tendermint/ansible/README.md

# Ansible playbook for Tendermint applications

![Ansible plus Tendermint](img/a_plus_t.png)

* [Prerequisites](#Prerequisites)
* [Ansible setup](#Ansible setup)
* [Running the playbook](#Running the playbook)

The playbooks in this folder run [ansible](http://www.ansible.com/) roles which:

* install and configure basecoin or ethermint
* start/stop basecoin or ethermint and reset their configuration

## Prerequisites

* Ansible 2.0 or higher
* SSH key to the servers

Optional for DigitalOcean droplets:
* DigitalOcean API Token
* python dopy package

Head over to the [Terraform folder](https://github.com/tendermint/tools/tree/master/terraform-digitalocean) for a description on how to get a DigitalOcean API Token.

Optional for Amazon AWS instances:
* Amazon AWS API access key ID and secret access key.

The cloud inventory scripts come from the ansible team at their [GitHub](https://github.com/ansible/ansible) page. You can get the latest version from the contrib/inventory folder.

## Ansible setup

Ansible requires a "command machine" or "local machine" or "orchestrator machine" to run on. This can be your laptop or any machine that can run ansible. (It does not have to be part of the cloud network that hosts your servers.)

Use the official [Ansible installation guide](http://docs.ansible.com/ansible/intro_installation.html) to install Ansible. Here are a few examples on basic installation commands:

Ubuntu/Debian:
```
sudo apt-get install ansible
```

CentOS/RedHat:
```
sudo yum install epel-release
sudo yum install ansible
```

Mac OSX:
If you have (Homebrew)[https://brew.sh] installed, then it's simply
```
brew install ansible
```

If not, you can install it using `pip`:
```
sudo easy_install pip
sudo pip install ansible
```


To make life easier, you can start an SSH Agent and load your SSH key(s). This way ansible will have an uninterrupted way of connecting to your servers.

```
ssh-agent > ~/.ssh/ssh.env
source ~/.ssh/ssh.env

ssh-add private.key
```

Subsequently, as long as the agent is running, you can use `source ~/.ssh/ssh.env` to load the keys to the current session.
Note: On Mac OSX, you can add the `-K` option to ssh-add to store the passphrase in your keychain. The security of this feature is debated but it is convenient.

### Optional cloud dependencies

If you are using a cloud provider to host your servers, you need the below dependencies installed on your local machine.

#### DigitalOcean inventory dependencies:

Ubuntu/Debian:
```
sudo apt-get install python-pip
sudo pip install dopy
```

CentOS/RedHat:
```
sudo yum install python-pip
sudo pip install dopy
```

Mac OSX:
```
sudo pip install dopy
```

#### Amazon AWS inventory dependencies:

Ubuntu/Debian:
```
sudo apt-get install python-boto
```

CentOS/RedHat:
```
sudo yum install python-boto
```

Mac OSX:
```
sudo pip install boto
```

## Refreshing the DigitalOcean inventory

If you just finished creating droplets, the local DigitalOcean inventory cache is not up-to-date. To refresh it, run:

```
DO_API_TOKEN="<The API token received from DigitalOcean>"
python -u inventory/digital_ocean.py --refresh-cache 1> /dev/null
```

## Refreshing the Amazon AWS inventory

If you just finished creating Amazon AWS EC2 instances, the local AWS inventory cache is not up-to-date. To refresh it, run:

```
AWS_ACCESS_KEY_ID='<The API access key ID received from Amazon>'
AWS_SECRET_ACCESS_KEY='<The API secret access key received from Amazon>'
python -u inventory/ec2.py --refresh-cache 1> /dev/null
```

Note: you don't need the access key and secret key set, if you are running ansible on an Amazon AMI instance with the proper IAM permissions set.

## Running the playbooks

The playbooks are locked down to only run if the environment variable `TF_VAR_TESTNET_NAME` is populated. This is a precaution so you don't accidentally run the playbook on all your servers.

The variable `TF_VAR_TESTNET_NAME` contains the testnet name which ansible translates into an ansible group. If you used Terraform to create the servers, it was the testnet name used there.

