> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blockscout.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Deploying The Blockscout Infrastructure

> Guide to deploying the infrastructure required for Blockscout using Ansible and Terraform.

<Warning>
  Deployment with Terraform 12 is unstable due to these bugs: [#144](https://github.com/poanetwork/blockscout-terraform/issues/144), [#147](https://github.com/poanetwork/blockscout-terraform/issues/147), [#148](https://github.com/poanetwork/blockscout-terraform/issues/148), [#149](https://github.com/poanetwork/blockscout-terraform/issues/149). Please use TF 11.11 - 11.14 and following branch for deployment [https://github.com/poanetwork/blockscout-terraform/tree/before-t12](https://github.com/poanetwork/blockscout-terraform/tree/before-t12)
</Warning>

<Tip>
  Go to [Deploying BlockScout](/setup/deployment/ansible-deployment/deploying-blockscout) if you already have an infrastructure and simply want to install or update your BlockScout instance.
</Tip>

1\) Check that all [infrastructure prerequisites](/setup/deployment/ansible-deployment/prerequisites) are installed with the correct version number.

2\) Create the AWS access key and secret access key for user with sufficient permissions;

3\) Create `hosts` file from `hosts.example` (`mv hosts.example hosts`) and adjust to your needs. Each host should represent each BlockScout instance you want to deploy.

<Info>
  Each host name should belong exactly to one group. Also, per Ansible requirements, hosts and groups names should be unique.
</Info>

The simplest `hosts` file with one BlockScout instance will look like:

```csharp theme={null}
[group]
host
```

Where `[group]` is a group name, which will be interpreted as a `prefix` for all created resources and `host` is a name of BlockScout instance.

4\) For each host merge `infrastructure.yml.example` and `all.yml.example` config template files in `host_vars` folder into single config file with the same name as in `hosts` file:

```bash theme={null}
cat host_vars/infrastructure.yml.example host_vars/all.yml.example > host_vars/host.yml
```

5\) For each group merge `infrastructure.yml.example` and `all.yml.example` config template files in `group_vars` folder into single config file with the same name as group name in `hosts` file:

```bash theme={null}
cat group_vars/infrastructure.yml.example group_vars/all.yml.example > group_vars/group.yml
```

6\) [Adjust the variables](/setup/deployment/ansible-deployment/variables) at `group_vars` and `host_vars`.

<Info>
  You can move variables between host and group vars depending on if variable should be applied to the host or to the entire group.
</Info>

Also, if you need to **distribute variables across all the hosts/groups**, you can add these variables to the `group_vars/all.yml` file.

<Tip>
  More on variable precedence => [Official Ansible Docs](https://docs.ansible.com/ansible/latest/user_guide/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable).
</Tip>

7\) Run `ansible-playbook deploy_infra.yml`

* During the deployment the "diffs didn't match" error may occur, it will be ignored automatically. If Ansible play recap shows 0 failed plays, then the deployment was successful despite the error.

* Optionally, you may want to check the variables that were uploaded to the [Parameter Store](https://console.aws.amazon.com/systems-manager/parameters) at AWS Console.