Apnotic
Apnotic is a gem for sending Apple Push Notifications using the HTTP-2 specifics.
Why "Yet Another APN" gem?
If you have used the previous Apple Push Notification specifications you may have noticed that it was hard to know whether a Push Notification was successful or not. It was a common problem that has been reported multiple times. In addition, you had to run a separate Feedback service to retrieve the list of the device tokens that were no longer valid, and ensure to purge them from your systems.
All of this is solved by using the HTTP-2 APN specifications. Every Push Notification you make returns a response stating if the Push was successful or, if not, which problems were encountered. This includes the case when invalid device tokens are used, hence making it unnecessary to have a separate Feedback service.
Installation
Just install the gem:
$ gem install apnotic
Or add it to your Gemfile:
gem 'apnotic'
Usage
Standalone
Sync pushes
Sync pushes are blocking calls that will wait for an APNs response before proceeding.
require 'apnotic'
# create a persistent connection
connection = Apnotic::Connection.new(cert_path: "apns_certificate.pem", cert_pass: "pass")
# create a notification for a specific device token
token = "6c267f26b173cd9595ae2f6702b1ab560371a60e7c8a9e27419bd0fa4a42e58f"
notification = Apnotic::Notification.new(token)
notification.alert = "Notification from Apnotic!"
# send (this is a blocking call)
response = connection.push(notification)
# read the response
response.ok? # => true
response.status # => '200'
response.headers # => {":status"=>"200", "apns-id"=>"6f2cd350-bfad-4af0-a8bc-0d501e9e1799"}
response.body # => ""
# close the connection
connection.close
Async pushes
If you are sending out a considerable amount of push notifications, you may consider using async pushes to send out multiple requests in non-blocking calls. This allows to take full advantage of HTTP/2 streams.
require 'apnotic'
# create a persistent connection
connection = Apnotic::Connection.new(cert_path: "apns_certificate.pem", cert_pass: "pass")
# create a notification for a specific device token
token = "6c267f26b173cd9595ae2f6702b1ab560371a60e7c8a9e27419bd0fa4a42e58f"
notification = Apnotic::Notification.new(token)
notification.alert = "Notification from Apnotic!"
# prepare push
push = connection.prepare_push(notification)
push.on(:response) do |response|
# read the response
response.ok? # => true
response.status # => '200'
response.headers # => {":status"=>"200", "apns-id"=>"6f2cd350-bfad-4af0-a8bc-0d501e9e1799"}
response.body # => ""
end
# send
connection.push_async(push)
# wait for all requests to be completed
connection.join(timeout: 5)
# close the connection
connection.close
Mobile Device Management (MDM) notifications
If you are building an iOS MDM solution, you can as well use apnotic to send mdm push notifications with the Apnotic::MdmNotification
class. Sending a MDM notification requires a token and a push magic value, which is sent by the iOS device during its MDM enrollment:
require 'apnotic'
# create a persistent connection
connection = Apnotic::Connection.new(cert_path: "apns_certificate.pem", cert_pass: "pass")
# create a notification for a specific device token
token = '6c267f26b173cd9595ae2f6702b1ab560371a60e7c8a9e27419bd0fa4a42e58f'
# push magic value given by the iOS device during enrollment
push_magic = '7F399691-C3D9-4795-ACF8-0B51D7073497'
notification = Apnotic::MdmNotification.new(token: token, push_magic: push_magic)
# send (this is a blocking call)
response = connection.push(notification)
# read the response
response.ok? # => true
response.status # => '200'
response.headers # => {":status"=>"200", "apns-id"=>"6f2cd350-bfad-4af0-a8bc-0d501e9e1799"}
response.body # => ""
# close the connection
connection.close
Token-based authentication
Token-based authentication is supported. There are several advantages with token-based auth:
- There is no need to renew push certificates annually.
- A single key can be used for every app in your developer account.
First, you will need a token signing key from your Apple developer account.
Then configure your connection for :token
authentication:
require 'apnotic'
connection = Apnotic::Connection.new(
auth_method: :token,
cert_path: "key.p8",
key_id: "p8_key_id",
team_id: "apple_team_id"
)
With Sidekiq / Resque / ...
In case that errors are encountered, Apnotic will raise the error and repair the underlying connection, but it will not retry the requests that have failed. This is by design, so that the job manager (Sidekiq, Resque,...) can retry the job that failed. For this reason, it is recommended to use a queue engine that will retry unsuccessful pushes.
