sbt immediately stops when running in docker container - docker

Question

I'm trying to set up our project to use Docker. I've created an image based on this image: https://github.com/mozilla/docker-sbt.
The command in my docker-compose.yml file is:
sbt -J-XX:MaxMetaspaceSize=500m -Dlogger.file=conf/dev-logback.xml -Dconfig.file=$dev -Dhttp.port=$srfPort -Dhttps.port=9443 -Djdbcdslog.showTime=true -J-Dakka.http.parsing.max-uri-length=16k run
(this command works in the non-docker environment.)
Below is the output of docker-compose up. Notice that right after it starts it says "Stopping server...". When I watch the console I notice that there is no pause between the "Listening" line and the "stopping" line.
[info] Loading settings for project my-project from build.sbt ...
[info] Set current project to my-project (in build file:/home/my-name/my-project/app/)
--- (Running the application, auto-reloading is enabled) ---
[info] p.c.s.AkkaHttpServer - Listening for HTTP on /0.0.0.0:9000
[info] p.c.s.AkkaHttpServer - Listening for HTTPS on /0.0.0.0:9443
(Server started, use Enter to stop and go back to the console...)
[info] p.c.s.AkkaHttpServer - Stopping server...
[warn] StaticRoutesGenerator is deprecated. Please use InjectedRoutesGenerator or a custom router instead.
[warn] For more info see https://www.playframework.com/documentation/2.6.x/JavaRouting#Dependency-Injection
[warn] StaticRoutesGenerator is deprecated. Please use InjectedRoutesGenerator or a custom router instead.
[warn] For more info see https://www.playframework.com/documentation/2.6.x/JavaRouting#Dependency-Injection
2020-04-07 21:32:10,984~[WARN]~Logger configuration in conf files is deprecated and has no effect. Use a logback configuration file instead.~
2020-04-07 21:32:14,313~[INFO]~Slf4jLogger started~
2020-04-07 21:32:15,413~[INFO]~Database [default] initialized at jdbc:mysql://srf_db:3306/srf2?socketTimeout=10000&verifyServerCertificate=false&useSSL=false&requireSSL=false~
2020-04-07 21:32:15,481~[INFO]~Creating Pool for datasource 'default'~
2020-04-07 21:32:15,514~[INFO]~HikariPool-1 - Starting...~
2020-04-07 21:32:16,066~[INFO]~HikariPool-1 - Start completed.~
2020-04-07 21:32:40,261~[INFO]~Application started (Dev)~
2020-04-07 21:32:40,319~[INFO]~Shutting down connection pool.~
2020-04-07 21:32:40,334~[INFO]~HikariPool-1 - Shutdown initiated...~
2020-04-07 21:32:40,366~[INFO]~HikariPool-1 - Shutdown completed.~
[success] Total time: 140 s (02:20), completed Apr 8, 2020 1:32:40 AM
I have no idea where to look for the error or what the nature of the error could be: a missing file? a missing folder? a missing dependency? a missing setup command? permission error?
I am at a loss for how to debug further. If you have any guesses about where to look, it would be greatly appreciated.
[edit]
Thanks to a hint from cbley below, I figured out what my docker-compose.yml file needs to look like:
sbt:
image: my-image
stdin_open: true
tty: true
depends_on:
- db
environment:
- MYSQL_HOST=db
- USER
volumes:
- ./:/home/docker1/
command: bash -c "sbt etc..."
ports:
- "9000:9000"
- "9443:9443"
Notice the added stdin_open and tty lines.

Answer 1

When running a Play service interactively (in development mode), it waits for the user to press Enter.
When inside the container, standard input is not connected to a TTY and thus the read from standard input fails immediately which causes the server to stop, which also exits SBT since the run task was the only one.
You can build a Docker image from your Play service by running sbt docker:publishLocal. (there's no need to have SBT inside the container)