Add Dockerfile

[tanishiking]

#6

I'm also interested in build and running this app in container and deploy it to somewhere like CloudRun 😃

• ./build-image.sh should archive the project and build it in docker container just docker build .

• docker run ember-app to run the server in http://localhost:8080

• However, the server gonna crash with the segmentation fault on receive the request and the container would hang. fixed

outdated

# Checking the process dies with segmentation fault in container
$ docker run -it ember-app:latest bash
root@5ef5f705125b:/app# apt update
...
root@5ef5f705125b:/app# apt install curl gdb -y
...
# Enable core dump
root@5ef5f705125b:/app# ulimit -c unlimited
root@5ef5f705125b:/app# cat /proc/sys/kernel/core_pattern
core

root@5ef5f705125b:/app# ./app &
[1] 2695
root@5ef5f705125b:/app# Starting Ember Example

root@5ef5f705125b:/app# curl http://localhost:8080
curl: (56) Recv failure: Connection reset by peer
[1]+  Segmentation fault      ./app

root@5ef5f705125b:/app# gdb app core
GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git
...
(No debugging symbols found in app)
[New LWP 2706]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
Core was generated by `./app'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00000000012debb4 in _SM42epollcat.unsafe.EventNotificationCallback$D7fromPtrL28scala.scalanative.unsafe.PtrL41epollcat.unsafe.EventNotificationCallbackEO ()
(gdb) backtrace
#0  0x00000000012debb4 in _SM42epollcat.unsafe.EventNotificationCallback$D7fromPtrL28scala.scalanative.unsafe.PtrL41epollcat.unsafe.EventNotificationCallbackEO ()
#1  0x0000000000bbe7f0 in _SM38epollcat.unsafe.EpollExecutorSchedulerD4pollL34scala.concurrent.duration.DurationzEO ()
#2  0x0000000000c78df0 in _SM43cats.effect.unsafe.PollingExecutorSchedulerD4loopuEPT43cats.effect.unsafe.PollingExecutorScheduler ()
#3  0x0000000000c786cc in _SM43cats.effect.unsafe.PollingExecutorSchedulerD27scheduleIfNeeded$$anonfun$1uEPT43cats.effect.unsafe.PollingExecutorScheduler ()
#4  0x0000000000a5817c in _SM53cats.effect.unsafe.PollingExecutorScheduler$$Lambda$2D3runuEO ()
#5  0x00000000012071a4 in _SM43scala.scalanative.runtime.ExecutionContext$D4loopuEO ()
#6  0x0000000000ee8c4c in _SM34scala.scalanative.runtime.package$D4loopuEO
    ()
#7  0x0000000000d597b8 in main ()

Any ideas? FYI @armanbilge

[tanishiking]

Oh, wait. Once I upgraded the epollcat and http4s servers, it worked 🎉

[armanbilge]

@tanishiking thanks for working on this!

FYI epollcat is heading towards deprecation, see armanbilge/epollcat#99.

Instead I recommend using this pre-release of FS2, then you can use IOApp instead of EpollApp.

• I/O polling typelevel/fs2#3240 (comment)

[tanishiking]

@armanbilge Thanks! awesome, I gonna check it out later 🎉

[armanbilge]

Also might be of interest: https://github.com/buntec/minimal-scala-native-http4s-server-app/

[armanbilge]

Instead of doing this it would be interesting if we could statically link openssl during the build process so we don't need to install it. This seems to be very challenging to do with the @link annotations unfortunately. That's why I think I intend to remove them in the next significant wave of releases.

[tanishiking]

One last thing I'm struggling with is that I'm not familiar with TLS and s2n, and couldn't make it work correctly 🤔
When I run curl http://localhost:8080/joke the server gonna returns 500 because of fs2.io.net.tls.S2nException: Certificate is untrusted.

Maybe it's better to focus on finishing it without s2n for now like https://github.com/buntec/minimal-scala-native-http4s-server-app/

[armanbilge]

One last thing I'm struggling with is that I'm not familiar with TLS and s2n, and couldn't make it work correctly 🤔
When I run curl http://localhost:8080/joke the server gonna returns 500 because of fs2.io.net.tls.S2nException: Certificate is untrusted.

Do you need to install ca-certificates maybe to fix that?

[tanishiking]

Ah, that's the case 😅 thanks!

[armanbilge]

btw ... 😂 I just remembered we also have another example repository. might be interesting to look at.

• scala-cli + distroless sndocker-test#3