I’m one of the developers of our Slack application. OpsGenie Community is a great place to reach our engineers, so thanks for using this channel!
Glad you asked this one. First of all, let me answer your question. Currently, there is no easy way to do this. We only sent messages to the channel that our app is installed, and there is no way to modify the message we sent to Slack (modify policy can be used to change the alert’s fields. But it won’t do it just for Slack, so it is a hacky solution).
Considering alerts are assigned to teams, not users, we think it is best to use different channels for different teams. Did you know you can assign integrations to teams? (https://www.opsgenie.com/docs/getting-started/team-segmentation)
Sending private messages to users when they are assigned to alerts is something I’ve been thinking for a while now. I’m creating an issue for this one!
About modifying Slack messages, we already have a feature request for this one. This is something we think in general as well. For both of these issues, they are definitely on our roadmap but may not be done in the short term.
As a note: if you would like to create an AWS Lambda function between OpsGenie and Slack to do what you want here there are some examples & libraries you can use;
https://github.com/johnagan/serverless-slack-app (an easy way to build a serverless Slack app)
https://github.com/opsgenie/slack-to-opsgenie-alert-creator (outgoing integration example)
https://github.com/opsgenie/opsgenie-nodejs-sdk (we have SDK’s for Java, Go and Python as well)
Let me know if you need anything else!