feat: make firebaseServiceAccount input optional

README.md

@@ -85,7 +85,7 @@ jobs:
 
 ## Options
 
-### `firebaseServiceAccount` _{string}_ (required)
+### `firebaseServiceAccount` _{string}_
 
 This is a service account JSON key. The easiest way to set it up is to run `firebase init hosting:github`. However, it can also be [created manually](./docs/service-account.md).
 
@@ -95,6 +95,8 @@ to prevent unintended access to your Firebase project. Set it in the "Secrets" a
 of your repository settings and add it as `FIREBASE_SERVICE_ACCOUNT`:
 `https://github.com/USERNAME/REPOSITORY/settings/secrets`.
 
+If not provided, the action will attempt to use the default application credentials configured in your environment.
+
 ### `repoToken` _{string}_
 
 Adding `repoToken: "${{secrets.GITHUB_TOKEN}}"` lets the action comment on PRs

bin/action.min.js

@@ -91689,6 +91689,9 @@ module.exports.setGracefulCleanup = setGracefulCleanup;
 // Set up Google Application Credentials for use by the Firebase CLI
 // https://cloud.google.com/docs/authentication/production#finding_credentials_automatically
 async function createGacFile(googleApplicationCredentials) {
+  if (!googleApplicationCredentials) {
+    return "";
+  }
   const tmpFile = tmp.fileSync({
     postfix: ".json"
   });
@@ -92958,7 +92961,10 @@ async function execWithCredentials(args, projectId, gacFilename, opts) {
       env: {
         ...process.env,
         FIREBASE_DEPLOY_AGENT: "action-hosting-deploy",
-        GOOGLE_APPLICATION_CREDENTIALS: gacFilename // the CLI will automatically authenticate with this env variable set
+        ...(gacFilename ? {
+          GOOGLE_APPLICATION_CREDENTIALS: gacFilename
+        } // the CLI will automatically authenticate with this env variable set
+        : {})
       }
     });
   } catch (e) {
@@ -92976,7 +92982,6 @@ async function execWithCredentials(args, projectId, gacFilename, opts) {
   }
   return deployOutputBuf.length ? deployOutputBuf[deployOutputBuf.length - 1].toString("utf-8") : ""; // output from the CLI
 }
-
 async function deployPreview(gacFilename, deployConfig) {
   const {
     projectId,
@@ -93171,9 +93176,7 @@ async function postChannelSuccessComment(github, context, result, commit) {
 // Inputs defined in action.yml
 const expires = core.getInput("expires");
 const projectId = core.getInput("projectId");
-const googleApplicationCredentials = core.getInput("firebaseServiceAccount", {
-  required: true
-});
+const googleApplicationCredentials = core.getInput("firebaseServiceAccount");
 const configuredChannelId = core.getInput("channelId");
 const isProductionDeploy = configuredChannelId === "live";
 const token = process.env.GITHUB_TOKEN || core.getInput("repoToken");

src/createGACFile.ts

@@ -20,8 +20,11 @@ import { writeSync } from "fs";
 // Set up Google Application Credentials for use by the Firebase CLI
 // https://cloud.google.com/docs/authentication/production#finding_credentials_automatically
 export async function createGacFile(googleApplicationCredentials: string) {
-  const tmpFile = fileSync({ postfix: ".json" });
+  if (!googleApplicationCredentials) {
+    return "";
+  }
 
+  const tmpFile = fileSync({ postfix: ".json" });
   writeSync(tmpFile.fd, googleApplicationCredentials);
 
   return tmpFile.name;

src/deploy.ts

@@ -99,7 +99,9 @@ async function execWithCredentials(
         env: {
           ...process.env,
           FIREBASE_DEPLOY_AGENT: "action-hosting-deploy",
-          GOOGLE_APPLICATION_CREDENTIALS: gacFilename, // the CLI will automatically authenticate with this env variable set
+          ...(gacFilename
+            ? { GOOGLE_APPLICATION_CREDENTIALS: gacFilename } // the CLI will automatically authenticate with this env variable set
+            : {}),
         },
       }
     );

src/index.ts

@@ -40,9 +40,7 @@ import {
 // Inputs defined in action.yml
 const expires = getInput("expires");
 const projectId = getInput("projectId");
-const googleApplicationCredentials = getInput("firebaseServiceAccount", {
-  required: true,
-});
+const googleApplicationCredentials = getInput("firebaseServiceAccount");
 const configuredChannelId = getInput("channelId");
 const isProductionDeploy = configuredChannelId === "live";
 const token = process.env.GITHUB_TOKEN || getInput("repoToken");