Thanks Ahmet. Looking at the source code, with my untrained python eyes, I 
think if the intention is to include the message id and the publish time in the 
attributes attribute of the PubSubMessage type, then the protobuf mapping is 
missing something:-


@staticmethod
def _from_proto_str(proto_msg):
"""Construct from serialized form of ``PubsubMessage``.

Args:
proto_msg: String containing a serialized protobuf of type
https://cloud.google.com/pubsub/docs/reference/rpc/google.pubsub.v1#google.pubsub.v1.PubsubMessage

Returns:
A new PubsubMessage object.
"""
msg = pubsub.types.pubsub_pb2.PubsubMessage()
msg.ParseFromString(proto_msg)
# Convert ScalarMapContainer to dict.
attributes = dict((key, msg.attributes[key]) for key in msg.attributes)
return PubsubMessage(msg.data, attributes)

The protobuf definition is here:-

https://cloud.google.com/pubsub/docs/reference/rpc/google.pubsub.v1#google.pubsub.v1.PubsubMessage

and so it looks as if the message_id and publish_time are not being parsed as 
they are seperate from the attributes. Perhaps the PubsubMessage class needs 
expanding to include these as attributes, or they would need adding to the 
dictionary for attributes. This would only need doing for the _from_proto_str 
as obviously they would not need to be populated when transmitting a message to 
PubSub.

My python is not great, I'm assuming the latter option would need to look 
something like this?

attributes = dict((key, msg.attributes[key]) for key in msg.attributes)
attributes.update({'message_id': msg.message_id, 'publish_time': 
msg.publish_time})
return PubsubMessage(msg.data, attributes)

On Wed, 2019-07-24 at 10:01 -0700, Ahmet Altay wrote:
This message originated from outside your organization
________________________________
No, I do not see any issues with the code you posted on stackoverflow. It might 
very well be an issue with Beam.

+Udi Meiri<mailto:[email protected]> is the author of this code, might have an 
idea.

On Wed, Jul 24, 2019 at 9:47 AM Matthew Darwin 
<[email protected]<mailto:[email protected]>> 
wrote:
Thanks Ahmet, I'm aware of the documentation and what should be happening, 
however, as you can see in the example I posted on stackoverflow, this does not 
appear to be the case, hence my question here! If there are any glaring issues 
with my code, I'd be grateful if you could point them out.

On Wed, 2019-07-24 at 09:16 -0700, Ahmet Altay wrote:
This message originated from outside your organization
________________________________
When with_attributes is set to True, the elements will be of type PubsubMessage 
[1]. I could not find a test/example for this, but documentation suggests [2], 
PubsubMessage will have an attributes map including the system provided values. 
One of those keys will be message_id [3].

[1] 
https://github.com/apache/beam/blob/a5ed104aeac91781492523808fa4d3df6f2e55f7/sdks/python/apache_beam/io/gcp/pubsub.py#L156
[2] 
https://github.com/apache/beam/blob/a5ed104aeac91781492523808fa4d3df6f2e55f7/sdks/python/apache_beam/io/gcp/pubsub.py#L94
[3] 
https://cloud.google.com/pubsub/docs/reference/rpc/google.pubsub.v1#google.pubsub.v1.PubsubMessage

On Wed, Jul 24, 2019 at 6:23 AM Matthew Darwin 
<[email protected]<mailto:[email protected]>> 
wrote:
Thank you both for you replies; apologies for the delay in responding, I was 
away from my machine over the weekend.

I'm still a bit confused over how the message id from PubSub is exposed.

From the documentation, I was expecting the PubSub message id to be in the 
attributes property of the message; but when running this into BigQuery as a 
string, the only properties are those that I pass in to my PubSub message as 
attributes. None of the examples you've linked use the with_attributes flag, 
unfortunately.

I've posted the code and output onto stackoverflow:- 
https://stackoverflow.com/questions/57183876/how-do-you-access-the-message-id-from-google-pub-sub-using-apache-beam

Secondly, is the 2.14 release available for preview?


Release candidate is not out yet. This will happen soon (~this week) and you 
can watch dev@ for this. If it makes sense for your case, you can also build 
yourself from head and test it out.


Kind regards,

Matthew


On Fri, 2019-07-19 at 13:22 -0700, Valentyn Tymofieiev wrote:
This message originated from outside your organization
________________________________
Also, see 
https://github.com/apache/beam/blob/master/sdks/python/apache_beam/examples/complete/game/leader_board.py
 which involves both PubSub and Bigquery IOs.

On Fri, Jul 19, 2019 at 12:31 PM Pablo Estrada 
<[email protected]<mailto:[email protected]>> wrote:
Beam 2.14.0 will include support for writing files in the fileio module (the 
support will include GCS, local files, HDFS). It will also support streaming. 
The transform is still marked as experimental, and is likely to receive 
improvements - but you can check it out for your pipelines, and see if it helps 
you : )
Best
-P.

On Fri, Jul 19, 2019 at 12:24 PM Valentyn Tymofieiev 
<[email protected]<mailto:[email protected]>> wrote:
As of today, Beam Python streaming does not support writing to GCS yet,  which  
explains 
https://stackoverflow.com/questions/54745869/how-to-create-a-dataflow-pipeline-from-pub-sub-to-gcs-in-python
 .

You are right - id_label and timestamp_attribute does not work on Direct runner 
yet as per https://issues.apache.org/jira/browse/BEAM-4275, I checked with a 
few folks and that seems to be the current status, but you can still give them 
a try on Dataflow runner.

