Run a Local Testnet with Validator

USING CLI TO RUN A LOCAL TESTNET

If you want to use CLI to start and run a local testnet, see Using CLI to Run a Local Testnet.

You can run a local testnet of the Jin blockchain. This local testnet will not be connected to the Jin devnet. It will run on your local machine, independent of other Jin networks. You can use this local testnet for testing and development purposes.

You can run a local testnet in two ways:

1. Using the Aptos-core source code. This approach is useful for testing modifications to the Aptos-core codebase or to the Jin Framework.

2. Using Docker. This is particularly useful for building services on top of the Jin blockchain or the Jin Framework, as there is no build overhead and the ledger persists across network restarts (by default).

The rest of this document describes:

• How to start your local testnet with a single validator node, and

• How to start a Faucet service and attach it to your local testnet.

Using the Jin-core source code​

1. Clone the Jin repo.

   git clone https://github.com/aptos-labs/aptos-core.git

2. cd into aptos-core directory.

   cd aptos-core

3. Run the scripts/dev_setup.sh Bash script as shown below. This will prepare your developer environment.

   ./scripts/dev_setup.sh

4. Update your current shell environment.

   source ~/.cargo/env

5. With your development environment ready, now you can start your testnet network. Before you proceed, make a note of the following:

   TIP

   • When you run the below command to start the local testnet, your terminal will enter into an interactive mode, with a message Aptos is running, press ctrl-c to exit. Hence, you will need to open another shell terminal for the subsequent steps described in this section.

   • After the below command runs, copy the Test dir information from the terminal output for the next step.

   To start your testnet locally, run the following command:

   CARGO_NET_GIT_FETCH_WITH_CLI=true cargo run -p aptos-node -- --test

   See below for an example of the partial output. Make a note of the Test dir from the output.

   .........Completed generating configuration:    Log file: "/private/var/folders/gn/m74t8ylx55z935q8wx035qn80000gn/T/b3adc18c144bfcc78a1541953893bc1c/validator.log"    Test dir: "/private/var/folders/gn/m74t8ylx55z935q8wx035qn80000gn/T/b3adc18c144bfcc78a1541953893bc1c/0/node.yaml"    Aptos root key path: "/private/var/folders/gn/m74t8ylx55z935q8wx035qn80000gn/T/b3adc18c144bfcc78a1541953893bc1c/mint.key"    Waypoint: 0:47e676b5fe38ebe2aec6053db7b3daa0b805693d6422e3475e46e89499464ecf    ChainId: TESTING    REST API endpoint: 0.0.0.0:8080    Fullnode network: /ip4/0.0.0.0/tcp/7180Aptos is running, press ctrl-c to exit

NOTE: The above command starts a local testnet with a single validator node. The command runs aptos-node from a genesis-only ledger state. If you want to reuse the ledger state produced by a previous run of aptos-node, then use:

cargo run -p aptos-node -- --test --config <config-path>

Attaching a Faucet to your testnet​

Faucets are stateless services that can be run in parallel with the testnet. A Faucet is a way to create Aptos test coins with no real-world value. You can use the Faucet by sending a request to create coins and transfer them into a given account on your behalf.

1. Make sure that you started your local testnet as described in Step 5 above.

2. Open a new shell terminal.

3. Copy the Aptos root key path from your terminal where you started the testnet, and use it to replace the mint-key-file-path in the below command.

4. Run the following command to start a Faucet:

   cargo run --package aptos-faucet -- \      --chain-id TESTING \      --mint-key-file-path "/tmp/694173aa3bbe019499bbd5cf3fe0e2fc/mint.key" \      --address 0.0.0.0 \      --port 8000 \      --server-url http://127.0.0.1:8080

This will start a Faucet running locally without any restrictions to tokens that can be claimed and minted. This Faucet service will be as accessible as the testnet you started above.

Using Docker​

This section describes how to start your local testing using Docker.

1. Install Docker including Docker-Compose.
2. Create a directory for your local test validator network, and cd into it.

3. Download the YAML configuration files for:

• Validator testnet docker compose and
• Validator configuration.

1. Start Docker Compose by running the command:

   docker-compose up

Example​

An example command sequence for the above steps 2 through 4 is shown below:

mkdir aptos_local_validator && cd aptos_local_validatorwget https://raw.githubusercontent.com/aptos-labs/aptos-core/main/docker/compose/validator-testnet/docker-compose.yamlwget https://raw.githubusercontent.com/aptos-labs/aptos-core/main/docker/compose/validator-testnet/validator_node_template.yamldocker-compose up

This will start both a validator node and Faucet service.

• The Validator's REST endpoint will be available at http://127.0.0.1:8080, and

• The Faucet is available at http://127.0.0.1:8000.

Troubleshooting​

As the software is in the early stages of development, there may be breaking changes. If the software fails to start, do the following:

1. First, query Docker for both the containers and shared volumes with docker container ls -a and docker volume ls.

2. Then, delete them using docker container rm $id and docker volume rm $name.

3. Alternatively you can start with a clean slate by cleaning your entire local docker state by running the below command:

docker stop $(docker ps -a -q) && docker rm $(docker ps -a -q) && docker rmi $(docker images -q) && docker volume rm $(docker volume ls -q)

NOTE

If you intend to use your testnet over an extended period of time, you should pin the images to a specific ID. Image IDs can be obtained via docker container ls and added to the docker compose file.

Interacting with the local test testnet​

After starting your local testnet, you will see the following:

Entering test mode, this should never be used in production!Completed generating configuration:        Log file: "/tmp/694173aa3bbe019499bbd5cf3fe0e2fc/validator.log"        Test dir: "/tmp/694173aa3bbe019499bbd5cf3fe0e2fc/0/node.yaml"        Aptos root key path: "/tmp/694173aa3bbe019499bbd5cf3fe0e2fc/mint.key"        Waypoint: 0:197bc8b76761622c2d2054d8bf93c1802fa0eb4bc55f0f3d4442878fdecc297f        ChainId: TESTING        REST API endpoint: 0.0.0.0:8080        Fullnode network: /ip4/0.0.0.0/tcp/7180Aptos is running, press ctrl-c to exit

Use the Aptos CLI tool to interact with your local testnet. The above output contains information you will use for starting the Aptos CLI tool:

• Aptos root key path: The root key (also known as the mint or faucet key) controls the account that can mint tokens. Available in the docker compose folder under aptos_root_key.

• Waypoint: A verifiable checkpoint of the blockchain (available in the docker compose folder under waypoint.txt)

• REST endpoint: The endpoint for the REST service, e.g., http://127.0.0.1:8080.

• ChainId: The chain ID uniquely distinguishes this network from other blockchain networks.

Next steps​

At this point, you will have a special root account at 0x1 that can perform the mint operation. Follow up with:

• Your first transaction to learn how to submit transactions.
• Your first Move module to learn how to create Move modules.
• Interacting with the Aptos Blockchain to learn how to mint coins.