Export HL7v2 messages to Pub/Sub

This page describes how to export HL7v2 messages to Pub/Sub using the projects.locations.datasets.hl7V2Stores.export method.

You can export HL7v2 messages to Pub/Sub for downstream processing. Suppose you have a Dataflow pipeline that transforms HL7v2 messages when new messages are ingested into an HL7v2 store. The pipeline reads from a Pub/Sub subscription and waits for notifications of new HL7v2 messages. When you import HL7v2 messages into an HL7v2 store using the hl7V2Stores.import method, the method doesn't send Pub/Sub notifications . To trigger the pipeline, import the HL7v2 messages and then use the hl7v2Stores.export method to export them to Pub/Sub.

Before you begin

Enable the Pub/Sub API

In the Google Cloud console, enable the Pub/Sub API:

Enable the API

Configure Pub/Sub permissions

To export messages from an HL7v2 store to Pub/Sub, you must add the pubsub.publisher role to your project's Cloud Healthcare Service Agent service account . See DICOM, FHIR, and HL7v2 store Pub/Sub permissions for steps to add the required role.

Create a Pub/Sub topic

To create a topic, see Create a topic .

Individual data stores can have their own Pub/Sub topic, or multiple data stores can share the same topic.

Use the following format when specifying the Pub/Sub topic:

projects/ PROJECT_ID 
/topics/ TOPIC_NAME

PROJECT_ID is your Google Cloud project ID and TOPIC_NAME is the name of the Pub/Sub topic.

Export HL7v2 messages to Pub/Sub

curl

To export HL7v2 messages to Pub/Sub, make a POST request and specify the following information:

The name of the parent dataset
The name of the HL7v2 store
The destination Pub/Sub topic

The following sample shows a POST request using curl .

curl  
-X  
POST  
 \ 
  
-H  
 "Authorization: Bearer 
 $( 
gcloud  
auth  
application-default  
print-access-token ) 
 " 
  
 \ 
  
-H  
 "Content-Type: application/json; charset=utf-8" 
  
 \ 
  
--data  
 "{ 
 'pubsubDestination': { 
 'pubsubTopic': 'projects/ PROJECT_ID 
/topics/ PUBSUB_TOPIC 
' 
 } 
 }" 
  
 "https://healthcare.googleapis.com/v1/projects/ PROJECT_ID 
/locations/ LOCATION 
/datasets/ DATASET_ID 
/hl7V2Stores/ HL7V2_STORE_ID 
:export"

If the request is successful, the server returns the response in JSON format:

{
  "name": "projects/ PROJECT_ID 
/locations/ LOCATION 
/datasets/ DATASET_ID 
/operations/ OPERATION_ID 
"
}

The response contains an operation name. To track the status of the operation, you can use the Operation get method :

curl  
-X  
GET  
 \ 
  
-H  
 "Authorization: Bearer 
 $( 
gcloud  
auth  
application-default  
print-access-token ) 
 " 
  
 \ 
  
 "https://healthcare.googleapis.com/v1/projects/ PROJECT_ID 
/locations/ LOCATION 
/datasets/ DATASET_ID 
/operations/ OPERATION_ID 
"

If the request is successful, the server returns a response with the status of the operation in JSON format:

{
  "name": "projects/ PROJECT_ID 
/locations/ LOCATION 
/datasets/ DATASET_ID 
/operations/ OPERATION_ID 
",
  "metadata": {
    "@type": "type.googleapis.com/google.cloud.healthcare.v1.OperationMetadata",
    "apiMethodName": "google.cloud.healthcare.v1.hl7v2.Hl7V2Service.ExportMessages",
    "createTime": " CREATE_TIME 
",
    "endTime": " END_TIME 
",
    "counter": {
      "success": " RESOURCE_COUNT 
"
    }
  },
  "done": true,
  "response": {
    "@type": "type.googleapis.com/google.cloud.healthcare.v1.hl7v2.ExportMessagesResponse"
  }
}

Export a subset of HL7v2 messages using a filter

You can use the following fields in your filter criteria:

startTime
endTime .

You can specify the following filter parameters as your filter criteria in the filter field. To learn the filter syntax and construct queries, see Query strings .

message_type : from the MSH.9.1 field. For example, NOT message_type = "ADT" .
send_date : the YYYY-MM-DD date the message was sent from the MSH.7 segment, specified in the time zone of the dataset. For example, send_date < "2017-01-02" .
send_time : the timestamp when the message was sent. This parameter is from the MSH.7 segment of the message. This parameter uses the RFC 3339 time format for comparisons. For example, send_time < "2017-01-02T00:00:00-05:00" .
create_time : the timestamp when the message was created in the Cloud Healthcare API, using the RFC 3339 time format for comparisons. For example: create_time < "2017-01-02T00:00:00-05:00" .
send_facility : the care center that the message came from, from the MSH.4 segment. For example, send_facility = "ABC" .

The following samples show how to specify a filter to only export HL7v2 messages of type ADT .

curl

curl  
-X  
POST  
 \ 
  
-H  
 "Authorization: Bearer 
 $( 
gcloud  
auth  
application-default  
print-access-token ) 
 " 
  
 \ 
  
-H  
 "Content-Type: application/json; charset=utf-8" 
  
 \ 
  
--data  
 "{ 
 'pubsubDestination': { 
 'pubsubTopic': 'projects/ PROJECT_ID 
/topics/ PUBSUB_TOPIC 
' 
 }, 
 'filter': 'message_type = \"ADT\"' 
 }" 
  
 "https://healthcare.googleapis.com/v1/projects/ PROJECT_ID 
/locations/ LOCATION 
/datasets/ DATASET_ID 
/hl7V2Stores/ HL7V2_STORE_ID 
:export"

View exported HL7v2 messages in Pub/Sub

To view the exported HL7v2 messages in Pub/Sub, run the gcloud pubsub subscriptions pull command. The command uses the --format=json flag to return the output as JSON instead of the default YAML.

gcloud  
pubsub  
subscriptions  
pull  
--auto-ack  
projects/ PROJECT_ID 
/subscriptions/ PUBSUB_SUBSCRIPTION 
  
 \ 
  
--format = 
json

PROJECT_ID is the ID of your Google Cloud project
PUBSUB_SUBSCRIPTION is the subscription attached to the Pub/Sub topic where you exported HL7v2 messages

The output is the following:

[
  {
    "ackId": " ACK_ID 
",
    "message": {
      "attributes": {
        "msgType": "TYPE"
      },
      "data": " DATA 
",
      "messageId": "8076570784126536",
      "publishTime": " YYYY-MM-DDTHH:MM:SS+ZZ:ZZ 
"
    }
  }
]