chore(util-endpoints): add utility to read service specific endpoints (#5324)

Author: trivikr

packages/util-endpoints/package.json

@@ -23,6 +23,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@aws-sdk/types": "*",
+    "@smithy/node-config-provider": "^2.0.13",
     "tslib": "^2.5.0"
   },
   "engines": {

packages/util-endpoints/src/getEndpointUrlConfig.spec.ts

@@ -0,0 +1,91 @@
+import { getEndpointUrlConfig } from "./getEndpointUrlConfig";
+
+const ENV_ENDPOINT_URL = "AWS_ENDPOINT_URL";
+const CONFIG_ENDPOINT_URL = "endpoint_url";
+
+describe(getEndpointUrlConfig.name, () => {
+  const serviceId = "mockServiceId";
+  const endpointUrlConfig = getEndpointUrlConfig(serviceId);
+
+  const mockEndpoint = "https://mock-endpoint.com";
+  const ORIGINAL_ENV = process.env;
+
+  beforeEach(() => {
+    process.env = {};
+  });
+
+  afterEach(() => {
+    process.env = ORIGINAL_ENV;
+  });
+
+  describe("environmentVariableSelector", () => {
+    beforeEach(() => {
+      process.env[ENV_ENDPOINT_URL] = mockEndpoint;
+    });
+
+    it.each([
+      ["foo", `${ENV_ENDPOINT_URL}_FOO`],
+      ["foobar", `${ENV_ENDPOINT_URL}_FOOBAR`],
+      ["foo bar", `${ENV_ENDPOINT_URL}_FOO_BAR`],
+    ])("returns endpoint for '%s' from environment variable %s", (serviceId, envKey) => {
+      const serviceMockEndpoint = `${mockEndpoint}/${envKey}`;
+      process.env[envKey] = serviceMockEndpoint;
+
+      const endpointUrlConfig = getEndpointUrlConfig(serviceId);
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toEqual(serviceMockEndpoint);
+    });
+
+    it(`returns endpoint from environment variable ${ENV_ENDPOINT_URL}`, () => {
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toEqual(mockEndpoint);
+    });
+
+    it("returns undefined, if endpoint not available in environment variables", () => {
+      process.env[ENV_ENDPOINT_URL] = undefined;
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toBeUndefined();
+    });
+  });
+
+  describe("configFileSelector", () => {
+    const profile = { [CONFIG_ENDPOINT_URL]: mockEndpoint };
+
+    // ToDo: Enable once support for services section is added.
+    it.skip.each([
+      ["foo", "foo"],
+      ["foobar", "foobar"],
+      ["foo bar", "foo_bar"],
+    ])("returns endpoint for '%s' from config file '%s'", (serviceId, serviceConfigId) => {
+      const serviceMockEndpoint = `${mockEndpoint}/${serviceConfigId}`;
+      const serviceSectionName = `services ${serviceConfigId}_dev`;
+
+      const profileWithServices = {
+        ...profile,
+        services: serviceSectionName,
+      };
+      const parsedIni = {
+        profileName: profileWithServices,
+        [serviceSectionName]: {
+          [serviceConfigId]: {
+            [CONFIG_ENDPOINT_URL]: serviceMockEndpoint,
+          },
+        },
+      };
+
+      // @ts-ignore
+      expect(endpointUrlConfig.environmentVariableSelector(profileWithServices, parsedIni)).toEqual(
+        serviceMockEndpoint
+      );
+    });
+
+    it("returns endpoint from config file, if available", () => {
+      expect(endpointUrlConfig.configFileSelector(profile)).toEqual(mockEndpoint);
+    });
+
+    it("returns undefined, if endpoint not available in config", () => {
+      expect(endpointUrlConfig.environmentVariableSelector({})).toBeUndefined();
+    });
+  });
+
+  it("returns undefined by default", () => {
+    expect(endpointUrlConfig.default).toBeUndefined();
+  });
+});

packages/util-endpoints/src/getEndpointUrlConfig.ts

@@ -0,0 +1,36 @@
+import { IniSection } from "@aws-sdk/types";
+import { LoadedConfigSelectors } from "@smithy/node-config-provider";
+
+const ENV_ENDPOINT_URL = "AWS_ENDPOINT_URL";
+const CONFIG_ENDPOINT_URL = "endpoint_url";
+
+export const getEndpointUrlConfig = (serviceId: string): LoadedConfigSelectors<string | undefined> => ({
+  environmentVariableSelector: (env: NodeJS.ProcessEnv) => {
+    // The value provided by a service-specific environment variable.
+    const serviceEndpointUrlSections = [ENV_ENDPOINT_URL, ...serviceId.split(" ").map((w) => w.toUpperCase())];
+    const serviceEndpointUrl = env[serviceEndpointUrlSections.join("_")];
+    if (serviceEndpointUrl) return serviceEndpointUrl;
+
+    // The value provided by the global endpoint environment variable.
+    const endpointUrl = env[ENV_ENDPOINT_URL];
+    if (endpointUrl) return endpointUrl;
+
+    return undefined;
+  },
+
+  configFileSelector: (profile: IniSection) => {
+    // The value provided by a service-specific parameter from a services definition section
+    // referenced in a profile in the shared configuration file.
+
+    // ToDo: profile is selected one. It does not have access to other 'services' section.
+    // The configFileSelector interface needs to be modified to pass ParsedIniData as optional second parameter.
+
+    // The value provided by the global parameter from a profile in the shared configuration file.
+    const endpointUrl = profile[CONFIG_ENDPOINT_URL];
+    if (endpointUrl) return endpointUrl;
+
+    return undefined;
+  },
+
+  default: undefined,
+});