[SPIKE] Figure out the responsibility between express middleware and LB4 routing and sequencing

[hacksparrow]

Description / Steps to reproduce / Feature proposal

Mount LB4 apps (REST servers) as Express (and Express-compatible) middleware

Current Behavior

None

Expected Behavior

#1082 (comment)

Acceptance Criteria

LB4 apps should be mountable as Express or Express-compatible middleware.

• Figure out how to have everything before and after the REST routing handled by express http transport-wise
• blocked by Change (req, res) pair to a single http context object #1292 and Allow app developers to configure custom Express middleware #1293

timeboxed to 1 week

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[shimks]

Technically, the acceptance criteria is already done. @hacksparrow Would you consider the issue non-relevant or do you have specific items in mind that allow express-specific aspects to be compatible with lb4?

@hacksparrow @bajtos @raymondfeng Please hash out the acceptance criteria with more details to how much we want express to be used in lb4.

EDIT: turning this into a spike

[bajtos]

For DP3, we agreed with @raymondfeng that we are not going to expose Express routing/middleware to app developers yet. I am removing this story from DP3 release and epic.