"Meteor code must always run within a Fiber" when calling Collection.insert on server

Question

I have the following code in server/statusboard.js;

var require = __meteor_bootstrap__.require,     request = require("request")      function getServices(services) {   services = [];   request('http://some-server/vshell/index.php?type=services&mode=json', function (error, response, body) {     var resJSON = JSON.parse(body);      _.each(resJSON, function(data) {        var host = data["host_name"];        var service = data["service_description"];        var hardState = data["last_hard_state"];        var currState = data["current_state"];        services+={host: host, service: service, hardState: hardState, currState: currState};        Services.insert({host: host, service: service, hardState: hardState, currState: currState});     });   }); }  Meteor.startup(function () {   var services = [];   getServices(services);   console.log(services); }); 

Basically, it's pulling some data from a JSON feed and trying to push it into a collection.

When I start up Meteor I get the following exception;

app/packages/livedata/livedata_server.js:781       throw exception;             ^ Error: Meteor code must always run within a Fiber     at [object Object].withValue (app/packages/meteor/dynamics_nodejs.js:22:15)     at [object Object].apply (app/packages/livedata/livedata_server.js:767:45)     at [object Object].insert (app/packages/mongo-livedata/collection.js:199:21)     at app/server/statusboard.js:15:16     at Array.forEach (native)     at Function.<anonymous> (app/packages/underscore/underscore.js:76:11)     at Request._callback (app/server/statusboard.js:9:7)     at Request.callback (/usr/local/meteor/lib/node_modules/request/main.js:108:22)     at Request.<anonymous> (/usr/local/meteor/lib/node_modules/request/main.js:468:18)     at Request.emit (events.js:67:17) Exited with code: 1 

I'm not too sure what that error means. Does anyone have any ideas, or can suggest a different approach?

Answer 1

Just wrapping your function in a Fiber might not be enough and can lead to unexpected behavior.

The reason is, along with Fiber, Meteor requires a set of variables attached to a fiber. Meteor uses data attached to a fiber as a dynamic scope and the easiest way to use it with 3rd party api is to use Meteor.bindEnvironment.

T.post('someurl', Meteor.bindEnvironment(function (err, res) {   // do stuff   // can access Meteor.userId   // still have MongoDB write fence }, function () { console.log('Failed to bind environment'); })); 

Watch these videos on evented mind if you want to know more: https://www.eventedmind.com/posts/meteor-dynamic-scoping-with-environment-variables https://www.eventedmind.com/posts/meteor-what-is-meteor-bindenvironment

Answer 2

As mentioned above it is because your executing code within a callback.

Any code you're running on the server-side needs to be contained within a Fiber.

Try changing your getServices function to look like this:

function getServices(services) {   Fiber(function() {      services = [];     request('http://some-server/vshell/index.php?type=services&mode=json', function (error, response, body) {       var resJSON = JSON.parse(body);        _.each(resJSON, function(data) {          var host = data["host_name"];          var service = data["service_description"];          var hardState = data["last_hard_state"];          var currState = data["current_state"];          services+={host: host, service: service, hardState: hardState, currState: currState};          Services.insert({host: host, service: service, hardState: hardState, currState: currState});       });     });   }).run();   } 

I just ran into a similar problem and this worked for me. What I have to say though is that I am very new to this and I do not know if this is how this should be done.

You probably could get away with only wrapping your insert statement in the Fiber, but I am not positive.