[Backport 7.x] Better message in case of unsupported build flavor

README.md

@@ -54,7 +54,9 @@ of `^7.10.0`).
 
 ### Compatibility
 
-The library is compatible with all Elasticsearch versions since 5.x, and you should use the same major version of the Elasticsearch instance that you are using.
+Elastic language clients are guaranteed to be able to communicate with Elasticsearch or Elastic solutions running on the same major version and greater or equal minor version.
+
+Language clients are forward compatible; meaning that clients support communicating with greater minor versions of Elasticsearch. Elastic language clients are not guaranteed to be backwards compatible.
 
 | Elasticsearch Version | Client Version |
 | --------------------- |----------------|

docs/installation.asciidoc

@@ -17,7 +17,7 @@ To install a specific major version of the client, run the following command:
 npm install @elastic/elasticsearch@<major>
 ----
 
-To learn more about the supported major versions, please refer to the 
+To learn more about the supported major versions, please refer to the
 <<js-compatibility-matrix>>.
 
 [discrete]
@@ -37,7 +37,7 @@ to support that version for at least another minor release. If you are using the
 with a version of Node.js that will be unsupported soon, you will see a warning
 in your logs (the client will start logging the warning with two minors in advance).
 
-Unless you are *always* using a supported version of Node.js, 
+Unless you are *always* using a supported version of Node.js,
 we recommend defining the client dependency in your
 `package.json` with the `~` instead of `^`. In this way, you will lock the
 dependency on the minor release and not the major. (for example, `~7.10.0` instead
@@ -62,9 +62,12 @@ of `^7.10.0`).
 [[js-compatibility-matrix]]
 === Compatibility matrix
 
-The library is compatible with all {es} versions since 5.x. We recommend you to
-use the same major version of the client as the {es} instance that you are
-using.
+Elastic language clients are guaranteed to be able to communicate with Elasticsearch
+or Elastic solutions running on the same major version and greater or equal minor version.
+
+Language clients are forward compatible; meaning that clients support communicating
+with greater minor versions of Elasticsearch. Elastic language clients are not
+guaranteed to be backwards compatible.
 
 [%header,cols=2*]
 |===
@@ -91,4 +94,4 @@ using.
 WARNING: There is no official support for the browser environment. It exposes
 your {es} instance to everyone, which could lead to security issues. We
 recommend you to write a lightweight proxy that uses this client instead,
-you can see a proxy example https://github.com/elastic/elasticsearch-js/tree/master/docs/examples/proxy[here].
+you can see a proxy example https://github.com/elastic/elasticsearch-js/tree/master/docs/examples/proxy[here].

lib/Transport.js

@@ -69,7 +69,7 @@ class Transport {
     this.generateRequestId = opts.generateRequestId || generateRequestId()
     this.name = opts.name
     this.opaqueIdPrefix = opts.opaqueIdPrefix
-    this[kProductCheck] = 0 // 0 = to be checked, 1 = checking, 2 = checked-ok, 3 checked-notok
+    this[kProductCheck] = 0 // 0 = to be checked, 1 = checking, 2 = checked-ok, 3 checked-notok, 4 checked-nodefault
     this[kApiVersioning] = process.env.ELASTIC_CLIENT_APIVERSIONING === 'true'
 
