chore: Migrated @newrelic/koa into mainline agent repo (#2148)

lib/instrumentation/grpc-js/grpc.js

@@ -7,7 +7,7 @@
 
 const recordExternal = require('../../metrics/recorders/http_external')
 const recordHttp = require('../../metrics/recorders/http')
-const specs = require('../../shim/specs')
+const { TransactionSpec } = require('../../shim/specs')
 const { DESTINATIONS } = require('../../config/attribute-filter')
 const DESTINATION = DESTINATIONS.TRANS_EVENT | DESTINATIONS.ERROR_EVENT
 const semver = require('semver')
@@ -149,7 +149,7 @@ function wrapRegister(shim, original) {
 
     args[1] = shim.bindCreateTransaction(
       instrumentedHandler,
-      new specs.TransactionSpec({ type: shim.WEB })
+      new TransactionSpec({ type: shim.WEB })
     )
 
     return original.apply(this, args)

lib/instrumentation/http-methods.js

@@ -0,0 +1,9 @@
+/*
+ * Copyright 2021 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const http = require('http')
+const methodsLower = http.METHODS.map((method) => method.toLowerCase())
+module.exports.METHODS = methodsLower

lib/instrumentation/koa/instrumentation.js

@@ -0,0 +1,197 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const symbols = require('../../symbols')
+const { MiddlewareSpec, MiddlewareMounterSpec } = require('../../shim/specs')
+
+module.exports = function initialize(shim, Koa) {
+  // Koa's exports are different depending on using CJS or MJS - https://github.com/koajs/koa/issues/1513
+  const proto = Koa.prototype || Koa.default?.prototype
+
+  if (!shim || !Koa || !proto || Object.keys(proto).length > 1) {
+    shim.logger.debug(
+      'Koa instrumentation function called with incorrect arguments, not instrumenting.'
+    )
+    return
+  }
+
+  shim.setFramework(shim.KOA)
+
+  shim.wrapMiddlewareMounter(
+    proto,
+    'use',
+    new MiddlewareMounterSpec({
+      wrapper: wrapMiddleware
+    })
+  )
+  shim.wrapReturn(proto, 'createContext', wrapCreateContext)
+
+  // The application is used to handle unhandled errors in the application. We
+  // want to notice those.
+  shim.wrap(proto, 'emit', function wrapper(shim, original) {
+    return function wrappedEmit(evt, err, ctx) {
+      if (evt === 'error' && ctx) {
+        shim.noticeError(ctx.req, err)
+      }
+      return original.apply(this, arguments)
+    }
+  })
+}
+
+function wrapMiddleware(shim, middleware) {
+  // Skip middleware that are already wrapped.
+  if (shim.isWrapped(middleware)) {
+    return middleware
+  }
+
+  if (middleware.router) {
+    shim.logger.info(
+      [
+        'Found uninstrumented router property on Koa middleware.',
+        'This may indicate either an unsupported routing library is being used,',
+        'or a particular version of a supported library is not fully instrumented.'
+      ].join(' ')
+    )
+  }
+
+  return shim.recordMiddleware(
+    middleware,
+    new MiddlewareSpec({
+      type: shim.MIDDLEWARE,
+      promise: true,
+      appendPath: true,
+      next: shim.LAST,
+      req: function getReq(shim, fn, fnName, args) {
+        return args[0] && args[0].req
+      }
+    })
+  )
+}
+
+/**
+ * Many of the properties on the `context` object are just aliases for the same
+ * property on the `request` or `response` objects. We take advantage of this
+ * by just intercepting the `request` or `response` property and don't touch
+ * the `context` property.
+ * See: https://github.com/koajs/koa/blob/master/lib/context.js#L186-L241
+ *
+ * @param {Shim} shim instance of shim
+ * @param {function} _fn createContext function
+ * @param {string} _fnName name of function
+ * @param {object} context koa ctx object
+ */
+function wrapCreateContext(shim, _fn, _fnName, context) {
+  wrapResponseBody(shim, context)
+  wrapMatchedRoute(shim, context)
+  wrapResponseStatus(shim, context)
+}
+
+function wrapResponseBody(shim, context) {
+  // The `context.body` and `context.response.body` properties are how users set
+  // the response contents. It is roughly equivalent to `res.send()` in Express.
+  // Under the hood, these set the `_body` property on the `context.response`.
+  context[symbols.koaBody] = context.response.body
+  context[symbols.koaBodySet] = false
+
+  Object.defineProperty(context.response, '_body', {
+    get: () => context[symbols.koaBody],
+    set: function setBody(val) {
+      if (!context[symbols.koaRouter]) {
+        shim.savePossibleTransactionName(context.req)
+      }
+      context[symbols.koaBody] = val
+      context[symbols.koaBodySet] = true
+    }
+  })
+}
+
+function wrapMatchedRoute(shim, context) {
+  context[symbols.koaMatchedRoute] = null
+  context[symbols.koaRouter] = false
+
+  Object.defineProperty(context, '_matchedRoute', {
+    get: () => context[symbols.koaMatchedRoute],
+    set: (val) => {
+      const match = getLayerForTransactionName(context)
+
+      // match should never be undefined given _matchedRoute was set
+      if (match) {
+        const currentSegment = shim.getActiveSegment()
+
+        // Segment/Transaction may be null, see:
+        //  - https://github.com/newrelic/node-newrelic-koa/issues/32
+        //  - https://github.com/newrelic/node-newrelic-koa/issues/33
+        if (currentSegment) {
+          const transaction = currentSegment.transaction
+
+          if (context[symbols.koaMatchedRoute]) {
+            transaction.nameState.popPath()
+          }
+
+          transaction.nameState.appendPath(match.path)
+          transaction.nameState.markPath()
+        }
+      }
+
+      context[symbols.koaMatchedRoute] = val
+      // still true if somehow match is undefined because we are
+      // using koa-router naming and don't want to allow default naming
+      context[symbols.koaRouter] = true
+    }
+  })
+}
+
+function wrapResponseStatus(shim, context) {
+  // Sometimes people just set `context.status` or `context.response.status`
+  // without setting a body. When this happens we'll want to use that as the
+  // response point to name the transaction. `context.status` is just an alias
+  // for `context.response.status` so we only wrap the latter.
+  const statusDescriptor = getInheritedPropertyDescriptor(context.response, 'status')
+  if (!statusDescriptor) {
+    shim.logger.debug('Failed to find status descriptor on context.response')
+    return
+  } else if (!statusDescriptor.get || !statusDescriptor.set) {
+    shim.logger.debug(statusDescriptor, 'Status descriptor missing getter/setter pair')
+    return
+  }
+
+  Object.defineProperty(context.response, 'status', {
+    get: () => statusDescriptor.get.call(context.response),
+    set: function setStatus(val) {
+      if (!context[symbols.koaBodySet] && !context[symbols.koaRouter]) {
+        shim.savePossibleTransactionName(context.req)
+      }
+      return statusDescriptor.set.call(this, val)
+    }
+  })
+}
+
+function getLayerForTransactionName(context) {
+  // Context.matched might be null
+  // See https://github.com/newrelic/node-newrelic-koa/pull/29
+  if (!context.matched) {
+    return null
+  }
+  for (let i = context.matched.length - 1; i >= 0; i--) {
+    const layer = context.matched[i]
+    if (layer.opts.end) {
+      return layer
+    }
+  }
+
+  return null
+}
+
+function getInheritedPropertyDescriptor(obj, property) {
+  let proto = obj
+  let descriptor = null
+  do {
+    descriptor = Object.getOwnPropertyDescriptor(proto, property)
+    proto = Object.getPrototypeOf(proto)
+  } while (!descriptor && proto)
+
+  return descriptor
+}

