# Step Flow
Step flow manager for Elixir applications
[](https://travis-ci.org/media-io/ex_step_flow)
[](https://hex.pm/packages/step_flow)
[](https://coveralls.io/github/media-io/ex_step_flow?branch=master)
## Generated documentation
[Step Flow Documentation](https://hexdocs.pm/step_flow/StepFlow.html)
## Usage
Add AMQP as a dependency in your `mix.exs` file.
```elixir
def deps do
[
{:step_flow, "~> 0.1.0"}
]
end
```
and add into extra applications:
```elixir
def application do
[
mod: {MyApplication.Application, []},
extra_applications: [
:step_flow
]
]
end
```
## Configurations to start
### Postgres configuration
Add into configuration files:
```elixir
config :step_flow, Ecto.Repo,
hostname: "localhost",
username: "postgres",
password: "postgres",
database: "step_flow_dev",
runtime_pool_size: 10
```
it can also be used with environment variables:
```elixir
config :step_flow, Ecto.Repo,
hostname: {:system, "DATABASE_HOSTNAME"},
username: {:system, "DATABASE_USERNAME"},
password: {:system, "DATABASE_PASSWORD"},
database: {:system, "DATABASE_NAME"},
runtime_pool_size: {:system, "DATABASE_POOL_SIZE"}
```
### RabbitMQ configuration
Add into configuration files:
```elixir
config :step_flow, StepFlow.Amqp,
hostname: "localhost",
port: 5672,
username: "guest",
password: "guest",
virtual_host: ""
```
it can also be used with environment variables:
```elixir
config :step_flow, StepFlow.Amqp,
hostname: {:system, "RABBITMQ_HOSTNAME"},
port: {:system, "RABBITMQ_PORT"},
username: {:system, "RABBITMQ_USERNAME"},
password: {:system, "RABBITMQ_PASSWORD"},
virtual_host: {:system, "RABBITMQ_VIRTUAL_HOST"},
```
### Slack integration (optional)
Configuring the Slack integration enable notification to Slack channel.
It's used to:
- send notification when job is in error
- send a notification via a Step
To enable integration, update configuration files:
```
config :step_flow, StepFlow,
exposed_domain_name: {:system, "EXPOSED_DOMAIN_NAME"},
slack_api_token: {:system, "SLACK_API_TOKEN"},
slack_api_channel: {:system, "SLACK_API_CHANNEL"}
```
Remarks: the `slack_api_channel` configure the channel for error jobs notification.
The message contains also a link to the workflow, so `exposed_domain_name` configure the hostname of the hosted application.
### Expose StepFlow Rest API
Step Flow provides the Rest API to mamage Workflows and Jobs.
Create a module with:
```elixir
defmodule MyApplicationWeb.StepFlow.Plug do
@moduledoc false
use StepFlow.Plug
end
```
Then in Phoenix router redirect the API part to the module:
```elixir
defmodule MyApplicationWeb.Router do
use MyApplicationWeb, :router
pipeline :api do
plug(:accepts, ["json"])
end
scope "/api", MyApplicationWeb do
pipe_through(:api)
scope "/step_flow", StepFlow do
forward("/", Plug)
end
# add other routes here
end
end
```
To enable authentication checks over Step Flow API configure callbacks in configuration:
```elixir
config :step_flow, StepFlow,
authorize: [
module: MyApplicationWeb.Authorize,
get_jobs: [:user_check, :right_technician_check],
get_workflows: [:user_check, :right_technician_check],
post_workflows: [:user_check, :right_technician_check],
put_workflows: [:user_check, :right_technician_check],
delete_workflows: [:user_check, :right_technician_check],
post_workflows_events: [:user_check, :right_technician_check],
get_definitions: [:user_check, :right_technician_check],
post_worker_definitions: [:user_check, :right_technician_check],
get_worker_definitions: [:user_check, :right_technician_check],
get_workflows_statistics: [:user_check]
]
```
### Enable StepFlow live notification to WebSocket
StepFlow can be configured to send messages on job updates (to enable refresh of UI via WebSocket for example).
To broadcast messages, the application endpoint needs to be configured.
```elixir
config :step_flow, StepFlow,
endpoint: MyApplicationWeb.Endpoint
```
### Configuration of the default working directory for workers
Each workers works with big data files, mostly on shared storage.
The default access point need to be configured using:
```elixir
config :step_flow, StepFlow,
workers_work_directory: "/data/mount/point"
```
