feat(README): add Host on Heroku

README.md

@@ -23,6 +23,7 @@ Provides an easy integration with the Allbridge Core ChainBridgeService for DApp
 - [How to get](#how-to-get)
     - [1. Use existing docker image](#1-use-existing-docker-image)
     - [2. Build and run the docker image](#2-build-and-run-the-docker-image)
+    - [Host on Heroku](#host-on-heroku)
 - [How to use](#how-to-use)
     - [Swagger](#swagger)
     - [Raw transactions](#raw-transactions)
@@ -160,6 +161,62 @@ docker run -p 3000:3000 \
     -d allbridge-core-rest-api 
 ```
 
+### Host on Heroku
+
+If you cannot host Docker, you can use a separate hosting service like Heroku to deploy the REST API.
+
+For detailed instructions on using Heroku's container registry and runtime, see [the official guide](https://devcenter.heroku.com/articles/container-registry-and-runtime).
+
+Below is a step-by-step guide on how to do this.
+
+#### Step-by-Step Guide
+
+1. Sign up for Heroku
+   * [Heroku Sing Up](https://id.heroku.com/login)
+2. Install Heroku CLI
+   * Follow the instructions [here](https://devcenter.heroku.com/articles/heroku-cli#install-the-heroku-cli)
+3. Login to Heroku CLI
+   * Run the command: `heroku login`
+   * If you encounter an 'IP address mismatch' error, disabling iCloud Private Relay may help. More details [here](https://help.heroku.com/CBF0T4AJ/can-t-login-to-heroku-using-cli-getting-ip-address-mismatch).
+4. Ensure Docker is Installed
+    * Verify Docker is working by running `docker ps`.
+    * Ensure you are logged in to Heroku with `heroku login`.
+5. Create a New Heroku App
+    * [Create a new app](https://dashboard.heroku.com/new-app) on the Heroku dashboard.
+6. Set Heroku Stack to Container
+    * Run the command: `heroku stack:set container --app <app-name>`
+
+##### Deploy and release REST-API container
+
+Repeat steps 7-11 to upgrade to a newer REST-API version.
+
+7. Login to Heroku Container Registry
+   * Run `heroku container:login` or log in via Docker following [these instructions](https://devcenter.heroku.com/articles/container-registry-and-runtime#logging-in-to-the-registry).
+8. Pull the REST-API Locally
+   * Run the command: `docker pull --platform linux/amd64 allbridge/io.allbridge.rest-api:<version>`
+9. Tag the Docker Image
+   * Run the command: `docker tag allbridge/io.allbridge.rest-api:<version> registry.heroku.com/<app-name>/web`
+10. Push the Tagged Image to Heroku
+    * Run the command: `docker push registry.heroku.com/<app-name>/web`
+11. Release the Container on Heroku
+    * Run the command: `heroku container:release web --app <app-name>`
+
+##### One-Time Setup (Optional for Updates)
+
+12. Set Configuration Variables
+    * Run the commands, like: `heroku config:set ETH_NODE_URL=https://ethereum-rpc.publicnode.com --app <app-name>`
+    * Alternatively, you can set it via the Heroku Dashboard under the app's settings. [See](https://devcenter.heroku.com/articles/config-vars#using-the-heroku-dashboard).
+
+#### Final Steps
+
+13. Retrieve the Base URL
+    * Find the base URL in the domains section of your app's settings (`https://dashboard.heroku.com/apps/<app-name>/settings`) on the Heroku Dashboard.
+    * Or click the button `Open App`
+14. Check API Availability
+    * Append `/api` to the base URL to check the availability of the Swagger.
+
+You are now ready to use your rest-api app.
+
 ## How to use
 
 ### Swagger