elastic-apm-http-client - npm Package Compare versions

Comparing version 9.7.1 to 9.8.0

CHANGELOG.md

 # elastic-apm-http-client changelog
 
+## v9.8.0
+
+- Add `client.addMetadataFilter(fn)`. See the
+  [APM agent issue](https://github.com/elastic/apm-agent-nodejs/issues/1916).
+
 ## v9.7.1
@@ -4,0 +9,0 @@

index.js

@@ -12,2 +12,4 @@ 'use strict'
 const zlib = require('zlib')
+
+const Filters = require('object-filter-sequence')
 const querystring = require('querystring')
@@ -75,5 +77,9 @@ const Writable = require('readable-stream').Writable
   this._configTimer = null
-  this._encodedMetadata = null
   this._backoffReconnectCount = 0
   this._intakeRequestGracefulExitFn = null // set in makeIntakeRequest
+  // _encodedMetadata is pre-encoded JSON of metadata from `_conf.metadata` and
+  // `_cloudMetadata` (asynchronously fetched via `_conf.cloudMetadataFetcher`)
+  this._encodedMetadata = null
+  this._cloudMetadata = null
+  this._metadataFilters = new Filters()
 
@@ -236,3 +242,3 @@ // Internal runtime stats for developer debugging/tuning.
   if (this._encodedMetadata) {
-    this.updateEncodedMetadata()
+    this._resetEncodedMetadata()
   }
@@ -242,13 +248,36 @@ }
 /**
- * Updates the encoded metadata without refetching cloud metadata
+ * Add a filter function used to filter the "metadata" object sent to APM
+ * server. See the APM Agent `addMetadataFilter` documentation for details.
+ * https://www.elastic.co/guide/en/apm/agent/nodejs/current/agent-api.html#apm-add-metadata-filter
  */
-Client.prototype.updateEncodedMetadata = function () {
-  const oldMetadata = JSON.parse(this._encodedMetadata)
-  const toEncode = { metadata: this._conf.metadata }
-  if (oldMetadata.metadata.cloud) {
-    toEncode.metadata.cloud = oldMetadata.metadata.cloud
+Client.prototype.addMetadataFilter = function (fn) {
+  assert.strictEqual(typeof fn, 'function', 'fn arg must be a function')
+  this._metadataFilters.push(fn)
+  if (this._encodedMetadata) {
+    this._resetEncodedMetadata()
   }
-  this._encodedMetadata = this._encode(toEncode, Client.encoding.METADATA)
 }
 
+/**
+ * (Re)set `_encodedMetadata` from this._conf.metadata and this._cloudMetadata.
+ */
+Client.prototype._resetEncodedMetadata = function () {
+  // Make a deep clone so that the originals are not modified when (a) adding
+  // `.cloud` and (b) filtering. This isn't perf-sensitive code, so this JSON
+  // cycle for cloning should suffice.
+  let metadata = JSON.parse(JSON.stringify(this._conf.metadata))
+  if (this._cloudMetadata) {
+    metadata.cloud = JSON.parse(JSON.stringify(this._cloudMetadata))
+  }
+
+  // Possible filters from APM agent's `apm.addMetadataFilter()`.
+  if (this._metadataFilters && this._metadataFilters.length > 0) {
+    metadata = this._metadataFilters.process(metadata)
+    this._log.trace({ filteredMetadata: metadata }, 'filtered metadata')
+  }
+
+  // This is the only code path that should set `_encodedMetadata`.
+  this._encodedMetadata = this._encode({ metadata }, Client.encoding.METADATA)
+}
+
 Client.prototype._pollConfig = function () {
@@ -915,28 +944,24 @@ const opts = this._conf.requestConfig
 /**
- * Fetches cloud metadata and encodes with other metadata
+ * Fetches cloud metadata, if any, and encodes metadata (to `_encodedMetadata`).
  *
- * This method will encode the fetched cloud-metadata with other metadata
- * and memoize the data into the _encodedMetadata property.  Data will
- * be "returned" to the calling function via the passed in callback.
- *
- * The cloudMetadataFetcher configuration values is an error first callback
- * that fetches the cloud metadata.
+ * @param {function} cb - Called, with no arguments, when complete.
  */
 Client.prototype._fetchAndEncodeMetadata = function (cb) {
-  const toEncode = { metadata: this._conf.metadata }
-
   if (!this._conf.cloudMetadataFetcher) {
     // no metadata fetcher from the agent -- encode our data and move on
-    this._encodedMetadata = this._encode(toEncode, Client.encoding.METADATA)
-
-    process.nextTick(cb, null, this._encodedMetadata)
+    this._resetEncodedMetadata()
+    process.nextTick(cb)
   } else {
-    // agent provided a metadata fetcher function.  Call it, use its return
-    // return-via-callback value to set the cloud metadata and then move on
     this._conf.cloudMetadataFetcher.getCloudMetadata((err, cloudMetadata) => {
-      if (!err && cloudMetadata) {
-        toEncode.metadata.cloud = cloudMetadata
+      if (err) {
+        // We ignore this error (other than logging it). A common case, when
+        // not running on one of the big 3 clouds, is "all callbacks failed",
+        // which is *fine*. Because it is a common "error" we don't log the
+        // stack trace.
+        this._log.trace('getCloudMetadata err: %s', err)
+      } else if (cloudMetadata) {
+        this._cloudMetadata = cloudMetadata
       }
-      this._encodedMetadata = this._encode(toEncode, Client.encoding.METADATA)
-      cb(err, this._encodedMetadata)
+      this._resetEncodedMetadata()
+      cb()
     })
@@ -943,0 +968,0 @@ }

