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Apollo Tracing

Ruby implementation of GraphQL trace data in the Apollo Tracing format.

Contents

• Installation
• Usage
  • Tracing
  • Engine Proxy
• Development
• Contributing
• License

Installation

Add this line to your application's Gemfile:

gem 'apollo-tracing'

And then execute:

$ bundle

Or install it yourself as:

$ gem install apollo-tracing

Usage

Define a GraphQL schema:

# Define a type
PostType = GraphQL::ObjectType.define do
  name "Post"

  field :id, !types.ID
  field :title, !types.String
end

# Define a query
QueryType = GraphQL::ObjectType.define do
  name "Query"

  field :posts, !types[PostType] do
    argument :user_id, !types.ID
    resolve ->(obj, args, ctx) { Post.where(user_id: args[:user_id]) }
  end
end

# Define a schema
Schema = GraphQL::Schema.define do
  query QueryType
end

# Execute query
query = "
  query($user_id: ID!) {
    posts(user_id: $user_id) {
      id
      title
    }
  }
"
Schema.execute(query, variables: { user_id: 1 })

Tracing

Add 'ApolloTracing' to your schema:

Now your response should look something like:

{
   "data":{
      "posts":[
         {
            "id":"1",
            "title":"Post Title"
         }
      ]
   },
   "extensions":{
      "tracing":{
         "version":1,
         "startTime":"2017-08-25T19:55:04.821Z",
         "endTime":"2017-08-25T19:55:04.823Z",
         "duration":1702785,
         "execution":{
            "resolvers":[
               {
                  "path":[
                     "posts"
                  ],
                  "parentType":"Query",
                  "fieldName":"posts",
                  "returnType":"[Post!]!",
                  "startOffset":1451015,
                  "duration":15735
               },
               {
                  "path":[
                     "posts",
                     0,
                     "id"
                  ],
                  "parentType":"Post",
                  "fieldName":"id",
                  "returnType":"ID!",
                  "startOffset":1556873,
                  "duration":6914
               },
               {
                  "path":[
                     "posts",
                     0,
                     "title"
                  ],
                  "parentType":"Post",
                  "fieldName":"title",
                  "returnType":"String!",
                  "startOffset":1604795,
                  "duration":4053
               },
               {
                  "path":[
                     "posts",
                     0,
                     "user_id"
                  ],
                  "parentType":"Post",
                  "fieldName":"user_id",
                  "returnType":"ID!",
                  "startOffset":1642942,
                  "duration":3814
               }
            ]
         }
      }
   }
}

Engine Proxy

Now you can start using the Apollo Engine service. Here is the general architecture overview of a sidecar mode – Proxy runs next to your application server:

 -----------------    request     -----------------    request     -----------------
|                 | -----------> |                 | -----------> |                 |
|     Client      |              |  Engine Proxy   |              |   Application   |
|                 | <----------- |                 | <----------- |                 |
 -----------------    response    -----------------    response    -----------------
                                          |
                                          |
                          GraphQL tracing | from response
                                          |
                                          ˅
                                  -----------------
                                 |                 |
                                 |  Apollo Engine  |
                                 |                 |
                                  -----------------

ApolloTracing gem comes with the Apollo Engine Proxy binary written in Go. To configure the Proxy create a Proxy config file:

# config/apollo-engine-proxy.json

{
  "apiKey": "service:YOUR_ENGINE_API_KEY",
  "logging": { "level": "INFO" },
  "origins": [{
    "http": { "url": "http://localhost:3000/graphql" }
  }],
  "frontends": [{
    "host": "localhost", "port": 3001, "endpoints": ["/graphql"]
  }]
}

• apiKey – get this on your Apollo Engine home page.
• logging.level – a log level for the Proxy ("INFO", "DEBUG" or "ERROR").
• origins – a list of URLs with your GraphQL endpoints in the Application.
• frontends – an address on which the Proxy will be listening.

To run the Proxy as a child process, which will be automatically terminated if the Application proccess stoped, add the following line to the config.ru file:

For example, if you use rails with puma application server and run it like:

bundle exec puma -w 2 -t 16 -p 3000

The proccess tree may look like:

                ---------------
               |  Puma Master  |
               |   Port 3000   |
                ---------------
                   |      |
         ----------        ----------
        |                            |    ----------------
        ˅                             -> |  Puma Worker1  |
 ----------------                    |    -----------------
|  Engine Proxy  |                   |    ----------------
|   Port 3001    |                    -> |  Puma Worker2  |
 ----------------                         ----------------

Now you can send requests to the reverse Proxy http://localhost:3001. It'll proxy any (GraphQL and non-GraphQL) requests to the Application http://localhost:3000. If the request matches the endpoints described in origins, it'll strip the tracing data from the response and will send it to the Apollo Engine service.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/uniiverse/apollo-tracing-ruby. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.