notifications-push

Notifications-push is a microservice that provides push notifications of publications or changes of articles and lists of content. The microservice consumes a specific Kafka (MSK) topic group, then it pushes a notification depending on the subscription type of the user.

How to Build & Run the binary

1. Install, build and test:

go get github.com/Financial-Times/notifications-push
cd $GOPATH/src/github.com/Financial-Times/notifications-push

go test ./... -race
go install

2. Run locally:

• Create a tunnel for kafka to your local machine, self host a kafka or run a kafka instance in a docker image.

• Start the service using environment variables:

  For Article content push notifications:

export NOTIFICATIONS_RESOURCE=content \
    && export API_URL_RESOURCE=content \
    && export KAFKA_ADDRESS=localhost:9092 \
    && export GROUP_ID=notifications-push-yourtest \
    && export TOPIC=PostPublicationEvents \
    && export NOTIFICATIONS_DELAY=10 \
    && export API_BASE_URL="http://api-t.ft.com" \
    && export CONTENT_TYPE_ALLOWLIST="application/vnd.ft-upp-article-internal+json,application/vnd.ft-upp-audio+json,application/vnd.ft-upp-live-blog-post-internal+json,application/vnd.ft-upp-live-blog-package-internal+json" \
    && export CONTENT_URI_ALLOWLIST="^http://(content|upp)(-collection|-content-placeholder|-notifications-creator)?(-mapper|-unfolder)?(-pr|-iw)?(-uk-.*)?\\.svc\\.ft\\.com(:\\d{2,5})?/(content|complementarycontent)/[\\w-]+.*$" \
    && export ALLOWED_ALL_CONTENT_TYPE="Article,ContentPackage,Audio" \
    && export SUPPORTED_SUBSCRIPTION_TYPE="Article,ContentPackage,Audio,All,LiveBlogPackage,LiveBlogPost,Content" \
    && export DEFAULT_SUBSCRIPTION_TYPE="Article" \
    && ./notifications-push

or for list push notifications:

export NOTIFICATIONS_RESOURCE=lists \
    && export API_URL_RESOURCE=lists \
    && export KAFKA_ADDRESS=localhost:9092 \
    && export GROUP_ID=notifications-push-yourtest \
    && export TOPIC=PostPublicationEvents \
    && export NOTIFICATIONS_DELAY=10 \
    && export API_BASE_URL="http://api-t.ft.com" \
    && export CONTENT_TYPE_ALLOWLIST="application/vnd.ft-upp-list+json" \
    && export CONTENT_URI_ALLOWLIST="$." \
    && export DEFAULT_SUBSCRIPTION_TYPE="List" \
    && ./notifications-push

or for pages push notifications:

export NOTIFICATIONS_RESOURCE=pages \
    && export API_URL_RESOURCE=pages \
    && export KAFKA_ADDRESS=localhost:9092 \
    && export GROUP_ID=notifications-push-yourtest \
    && export TOPIC=PostPublicationEvents \
    && export NOTIFICATIONS_DELAY=10 \
    && export API_BASE_URL="http://api-t.ft.com" \
    && export CONTENT_TYPE_ALLOWLIST="application/vnd.ft-upp-page+json" \
    && export CONTENT_URI_ALLOWLIST="$." \
    && export DEFAULT_SUBSCRIPTION_TYPE="Page" \
    && ./notifications-push

or for annotations push notifications:

export NOTIFICATIONS_RESOURCE=annotations \
    && export API_URL_RESOURCE=content \
    && export MONITOR_NOTIFICATIONS=false \
    && export KAFKA_ADDRESS=localhost:9092 \
    && export GROUP_ID=notifications-push-yourtest \
    && export TOPIC=PostConceptAnnotations \
    && export NOTIFICATIONS_DELAY=10 \
    && export API_BASE_URL="http://api-t.ft.com" \
    && export CONTENT_TYPE_ALLOWLIST="application/json" \
    && export CONTENT_URI_ALLOWLIST="^http://(pac|next-video)\\.annotations-rw-neo4j\\.svc\\.ft\\.com/annotations/[\\w-]+.*$" \
    && export DEFAULT_SUBSCRIPTION_TYPE="Annotations" \
    && ./notifications-push

• or via command-line parameters (for Article type):