You may also find the following examples helpful:

https://github.com/apache/beam/blob/master/sdks/python/apache_beam/examples/streaming_wordcount.py
  (streaming pipeline).
https://github.com/apache/beam/blob/master/sdks/python/apache_beam/examples/cookbook/bigquery_tornadoes.py
 (batch pipeline)
https://stackoverflow.com/questions/46854167/dataflow-streaming-using-python-sdk-transform-for-pubsub-messages-to-bigquery-o.

On Mon, Jul 15, 2019 at 2:12 AM Matthew Darwin 
<[email protected]<mailto:[email protected]>> 
wrote:
Hi Valentyn,

Thank you for your reply. I'm already using the with_attributes=True option, 
however this returns the attributes property of the JSON, i.e :-

{
      "attributes": {
        "source": "python"
      }



My pipeline currently looks like this (id_label is commented out when running 
directly, as it causes a not implemented error):-

messages = (p
| 'Read From Pub Sub' >> 
ReadFromPubSub(subscription=known_args.input_subscription,with_attributes=True)#,id_label='message_id')
| 'Parse JSON' >> beam.Map(format_message_element)

My function to parse the message looks like this:-

def format_message_element(message, timestamp=beam.DoFn.TimestampParam):
messagedict = json.loads(message.data)
rownumber = messagedict['rownumber']
fullmessage = {'data' : json.dumps(message.data),
'rownumber' : int(rownumber),
'attributes' : json.dumps(message.attributes),
'timestamp' : float(timestamp)}

logging.info<http://logging.info>(message.attributes)
logging.info<http://logging.info>(message)

return (rownumber, fullmessage)

I'm aware there are the id_label and with_timestamp parameters for the 
ReadFromPubSub method, however, these don't seem to work with the direct 
runner, as per 
https://issues.apache.org/jira/browse/BEAM-4275?jql=text%20~%20%22python%20id_label%22
 which makes testing somewhat difficult.

My full code is attached, when running above 2.9.0 of the SDK I can't get 
passed the windowing function, due to an issue that appears related to this 
https://stackoverflow.com/questions/54745869/how-to-create-a-dataflow-pipeline-from-pub-sub-to-gcs-in-python
 and this 
https://stackoverflow.com/questions/55109403/apache-beam-python-sdk-upgrade-issue
 as I was receiving the following error when running on 2.12.0:

Cannot convert GlobalWindow to 
apache_beam.utils.windowed_value._IntervalWindowBase [while running 
'generatedPtransform-150']

On 2.9.0 when running on the local runner, I receive the following output from 
the logging.info<http://logging.info> calls in format_message_element:

INFO:root:{u'source': u'python'}
INFO:root:PubsubMessage({"rownumber": 1}, {u'source': u'python'})

I was expecting the messageId and publishTime as part of the object returned; 
but as you can see there's nothing there for those attributes.

(The code does not quite map correctly to the BigQuery table so it fails 
inserts at that point, which I'm currently trying to resolve!)

Kind regards,

Matthew



On Fri, 2019-07-12 at 09:13 -0700, Valentyn Tymofieiev wrote:
This message originated from outside your organization
________________________________
Hi Matthew,

Welcome to Beam!

Looking at Python PubSub IO API, you should be able to access id and timestamp 
by setting `with_attributes=True` when using `ReadFromPubSub` PTransform, see 
[1,2].

[1] 
https://github.com/apache/beam/blob/0fce2b88660f52dae638697e1472aa108c982ae6/sdks/python/apache_beam/io/gcp/pubsub.py#L61
[2] 
https://github.com/apache/beam/blob/0fce2b88660f52dae638697e1472aa108c982ae6/sdks/python/apache_beam/io/gcp/pubsub.py#L138

On Fri, Jul 12, 2019 at 1:36 AM Matthew Darwin 
<[email protected]<mailto:[email protected]>> 
wrote:
Good morning,

I'm very new to Beam, and pretty new to Python so please first accept my 
apologies for any obvious misconceptions/mistakes in the following.

I am currently trying to develop a sample pipeline in Python to pull messages 
from Pub/Sub and then write them to either files in cloud storage or to 
BigQuery. The ultimate goal will be to utilise the pipeline for real time 
streaming of event data to BigQuery (with various transformations) but also to 
store the raw messages long term in files in cloud storage.

At the moment, I'm simply trying to parse the message to get the PubSub 
messageId and publishTime in order to be able to write them into the output. 
The json of my PubSub message looks like this:-

[
  {
    "ackId": 
"BCEhPjA-RVNEUAYWLF1GSFE3GQhoUQ5PXiM_NSAoRRIICBQFfH1xU1t1Xl8aB1ENGXJ8Zyc_XxcIB0BTeFVaEQx6bVxXOFcMEHF8YXZpWhUIA0FTfXeq5cveluzJNksxIbvE8KxfeqqmgfhiZho9XxJLLD5-PT5FQV5AEkw2C0RJUytDCypYEU4",
    "message": {
      "attributes": {
        "source": "python"
      },
      "data": "eyJyb3dudW1iZXIiOiAyfQ==",
      "messageId": "619310330691403",
      "publishTime": "2019-07-12T08:27:58.522Z"
    }
  }
]
According to the 
documentation<https://beam.apache.org/releases/pydoc/2.13.0/apache_beam.io.gcp.pubsub.html>
 the PubSub message payload returns the data and attributes properties; is 
there simply no way of retrieving the messageId and publishTime, or are these 
exposed somewhere else? If not, will the inclusion of these be in the roadmap, 
and are they available if using Java (I have zero Java experience hence why 
reaching for Python first).

Kind regards,

Matthew




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