package.json

 {
   "name": "elastic-apm-http-client",
-  "version": "9.7.1",
+  "version": "9.8.0",
   "description": "A low-level HTTP client for communicating with the Elastic APM intake API",
@@ -28,2 +28,3 @@ "main": "index.js",
     "fast-stream-to-buffer": "^1.0.0",
+    "object-filter-sequence": "^1.0.0",
     "readable-stream": "^3.4.0",
@@ -30,0 +31,0 @@ "stream-chopper": "^3.0.1",

README.md

@@ -60,3 +60,3 @@ # elastic-apm-http-client
 
-Data sent to the APM Server as part of the metadata package:
+Data sent to the APM Server as part of the [metadata object](https://www.elastic.co/guide/en/apm/server/current/metadata-api.html):
 
@@ -264,2 +264,36 @@ - `agentName` - (required) The APM agent name
 
+### `client.addMetadataFilter(fn)`
+
+Add a filter function for the ["metadata" object](https://www.elastic.co/guide/en/apm/server/current/metadata-api.html)
+sent to APM server. This will be called once at client creation, and possibly
+again later if `client.config()` is called to reconfigure the client or
+`client.addMetadataFilter(fn)` is called to add additional filters.
+
+Here is an example of a filter that removes the `metadata.process.argv` field:
+
+```js
+apm.addMetadataFilter(function dropArgv(md) {
+  if (md.process && md.process.argv) {
+    delete md.process.argv
+  }
+  return md
+})
+```
+
+It is up to the user to ensure the returned object conforms to the
+[metadata schema](https://www.elastic.co/guide/en/apm/server/current/metadata-api.html),
+otherwise APM data injest will be broken. An example of that (when used with
+the Node.js APM agent) is this in the application's log:
+
+```
+[2021-04-14T22:28:35.419Z] ERROR (elastic-apm-node): APM Server transport error (400): Unexpected APM Server response
+APM Server accepted 0 events in the last request
+Error: validation error: 'metadata' required
+  Document: {"metadata":null}
+```
+
+See the [APM Agent `addMetadataFilter` documentation](https://www.elastic.co/guide/en/apm/agent/nodejs/current/agent-api.html#apm-add-metadata-filter)
+for further details.
+
+
 ### `client.sendSpan(span[, callback])`
@@ -266,0 +300,0 @@

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Found 1 instance in 1 package

Fixed alerts

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Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

73122

increased by3.65%

Lines of code

1471

increased by1.59%

Number of lines in readme file

368

increased by10.18%

Worsened metrics

Dependency count

9

increased by12.5%

Dependency changes

• + Addedobject-filter-sequence@^1.0.0

• + Addedobject-filter-sequence@1.0.0(transitive)