Allow node patch versions to be different on runtime

This adjusts the runtime node version check to only compare major and
minor version requirements. Systems that don't use the bundled NodeJS
might update their node due to security patches, which would currently
break OpenSearch Dashboards unecessarily.

```shell
% grep 14.18 ../../package.json
    "node": "14.18.2",
% nvm use 12
Now using node v12.22.8 (npm v6.14.15)
% node node_version_validator.js
OpenSearch Dashboards does not support the current Node.js version v12.22.8. Please use Node.js ~v14.18.
% nvm use 14
Now using node v14.18.3 (npm v6.14.15)
% node node_version_validator.js
%
```

Signed-off-by: Justin Kromlinger <[email protected]>

src/setup_node_env/node_version_validator.js

@@ -37,15 +37,16 @@ var pkg = require('../../package.json');
 var currentVersion = (process && process.version) || null;
 var rawRequiredVersion = (pkg && pkg.engines && pkg.engines.node) || null;
 var requiredVersion = rawRequiredVersion ? 'v' + rawRequiredVersion : rawRequiredVersion;
-var isVersionValid = !!currentVersion && !!requiredVersion && currentVersion === requiredVersion;
+var requiredVersionMajorMinor = requiredVersion.match(/^v(\d+\.\d+)/)[1]
+var isVersionValid = requiredVersionMajorMinor === currentVersion.match(/^v(\d+\.\d+)/)[1]
 
 // Validates current the NodeJS version compatibility when OpenSearch Dashboards starts.
 if (!isVersionValid) {
   var errorMessage =
     'OpenSearch Dashboards does not support the current Node.js version ' +
     currentVersion +
-    '. Please use Node.js ' +
-    requiredVersion +
+    '. Please use Node.js ~v' +
+    requiredVersionMajorMinor +
     '.';
 
   // Actions to apply when validation fails: error report + exit.

src/setup_node_env/node_version_validator.test.js

@@ -68,4 +68,25 @@ describe('NodeVersionValidator', function () {
       done();
     });
   });
+
+  it('should run the script WITHOUT error', function (done) {
+    var matches = REQUIRED_NODE_JS_VERSION.match(/^v(\d+)\.(\d+)\.(\d+)/)
+    let major = matches[1]
+    let minor = matches[2]
+    let patch = parseInt(matches[3]) + 1 // change patch version to be higher than required
+
+    var processVersionOverwrite =
+      "Object.defineProperty(process, 'version', { value: '" +
+      "v" + major + "." + minor + "." + patch +
+      "', writable: true });";
+    var command =
+      'node -e "' + processVersionOverwrite + "require('./node_version_validator.js')\"";
+
+    exec(command, { cwd: __dirname }, function (error, stdout, stderr) {
+      expect(error).toBeNull();
+      expect(stderr).toBeDefined();
+      expect(stderr).toHaveLength(0);
+      done();
+    });
+  });
 });