     this.nodeFilter = opts.nodeFilter || defaultNodeFilter
@@ -455,9 +455,12 @@ class Transport {
         prepareRequest()
       } else {
         // wait for product check to finish
-        productCheckEmitter.once('product-check', status => {
+        productCheckEmitter.once('product-check', (error, status) => {
           if (status === false) {
-            const err = new ProductNotSupportedError(result)
+            const err = error || new ProductNotSupportedError(result)
+            if (this[kProductCheck] === 4) {
+              err.message = 'The client noticed that the server is not a supported distribution of Elasticsearch'
+            }
             this.emit('request', err, result)
             process.nextTick(callback, err, result)
           } else {
@@ -470,8 +473,11 @@ class Transport {
         }
       }
     // the product check is finished and it's not Elasticsearch
-    } else if (this[kProductCheck] === 3) {
+    } else if (this[kProductCheck] === 3 || this[kProductCheck] === 4) {
       const err = new ProductNotSupportedError(result)
+      if (this[kProductCheck] === 4) {
+        err.message = 'The client noticed that the server is not a supported distribution of Elasticsearch'
+      }
       this.emit('request', err, result)
       process.nextTick(callback, err, result)
     // the product check finished and it's Elasticsearch
@@ -550,42 +556,48 @@ class Transport {
         if (err.statusCode === 401 || err.statusCode === 403) {
           this[kProductCheck] = 2
           process.emitWarning('The client is unable to verify that the server is Elasticsearch due to security privileges on the server side. Some functionality may not be compatible if the server is running an unsupported product.')
-          productCheckEmitter.emit('product-check', true)
+          productCheckEmitter.emit('product-check', null, true)
         } else {
           this[kProductCheck] = 0
-          productCheckEmitter.emit('product-check', false)
+          productCheckEmitter.emit('product-check', err, false)
         }
       } else {
         debug('Checking elasticsearch version', result.body, result.headers)
         if (result.body.version == null || typeof result.body.version.number !== 'string') {
           debug('Can\'t access Elasticsearch version')
-          return productCheckEmitter.emit('product-check', false)
+          return productCheckEmitter.emit('product-check', null, false)
         }
         const tagline = result.body.tagline
         const version = result.body.version.number.split('.')
         const major = Number(version[0])
         const minor = Number(version[1])
         if (major < 6) {
-          return productCheckEmitter.emit('product-check', false)
+          return productCheckEmitter.emit('product-check', null, false)
         } else if (major >= 6 && major < 7) {
           if (tagline !== 'You Know, for Search') {
             debug('Bad tagline')
-            return productCheckEmitter.emit('product-check', false)
+            return productCheckEmitter.emit('product-check', null, false)
           }
         } else if (major === 7 && minor < 14) {
-          if (tagline !== 'You Know, for Search' || result.body.version.build_flavor !== 'default') {
-            debug('Bad tagline or build_flavor')
-            return productCheckEmitter.emit('product-check', false)
+          if (tagline !== 'You Know, for Search') {
+            debug('Bad tagline')
+            return productCheckEmitter.emit('product-check', null, false)
+          }
+
+          if (result.body.version.build_flavor !== 'default') {
+            debug('Bad build_flavor')
+            this[kProductCheck] = 4
+            return productCheckEmitter.emit('product-check', null, false)
           }
         } else {
           if (result.headers['x-elastic-product'] !== 'Elasticsearch') {
             debug('x-elastic-product not recognized')
-            return productCheckEmitter.emit('product-check', false)
+            return productCheckEmitter.emit('product-check', null, false)
           }
         }
         debug('Valid Elasticsearch distribution')
         this[kProductCheck] = 2
-        productCheckEmitter.emit('product-check', true)
+        productCheckEmitter.emit('product-check', null, true)
       }
     })
   }

test/acceptance/product-check.test.js

@@ -24,6 +24,7 @@ const { Client } = require('../../')
 const {
   connection: {
     MockConnectionTimeout,
+    MockConnectionError,
     buildMockConnection
   }
 } = require('../utils')
@@ -210,7 +211,7 @@ test('No errors ≤v7.13', t => {
   })
 })
 
-test('Errors ≤v7.13', t => {
+test('Errors ≤v7.13 (tagline)', t => {
   t.plan(3)
   const MockConnection = buildMockConnection({
     onRequest (params) {
@@ -222,7 +223,7 @@ test('Errors ≤v7.13', t => {
           cluster_uuid: 'cQ5pAMvRRTyEzObH4L5mTA',
           version: {
             number: '7.13.0-SNAPSHOT',
-            build_flavor: 'other',
+            build_flavor: 'default',
             build_type: 'docker',
             build_hash: '5fb4c050958a6b0b6a70a6fb3e616d0e390eaac3',
             build_date: '2021-07-10T01:45:02.136546168Z',
@@ -271,6 +272,83 @@ test('Errors ≤v7.13', t => {
   })
 })
 
