Supported `ordering key` in googlecloudpubsub exporter

[brandonbirdj]

Component(s)

exporter/googlecloudpubsub

Is your feature request related to a problem? Please describe.

Allow for ordered messages to be published to pubsub

Describe the solution you'd like

Add new support for field ordering key in exporter

Ordering keys can be used like this in pubsub. I propose we configure an attribute to contain the key used for the exporter.

Messages: []*pubsubpb.PubsubMessage{
			{
				Attributes: attributes,
				Data:       data,
				OrderingKey: attributes["OrderingKey"],
			},
		},

The name of the attribute would be configured in the exporter like so.

exporters:
  googlecloudpubsub:
    project: abc
    endpoint: mytestendpoint
    user_agent: projects/abc/topics/requests
    ordering_key_attribute: OderingKey 

Describe alternatives you've considered

na

Additional context

https://cloud.google.com/pubsub/docs/ordering

https://medium.com/google-cloud/google-cloud-pub-sub-ordered-delivery-1e4181f60bc8

[github-actions]

Pinging code owners:

• exporter/googlecloudpubsub: @alexvanboxel

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[alexvanboxel]

Funny, it was already on my planned short list; this can be assigned to me.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• exporter/googlecloudpubsub: @alexvanboxel

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[alexvanboxel]

still planned, don't close

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• exporter/googlecloudpubsub: @alexvanboxel

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.