How to use AWS Document DB with Ruby On Rails? Compatibility with version 3.6?

Question

recently AWS implemented compatibility with MongoDB version 3.6 via DocumentDB.

Document DB requires a certificate that can be downloaded at:

https://s3-us-gov-west-1.amazonaws.com/rds-downloads/rds-GovCloud-Root-CA-2017.pem

Using a configuration file similar to:

https://github.com/mongodb/mongoid/blob/master/lib/rails/generators/mongoid/config/templates/mongoid.yml

I would like to know if there is a way to set compatibility with 3.6 in mongoid gem or if there is a specific version that ensures that version 3.6 is used?

Thank you

Answer 1

First, it is important to note that DocumentDB implements only partial compatibility with "MongoDB 3.6" as Amazon advertises. You can read more about some of the incompatibilities here: https://www.mongodb.com/blog/post/documents-are-everywhere

Mongoid works, and is tested, with the actual MongoDB 3.6 server. No special configuration is needed.

Using Mongoid with DocumentDB may work or may expose incompatibilities/omissions in Amazon's document database, depending on exact operations attempted.

Answer 2

First, you may need to download the RDS combined bundle as opposed to the rds-GovCloud-Root-CA-2017.pem . Link: https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem

Try this as your yaml file:

development:
  clients:
    default:
      uri: mongodb://myuser:mypassword@<your_cluster_endpoint>:<cluster_port>/test?ssl=true
      options:
        ssl_ca_cert: /path/to/rds-combined-ca-bundle.pem

Answer 3

Sample Working Configuration

production:
    clients:
        default:
            uri: "mongodb://user:pass@db_end_point:27017/db_name?ssl=true&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false"
            app_name: AppName
            options:
                ssl_ca_cert: "./config/rds-combined-ca-bundle.pem"

development:
    clients:
        default:
            uri: "mongodb://user:pass@db_end_point:27017/db_name?ssl=true&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false"
            app_name: AppName
            options:
                ssl_ca_cert: "./config/rds-combined-ca-bundle.pem"


test:
    clients:
        default:
            uri: "mongodb://user:pass@db_end_point:27017/db_name?ssl=true&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false"
            app_name: AppName
            options:
                ssl_ca_cert: "./config/rds-combined-ca-bundle.pem"

Answer 4

as of 2022, aws provided uri with protocol( mongodb ://) and query seems not working with mongoid..?

( as I got error below

Mongoid::Errors::MixedClientConfiguration: message: Both uri and standard configuration options defined for client: 'default'.

then, I modified config/mongoid.yml

working example should be like this:

development:
  clients:
    default:
      database: your_db
      hosts:
        - xxx.ap-northeast-1.docdb.amazonaws.com:27017
      options:
        user: mongo_user
        password: password
        ssl: true
        ssl_verify: false
        ssl_cert: path/to/rds-combined-ca-bundle.pem

reference:

https://github.com/mongodb/mongoid/blob/master/lib/rails/generators/mongoid/config/templates/mongoid.yml