refactor: Use google's application default credentials instead of usi…

…ng multiple env vars

- This is the first step to reuse service accounts with BigQuery in the future

.env.sample

@@ -87,10 +87,10 @@ REVIEW_REPLY_BUFFER={"seconds":0,"minutes":0,"hours":-12,"days":0}
 # LINE add friend url, used for the message to guide user from LINE Notify to cofacts
 LINE_FRIEND_URL=https://line.me/R/ti/p/@cofacts
 
+# Google service
+GOOGLE_APPLICATION_CREDENTIALS=<path-to-service-account-credential>
+
 # Dialogflow
-DAILOGFLOW_CLIENT_EMAIL=
-DAILOGFLOW_PRIVATE_KEY=
-DAILOGFLOW_PROJECT_ID=
 DAILOGFLOW_LANGUAGE=
 DAILOGFLOW_ENV=
 

README.md

@@ -204,25 +204,26 @@ $ npm run notify
 $ node build/scripts/scanRepliesAndNotify.js
 ```
 
-### Dialogflow
+### Google cloud services
 
-We use dialogflow to detect if user is chatting with bot.
-If userinput matches one of dialogflow intents, we can directly return predefined responses in that intent.
+rumors-line-bot uses Google cloud services that is authenticated and authorized using Google Cloud
+service accounts and [Application Default Credentials](https://cloud.google.com/docs/authentication/application-default-credentials).
 
-To use Dialogflow,
+Please create a service account under the project, download its key and use `GOOGLE_APPLICATION_CREDENTIALS` env var to
+provide the path to your downloaded service account key. See [documentation](https://cloud.google.com/docs/authentication/provide-credentials-adc#local-key) for detail.
 
-1. You should [create a project](https://cloud.google.com/dialogflow/es/docs/quick/setup#project) and take note of the project ID then [enable api](https://cloud.google.com/dialogflow/es/docs/quick/setup#api).
-2. [Build an agent](https://cloud.google.com/dialogflow/es/docs/quick/build-agent).
-3. You will get a JSON file after [seting up authentication](https://cloud.google.com/dialogflow/es/docs/quick/setup#auth), copy `client_email` and `private_key` in the file.
-4. sets in `.env` file
+#### Dialogflow
 
-    ```
-    DAILOGFLOW_CLIENT_EMAIL=<paste client_email get from step3 here>
-    DAILOGFLOW_PRIVATE_KEY=<paste private_key get from step3 here>
-    DAILOGFLOW_PROJECT_ID=<paste project_id get from step1 here>
-    ```
+We use Dialogflow to detect if user is chatting with bot.
 
-    Optional env variables:
+If user input matches one of dialogflow intents, we can directly return predefined responses in that intent.
+
+To use Dialogflow, please do the following setup:
+
+1. Please ensure your [GCP project](https://cloud.google.com/dialogflow/es/docs/quick/setup#project) has [enabled Dialogflow api](https://cloud.google.com/dialogflow/es/docs/quick/setup#api).
+2. [Build an agent](https://cloud.google.com/dialogflow/es/docs/quick/build-agent) connected to the GCP project.
+3. Please ensure the service account has `dialogflow.sessions.detectIntent` permission.
+4. Set these env variables (optional):
     - `DAILOGFLOW_LANGUAGE` : Empty to agent's default language, or you can specify a [language](https://cloud.google.com/dialogflow/es/docs/reference/language).
     - `DAILOGFLOW_ENV` : Default to draft agent, or you can create different [versions](https://cloud.google.com/dialogflow/es/docs/agents-versions).
 

src/lib/detectDialogflowIntent.js

@@ -2,21 +2,28 @@
 import dialogflow from '@google-cloud/dialogflow';
 import crypto from 'crypto';
 
-const projectId = process.env.DAILOGFLOW_PROJECT_ID;
-const credentials = {
-  client_email: process.env.DAILOGFLOW_CLIENT_EMAIL,
-  // https://stackoverflow.com/questions/39492587/escaping-issue-with-firebase-privatekey-as-a-heroku-config-variable/41044630#41044630
-  private_key: (process.env.DAILOGFLOW_PRIVATE_KEY || '').replace(/\\n/g, '\n'),
-};
+// const projectId = process.env.DAILOGFLOW_PROJECT_ID;
+// const credentials = {
+//   client_email: process.env.DAILOGFLOW_CLIENT_EMAIL,
+//   // https://stackoverflow.com/questions/39492587/escaping-issue-with-firebase-privatekey-as-a-heroku-config-variable/41044630#41044630
+//   private_key: (process.env.DAILOGFLOW_PRIVATE_KEY || '').replace(/\\n/g, '\n'),
+// };
 
 // https://googleapis.dev/nodejs/dialogflow/latest/v2beta1.SessionsClient.html
-const sessionClient = new dialogflow.SessionsClient({ credentials });
+const sessionClient = new dialogflow.SessionsClient(/* { credentials } */);
+let projectId = null;
+sessionClient
+  .getProjectId()
+  .then((id) => {
+    if (!id) return;
+
+    projectId = id;
+    console.log(`[Dialogflow] Connected to project ID = ${id}`);
+  })
+  .catch((e) => ('[Dialogflow]', e));
 
 export default async function (input) {
-  if (!projectId || !credentials.client_email || !credentials.private_key) {
-    console.log(
-      '[Dialogflow] Skip detecting intent, one of env variables not set.'
-    );
+  if (!projectId) {
     return;
   }
   // https://cloud.google.com/dialogflow/es/docs/api-overview#sessions