explorer/site: Add support for TOML-based configuration

This update improves the configuration setup for the explorer site by replacing hardcoded values with a TOML-based configuration file, enabling easier configuration and deployment across different networks, such as devnet, testnet, and mainnet.

- Introduced a `load_toml_config` function to load environment-specific key-value pairs from a TOML configuration file into the Flask app's `app.config`
- Created an initial `site_config.toml` file to define default configurations for various environments (e.g., localnet, devnet, testnet, and mainnet). The configurations for devnet, testnet, and mainnet are still a work in progress and marked as TODOs.
- Updated the RPC module to connect to the explorerd using the values specified in the configuration file
- Added tomli to requirements.txt

bin/explorer/site/app.py

@@ -23,6 +23,9 @@ related to blocks, contracts, transactions, search, and the explore section, inc
 error handlers, ensuring appropriate responses for these common HTTP errors.
 """
 
+import os
+import tomli
+
 from flask import Flask, render_template
 
 from blueprints.explore import explore_bp
@@ -41,6 +44,10 @@ def create_app():
     """
     app = Flask(__name__)
 
+    # Load the app TOML configuration
+    env = os.getenv("FLASK_ENV", "localnet")
+    load_toml_config(app, env)
+
     # Register Blueprints
     app.register_blueprint(explore_bp)
     app.register_blueprint(block_bp)
@@ -74,3 +81,45 @@ def create_app():
         return render_template('500.html'), 500
 
     return app
+
+def load_toml_config(app, env="localnet", config_path="site_config.toml"):
+    """
+    Loads environment-specific key-value pairs from a TOML configuration file into `app.config`.
+
+    Args:
+        app (Flask): The Flask application.
+        env (str): The name of the environment section to load (default is "localnet").
+        config_path (str): The path to the TOML configuration file.
+
+    Raises:
+        FileNotFoundError: If the configuration file cannot be found.
+        KeyError: If the specified environment section does not exist.
+    """
+
+    # Verify that the configuration file exists
+    if not os.path.isfile(config_path):
+        raise FileNotFoundError(f"Configuration file '{config_path}' not found.")
+
+    # Open and parse the configuration file (TOML)
+    with open(config_path, "rb") as f:
+        config = tomli.load(f)
+
+    # Ensure the specified environment section exists in the configuration
+    if env not in config:
+        raise KeyError(f"Environment '{env}' not found in {config_path}")
+
+    # Load the environment specific configurations into the Flask app's config object
+    for key, value in config[env].items():
+        app.config[key.upper()] = value
+
+    # Print the loaded configuration for debugging or confirmation purposes
+    print("\n" + "=" * 40)
+    print("Loaded Explorer Site Configuration")
+    print("=" * 40)
+
+    for key in config[env]:
+        print(f"{key.upper()} = {app.config[key.upper()]}")
+
+    print("=" * 40 + "\n")
+
+

bin/explorer/site/requirements.txt

@@ -1,2 +1,3 @@
 flask[async]
-Pygments
+Pygments
+tomli

bin/explorer/site/rpc.py

@@ -25,11 +25,7 @@ and handle responses from the server.
 
 import asyncio, json, random
 
-from flask import abort
-
-# DarkFi explorer daemon JSON-RPC configuration
-URL = "127.0.0.1"
-PORT = 14567
+from flask import abort, current_app
 
 class Channel:
     """Class representing the channel with the JSON-RPC server."""
@@ -82,7 +78,7 @@ async def query(method, params):
      returning the result of the query or raising an error if the request fails.
     """
     # Create the channel to send RPC request
-    channel = await create_channel(URL, PORT)
+    channel = await create_channel(current_app.config['EXPLORER_RPC_URL'], current_app.config['EXPLORER_RPC_PORT'])
 
     # Prepare request
     request = {

bin/explorer/site/site_config.toml

@@ -0,0 +1,36 @@
+# This file is part of DarkFi (https://dark.fi)
+#
+# Copyright (C) 2020-2025 Dyne.org foundation
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# Localnet Configuration
+[localnet]
+EXPLORER_RPC_URL = "127.0.0.1"
+EXPLORER_RPC_PORT = 14567
+
+# Devnet Configuration
+[devnet]
+EXPLORER_RPC_URL = "TODO"
+EXPLORER_RPC_PORT = "TODO"
+
+# Testnet Configuration
+[testnet]
+EXPLORER_RPC_URL = "TODO"
+EXPLORER_RPC_PORT = "TODO"
+
+# Mainnet Configuration
+[mainnet]
+EXPLORER_RPC_URL = "TODO"
+EXPLORER_RPC_PORT = "TODO"