+test('Errors ≤v7.13 (build flavor)', t => {
+  t.plan(5)
+  const MockConnection = buildMockConnection({
+    onRequest (params) {
+      return {
+        statusCode: 200,
+        body: {
+          name: '1ef419078577',
+          cluster_name: 'docker-cluster',
+          cluster_uuid: 'cQ5pAMvRRTyEzObH4L5mTA',
+          version: {
+            number: '7.13.0-SNAPSHOT',
+            build_flavor: 'other',
+            build_type: 'docker',
+            build_hash: '5fb4c050958a6b0b6a70a6fb3e616d0e390eaac3',
+            build_date: '2021-07-10T01:45:02.136546168Z',
+            build_snapshot: true,
+            lucene_version: '8.9.0',
+            minimum_wire_compatibility_version: '7.15.0',
+            minimum_index_compatibility_version: '7.0.0'
+          },
+          tagline: 'You Know, for Search'
+        }
+      }
+    }
+  })
+
+  const requests = [{
+    method: 'GET',
+    path: '/'
+  }, {
+    method: 'POST',
+    path: '/foo/_search'
+  }, {
+    method: 'POST',
+    path: '/foo/_search'
+  }]
+
+  const client = new Client({
+    node: 'http://localhost:9200',
+    Connection: MockConnection
+  })
+
+  client.on('request', (err, event) => {
+    const req = requests.shift()
+    if (req.method === 'GET') {
+      t.error(err)
+    } else {
+      t.equal(err.message, 'The client noticed that the server is not a supported distribution of Elasticsearch')
+    }
+  })
+
+  client.search({
+    index: 'foo',
+    body: {
+      query: {
+        match_all: {}
+      }
+    }
+  }, (err, result) => {
+    t.equal(err.message, 'The client noticed that the server is not a supported distribution of Elasticsearch')
+  })
+
+  setTimeout(() => {
+    client.search({
+      index: 'foo',
+      body: {
+        query: {
+          match_all: {}
+        }
+      }
+    }, (err, result) => {
+      t.equal(err.message, 'The client noticed that the server is not a supported distribution of Elasticsearch')
+    })
+  }, 100)
+})
+
 test('No errors v6', t => {
   t.plan(7)
   const MockConnection = buildMockConnection({
@@ -571,7 +649,7 @@ test('500 error', t => {
       }
     }
   }, (err, result) => {
-    t.equal(err.message, 'The client noticed that the server is not Elasticsearch and we do not support this unknown product.')
+    t.equal(err.message, 'Response Error')
 
     client.search({
       index: 'foo',
@@ -608,7 +686,7 @@ test('TimeoutError', t => {
     if (req.method === 'GET') {
       t.error(err)
     } else {
-      t.equal(err.message, 'The client noticed that the server is not Elasticsearch and we do not support this unknown product.')
+      t.equal(err.message, 'Request timed out')
     }
   })
 
@@ -620,7 +698,45 @@ test('TimeoutError', t => {
       }
     }
   }, (err, result) => {
-    t.equal(err.message, 'The client noticed that the server is not Elasticsearch and we do not support this unknown product.')
+    t.equal(err.message, 'Request timed out')
+  })
+})
+
+test('ConnectionError', t => {
+  t.plan(3)
+
+  const requests = [{
+    method: 'GET',
+    path: '/'
+  }, {
+    method: 'POST',
+    path: '/foo/_search'
+  }]
+
+  const client = new Client({
+    node: 'http://localhost:9200',
+    Connection: MockConnectionError,
+    maxRetries: 0
+  })
+
+  client.on('request', (err, event) => {
+    const req = requests.shift()
+    if (req.method === 'GET') {
+      t.error(err)
+    } else {
+      t.equal(err.message, 'Kaboom')
+    }
+  })
+
+  client.search({
+    index: 'foo',
+    body: {
+      query: {
+        match_all: {}
+      }
+    }
+  }, (err, result) => {
+    t.equal(err.message, 'Kaboom')
   })
 })