Advanced configuration
editAdvanced configuration
editIf you need to customize the client behavior heavily, you are in the right place! The client enables you to customize the following internals:
-
ConnectionPool
class -
Connection
class -
Serializer
class
For information about the Transport
class, refer to Transport.
ConnectionPool
editThis class is responsible for keeping in memory all the Elasticsearch Connection that you are using. There is a single Connection for every node. The connection pool handles the resurrection strategies and the updates of the pool.
const { Client, ConnectionPool } = require('@elastic/elasticsearch') class MyConnectionPool extends ConnectionPool { markAlive (connection) { // your code super.markAlive(connection) } } const client = new Client({ ConnectionPool: MyConnectionPool, cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' } })
Connection
editThis class represents a single node, it holds every information we have on the
node, such as roles, id, URL, custom headers and so on. The actual HTTP request
is performed here, this means that if you want to swap the default HTTP client
(Node.js core), you should override the request
method of this class.
const { Client, BaseConnection } = require('@elastic/elasticsearch') class MyConnection extends BaseConnection { request (params, callback) { // your code } } const client = new Client({ Connection: MyConnection, cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' } })
Serializer
editThis class is responsible for the serialization of every request, it offers the following methods:
-
serialize(object: any): string;
serializes request objects. -
deserialize(json: string): any;
deserializes response strings. -
ndserialize(array: any[]): string;
serializes bulk request objects. -
qserialize(object: any): string;
serializes request query parameters.
const { Client, Serializer } = require('@elastic/elasticsearch') class MySerializer extends Serializer { serialize (object) { // your code } } const client = new Client({ Serializer: MySerializer, cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' } })
Redaction of potentially sensitive data
editWhen the client raises an Error
that originated at the HTTP layer, like a ConnectionError
or TimeoutError
, a meta
object is often attached to the error object that includes metadata useful for debugging, like request and response information. Because this can include potentially sensitive data, like authentication secrets in an Authorization
header, the client takes measures to redact common sources of sensitive data when this metadata is attached and serialized.
If your configuration requires extra headers or other configurations that may include sensitive data, you may want to adjust these settings to account for that.
By default, the redaction
option is set to { type: 'replace' }
, which recursively searches for sensitive key names, case insensitive, and replaces their values with the string [redacted]
.
const { Client } = require('@elastic/elasticsearch') const client = new Client({ cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' }, }) try { await client.indices.create({ index: 'my_index' }) } catch (err) { console.log(err.meta.meta.request.options.headers.authorization) // prints "[redacted]" }
If you would like to redact additional properties, you can include additional key names to search and replace:
const { Client } = require('@elastic/elasticsearch') const client = new Client({ cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' }, headers: { 'X-My-Secret-Password': 'shhh it's a secret!' }, redaction: { type: "replace", additionalKeys: ["x-my-secret-password"] } }) try { await client.indices.create({ index: 'my_index' }) } catch (err) { console.log(err.meta.meta.request.options.headers['X-My-Secret-Password']) // prints "[redacted]" }
Alternatively, if you know you’re not going to use the metadata at all, setting the redaction type to remove
will remove all optional sources of potentially sensitive data entirely, or replacing them with null
for required properties.
const { Client } = require('@elastic/elasticsearch') const client = new Client({ cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' }, redaction: { type: "remove" } }) try { await client.indices.create({ index: 'my_index' }) } catch (err) { console.log(err.meta.meta.request.options.headers) // undefined }
Finally, if you prefer to turn off redaction altogether, perhaps while debugging on a local developer environment, you can set the redaction type to off
. This will revert the client to pre-8.11.0 behavior, where basic redaction is only performed during common serialization methods like console.log
and JSON.stringify
.
Setting redaction.type
to off
is not recommended in production environments.
const { Client } = require('@elastic/elasticsearch') const client = new Client({ cloud: { id: '<cloud-id>' }, auth: { apiKey: 'base64EncodedKey' }, redaction: { type: "off" } }) try { await client.indices.create({ index: 'my_index' }) } catch (err) { console.log(err.meta.meta.request.options.headers.authorization) // the actual header value will be logged }
Migrate to v8
editThe Node.js client can be configured to emit an HTTP header
Accept: application/vnd.elasticsearch+json; compatible-with=7
which signals to Elasticsearch that the client is requesting
7.x
version of request and response bodies. This allows for
upgrading from 7.x to 8.x version of Elasticsearch without upgrading
everything at once. Elasticsearch should be upgraded first after
the compatibility header is configured and clients should be upgraded
second.
To enable to setting, configure the environment variable
ELASTIC_CLIENT_APIVERSIONING
to true
.