as part of the metadata package:

• agentName - (required) The APM agent name
• agentVersion - (required) The APM agent version
• serviceName - (required) The name of the service being instrumented
• serviceVersion - The version of the service being instrumented
• frameworkName - If the service being instrumented is running a specific framework, use this config option to log its name
• frameworkVersion - If the service being instrumented is running a specific framework, use this config option to log its version
• hostname - Custom hostname (default: OS hostname)
• environment - Environment name (default: process.env.NODE_ENV || 'development')
• containerId - Docker container id, if not given will be parsed from /proc/self/cgroup
• kubernetesNodeName - Kubernetes node name
• kubernetesNamespace - Kubernetes namespace
• kubernetesPodName - Kubernetes pod name, if not given will be the hostname
• kubernetesPodUID - Kubernetes pod id, if not given will be parsed from /proc/self/cgroup
• globalLabels - An object of key/value pairs to use to label all data reported (only applied when using APM Server 7.1+)

HTTP client configuration:

• userAgent - (required) The HTTP user agent that your module should identify it self as
• secretToken - The Elastic APM intake API secret token
• serverUrl - The APM Server URL (default: http://localhost:8200)
• headers - An object containing extra HTTP headers that should be used when making HTTP requests to he APM Server
• rejectUnauthorized - Set to false if the client shouldn't verify the APM Server TLS certificates (default: true)
• serverTimeout - HTTP request timeout in milliseconds. If no data is sent or received on the socket for this amount of time, the request will be aborted. It's not recommended to set a serverTimeout lower than the time config option. That might result in healthy requests being aborted prematurely (default: 15000 ms)
• keepAlive - If set the false the client will not reuse sockets between requests (default: true)
• keepAliveMsecs - When using the keepAlive option, specifies the initial delay for TCP Keep-Alive packets. Ignored when the keepAlive option is false or undefined (default: 1000 ms)
• maxSockets - Maximum number of sockets to allow per host (default: Infinity)
• maxFreeSockets - Maximum number of sockets to leave open in a free state. Only relevant if keepAlive is set to true (default: 256)

APM Agent Configuration via Kibana:

• centralConfig - Whether or not the client should poll the APM Server regularly for new agent configuration. If set to true, the config event will be emitted when there's an update to an agent config option (default: false). Requires APM Server v7.3 or later and that the APM Server is configured with kibana.enabled: true.

Streaming configuration:

• size - The maxiumum compressed body size (in bytes) of each HTTP request to the APM Server. An overshoot of up to the size of the internal zlib buffer should be expected as the buffer is flushed after this limit is reached. The default zlib buffer size is 16 kb (default: 768000 bytes)
• time - The maxiumum number of milliseconds a streaming HTTP request to the APM Server can be ongoing before it's ended. Set to -1 to disable (default: 10000 ms)
• bufferWindowTime - Objects written in quick succession are buffered and grouped into larger clusters that can be processed as a whole. This config option controls the maximum time that buffer can live before it's flushed (counted in milliseconds). Set to -1 for no buffering (default: 20 ms)
• bufferWindowSize - Objects written in quick succession are buffered and grouped into larger clusters that can be processed as a whole. This config option controls the maximum size of that buffer (counted in number of objects). Set to -1 for no max size (default: 50 objects)

Data sanitizing configuration:

• truncateKeywordsAt - Maximum size in bytes for strings stored as Elasticsearch keywords. Strings larger than this will be trucated (default: 1024 bytes)
• truncateErrorMessagesAt - The maximum size in bytes for error messages. Messages above this length will be truncated. Set to -1 to disable truncation. This applies to the following properties: error.exception.message and error.log.message (default: 2048 bytes)
• truncateStringsAt - The maximum size in bytes for strings. String values above this length will be truncated (default: 1024 bytes)
• truncateQueriesAt - The maximum size in bytes for database queries. Queries above this length will be truncated (default: 10000 bytes)

Debug options:

• payloadLogFile - Specify a file path to which a copy of all data sent to the APM Server should be written. The data will be in ndjson format and will be uncompressed

Event: config

Emitted every time a change to the agent config is pulled from the APM Server. The listener is passed the updated config options as a key/value object.

Each key is the lowercase version of the environment variable, without the ELASTIC_APM_ prefix, e.g. transaction_sample_rate instead of ELASTIC_APM_TRANSACTION_SAMPLE_RATE.

If no central configuration is set up for the given serviceName / environment when the client is started, this event will be emitted once with an empty object. This will also happen after central configuration for the given serviceName / environment is deleted.

Event: close

The close event is emitted when the client and any of its underlying resources have been closed. The event indicates that no more events will be emitted, and no more data can be sent by the client.

Event: error

Emitted if an error occurs. The listener callback is passed a single Error argument when called.

Event: finish

The finish event is emitted after the client.end() method has been called, and all data has been flushed to the underlying system.

Event: request-error

Emitted if an error occurs while communicating with the APM Server. The listener callback is passed a single Error argument when called.

The request to the APM Server that caused the error is terminated and the data included in that request is lost. This is normally only important to consider for requests to the Intake API.

If a non-2xx response was received from the APM Server, the status code will be available on error.code.

For requests to the Intake API where the response is a structured error message, the error object will have the following properties:

• error.accepted - An integer indicating how many events was accepted as part of the failed request. If 100 events was sent to the APM Server as part of the request, and the error reports only 98 as accepted, it means that two events either wasn't received or couldn't be processed for some reason
• error.errors - An array of error messages. Each element in the array is an object containing a message property (String) and an optional document property (String). If the document property is given it will contain the failed event as it was received by the APM Server

If the response contained an error body that could not be parsed by the client, the raw body will be available on error.response.

The client is not closed when the request-error event is emitted.

client.sent

An integer indicating the number of events (spans, transactions, or errors) sent by the client. An event is considered sent when the HTTP request used to transmit it have ended.

client.config(options)

Update the configuration given to the Client constructor. All configuration options can be updated except:

• The protocol part of the serverUrl (http vs https)
• size
• time
• keepAlive
• keepAliveMsecs
• maxSockets
• maxFreeSockets
• centralConfig

client.sendSpan(span[, callback])

Send a span to the APM Server.

Arguments:

• span - A span object that can be serialized to JSON
• callback - Callback is called when the span have been flushed to the underlying system

client.sendTransaction(transaction[, callback])

Send a transaction to the APM Server.

Arguments:

• transaction - A transaction object that can be serialized to JSON
• callback - Callback is called when the transaction have been flushed to the underlying system

client.sendError(error[, callback])

Send a error to the APM Server.

Arguments:

• error - A error object that can be serialized to JSON
• callback - Callback is called when the error have been flushed to the underlying system

client.sendMetricSet(metricset[, callback])

Send a metricset to the APM Server.

Arguments:

• error - A error object that can be serialized to JSON
• callback - Callback is called when the metricset have been flushed to the underlying system

client.flush([callback])

Flush the internal buffer and end the current HTTP request to the APM Server. If no HTTP request is in process nothing happens.

Arguments:

• callback - Callback is called when the internal buffer have been flushed and the HTTP request ended. If no HTTP request is in progress the callback is called in the next tick.

client.end([callback])

Calling the client.end() method signals that no more data will be sent to the client. If the internal buffer contains any data, this is flushed before ending.

Arguments:

• callback - If provided, the optional callback function is attached as a listener for the 'finish' event

client.destroy()

Destroy the client. After this call, the client has ended and subsequent calls to sendSpan(), sendTransaction(), sendError(), flush(), or end() will result in an error.

License

MIT