A practical usage of a Sidekiq / Rescue worker probably has to:
- Use a pool of persistent connections.
- Send a push notification.
- Remove a device with an invalid token.
- Raise errors when requests timeout, so that the queue engine can retry those.
An example of a Sidekiq worker with such features follows. This presumes a Rails environment, and a model Device
.
require 'apnotic'
class MyWorker
include Sidekiq::Worker
queue: :push_notifications
APNOTIC_POOL = Apnotic::ConnectionPool.new({
cert_path: Rails.root.join("config", "certs", "apns_certificate.pem"),
cert_pass: "mypass"
}, size: 5) do |connection|
connection.on(:error) { |exception| puts "Exception has been raised: #{exception}" }
end
def perform(token)
APNOTIC_POOL.with do |connection|
notification = Apnotic::Notification.new(token)
notification.alert = "Hello from Apnotic!"
response = connection.push(notification)
raise "Timeout sending a push notification" unless response
if response.status == '410' ||
(response.status == '400' && response.body['reason'] == 'BadDeviceToken')
Device.find_by(token: token).destroy
end
end
end
end
The official APNs Provider API documentation explains how to interpret the responses given by the APNS.
You may also consider using async pushes instead in a Sidekiq / Rescue worker.
Objects
Apnotic::Connection
To create a new persistent connection:
Apnotic::Connection.new()
Option | Description |
---|---|
:cert_path | Required The path to a valid APNS push certificate or any object that responds to :read . Supported formats: .pem , .p12 (:cert auth), or .p8 (:token auth). |
:cert_pass | Optional The certificate's password. |
:auth_method | Optional The options are :cert or :token . Defaults to :cert . |
:team_id | Required for :token auth Team ID from Membership Details. |
:key_id | Required for :token auth ID from Certificates, Identifiers & Profiles. |
:url | Optional Defaults to https://api.push.apple.com:443. |
:connect_timeout | Optional Expressed in seconds, defaults to 30. |
:proxy_addr | Optional Proxy server. e.g. http://proxy.example.com |
:proxy_port | Optional Proxy port. e.g. 8080 |
:proxy_user | Optional User name for proxy authentication. e.g. user_name |
:proxy_pass | Optional Password for proxy authentication. e.g. pass_word |
Note that since :cert_path
can be any object that responds to :read
, it is possible to pass in a certificate string directly by wrapping it up in a StringIO
object:
Apnotic::Connection.new(cert_path: StringIO.new("pem cert as string"))
It is also possible to create a connection that points to the Apple Development servers by calling instead:
Apnotic::Connection.development()
The concepts of PRODUCTION and DEVELOPMENT are different from what they used to be in previous specifications. Anything built directly from Xcode and loaded on your phone will have the app generate DEVELOPMENT tokens, while everything else (TestFlight, Apple Store, HockeyApp, ...) will be considered as PRODUCTION environment.
Methods
cert_path →
string
Returns the path to the certificate.
on(event, &block)
Allows to set a callback for the connection. The only available event is
:error
, which allows to set a callback when an error is raised at socket level, hence in the underlying socket thread.connection.on(:error) { |exception| puts "Exception has been raised: #{exception}" }
If the
:error
callback is not set, the underlying socket thread may raise an error in the main thread at unexpected execution times.url →
URL
Returns the URL of the APNS endpoint.
Blocking calls
push(notification, timeout: 30) →
Apnotic::Response
ornil
Sends a notification. Returns
nil
in case a timeout occurs.
Non-blocking calls
prepare_push(notification) →
Apnotic::Push
Prepares an async push.
push = client.prepare_push(notification)
push_async(push)
Sends the push asynchronously.
Apnotic::ConnectionPool
For your convenience, a wrapper around the Connection Pool gem is here for you. To create a new connection pool:
Apnotic::ConnectionPool.new(, ) do |connection|
connection.on(:error) { |exception| puts "Exception has been raised: #{exception}" }
end
For example:
APNOTIC_POOL = Apnotic::ConnectionPool.new({
cert_path: "apns_certificate.pem"
}, size: 5) do |connection|
connection.on(:error) { |exception| puts "Exception has been raised: #{exception}" }
end
It is also possible to create a connection pool that points to the Apple Development servers by calling instead:
Apnotic::ConnectionPool.development(, ) do |connection|
connection.on(:error) { |exception| puts "Exception has been raised: #{exception}" }
end
Since
1.4.0.
you are required to pass in a block when defining anApnotic::ConnectionPool
. This is to enforce a proper implementation of the library. You can read more here.