If the playbook cannot connect to the servers because of public key denial, your SSH Agent is not set up properly. Alternatively you can add the SSH key to ansible using the `--private-key` option.

If you need to connect to the nodes as root but your local username is different, use the ansible option `-u root` to tell ansible to connect to the servers and authenticate as the root user.

If you secured your server and you need to `sudo` for root access, use the the `-b` or `--become` option to tell ansible to sudo to root after connecting to the server. In the Terraform-DigitalOcean example, if you created the ec2-user by adding the `noroot=true` option (or if you are simply on Amazon AWS), you need to add the options `-u ec2-user -b` to ansible to tell it to connect as the ec2-user and then sudo to root to run the playbook.

### DigitalOcean
```
DO_API_TOKEN="<The API token received from DigitalOcean>"
TF_VAR_TESTNET_NAME="testnet-servers"
ansible-playbook -i inventory/digital_ocean.py install.yml -e service=basecoin
```

### Amazon AWS
```
AWS_ACCESS_KEY_ID='<The API access key ID received from Amazon>'
AWS_SECRET_ACCESS_KEY='<The API secret access key received from Amazon>'
TF_VAR_TESTNET_NAME="testnet-servers"
ansible-playbook -i inventory/ec2.py install.yml -e service=basecoin
```

### Installing custom versions

By default ansible installs the tendermint, basecoin or ethermint binary versions from the latest release in the repository. If you build your own version of the binaries, you can tell ansible to install that instead.

```
GOPATH="<your go path>"
go get -u github.com/tendermint/basecoin/cmd/basecoin

DO_API_TOKEN="<The API token received from DigitalOcean>"
TF_VAR_TESTNET_NAME="testnet-servers"
ansible-playbook -i inventory/digital_ocean.py install.yml -e service=basecoin -e release_install=false
```

Alternatively you can change the variable settings in `group_vars/all`.

## Other commands and roles

There are few extra playbooks to make life easier managing your servers.

* install.yml - Install basecoin or ethermint applications. (Tendermint gets installed automatically.) Use the `service` parameter to define which application to install. Defaults to `basecoin`.
* reset.yml - Stop the application, reset the configuration and data, then start the application again. You need to pass `-e service=<servicename>`, like `-e service=basecoin`. It will restart the underlying tendermint application too.
* restart.yml - Restart a service on all nodes. You need to pass `-e service=<servicename>`, like `-e service=basecoin`. It will restart the underlying tendermint application too.
* stop.yml - Stop the application. You need to pass `-e service=<servicename>`.
* status.yml - Check the service status and print it. You need to pass `-e service=<servicename>`.
* start.yml - Start the application. You need to pass `-e service=<servicename>`.
* ubuntu16-patch.yml - Ubuntu 16.04 does not have the minimum required python package installed to be able to run ansible. If you are using ubuntu, run this playbook first on the target machines. This will install the python pacakge that is required for ansible to work correctly on the remote nodes.
* upgrade.yml - Upgrade the `service` on your testnet. It will stop the service and restart it at the end. It will only work if the upgraded version is backward compatible with the installed version.
* upgrade-reset.yml - Upgrade the `service` on your testnet and reset the database. It will stop the service and restart it at the end. It will work for upgrades where the new version is not backward-compatible with the installed version - however it will reset the testnet to its default.

The roles are self-sufficient under the `roles/` folder.

* install - install the application defined in the `service` parameter. It can install release packages and update them with custom-compiled binaries.
* unsafe_reset - delete the database for a service, including the tendermint database.
* config - configure the application defined in `service`. It also configures the underlying tendermint service. Check `group_vars/all` for options.
* stop - stop an application. Requires the `service` parameter set.
* status - check the status of an application. Requires the `service` parameter set.
* start - start an application. Requires the `service` parameter set.

## Default variables

Default variables are documented under `group_vars/all`. You can the parameters there to deploy a previously created genesis.json file (instead of dynamically creating it) or if you want to deploy custom built binaries instead of deploying a released version.