lib/instrumentation/koa/nr-hooks.js

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const InstrumentationDescriptor = require('../../instrumentation-descriptor')
+
+module.exports = [
+  {
+    type: InstrumentationDescriptor.TYPE_WEB_FRAMEWORK,
+    moduleName: 'koa',
+    shimName: 'koa',
+    onRequire: require('./instrumentation')
+  },
+  {
+    type: InstrumentationDescriptor.TYPE_WEB_FRAMEWORK,
+    moduleName: 'koa-router',
+    shimName: 'koa',
+    onRequire: require('./router-instrumentation')
+  },
+  {
+    type: InstrumentationDescriptor.TYPE_WEB_FRAMEWORK,
+    moduleName: '@koa/router',
+    shimName: 'koa',
+    onRequire: require('./router-instrumentation')
+  },
+  {
+    type: InstrumentationDescriptor.TYPE_WEB_FRAMEWORK,
+    moduleName: 'koa-route',
+    shimName: 'koa',
+    onRequire: require('./route-instrumentation')
+  }
+]

lib/instrumentation/koa/route-instrumentation.js

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const { METHODS } = require('../http-methods')
+const { MiddlewareSpec } = require('../../shim/specs')
+
+module.exports = function instrumentRoute(shim, route) {
+  shim.setFramework(shim.KOA)
+
+  METHODS.forEach(function wrap(method) {
+    shim.wrap(route, method, function wrapMethod(shim, methodFn) {
+      return function wrappedMethod() {
+        const middleware = methodFn.apply(route, arguments)
+        return shim.recordMiddleware(
+          middleware,
+          new MiddlewareSpec({
+            route: arguments[0],
+            next: shim.LAST,
+            name: shim.getName(arguments[1]),
+            promise: true,
+            req: function getReq(shim, fn, fnName, args) {
+              return args[0] && args[0].req
+            }
+          })
+        )
+      }
+    })
+  })
+}