gl-store-s3.js/node_modules/aws-sdk/lib/metadata_service.js

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2019-05-08 11:19:12 +00:00
var AWS = require('./core');
require('./http');
var inherit = AWS.util.inherit;
/**
* Represents a metadata service available on EC2 instances. Using the
* {request} method, you can receieve metadata about any available resource
* on the metadata service.
*
* You can disable the use of the IMDS by setting the AWS_EC2_METADATA_DISABLED
* environment variable to a truthy value.
*
* @!attribute [r] httpOptions
* @return [map] a map of options to pass to the underlying HTTP request:
*
* * **timeout** (Number) — a timeout value in milliseconds to wait
* before aborting the connection. Set to 0 for no timeout.
*
* @!macro nobrowser
*/
AWS.MetadataService = inherit({
/**
* @return [String] the hostname of the instance metadata service
*/
host: '169.254.169.254',
/**
* @!ignore
*/
/**
* Default HTTP options. By default, the metadata service is set to not
* timeout on long requests. This means that on non-EC2 machines, this
* request will never return. If you are calling this operation from an
* environment that may not always run on EC2, set a `timeout` value so
* the SDK will abort the request after a given number of milliseconds.
*/
httpOptions: { timeout: 0 },
/**
* Creates a new MetadataService object with a given set of options.
*
* @option options host [String] the hostname of the instance metadata
* service
* @option options httpOptions [map] a map of options to pass to the
* underlying HTTP request:
*
* * **timeout** (Number) — a timeout value in milliseconds to wait
* before aborting the connection. Set to 0 for no timeout.
* @option options maxRetries [Integer] the maximum number of retries to
* perform for timeout errors
* @option options retryDelayOptions [map] A set of options to configure the
* retry delay on retryable errors. See AWS.Config for details.
*/
constructor: function MetadataService(options) {
AWS.util.update(this, options);
},
/**
* Sends a request to the instance metadata service for a given resource.
*
* @param path [String] the path of the resource to get
* @callback callback function(err, data)
* Called when a response is available from the service.
* @param err [Error, null] if an error occurred, this value will be set
* @param data [String, null] if the request was successful, the body of
* the response
*/
request: function request(path, callback) {
if (process.env[AWS.util.imdsDisabledEnv]) {
callback(new Error('EC2 Instance Metadata Service access disabled'));
return;
}
path = path || '/';
var httpRequest = new AWS.HttpRequest('http://' + this.host + path);
httpRequest.method = 'GET';
AWS.util.handleRequestWithRetries(httpRequest, this, callback);
},
/**
* @api private
*/
loadCredentialsCallbacks: [],
/**
* Loads a set of credentials stored in the instance metadata service
*
* @api private
* @callback callback function(err, credentials)
* Called when credentials are loaded from the resource
* @param err [Error] if an error occurred, this value will be set
* @param credentials [Object] the raw JSON object containing all
* metadata from the credentials resource
*/
loadCredentials: function loadCredentials(callback) {
var self = this;
var basePath = '/latest/meta-data/iam/security-credentials/';
self.loadCredentialsCallbacks.push(callback);
if (self.loadCredentialsCallbacks.length > 1) { return; }
function callbacks(err, creds) {
var cb;
while ((cb = self.loadCredentialsCallbacks.shift()) !== undefined) {
cb(err, creds);
}
}
self.request(basePath, function (err, roleName) {
if (err) callbacks(err);
else {
roleName = roleName.split('\n')[0]; // grab first (and only) role
self.request(basePath + roleName, function (credErr, credData) {
if (credErr) callbacks(credErr);
else {
try {
var credentials = JSON.parse(credData);
callbacks(null, credentials);
} catch (parseError) {
callbacks(parseError);
}
}
});
}
});
}
});
/**
* @api private
*/
module.exports = AWS.MetadataService;