Running SBT as Daemon

Question

I have an SBT scala application that runs fine using "sbt run". However, this locks up the console, and I'd rather start it as a service/daemon so that I can use the console, and also so that I can add it to init.d to ensure that my application is started automatically on startup.

I can't seem to find a way to do this. Running "sbt run &" seems to hang the app in the background.

Does anybody know how to do this?

score 9 · Answer 1 · edited Sep 06 '17 at 18:05

9

You could also jar up your application into a "fat" jar using either sbt-assembly or sbt-onejar.

This will make it an executable jar and easily runnable via java -jar jarname.jar.

edited Sep 06 '17 at 18:05

charego

137
9

answered May 14 '11 at 15:16

Luke Amdor

91
2

I guess I was hoping this would be built into SBT so that I could skip the package step, but I'll look into these. – devinfoley May 16 '11 at 04:03

score 8 · Accepted Answer · answered May 16 '11 at 17:30

8

We launch test/demo apps with SBT in init.d all the time:

#!/bin/sh
# test lift web app

case "$1" in
'start')
    cd /home/demouser/wa/HTML5DemoLift231/HTML5demo/
    sbt jetty run
    ;;
'stop')
    cd /home/demouser/wa/HTML5DemoLift231/HTML5demo/
    sbt jetty stop
    ;;
*)
    echo "Usage: $0 { start | stop }"
    ;;
esac
exit 0

This just works - we have had no problems with it. It may be different with a non-web app though.

answered May 16 '11 at 17:30

Johan Prinsloo

1,188
9
9

Thanks. Changing this to the correct answer. This eliminates the package step and allows me to deploy faster. – devinfoley May 17 '11 at 14:59
5

It does starts but quits immediately. In my case I'm using sbt container:start. Any ideas? – Johnny Everson Feb 08 '12 at 15:38
1

Same here. It starts but then quits immediately. Any ideas? – Jack Mar 08 '12 at 14:52
2

@JhonnyEverson @JacobusR `sbt container:start shell` works around this by starting a command line shell after the container. But what's the correct way to do this? (Not use `sbt` directly, I suppose.) – wodow Oct 18 '13 at 21:49
@wodow That's really useful. You want to answer my question here: http://stackoverflow.com/questions/32544032/how-to-keep-sbt-running-after-executing-a-command/32544892?noredirect=1#comment52946920_32544892 – WestCoastProjects Sep 13 '15 at 05:01

score 6 · Answer 3 · answered May 14 '11 at 07:20

6

You can use GNU Screen for keeping it in background. Anyway I can't think a good reason to do that. Whouldn't it be better to package the application and run the generated binaries in the background?

answered May 14 '11 at 07:20

Rafa de Castro

2,474
1
24
44

3

A good reason would be have a remote development machine, where designers can just upload html files and don't have to restart the service. I don't know how to do that in a packaged app. – Johnny Everson Feb 08 '12 at 15:24
I didn't thought about that. Nice. – Rafa de Castro Feb 14 '12 at 10:39

score 2 · Answer 4 · answered Sep 21 '17 at 23:35

2

Just type sbt runProd And then press Ctrl+D The process will be running as a daemon process.

answered Sep 21 '17 at 23:35

Karan Sharma

475
1
5
16

Running SBT as Daemon

4 Answers4

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