tokenbridge/deployment/EXECUTION.md

# POA Token Bridge / Deployment Execution

Please refer to the [Configuration](./CONFIGURATION.md) first.

## Dependencies

On your local machine install:
  * Python 2 (v2.6-v2.7)/Python3 (v3.5+)
  * [Ansible v2.3+](https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html)
  * Git

The playbook will automatically install `Docker`, `docker-compose`, `Python`, `Git` and it dependencies (such as `curl`, `ca-certificates`, `apt-transport-https`, etc.) to the node. Also this playbooks creates an additional non-sudo docker user to run service as.

## Running the playbook

```yaml
ansible-playbook -i hosts.yml site.yml
```

## Useful arguments

To be used with the ansible-playbook command, for example:

```yaml
ansible-playbook -i hosts.yml site.yml --ask-become-pass
```

* `--ask-pass` - ask for the password used to connect to the bridge VM.

* `--ask-become-pass` - ask for the `become` password used to execute some commands (such as Docker installation) with root privileges.

* `-i <file>` - use specified file as a `hosts.yml` file.

* `-e "<variable>=<value>"` - override default variable.

* `--private-key=<file_name>` - if private keyfile is required to connect to the ubuntu instance.

* `--user=<username>` - connect as this username

## Service commands

The deployed components have the following services:

Component | Service Name
--- | ---
Oracle | poabridge
UI | tokenbridge-ui
Monitor | tokenbridge-monitor

Use the default `SysVinit` commands to `start`, `stop`, `restart`, and `rebuild` the service and to check the `status` of the service. 

Commands format:
```bash
sudo service <service_name> [start|stop|restart|status|rebuild]
```

## Rollback the Last Processed Block in Redis

If the bridge does not handle an event properly (i.e. a transaction stalls due to a low gas price), the Redis DB can be rolled back. You must identify which watcher needs to re-run. For example, if the validator signatures were collected but the transaction with signatures was not sent to the Foreign network, the `collected-signatures` watcher must look at the block where the corresponding `CollectedSignatures` event was raised.

Execute the `reset-lastBlock.sh` script in the bridge root directory. For example, if you've installed your bridge with this deployment script and all the default parameters, use the following set of commands:

```shell
$ sudo su poadocker
$ cd ~/bridge
$ docker-compose stop bridge_affirmation bridge_request bridge_collected
$ docker-compose exec bridge_senderhome bash ./reset-lastBlock.sh <watcher> <block num>
$ exit
$ sudo service poabridge restart
```
where the _<watcher>_ could be one of the following:

- `signature-request`
- `collected-signatures`
- `affirmation-request`

## Logs

If the `syslog_server_port` option in the hosts.yml file is not set, all logs will be stored in `/var/log/docker/` folder in the set of folders with the `bridge_` prefix. 

If the `syslog_server_port` is set, logs will be redirected to the specified server and cannot be accessed on the bridge machine.

```yaml 
syslog_server_port: "<protocol>://<ip>:<port>" # When this parameter is set all bridge logs will be redirected to the <ip>:<port> address.
```