./notifications-push \
    --notifications_resource="content" \
    --consumer_addr="localhost:9092" \
    --consumer_group_id="notifications-push" \
    --topic="PostPublicationEvents" \
    --notifications_delay=10 \
    --api_base_url="http://api-t.ft.com" \
    --api_key_validation_endpoint="t800/a" \
    --content_type_allowlist="application/vnd.ft-upp-article+json" \
    --content_uri_allowlist="^http://(content|upp)(-collection|-content-placeholder|-notifications-creator)?(-mapper|-unfolder)?(-pr|-iw)?(-uk-.*)?\\.svc\\.ft\\.com(:\\d{2,5})?/(content|complementarycontent)/[\\w-]+.*$" \
    --allowed_all_contentType="Article,ContentPackage,Audio" \
    --supported_subscription_type="Annotations,Article,ContentPackage,Audio,All,LiveBlogPackage,LiveBlogPost,Content"
    --default_subscription_type="Article"

NB: for the complete list of options run ./notifications-push -h

HTTP endpoints

For content:

curl -i --header "x-api-key: «api_key»" https://api.ft.com/content/notifications-push

API Keys that allow subscription to content push notifications are Push API - Content and Push API - Internal.

The following subscription types could be also specified for which the client would like to receive notifications by setting a "type" parameter on the request:

• Article
• ContentPackage
• Content a.k.a ContentPlaceholder
• Audio
• LiveBlogPackage
• LiveBlogPost
• All- all content changes (Article, ContentPackage, Audio, Content), but not LiveBlogPackage and LiveBlogPost changes.

If not specified, by default Article is used. If an invalid type is requested an HTTP 400 Bad Request is returned.

If a policy called ADVANCED_NOTIFICATIONS is attached to the API key, then the subscriber will be able to distinguish between content creation and updates for the Article, LiveBlogPackage, LiveBlogPost and Content types.

E.g. curl -i --header "x-api-key: «api_key»" https://api.ft.com/content/notifications-push?type=Article

You can be subscribed for multiple types: curl -i --header "x-api-key: «api_key»" https://api.ft.com/content/notifications-push?type=All&type=LiveBlogPost&type=LiveBlogPackage

For lists:

API Key that allows subscription to list push notifications is Push API - Internal.

curl -i --header "x-api-key: «api_key»" https://api.ft.com/lists/notifications-push

For pages:

API Key that allows subscription to page push notifications is Push API - Internal.

curl -i --header "x-api-key: «api_key»" https://api.ft.com/pages/notifications-push

Note:

The lists and pages endpoints only support push notifications of their type (List and Page respectively), so no ?type= parameter is supported. Lists and pages also do not have metadata, and they don't support Annotations or other metadata subscription types.

Filter DELETE messages by type

When a content has been deleted (http://www.ft.com/thing/ThingChangeType/DELETE), the kafka payload is empty and we cannot extract the content type from the message. In this case, there are 2 possible behaviours:

• if the Content-Type header is empty or equal to application-json, then we cannot resolve the content type of the message. Therefore, the notification will be sent to all the subscribers despite their accepted content type.
• if the Content-Type header has been specified and it is not equal to application-json, then we can resolve the content type based on this header.

e.g. a DELETE message with header Content-Type: application/vnd.ft-upp-audio+json will be considered an Audio content. Therefore, the notification will be sent to those subscribers who accept type=Audio or type=All, but not type=Annotations.

Content Push stream

By opening a HTTP connection with a GET method to the /{resource}/notifications-push endpoint, subscribers can consume the notifications push stream for the resource specified in the configuration (content or lists). The stream will look like the following one.

data: []

data: []

data: [{"apiUrl":"http://api.ft.com/content/648bda7b-1187-3496-b48e-57ecb14d5b0a","id":"http://www.ft.com/thing/648bda7b-1187-3496-b48e-57ecb14d5b0a","type":"http://www.ft.com/thing/ThingChangeType/UPDATE","title":"For Ioana & Ioana only;","standout":{"scoop":true}}]

data: []

data: []

data: []

data: [{"apiUrl":"http://api.ft.com/content/e2e49a44-ef3c-11e5-aff5-19b4e253664a","id":"http://www.ft.com/thing/e2e49a44-ef3c-11e5-aff5-19b4e253664a","type":"http://www.ft.com/thing/ThingChangeType/UPDATE","title":"For Ioana 2","standout":{"scoop":false}}]

data: []