Apnotic::Notification
To create a notification for a specific device token:
notification = Apnotic::Notification.new(token)
Methods
These are all Accessor attributes.
Method | Documentation |
---|---|
alert |
Refer to the official Apple documentation of The Payload Key Reference for details. |
badge |
" |
sound |
" |
content_available |
" |
category |
" |
custom_payload |
" |
thread_id |
" |
target_content_id |
" |
interruption_level |
Refer to Payload Key Reference for details. iOS 15+ |
relevance_score |
Refer to Payload Key Reference for details. iOS 15+ |
stale_date |
Refer to Payload Key Reference for details. iOS 16+ |
content_state |
Refer to Payload Key Reference for details. iOS 16+ |
timestamp |
Refer to Payload Key Reference for details. iOS 16+ |
event |
Refer to Payload Key Reference for details. iOS 16+ |
dismissal_date |
Refer to Payload Key Reference for details. iOS 16+ |
apns_id |
Refer to Communicating with APNs for details. |
expiration |
" |
priority |
" |
topic |
" |
push_type |
Refer to Sending Notification Requests to APNs for details, defaults to alert or background (when content-availabe key is set to 1) |
url_args |
Values for Safari push notifications. |
mutable_content |
Key for UNNotificationServiceExtension. |
apns_collapse_id |
Key for setting the identification of a notification and allowing for the updating of the content of that notification in a subsequent push. More information avaible in WWDC 2016 - Session 707 Introduction to Notifications. iOS 10+ |
For example:
notification = Apnotic::Notification.new(token)
notification.alert = "Notification from Apnotic!"
notification.badge = 2
notification.sound = "bells.wav"
notification.priority = 5
For a Safari push notification:
notification = Apnotic::Notification.new(token)
notification.alert = {
title: "Flight A998 Now Boarding",
body: "Boarding has begun for Flight A998.",
action: "View"
}
notification.url_args = ["boarding", "A998"]
Apnotic::Response
The response to a call to connection.push
.
Methods
body →
hash
orstring
Returns the body of the response in Hash format if a valid JSON was returned, otherwise just the RAW body.
headers →
hash
Returns a Hash containing the Headers of the response.
ok? →
boolean
Returns if the push was successful.
status →
string
Returns the status code.
Apnotic::Push
The push object to be sent in an async call.
Methods
http2_request →
NetHttp2::Request
Returns the HTTP/2 request of the push.
on(event, &block)
Allows to set a callback for the request. Available events are:
:response
: triggered when a response is fully received (called once).Even if Apnotic is thread-safe, the async callbacks will be executed in a different thread, so ensure that your code in the callbacks is thread-safe.
push.on(:response) { |response| p response.headers }
Getting Your APNs Certificate
These instructions come from another great gem, apn_on_rails.
Once you have the certificate from Apple for your application, export your key and the apple certificate as p12 files. Here is a quick walkthrough on how to do this:
- Click the disclosure arrow next to your certificate in Keychain Access and select the certificate and the key.
- Right click and choose
Export 2 items…
. - Choose the p12 format from the drop down and name it
cert.p12
.
Optionally, you may covert the p12 file to a pem file (this step is optional because Apnotic natively supports p12 files):
$ openssl pkcs12 -in cert.p12 -out apple_push_notification_production.pem -nodes -clcerts
Thread-Safety
Apnotic is thread-safe. However, some caution is imperative:
- The async callbacks will be executed in a different thread, so ensure that your code in the callbacks is thread-safe.
- Errors in the underlying socket loop thread will be raised in the main thread at unexpected execution times, unless you specify the
:error
callback on the Connection. If you're using Apnotic with a job manager you should be fine by not specifying this callback.
Contributing
So you want to contribute? That's great! Please follow the guidelines below. It will make it easier to get merged in.
Before implementing a new feature, please submit a ticket to discuss what you intend to do. Your feature might already be in the works, or an alternative implementation might have already been discussed.
Do not commit to master in your fork. Provide a clean branch without merge commits. Every pull request should have its own topic branch. In this way, every additional adjustments to the original pull request might be done easily, and squashed with git rebase -i
. The updated branch will be visible in the same pull request, so there will be no need to open new pull requests when there are changes to be applied.
Ensure that proper testing is included. To run tests you simply have to be in the project's root directory and run:
$ rake