Added follow redirects feature.

modules/engine/lib/engine/http/request.js

@@ -81,8 +81,58 @@ function putInCache(key, cache, result, res, timeout) {
     }
 }
 
-function sendHttpRequest(client, options, args, start, timings, reqStart, key, cache, timeout, uniqueId, status, retry) {
+var followRedirects = true, maxRedirects = 10;
+
+function sendHttpRequest(client, options, args, start, timings, reqStart, key, cache, timeout, uniqueId, status, retry, redirects) {
     var clientRequest = client.request(options, function (res) {
+        if (followRedirects && (res.statusCode >= 301 && res.statusCode <= 307) &&
+            (options.method.toUpperCase() === 'GET' || options.method.toUpperCase() === 'HEAD')) {
+            res.socket.destroy();
+            if (res.statusCode === 305) { // Log but don't follow
+                args.logEmitter.emitWarning(args.httpReqTx.event, 'Warning with uri - ' + args.uri + ' - ' +
+                    'Received status code 305 ' + (Date.now() - start) + 'msec');
+                var err = new Error('Received status code 305 from downstream server');
+                err.uri = args.uri;
+                err.status = 502;
+                return args.httpReqTx.cb(err);
+            } else if (res.statusCode !== 304 && res.statusCode !== 306) { // Only follow 301, 302, 303, 307
+                if (res.headers.location) {
+                    if (redirects++ >= maxRedirects) {
+                        args.logEmitter.emitError(args.httpReqTx.event, 'Error with uri - ' + args.uri + ' - ' +
+                            'Exceeded max redirects (' + maxRedirects + '). In a loop? ' + (Date.now() - start) + 'msec');
+                        var err = new Error('Exceeded max redirects');
+                        err.uri = args.uri;
+                        err.status = 502;
+                        return args.httpReqTx.cb(err);
+                    }
+
+                    var location = new URI(res.headers.location);
+
+                    if (location.isAbsolute()) {
+                        options.host = location.heirpart().authority().host();
+                        options.port = location.heirpart().authority().port();
+                    } else {
+                        location = new URI(args.uri);
+                        location = location.resolveReference(res.headers.location);
+                    }
+                    options.path = location.heirpart().path();
+
+                    args.logEmitter.emitEvent(args.httpReqTx.event, 'being redirected for the ' + redirects + ' time, ' +
+                        'going to ' + options.host + ':' + options.port + options.path + ' - ' + args.uri + ' - ' + (Date.now() - start) + 'msec');
+                    sendHttpRequest(client, options, args, start, timings, reqStart, key, cache, timeout, uniqueId, status, retry, redirects);
+                    return;
+                } else {
+                    args.logEmitter.emitError(args.httpReqTx.event, 'Error with uri - ' + args.uri + ' - ' +
+                        'Received status code ' + res.statusCode + ', but Location header was not provided' +
+                        ' ' + (Date.now() - start) + 'msec');
+                    var err = new Error('Missing Location header in redirect');
+                    err.uri = args.uri;
+                    err.status = 502;
+                    return args.httpReqTx.cb(err);
+                }
+            }
+        }
+
         var bufs = []; // array for bufs for each chunk
         var responseLength = 0;
         var contentEncoding = res.headers['content-encoding'];
@@ -228,15 +278,15 @@ function sendMessage(args, client, options, retry) {
         cache.get(key,function(err,result){
             if(err || !result.data){
                 sendHttpRequest(client, options, args, start, timings, reqStart,
-                    key, cache, timeout, uniqueId, status, retry);
+                    key, cache, timeout, uniqueId, status, retry, 0);
             }
             else {
                 response.exec(timings, reqStart, args, uniqueId, res, result.start, result.result, options, status);
             }
         });
     }
     else {
-        sendHttpRequest(client, options, args, start, timings, reqStart, key, cache, timeout, uniqueId, status, retry);
+        sendHttpRequest(client, options, args, start, timings, reqStart, key, cache, timeout, uniqueId, status, retry, 0);
     }
 }
 

modules/engine/package.json

@@ -1,7 +1,7 @@
 {
     "author": "ql.io",
     "name": "ql.io-engine",
-    "version": "0.4.19",
+    "version": "0.4.20",
     "repository": {
         "type": "git",
         "url": "https://github.com/ql-io/ql.io"

modules/engine/test/mock/redirect-rel.ql

@@ -0,0 +1,5 @@
+create table redirect 
+  on select get from "http://127.0.0.1:8300/rel/redirect-response.json"
+response = select * from redirect;
+
+return response;

modules/engine/test/mock/redirect-response.json

@@ -0,0 +1,4 @@
+{
+    "id": "42",
+    "title":"Redirect Response"
+}

modules/engine/test/mock/redirect.ql

@@ -0,0 +1,6 @@
+create table redirect 
+  on select get from "http://127.0.0.1:8300/redirect-response.json"
+
+response = select * from redirect;
+
+return response;