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Author SHA1 Message Date
Alexander Chan 087a2f135f S3C-4618: backport HealthProbeServer 2021-06-25 12:33:45 -07:00
2 changed files with 99 additions and 0 deletions

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@ -62,6 +62,8 @@ module.exports = {
},
probe: {
ProbeServer: require('./lib/network/probe/ProbeServer'),
HealthProbeServer:
require('./lib/network/probe/HealthProbeServer'),
},
RoundRobin: require('./lib/network/RoundRobin'),
kmip: require('./lib/network/kmip'),

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@ -0,0 +1,97 @@
const httpServer = require('../http/server');
const werelogs = require('werelogs');
const errors = require('../../errors');
const ZenkoMetrics = require('../../metrics/ZenkoMetrics');
function sendError(res, log, error, optMessage) {
res.writeHead(error.code);
let message;
if (optMessage) {
message = optMessage;
} else {
message = error.description || '';
}
log.debug('sending back error response', { httpCode: error.code,
errorType: error.message,
error: message });
res.end(`${JSON.stringify({ errorType: error.message,
errorMessage: message })}\n`);
}
function sendSuccess(res, log, msg) {
res.writeHead(200);
log.debug('replying with success');
const message = msg || 'OK';
res.end(message);
}
function checkStub(log) { // eslint-disable-line
return true;
}
class HealthProbeServer extends httpServer {
constructor(params) {
const logging = new werelogs.Logger('HealthProbeServer');
super(params.port, logging);
this.logging = logging;
this.setBindAddress(params.bindAddress || 'localhost');
// hooking our request processing function by calling the
// parent's method for that
this.onRequest(this._onRequest);
this._reqHandlers = {
'/_/health/liveness': this._onLiveness.bind(this),
'/_/health/readiness': this._onReadiness.bind(this),
'/_/monitoring/metrics': this._onMetrics.bind(this),
};
this._livenessCheck = params.livenessCheck || checkStub;
this._readinessCheck = params.readinessCheck || checkStub;
}
onLiveCheck(f) {
this._livenessCheck = f;
}
onReadyCheck(f) {
this._readinessCheck = f;
}
_onRequest(req, res) {
const log = this.logging.newRequestLogger();
log.debug('request received', { method: req.method,
url: req.url });
if (req.method !== 'GET') {
sendError(res, log, errors.MethodNotAllowed);
}
if (req.url in this._reqHandlers) {
this._reqHandlers[req.url](req, res, log);
} else {
sendError(res, log, errors.InvalidURI);
}
}
_onLiveness(req, res, log) {
if (this._livenessCheck(log)) {
sendSuccess(res, log);
} else {
sendError(res, log, errors.ServiceUnavailable);
}
}
_onReadiness(req, res, log) {
if (this._readinessCheck(log)) {
sendSuccess(res, log);
} else {
sendError(res, log, errors.ServiceUnavailable);
}
}
// expose metrics to Prometheus
_onMetrics(req, res) {
res.writeHead(200, {
'Content-Type': ZenkoMetrics.asPrometheusContentType(),
});
res.end(ZenkoMetrics.asPrometheus());
}
}
module.exports = HealthProbeServer;