What should be in mongo_url and mongo_oplog_url for monglab

1

Trying my first deploy to meteorapp.com. I’m using mongolab for the db but on the page I keep getting:

I’m getting a ‘502 Bad Gateway: Registered endpoints failed to handle the request.’

and in the log I get:
Error: MONGO_URL must be set in environment

The docs are a bit vague (to me) about what the string should be. Can someone post where to get the mongo_url and mongo_oplog_url from on mongolab. And perhaps an example of a settings.json file setup for mongolab.

2 Likes
2

In mLab once you have created your database there is a page which has this:

To connect using the mongo shell:
mongo xxxxx.mlab.com:37283/xxxxx -u <dbuser> -p <dbpassword>

To connect using a driver via the standard MongoDB URI (what's this?):
mongodb://<dbuser>:<dbpassword>@xxxxx.mlab.com:37283/xxxx

You need to copy that string into your settings.json file, mine looks like this:

{
  "kadira": {
    "appId":      "xxxxxxx",
    "appSecret":  "xxxxxxxx"
 },
 "galaxy.meteor.com": {
   "env": {
     "ROOT_URL":  "https://www.xxxxx.com.au",
     "MONGO_URL": "mongodb://xxxxx:xxxxxx@xxxxx.mlab.com:37283/xxxxx",
     "MAIL_URL":  "smtp://xxxxxx@xxxxx.com.au:xxxxxxxx@smtp.mailgun.org:25"
   }
 }
}
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3

Sorry in case it wasn’t clear - you need to create the database, and create a user for that database - insert the right credentials where they belong in that URL.

4

Thanks Chris but no luck yet. Deploying to meteor.com was so easy. Not sure
why this is so much harder. Once I get the config right once I’ll be fine.

From within the project folder I deploy from the Terminal using:

DEPLOY_HOSTNAME=galaxy.meteor.com meteor deploy appname.meteorapp.com
–settings settings.json
Here’s my settings.json which is in the root of the project.

{
“galaxy.meteor.com”: {
“env”: {
“ROOT_URL”: “http://appname.meteorapp.com”,
“MONGO_URL”: “mongodb://
dbusername:dbpassword@xxxxxx.mongolab.com:63461/dbname”,
“MONGO_OPLOG_URL”: “mongodb://
dbusername:dbpassword@xxxxxx.mongolab.com:63461/dbname”
}
}
}

I haven’t setup a dns yet so try and access the app at:
appname.meteorapp.com

5

Here’s the thing, to enable oplog, you should first have a replicaset and I think it is not available for the free tier. So if you go for the regular, entry level paid tier, and deploy a standard replica set, you’ll end up with a database dbname and an admin database. You’ll need to create a user for your dbname and a separate oplog user for your admin database and then configure the url’s like below:

{
  "galaxy.meteor.com": {
    "env": {
      "ROOT_URL": "http://appname.meteorapp.com",
      "MONGO_URL": "mongodb://dbusername:dbpassword@xxxxxx-xx,xxxxxx-xx.mongolab.com:63461/dbname?replicaSet=rs-xxxxxx",
      "MONGO_OPLOG_URL": "mongodb://oplogdbusername:oplogdbpassword@xxxxxx-xx,xxxxxx-xx.mongolab.com:63461/local?authSource=admin"
    }
  }
}

Notice the different username:password for the oplog and the authSource parameter at the end.

4 Likes
6

should this be possible with the 15$ tier? Tried to set it up but got authorization errors.

7

Yep I got this working with the $15 tier.

Make sure you get the oplog url right (notice the very last parameter) and that you do have an oplog user defined over your admin database (not the app database)

1 Like
8

Success!!! Thanks cstrat and serkandurusoy for clarifying this. The last hurdle was I hadn’t setup a user for the oplog access. From mlab docs:
"The oplog provides valuable information that can be used in a variety of applications. For example, Meteor-built websites rely on the oplog to get real-time updates on data changes."
Here the last bit of detail I needed:
http://docs.mlab.com/oplog/

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9

So there is no free MongoDB hosting with oplog tailing?

10

I guess not :frowning: but there are lots of providers out there of which, some may be providing that.

11

Can you point me to any?

12

Well I was just being wishfull but I sure will let you know if/when I spot one.

1 Like
13

@mitar @serkandurusoy just spot this question and for anybody who will be looking for free hosting of MongoDB with oplog tailing - official hosting of Mongo Atlas have a free tier with oplog

1 Like