sla4oai
v0.1.1
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SLA for Open API Initiative Library
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SLA4OAI (SLA for Open API Initiative) Library
SLA4OAI is an open source library for applying SLA in your node application.
SLA4OAI is Express-compatible SLA Checking and Monitoring middleware for Node.js.
SLA4OAI is based on SLA for Open API Initiative Specification. And follows the Basic SLA Management Service proposal.
Install
$ npm install sla4aoi
Basic Usage
You can simply use the library by registering it with the Express app and backend connections for Supervisor & Monitor:
var app = express();
var supervisorConnection = {
url: 'http://supervisor.oai.governify.io/api/v1'
};
var monitorConnection = {
url: 'http://monitor.oai.governify.io/api/v1'
};
slaManager.register(app, supervisorConnection, monitorConnection);
API Reference
1. SlaManager
register
Register all library components as express middlewares. Called once when the server getting up.
Parameters:
| Name | Type | Description |
|:-------------------- |:------------------------------------------------------- |:------------------------------- |
| app | Express
| Required - The express app. |
| supervisorConnection | ConnectionObject
| Required - The connection details of the Supervisor. |
| monitorConnection | ConnectionObject
| Optional - The connection details of the Monitor. In case of missing, the Reporter component will be disabled. |
ConnectionObject:
| Name | Type | Description |
|:-------------------- |:---------------- |:--------------------- |
| host | string
| Host url. |
| port | integer
| Port number. |
| username | string
| Credentials username. |
| password | string
| Credentials password. |
Example:
var app = express();
var supervisorConnection = {
url: 'http://supervisor.oai.governify.io/api/v1',
port: 80,
username: 'marck',
password: 'm4321'
};
slaManager.register(app, supervisorConnection);
2. Scope Resolver
configure
Use this method to set the configuration parameters of the Scope Resolver.
Configuration parameters:
| Name | Type | Description |
|:-------------------- |:--------------------------------------------------------------------- |:-------------------- |
| defaultOAuthProvider | string
| The default provider when oauthprovider is missing in the request header. |
| config | <provider, OAuthConfigObject>
| OAuth provider configurations. |
OAuthConfigObject:
| Name | Type | Description |
|:------------ |:------------- |:-------------------- |
| clientId | string
| The provider application id. |
| clientSecret | string
| The provider application secret. |
| callbackURL | string
| The callback registered in the provider application. |
Example:
var options = {
defaultOAuthProvider: 'google',
config: {
google: {
clientId: '6076-d1m.apps.googleusercontent.com',
clientSecret: '1lWx9DDDaPo9kxF4yu6t_loJ',
callbackURL: 'https://app.myservice.com/google/callback'
}
}
};
slaManager.scopeResolver.configure(options);
getAccountName
Use this method to get the account name from the OAuth provider by the specified token.
Example:
slaManager.scopeResolver.getAccountName(oauthProvider, token, function (err, accountName) {
// get accountName
});
getAccountScope
Using this method to get the scope object from the supervisor by the specifying the apikey or the account name.
Example:
slaManager.scopeResolver.getAccountScope('apikey', 'NbfiS7wjwjwb=', function (err, result) {
// get result.scope
});
//or
slaManager.scopeResolver.getAccountScope('account', '[email protected]', function (err, result) {
// get result.scope
});
OAuth Providers
Using the powerful PassportJS framework and family of plugins SLA4OAI can be configured to support the following providers:
3. Bouncer
configure
Use this method to set the configuration parameters of the Bouncer.
Configuration parameters:
| Name | Type | Description |
|:--------------- |:----------- |:-------------------- |
| environment | string
| The deploying environment (devel, qa, or production). |
Example:
var options = {
environment: 'qa'
};
slaManager.bouncer.configure(options);
needChecking
By default, all incoming requests are verified by SLA Check, but you can customize this behaviour and specify which requests need checking in both bouncer and scopeResolver components.
Example:
slaManager.bouncer.needChecking = function(req) {
if (req.originalUrl.startsWith('/api/')) {
return true;
}
return false;
}
slaManager.scopeResolver.needChecking = function(req) {
if (req.originalUrl.startsWith('/api/')) {
return true;
}
return false;
}
decline
By default, bouncer declines all not accepted requested with status code 403
and the body that comes from the Supervisor. But you can customize the decline response message.
Example:
slaManager.bouncer.decline = function(req, res, next, supervisorPayload) {
if(supervisorPayload.reason === 'Too many requests') {
res.status(429).json(supervisorPayload.reason).end();
}
else {
res.status(403).json(supervisorPayload).end();
}
}
resolveMetrics
In order to resolve the required metrics for the check API, you need to define resolveMetrics
function and return all metrics in single object.
Example:
slaManager.bouncer.resolveMetrics = function (requestedMetrics, req) {
return {
nameLegth: 12
};
};
3. Reporter
configure
Use this method to set the configuration parameters of the Reporter.
Configuration parameters:
| Name | Type | Description |
|:----------------- |:----------- |:-------------------- |
| autoReport | boolean
| In case of true
, all API calls will be reported one by one, else the developer can aggregate multiple API calls in one report (default = true). |
| aggregate | boolean
| Aggregate multiple measures in one report, this aggregated measures will be frequently sended based on the aggregationPeriod
(default = false). This features is disabled if the autoReport = false. |
| aggregationPeriod | double
| All requests during this period will be aggregated in one report. It is calculated in milliseconds. |
| cluster | string
| The cluster that process this API. |
| environment | string
| The deploying environment (devel, qa, or production). |
Example:
var options = {
autoReport: true,
aggregate: true,
aggregationPeriod: 100,
cluster: 'cl1.acme.com',
environment: 'qa'
};
slaManager.reporter.configure(options);
reportMetrics
In case of autoReport=false
, the developer will have the responsibility to call this method to report the aggregated metrics.
Example:
slaManager.reporter.reportMetrics();
setMetric
At any stage of the API logic, the developer can set a custom metric by simply passing its name and value.
Example:
slaManager.reporter.setMetric(req, 'animalTypes', records.length);
preCalculateMetrics
This method enables the developer to set the metrics that need to be calculated before the API logic.
Example:
slaManager.reporter.preCalculateMetrics = function(requestedMetrics, req, next) {
req.sla.metrics['x-origin'] = req.headers['origin'];
next();
};
postCalculateMetrics
This method enables the developer to set the metrics that need to be calculated after the API logic.
Example:
slaManager.reporter.postCalculateMetrics = function(requestedMetrics, req, res, next) {
req.sla.metrics['x-animalType'] = getAnimalTypes(res.Body);
next();
};
Predefined metrics
- responseTime: The API processing time.
- requestBody: The body of the request.
- responseHeaders: The headers of the request.
- responseBody: The body of the response.
- userAgent: Some information about the browser and operating system of the API consumer.
4. Winston
SLA4OAI uses Winston to log all SLA connection activities.
You can customize the Winston logging behaviour by accessing slaManager.winston
object.
Example: In the following example we change the logging from the Console to the file system:
slaManager.winston.add(slaManager.winston.transports.File, { filename: 'somefile.log' });
slaManager.winston.remove(slaManager.winston.transports.Console);