[serverless] add support for loading serverless specific config locally

.gitignore

@@ -50,6 +50,7 @@ disabledPlugins
 webpackstats.json
 /config/*
 !/config/kibana.yml
+!/config/kibana.serverless.yml
 !/config/node.options
 coverage
 selenium

config/kibana.serverless.yml

@@ -0,0 +1,9 @@
+# as work on serverless picks up we will add config values to this file that
+# define how Kibana will run in "serverless" mode. To start Kibana locally with
+# this configuration, pass `--serverless` or run `yarn start-serverless`
+
+# configuration is applied in the following order, later values override
+#  1. kibana.yml
+#  2. kibana.serverless.yml (when --serverless is passed)
+#  3. kibana.dev.yml
+#  4. kibana.serverless.dev.yml (when --serverless is passed)

package.json

@@ -56,6 +56,7 @@
     "makelogs": "node scripts/makelogs",
     "spec_to_console": "node scripts/spec_to_console",
     "start": "node scripts/kibana --dev",
+    "start-serverless": "node scripts/kibana --dev --serverless",
     "storybook": "node scripts/storybook",
     "test:ftr": "node scripts/functional_tests",
     "test:ftr:runner": "node scripts/functional_test_runner",

src/cli/serve/serve.js

@@ -12,8 +12,8 @@ import { statSync } from 'fs';
 import { resolve } from 'path';
 import url from 'url';
 
-import { getConfigPath } from '@kbn/utils';
-import { fromRoot, isKibanaDistributable } from '@kbn/repo-info';
+import { getConfigPath, getConfigDirectory } from '@kbn/utils';
+import { isKibanaDistributable } from '@kbn/repo-info';
 import { readKeystore } from '../keystore/read_keystore';
 
 function canRequire(path) {
@@ -55,6 +55,40 @@ const pathCollector = function () {
 const configPathCollector = pathCollector();
 const pluginPathCollector = pathCollector();
 
+/**
+ * @param {string} name
+ * @param {string[]} configs
+ * @param {'push' | 'unshift'} method
+ */
+function maybeAddConfig(name, configs, method) {
+  const path = resolve(getConfigDirectory(), name);
+  try {
+    if (statSync(path).isFile()) {
+      configs[method](path);
+    }
+  } catch (err) {
+    if (err.code === 'ENOENT') {
+      return;
+    }
+
+    throw err;
+  }
+}
+
+/**
+ * @returns {string[]}
+ */
+function getEnvConfigs() {
+  const val = process.env.KBN_CONFIG_PATHS;
+  if (typeof val === 'string') {
+    return val
+      .split(',')
+      .filter((v) => !!v)
+      .map((p) => resolve(p.trim()));
+  }
+  return [];
+}
+
 function applyConfigOverrides(rawConfig, opts, extraCliOptions) {
   const set = _.partial(lodashSet, rawConfig);
   const get = _.partial(_.get, rawConfig);
@@ -152,7 +186,7 @@ export default function (program) {
       '-c, --config <path>',
       'Path to the config file, use multiple --config args to include multiple config files',
       configPathCollector,
-      [getConfigPath()]
+      []
     )
     .option('-p, --port <port>', 'The port to bind to', parseInt)
     .option('-Q, --silent', 'Set the root logger level to off')
@@ -177,7 +211,8 @@ export default function (program) {
       .option(
         '--run-examples',
         'Adds plugin paths for all the Kibana example plugins and runs with no base path'
-      );
+      )
+      .option('--serverless', 'Start Kibana with serverless configuration overrides');
   }
 
   if (DEV_MODE_SUPPORTED) {
@@ -200,19 +235,22 @@ export default function (program) {
   }
 
   command.action(async function (opts) {
+    const unknownOptions = this.getUnknownOptions();
+    const configs = [getConfigPath(), ...getEnvConfigs(), ...(opts.config || [])];
+
+    // we "unshift" .serverless. config so that it only overrides defaults
+    if (opts.serverless) {
+      maybeAddConfig('kibana.serverless.yml', configs, 'unshift');
+    }
+
+    // .dev. configs are "pushed" so that they override all other config files
     if (opts.dev && opts.devConfig !== false) {
-      try {
-        const kbnDevConfig = fromRoot('config/kibana.dev.yml');
-        if (statSync(kbnDevConfig).isFile()) {
-          opts.config.push(kbnDevConfig);
-        }
-      } catch (err) {
-        // ignore, kibana.dev.yml does not exist
+      maybeAddConfig('kibana.dev.yml', configs, 'push');
+      if (opts.serverless) {
+        maybeAddConfig('kibana.serverless.dev.yml', configs, 'push');
       }
     }
 
-    const unknownOptions = this.getUnknownOptions();
-    const configs = [].concat(opts.config || []);
     const cliArgs = {
       dev: !!opts.dev,
       envName: unknownOptions.env ? unknownOptions.env.name : undefined,
@@ -231,6 +269,7 @@ export default function (program) {
       oss: !!opts.oss,
       cache: !!opts.cache,
       dist: !!opts.dist,
+      serverless: !!opts.serverless,
     };
 
     // In development mode, the main process uses the @kbn/dev-cli-mode