Tangle Validator Node

❗ Current development should be considered a work in progress.

Setting up a Tangle Node

This repo includes code to run a Tangle Validator Node on AWS using Terraform and Ansible. To get started, ensure you have both Terraform and Ansible installed locally.

In addition, create an AWS account and an IAM role that has the appropriate permissions for the contained infrastructure setup. Ensure the AWS credentials are exported to the appropriate computer running the setup. When setup, you should have the following files in ~/.aws :

• config
• credentials

Ensure that you chose the right AWS region.

Building AWS Infra

TODO: add scripts for bucket and table creation

From the root directory, you should first set-up an AWS account and create a bucket to store your terraform state. You must remember to do the following steps:

• Click create bucket
• Name the bucket something you will remember
• Ensure you choose the correct region
• Use the default settings

Then create a dynamodb table to manage state locks. This requires that you do:

• Go to dynamodb and click create table
• Name the bucket something you will remember
• Name the primary key LockID and keep as string
• Keep default settings and create

Then run:

terraform init -upgrade \
  -backend-config="bucket=YOUR-BUCKET-NAME" \
  -backend-config="dynamodb_table=YOUR-TABLE-NAME" \
  -backend-config="key=terraform.tfstate" \
  -backend-config="region=us-east-1"

Note: if you have an error, you may need to review your AWS credentials for Terraform.

Also, you will need to create a public & private key pair to access your instance. We assume that's defined in ~/.ssh/tangle-node.pub. It can be created with:

ssh-keygen -P "" -m PEM -f SSH-KEY-PAIR-NAME

Then add this key to your ssh agent:

ssh-add ~/.ssh/<SSH_PRIV_KEY>

You will also have to add this ssh key to your approved github ssh keys, since ansible tries to pull the tangle repository through ssh.

Next, plan the terraform changes:

terraform plan \
  -var admin_public_key="$(cat ~/.ssh/tangle-node.pub)"

Then, if that looks good, apply the terraform changes:

terraform apply \
  -var admin_public_key="$(cat ~/.ssh/tangle-node.pub)"

The resulting outputs should read out the following:

authority_node_ip_address = "<PRIVATE_IP_ADDR>"
bastion_ip_address = "<PUBLIC_IP_ADDR>"
validator_node_ip_address = [
  "<PRIVATE_IP_ADDR>",
]
validator_node_secondary_ip_address = [
  "<PRIVATE_IP_ADDR>",
]

Once you have everything up, you'll need to construct your Ansible inventory and ssh_config. This can be done by running:

terraform output -json >> output.json

The above command will create a file output.json that outlines the terraform instances.

Next we will use the output.json file we created above to generate our Ansible host file and ssh_config by running the following command:

cat output.json | python3 ./ansible/generate_inv.py

Note: you'll need python3 installed. You may need to run this command differently in Powershell.

Note: after you change any nodes created by terraform, you will need to re-run this command.

To make sure the command was successfully executed please ls the current directory. You should see a host and ssh_config file present.

You will then have to update your hosts file manually so it has the ansible_ssh_private_key_file variable added in, like so:

[authority_node]
<PRIV_IP_ADDR>

[bastion]
<PUB_IP_ADDR> ansible_ssh_private_key_file=~/.ssh/<SSH_PRIV_KEY>

[validator_node]
<PRIV_IP_ADDR> ansible_ssh_private_key_file=~/.ssh/<SSH_PRIV_KEY>
<PRIV_IP_ADDR> ansible_ssh_private_key_file=~/.ssh/<SSH_PRIV_KEY>

TODO - make this automatic, so we don't have to worry about the above variables added to be overwriten when running the generate_inv.py script

Setting up Tangle application

Setting up each node is a matter of simply running the Ansible playbooks. Make sure your inventory is up-to-date by running the generate_inv.py command above!

To run the playbook and configure the servers, run:

ansible-playbook -i hosts --ssh-extra-args "-F ./ssh_config" ansible/playbooks/chain.yml

Note - this will take about 30 or more minutes to compile, specifically the compiling of the tangle-validator-node is what takes super long. You can expect around 300 retries.

See node logs

To view validator node logs:

ansible-playbook -i hosts --ssh-extra-args "-F ./ssh_config" ansible/playbooks/peek_validator_logs.yml

To view authority node logs:

ansible-playbook -i hosts --ssh-extra-args "-F ./ssh_config" ansible/playbooks/peek_logs_validator.yml

Restarting the whole infrastructure

You may run into a scenario where you want to start from a clean slate. See steps below:

Get a clean slate locally

• Run terraform destroy -var admin_public_key="$(cat ~/.ssh/<YOUR_SSH_PUB_KEY)"
• Manually delete the .terraform folder and the .terraform.lock.hcl and output.json files
• Delete the hosts and ssh_config file

Clean up AWS

• Delete the terraform s3 state, which is named terraform.tfstate in the s3 console. You select the file with the checkbox, and then click delete.
• Go into dynamodb --> tables --> click the items tab --> click the check mark --> click actions and delete

Make sure your ssh is configured

• You might have to run ssh-add ~/.ssh/<YOUR_PRIV_SSH_KEY> to add it back to your ssh agent. You can always double check with ssh-add -L
• If you change the ssh key you use, you will have to configure the new one, the same way you did before. And you will have to make sure you rename the commands to match this new ssh key file