refactor!: options change (#69)

* refactor!: get options programmatically be the user

* chore: more work on integration

* chore: changed version to original

* fix: removed unneeded call for config

* refactor: changed version to serviceVersion

* fix: removed commented line

package.json

@@ -11,6 +11,10 @@
     "./conventions": {
       "default": "./dist/semanticConventions/index.js",
       "types": "./dist/semanticConventions/index.d.ts"
+    },
+    "./prom-metrics": {
+      "default": "./dist/metrics/middleware/metrics.js",
+      "types": "./dist/metrics/middleware/metrics.d.ts"
     }
   },
   "scripts": {
@@ -50,6 +54,7 @@
   ],
   "homepage": "https://github.com/MapColonies/telemetry#readme",
   "dependencies": {
+    "@apideck/better-ajv-errors": "^0.3.6",
     "@map-colonies/read-pkg": "^0.0.1",
     "@opentelemetry/api": "^1.7.0",
     "@opentelemetry/auto-instrumentations-node": "^0.40.2",
@@ -59,7 +64,8 @@
     "@opentelemetry/sdk-node": "^0.46.0",
     "@opentelemetry/sdk-trace-base": "^1.19.0",
     "@opentelemetry/sdk-trace-node": "^1.19.0",
-    "env-var": "^7.1.1",
+    "ajv": "^8.16.0",
+    "ajv-formats": "^3.0.1",
     "express-prom-bundle": "^6.6.0",
     "prom-client": "^15.1.0"
   },
@@ -72,7 +78,6 @@
     "@types/express": "^4.17.12",
     "@types/faker": "^5.5.3",
     "@types/node": "^14.14.12",
-    "ajv": "^8.12.0",
     "change-case-all": "^2.1.0",
     "comment-json": "^4.2.3",
     "commitlint": "^11.0.0",
@@ -87,7 +92,7 @@
     "standard-version": "^9.0.0",
     "ts-node": "^9.1.1",
     "tsimp": "2.0.11",
-    "typescript": "^5.3.3",
-    "typedoc": "^0.25.13"
+    "typedoc": "^0.25.13",
+    "typescript": "^5.3.3"
   }
 }

src/common/config.ts

@@ -1,27 +1,97 @@
 import { hostname } from 'os';
-import * as env from 'env-var';
+import Ajv, { type JSONSchemaType } from 'ajv';
+import addFormats from 'ajv-formats';
+import { betterAjvErrors } from '@apideck/better-ajv-errors';
 import { loadPackageInfo } from '../common/packageInfoLoader';
 
+/**
+ * Represents the configuration for common settings.
+ */
 interface CommonConfig {
+  /**
+   * The name of the service to put as attribute.
+   * By default will be read from the package.json file.
+   */
   serviceName: string;
+  /**
+   * The value of the hostname attribute to use, will override the hostname.
+   */
   hostname: string;
-  version: string;
+  /**
+   * The version of the service to put as attribute.
+   * By default will be read from the package.json file.
+   */
+  serviceVersion: string;
 }
 
+const ajv = addFormats(
+  new Ajv({
+    useDefaults: true,
+    coerceTypes: true,
+    allErrors: true,
+    verbose: true,
+  })
+);
+
+const JSON_INDENTATION = 2;
+
+function mergeAndValidateConfig<T extends Record<keyof T, string | boolean | undefined | null | number>>(
+  inputConfig: Partial<T>,
+  envConfig: Partial<Record<keyof T, string>>,
+  schema: JSONSchemaType<T>
+): T {
+  // clean up undefined values so that they don't override the defaults
+  for (const key in envConfig) {
+    if (envConfig[key] === undefined) {
+      delete envConfig[key];
+    }
+  }
+
+  const mergedConfig = { ...inputConfig, ...envConfig };
+
+  const isValid = ajv.validate(schema, mergedConfig);
+
+  if (!isValid) {
+    const betterErrors = betterAjvErrors({
+      // eslint-disable-next-line @typescript-eslint/no-magic-numbers
+      schema: schema as Parameters<typeof betterAjvErrors>[0]['schema'],
+      data: mergedConfig,
+      errors: ajv.errors,
+    });
+    throw new Error(JSON.stringify(betterErrors, null, JSON_INDENTATION));
+  }
+
+  return mergedConfig;
+}
+
+const packageJsonInfo = loadPackageInfo();
+
+const commonConfigSchema: JSONSchemaType<CommonConfig> = {
+  type: 'object',
+  properties: {
+    serviceName: { type: 'string', default: packageJsonInfo.name },
+    hostname: { type: 'string', default: hostname() },
+    serviceVersion: { type: 'string', default: packageJsonInfo.version },
+  },
+  required: ['serviceName', 'hostname', 'serviceVersion'],
+};
+
+const envCommonConfig: Partial<CommonConfig> = {
+  serviceName: process.env.TELEMETRY_SERVICE_NAME,
+  hostname: process.env.TELEMETRY_HOST_NAME,
+  serviceVersion: process.env.TELEMETRY_SERVICE_VERSION,
+};
+
 let commonConfig: CommonConfig | undefined;
 
-const getCommonConfig = (): CommonConfig => {
+function getCommonConfig(options: Partial<CommonConfig>): CommonConfig {
   if (commonConfig) {
     return commonConfig;
   }
 
-  const packageConfig = loadPackageInfo();
-  commonConfig = {
-    serviceName: env.get('TELEMETRY_SERVICE_NAME').asString() ?? packageConfig.name,
-    hostname: env.get('TELEMETRY_HOST_NAME').asString() ?? hostname(),
-    version: env.get('TELEMETRY_SERVICE_VERSION').asString() ?? packageConfig.version,
-  };
+  commonConfig = mergeAndValidateConfig<CommonConfig>(options, envCommonConfig, commonConfigSchema);
+
   return commonConfig;
-};
+}
 
-export { CommonConfig, getCommonConfig };
+export { CommonConfig, getCommonConfig, mergeAndValidateConfig };

src/common/types.ts

@@ -0,0 +1,4 @@
+export type Prettify<T> = {
+  [K in keyof T]: T[K];
+  // eslint-disable-next-line @typescript-eslint/ban-types
+} & {};