Leo Configuration

Leo configuration consists of two files. leo_config.js and leo_cli_config.js. As their names suggest, they configure two different aspects of a Leo Microservice

leo_config.js - Configures the runtime of a Microservice

leo_cli_config.js - Configures the leo-cli to execute/publish/deploy a Microservice

leo-config

example config file

Leo Config is designed as a NODE_ENV based system for storing configuration for as many deployment environments as you want
using a hierarchical approach, and securely accessing stored credentials.

We recommend using AWS Secrets Manager for storing database credentials.

#### Basic usage example
In your application, require leo-config, then you can use any of the configuration settings outlined in the following steps.
Note: Config uses async and wait, which, for example, enables the code to wait for database settings BEFORE trying to
connect to the database.
``javascript
const config = require('leo-config');

exports.handler = async function(event, context, callback) {
// your config settings are now in the config object

// Example getting the database credentials:
// use await to make sure your code waits for database credentials before trying to connect to the database
let dbConfig = await config.database;

// Output the database host for our environment
console.log(dbConfig.host);

callback();
}
`

#### Basic configuration example
Create a file named leo_config.js in any directory of your project that you use the LEO Platform.
#### Basic structure example
`javascript
const leoaws = require('leo-aws');

module.exports = {
// predefined options
_global: {},
_local: {},

// your user-defined configuration options
prod: {},
stage: {},
dev: {},
prodServer1: {},
prodServer2: {},
etc: {}
}
`

$3


Each configuration option can be written as a static object for basic configuration settings (not recommended for connection
information such as usernames, passwords, etc), or a dynamic function for getting settings such as database connection
information or other configuration settings you want to keep secret or stored somewhere secure.
##### Static object
`javascript
_global: {}
`
##### dynamic function
`javascript
_global: function() {}
`

#### Predefined options

`javascript
_global
`
Sets default configuration settings for all environments. Any user-defined environment will override anything in global.

`javascript
_local
`
Used for when you're testing locally. Will override settings in your current environment when LEO_LOCAL=true

#### Using custom ENV options
Any option in here should match exactly the NODE_ENV for the environment you will be deploying and running this code.
For this example, I will be using a basic dev, stage, prod; but you can use any value you like and have defined
in your NODE_ENV.
`javascript
// if NODE_ENV=prod, use settings for the prod environment
prod: {
// using database as a dynamic function, get the credentials from AWS Secrets Manager
database: function() {
return this.leoaws.secrets.getSecret('mysql_prod_secret')
},
// setting your AWS configuration
"leo-sdk": {
"resources": {
"Region": "us-west-2",
"LeoArchive": "DevBus-LeoArchive-AB01CD23EF45GH67IJ89KL0M",
"LeoCron": "DevBus-LeoCron-CD23EF45GH67IJ89KL01MN2O",
"LeoEvent": "DevBus-LeoEvent-EF45GH67IJ89KL01MN23OP4Q",
"LeoFirehoseStream": "DevBus-LeoFirehoseStream-GH67IJ89KL01MN23OP45QR6S",
"LeoKinesisStream": "DevBus-LeoKinesisStream-IJ89KL01MN23OP45QR67ST8U",
"LeoS3": "devbus-leos3-KL01MN23OP45QR67ST89UV0W",
"LeoSettings": "DevBus-LeoSettings-MN23OP45QR67ST89UV01WX2Y",
"LeoStream": "DevBus-LeoStream-OP45QR67ST89UV01WX23YZ4A",
"LeoSystem": "DevBus-LeoSystem-QR67ST89UV01WX23YZ45AB6C"
},
"firehose": "DevBus-LeoFirehoseStream-ST89UV01WX23YZ45AB67CD8E",
"kinesis": "DevBus-LeoKinesisStream-UV01WX23YZ45AB67CD89EF0G",
"s3": "devbus-leos3-WX23YZ45AB67CD89EF01GH2I"
}
},
// if NODE_ENV=stage, use settings for the stage environment
stage: {
database: function() {
return this.leoaws.secrets.getSecret('mysql_stage_secret')
}
},
// if NODE_ENV=dev, use settings for the dev environment
dev: {
// using database as a static object
database: {
username: 'root',
password: 'mySuperSecretAndVerySecurePasswordNowStoredInTheCode',
host: 'db.mydomain.com',
port: '1234',
database: 'test'
}
}
`


$3


If you have an environment variable LEO_LOCAL=true, you can use _local and override any settings in _global and env section.
`javascript
_local: {
// required for local testing with AWS.
leoaws: {
profile: "default", // set in your ~/.aws/credentials
region: "us-west-2"
}
}
`

If you use a dynamic function, you can cache the value by first passing in cache into the function, then wrapping
your call in the cache function.
##### Example
`javascript
dev: {
dynamodbSettings: function(cache) {
return cache(this.leoaws.dynamodb.get("DevBus-LeoSettings-14HODE41JWL2O", "healthSNS_data"));
}
}
`

$3


If you have created a Leo React App you can a configuration profile that may be passed to the front end
`
'use strict';
module.exports = {
_global: {
ui: {
cognito: {
id: "some-cognito-id"
},
region: "some-aws-region"
}
}
}
`
Find the LEOCognito object here

The following shows examples of how to extract some or all of the leo_config via the leo server side object
`








Hello World




`
Also, note the basehref coming from leo. That is intended to be the HTML so your urls are relative to the deployment

leo_cli_config.js

`javascript
module.exports = {
linkedStacks: [
"LeoBus" // must match the parameter name in deploy
],
publish: [{
leoaws: {
profile: "default", // defined in ~/.aws/credentials
region: "us-west-2" // supported regions: us-west-2 and us-east-1
},
public: false
}],
deploy: {
dev: {
stack: "QuickStart",
parameters: {
LeoBus: "DevBus",
AlarmEmail: "default@email.com"
}
}
}
}
`
You may add a test section to configure an application port
`
module.exports = {
test: {
port: 8080
}
}
``

Support

Want to hire an expert, or need technical support? Reach out to the Leo team: https://leoinsights.com/contact