Send log messages through centralized logger

Log messages that need to be recorded are now sent through the
centralized logger.

packages/nodejs/.changesets/add-centralized-logger.md

@@ -0,0 +1,8 @@
+---
+bump: "patch"
+type: "add"
+---
+
+Log messages are now sent through a new centralized logger that writes to `/tmp/appsignal.log` by default.
+A warning is printed to STDERR when the default or provided logPath is not accessible, and the Logger
+automatically falls back to STDOUT. Use config option `log: stdout` to log AppSignal messages to STDOUT instead.

packages/nodejs/src/bootstrap.ts

@@ -1,6 +1,7 @@
 import { Metrics } from "./interfaces"
 import { Instrumentation } from "./instrument"
 import { httpPlugin, httpsPlugin } from "./instrumentation/http"
+import { BaseClient } from "./client"
 import * as pgPlugin from "./instrumentation/pg"
 import * as redisPlugin from "./instrumentation/redis"
 import * as gcProbe from "./probes/v8"
@@ -30,7 +31,9 @@ export function initCorePlugins(
     try {
       instrumentation.load(PLUGIN_NAME, instrument)
     } catch (e) {
-      console.warn(`Failed to instrument "${PLUGIN_NAME}": ${e.message}`)
+      BaseClient.logger.warn(
+        `Failed to instrument "${PLUGIN_NAME}": ${e.message}`
+      )
     }
   })
 }

packages/nodejs/src/client.ts

@@ -23,7 +23,7 @@ export class BaseClient implements Client {
   readonly VERSION = VERSION
 
   config: Configuration
-  logger: Logger
+  readonly logger: Logger
   extension: Extension
   instrumentation: Instrumentation
 

packages/nodejs/src/instrument.ts

@@ -1,4 +1,5 @@
 import { Plugin, Tracer, Metrics } from "./interfaces"
+import { BaseClient } from "./client"
 
 import Hook from "require-in-the-middle"
 import semver from "semver"
@@ -46,7 +47,7 @@ export class Instrumentation {
       if (semver.satisfies(version, plugin.version)) {
         return plugin.install()
       } else {
-        console.warn(
+        BaseClient.logger.warn(
           `Unable to instrument module ${name}, module version needs to satisfy version range ${plugin.version}`
         )
 

packages/nodejs/src/logger.ts

@@ -19,7 +19,11 @@ export class Logger {
     }
 
     const logFormat = printf(({ level, message, timestamp }) => {
-      return `[${timestamp} (process) #${process.pid}][appsignal][${level}] ${message}`
+      if (type == "file") {
+        return `[${timestamp} (process) #${process.pid}][${level}] ${message}`
+      } else {
+        return `[${timestamp} (process) #${process.pid}][appsignal][${level}] ${message}`
+      }
     })
 
     this.logger = winston.createLogger({

packages/nodejs/src/span.ts

@@ -132,7 +132,7 @@ export class BaseSpan implements Span {
     try {
       span.setSpanSampleData(this._ref, key, Data.generate(data))
     } catch (e) {
-      console.error(
+      BaseClient.logger.error(
         `Error generating data (${e.name}: ${e.message}) for '${JSON.stringify(
           data
         )}'`