data: [{"apiUrl":"http://api.ft.com/content/d38489fa-ecf4-11e5-888e-2eadd5fbc4a4","id":"http://www.ft.com/thing/d38489fa-ecf4-11e5-888e-2eadd5fbc4a4","type":"http://www.ft.com/thing/ThingChangeType/UPDATE","title":"For Ioana 3","standout":{"scoop":false}}]

data: [{"apiUrl":"http://api.ft.com/content/648bda7b-1187-3496-b48e-57ecb14d5b0a","id":"http://www.ft.com/thing/648bda7b-1187-3496-b48e-57ecb14d5b0a","type":"http://www.ft.com/thing/ThingChangeType/UPDATE","title":"For Ioana 4","standout":{"scoop":false}}]

data: [{"apiUrl":"http://api.ft.com/content/648bda7b-1187-3496-b48e-57ecb14d5b0a","id":"http://www.ft.com/thing/648bda7b-1187-3496-b48e-57ecb14d5b0a","type":"http://www.ft.com/thing/ThingChangeType/UPDATE","title":"For Ioana 4","standout":{"scoop":false}}]

The empty [] lines are heartbeats. Notifications-push will send a heartbeat every 30 seconds to keep the connection active.

Annotations Push Stream

curl -i --header "x-api-key: «api_key»" https://api.ft.com/annotations/notifications-push

By opening a HTTP connection with a GET method to the /annotations/notifications-push endpoint, subscribers can consume the notifications push stream for annotation changes. The stream will look similar to the content one, with the exception that notification types are ANNOTATIONS_UPDATE instead of UPDATE

Message format

{
  "apiUrl":"http://api.ft.com/content/4de8b414-c5aa-11e9-a8e9-296ca66511c9",
  "id":"http://www.ft.com/thing/4de8b414-c5aa-11e9-a8e9-296ca66511c9",
  "type":"http://www.ft.com/thing/ThingChangeType/ANNOTATIONS_UPDATE"
}

Monitoring

The notifications-push stream endpoint allows a monitor query parameter. By setting the monitor flag as true, the push stream returns publishReference and lastModified attributes in the notification message, which is necessary information for UPP internal monitors such as PAM.

There is a special kind of synthetic e2e test publishes that are used for capability monitoring and notifications for them are send only to monitoring subscribers e.g. PAM. The way these kind of publishes are distinguished from any other is by their transaction id which should contain a content UUID that is contained in a configured allowlist.

To test the stream endpoint you can run the following CURL commands :

curl -X GET "http://localhost:8080/content/notifications-push"
curl -X GET "http://localhost:8080/content/notifications-push?monitor=true"
curl -X GET "https://<user>@<password>:pre-prod-up.ft.com/content/notifications-push"

WARNING: In CoCo, this endpoint does not work under /__notifications-push/. The reason for this is because Vulcan does not support long polling of HTTP requests. We worked around this issue by forwarding messages through Varnish to a fixed port for both services.

Productionizing Push API: The API Gateway does not support long polling of HTTP requests, so the requests come through Fastly. Everytime a client tries to connect to Notifications Push, the service performs a call to the API Gateway in order to validate the API key from the client.

Notification history

An HTTP GET to the /__history endpoint will return the history of the last notifications consumed from the Kafka queue. In order to access this endpoint port-forwarding must be used:

kubectl port-forward <pod-name> 8080:8080

The expected payload should look like the following one:

[
	{
		"apiUrl": "http://api.ft.com/content/eabefe3e-a4b9-11e6-8b69-02899e8bd9d1",
		"id": "http://www.ft.com/thing/eabefe3e-a4b9-11e6-8b69-02899e8bd9d1",
		"type": "http://www.ft.com/thing/ThingChangeType/UPDATE",
		"publishReference": "tid_jwhfe7n6dj",
		"lastModified": "2016-11-07T13:59:44.950Z"
	},
	{
		"apiUrl": "http://api.ft.com/content/c92d7b0c-a4c7-11e6-8b69-02899e8bd9d1",
		"id": "http://www.ft.com/thing/c92d7b0c-a4c7-11e6-8b69-02899e8bd9d1",
		"type": "http://www.ft.com/thing/ThingChangeType/UPDATE",
		"publishReference": "tid_owd5zqw11m",
		"lastModified": "2016-11-07T13:59:04.546Z"
	},
	{
		"apiUrl": "http://api.ft.com/content/58437fc0-a4f1-11e6-8898-79a99e2a4de6",
		"id": "http://www.ft.com/thing/58437fc0-a4f1-11e6-8898-79a99e2a4de6",
		"type": "http://www.ft.com/thing/ThingChangeType/DELETE",
		"publishReference": "tid_5z8dxzsesj",
		"lastModified": "2016-11-07T13:58:36.285Z"
	}
]

