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Diffstat (limited to 'lib/consul.js')
| -rw-r--r-- | lib/consul.js | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/lib/consul.js b/lib/consul.js new file mode 100644 index 0000000..5b76ffc --- /dev/null +++ b/lib/consul.js @@ -0,0 +1,66 @@ +/* +Copyright(c) 2017 AT&T Intellectual Property. All rights reserved. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. + +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR +CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and limitations under the License. +*/ + +/* Low-level routines for using the Consul REST API */ + +const KEY = '/v1/kv/'; +const SERVICE = '/v1/catalog/service/'; +const DEFAULT_URL = 'http://localhost:8500'; + +const doRequest = require('./promise_request').doRequest; + +module.exports = function(options) { + const url = options.url || DEFAULT_URL; + + return { + + /* Fetch (a promise for) the decoded value of a single key from Consul KV store. + * If the value is a string representation of a JSON object, return as an object. + * If there is no such key, resolve to null. + */ + getKey: function(key) { + return doRequest({method: 'GET', uri: url + KEY + key + '?raw'}) + .then(function(res) { + return res.json || res.body; + }) + .catch(function(err) { + if (err.status === 404) { + /* Key wasn't found */ + return null; + } + else { + /* Some other error, rethrow it */ + throw err; + } + }); + }, + + /* Retrieve (a promise for) address:port information for a named service from the Consul service catalog. + * If the service has tag(s), return the first one. (Should be the full URL of the service if it exists. + * Since a service can be registered at multiple nodes, the result is an array. + * If the service is not found, returns a zero-length array. + */ + getService: function(serviceId) { + return doRequest({method: 'GET', uri: url + SERVICE + serviceId}) + .then(function(res){ + return res.json.map(function(r) { + /* Address for external service is in r.Address with r.ServiceAddress empty */ + return {address: r.ServiceAddress || r.Address, port: r.ServicePort, url: r.ServiceTags ? r.ServiceTags[0] : ""}; + }); + }); + } + } +};
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