Describes set of actions to migrate an existing setup of the TokenBridge oracle to a new server
Steps to follow
In short, the following procedure looks like this:
create new server, check connection
stop bridge oracle on the current server
get last block numbers processed by the current server
run ansible playbook on the new server and provide it with values from previous step, so that new service would start where current one stopped
Step 1: Create a new server
Create a new server instance with your hosting provider (e.g. AWS, Digital Ocean, etc), you can use same specs as the current one (or at least 2 Core CPU, 4 GB RAM, Ubuntu 16.04 LTS, 32 GB Disk).
Important: don’t stop or terminate your current server yet! We might need it to roll back if any errors occur. If you’re currently running both xDai bridge validator and xDai network validator on the same server, let us know and we’ll provide you with instructions on how to move network validator to your new server after bridge migration is completed successfully
When you created new server, please note down its’ IP address and try to connect to it via ssh from your local computer to make sure that the server is accessible to you. When connected to the server, check that your user has sudo-privileges by running
It should complete without errors and not asking for password. Please copy your server’s hostname so that we can identify it later.
Also note what is your username on the new server
(most likely it’s ubuntu or root).
When these checks are done, logout from your new server to return to your local computer
Step 2: TokenBridge repo preparation
Installation procedure of new oracle involves running an ansible playbook from your local computer. Ansible will connect to new server, install required dependencies, code of the oracle and start bridge service. To use ansible, you first need to install required dependencies and ansible itself on your local computer. They can be found here.
After all the prerequisites are installed, download code of the new oracle to your local computer:
Please check that whitespaces were pasted correctly! Padding is important in this configuration file.
Set values of the following configuration options:
22.214.171.124: replace it with real IP address of your new server
ansible_user: change this to your username from the step 1 if it differs from ubuntu
ORACLE_VALIDATOR_ADDRESS_PRIVATE_KEY: your private key (this value must be 64 characters long)
ORACLE_HOME_START_BLOCK: use the value you get from the erc-native-signature-request:lastProcessedBlock redis key
ORACLE_FOREIGN_START_BLOCK: use value from erc-native-affirmation-request:lastProcessedBlock
Modify group_vars/dai.yml to reflect your own URL for COMMON_FOREIGN_RPC_URL. Also it makes sense to have a reasonable value for ORACLE_FOREIGN_RPC_POLLING_INTERVAL which should be slightly greater or equal of the average block mining time (e.g. for the Ethereum Mainnet it could be 15).
Launch the playbook
ansible-playbook -i hosts.yml site.yml
Playbook should complete without errors. In this case new oracle service is started automatically and upgrade procedure is finished.