Stats

An HTTP GET to the /__stats endpoint will return the stats about the current subscribers that are consuming the notifications push stream. In order to access this endpoint port-forwarding must be used:

kubectl port-forward <pod-name> 8080:8080

The expected payload should look like the following one:

{
	"nrOfSubscribers": 2,
	"subscribers": [
		{
			"addr": "127.0.0.1:61047",
			"since": "Nov  7 14:26:04.018",
			"connectionDuration": "2m41.693365011s",
			"type": "dispatcher.standardSubscriber"
		},
		{
			"addr": "192.168.1.3:65345",
			"since": "Nov  7 14:26:06.259",
			"connectionDuration": "2m39.453175004",
			"type": "dispatcher.monitorSubscriber"
		}
	]
}

How to Build & Run with Docker

    docker build -t coco/notifications-push .

    docker run --env NOTIFICATIONS_RESOURCE=content \
        --env KAFKA_ADDRESS=localhost:9092 \
        --env GROUP_ID="notifications-push-yourtest" \
        --env TOPIC="PostPublicationEvents" \
        --env NOTIFICATIONS_DELAY=10 \
        --env API_BASE_URL="http://api.ft.com" \
        --env CONTENT_TYPE_ALLOWLIST="application/vnd.ft-upp-article+json,application/vnd.ft-upp-content-package+json" \
        --env CONTENT_URI_ALLOWLIST="^http://(content|upp)(-collection|-content-placeholder|-notifications-creator)?(-mapper|-unfolder)?(-pr|-iw)?(-uk-.*)?\\.svc\\.ft\\.com(:\\d{2,5})?/(content|complementarycontent)/[\\w-]+.*$" \
        --env ALLOWED_ALL_CONTENT_TYPE="Article,ContentPackage,Audio" \
        --env SUPPORTED_SUBSCRIPTION_TYPE="Annotations,Article,ContentPackage,Audio,All,LiveBlogPackage,LiveBlogPost,Content" \
        --env DEFAULT_SUBSCRIPTION_TYPE="Article" \
        coco/notifications-push

Running locally with docker-compose

docker build -t local/notifications-push:latest .
docker-compose up -d

!Note: If the app crashes it is probably kafka is not ready yet, give it a minute and then execute:

docker-compose up -d app

Install kafkacat and configure it like this:

printf "api.version.request=false\nbroker.version.fallback=0.8.2.0" > ~/.config/kafkacat.conf

Prepare a file like this one payload.ftmessage containing similar payload:

FTMSG/1.0
Content-Type: application/vnd.ft-upp-live-blog-post+json

{
    "payload": {
        "brands": [
            {
                "id": "http://api.ft.com/things/5c7592a8-1f0c-11e4-b0cb-b2227cce2b54"
            }
        ],
        "title": "LiveBlogPostTitle",
        "uuid": "661516b6-2917-42fb-92b9-326bb205ae53",
        "type": "LiveBlogPost",
        "bodyXML": "<body />"
    },
    "lastModified": "2020-08-11T09:00:00.020Z",
    "contentURI": "http://methode-article-internal-components-mapper.svc.ft.com/internalcomponents/661516b6-2917-42fb-92b9-326bb205ae53"
}

and send it to kafka like this:

kafkacat -P -b localhost:9092 -t PostPublicationEvents -p 0 payload.ftmessage

Clients

Example client code is provided in bin/client directory

Spark for everyone (S4E)

Blocking notifications by publication

If you need to block any notifications from specific publication you need to edit the rego rule in
opa_modules/special_content.rego and add the publication uuid in the block_notication_for_publication list.

Logging

• The application uses go-logger; the log file is initialised in app.go.

Useful Links

• Production:

https://api.ft.com/content/notifications-push (needs API key)

• For internal use:

https://prod-coco-up-read.ft.com/content/notifications-push (needs credentials)

https://prod-coco-up-read.ft.com/lists/notifications-push (needs credentials)