What to do when useradd is not available?

[mrubin]

I am upgrading from Play Framework 2.6.x to 2.7.x. I use sbt docker:publishLocal to create docker images. The sbt-native-packager that is being used by Play 2.7.x now introduces an demiourgos728 user instead of using a daemon user and is using useradd during docker build time. The base image I'm using (https://hub.docker.com/_/amazoncorretto) does not have useradd. What should I do in this case? Why was the approach changed from using the daemon user and not doing all the weird stuff with useradd?

Information

• What sbt-native-packager are you using: Whatever comes with Play 2.7.1
• sbt: 1.2.8
• What is your build system: MacOS
• What package are you building: docker
• Docker version: 19.03.2
• What is your target system: Amazon Linux

[mrubin]

Updating to latest sbt-native-packager, as opposed to using an older version that's referenced out of the box by Play 2.7.1, gets around this issue.