Using Dev Mode in meroctl CLI

Overview

The meroctl CLI provides a powerful feature called "dev mode" that allows developers to test their applications locally before publishing them to the network. This mode is particularly useful during the development and testing phases of your application.

All of the communication with your node through the meroctl CLI is protected by your nodes private key.

Why Use Dev Mode?

Dev mode offers several advantages:

1. Local Testing: Test your application on your local machine without needing to publish it to the network.
2. Quick Iterations: Make changes to your application and immediately test them without going through the full publication process.
3. Context Creation: Automatically create a context and link it to your local application.
4. Hot Reload-like Functionality: Any changes to the binary will automatically reflect in the context, eliminating the need to "upload" the app again after every change.

Prerequisites

Before using dev mode, ensure you have a node and a coordinator node running. This should be done in a separate terminal window. For more information, see the Setup guide.

How to Use Dev Mode

To list all supported commands, run the following command:

Terminal

cargo run -p meroctl -- help

Supported commands:

• init Initialize node configuration
• config Configure the node
• run Run a node
• context Manage contexts
• app Manage applications
• help Print this message or the help of the given subcommand(s)

Here's the basic syntax:

All commands share the same prefix:

Terminal

cargo run -p meroctl -- --home <path_to_home> --node-name <node_name> <command>

Parameters:

• --home: Specifies the path to the home directory. ( In our example we are using data as the home directory)

• --node-name: Specifies the name of the node.

• --path: Specifies the absolute path to your WASM file.

Create dev context using installed app

Terminal

cargo run -p meroctl -- --home <path_to_home> --node-name <node_name> context create --watch <path>

Output

Terminal

$ cargo run -p meroctl -- --home data --node-name node1 context create  --watch ./path/to/binary.wasm
Application `<appId>` installed!
Context `<contextId>` created!
Context{contextId} -> Application{appId}
(i) Watching for changes to "./path/to/binary.wasm"

Invite coordinator or other local nodes to participate in the context

Terminal

cargo run -p  meroctl -- --node-name coordinator --home data  context join --context-id contextId

Output

Terminal

Context <contextId> sucesfully joined

Create context command will:

1. Install your application locally.
2. Create a new context.
3. Link the context to your local application.

Automatic Updates

One of the key benefits of dev mode is its ability to automatically reflect changes in your application. When you modify and recompile your WASM binary, these changes are immediately available in the context without requiring you to "upload" or reinstall the application. This feature provides a seamless development experience, similar to "hot reload" functionality in other development environments.

Other useful commands

1. List existing contexts

Terminal

$ cargo run -p meroctl -- --home data --node-name node1 context ls

2. Create a context for a published application:

Terminal

$ cargo run -p meroctl -- --home data --node-name node1 context create --application-id <appId>

Output

Terminal

Context `contextId` created!
Context{contextId} -> Application{appId}

From development to Publication

When you're ready to move from local development to publishing your application:

1. Test your application thoroughly using dev mode.

2. When satisfied with your application's performance, follow the steps in the Publish App guide to publish your application to the network.

3. After publication, you can create contexts for your published application using the --application-id flag instead of dev mode.

Install the local app on node for debugging

Terminal

cargo run -p meroctl -- --home <path_to_home> --node-name <node_name> app install –-path <path>

Output

Terminal

Application installed successfully. Application ID: <appId>