devcontainer support

[tanishiking]

https://discord.com/channels/632642981228314653/632652693013528589/1025235279675674624

Tin — Today at 11:38 AM
👋  hello, I'm trying to add scalameta.metals inside a devcontainer and keep running into this issue:
2022.09.30 02:16:07 ERROR Failed to connect with build server, no functionality will work.java.lang.RuntimeException: The server did not start, got FailedToOpenBspConnection
    at bloop.launcher.LauncherMain.failPromise$1(Launcher.scala:92)

I made sure that I have Java in my PATH and the correct JAVA_HOME but since I'm new to Scala I have no idea where to go from there. Any pointer is appreciated 🙏

Tomasz Godzik — Today at 3:29 PM
Looks like the build server didn't start. Do you have any more logs than that? Alternatively, you could try running switch build server command if you are running mill or sbt

Tin — Today at 3:42 PM
Mainly it complains about waiting for the bsp connection
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR error: Giving up on waiting for a connection, printing embedded bloop logs:
2022.09.30 05:53:55 ERROR > No server running at 127.0.0.1:8212, let's fire one...
2022.09.30 05:53:55 ERROR > Resolving ch.epfl.scala:bloop-frontend_2.12:1.5.3...
2022.09.30 05:53:55 ERROR error: Trying a tcp-based connection to the server instead...
2022.09.30 05:53:55 ERROR Opening a bsp server connection with 'bsp --protocol tcp --port 44889'...
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR Waiting for the bsp connection to come up...
2022.09.30 05:53:55 ERROR error: The command bsp --protocol local --socket /tmp/bsp-launcher13842463928997524577/bsp.socket returned with an error
2022.09.30 05:53:55 ERROR > No server running at 127.0.0.1:8212, let's fire one...
2022.09.30 05:53:55 ERROR > Resolving ch.epfl.scala:bloop-frontend_2.12:1.5.3...
2022.09.30 05:53:55 ERROR error: The launcher failed to establish a bsp connection, aborting...
2022.09.30 05:53:55 ERROR Failed to connect with build server, no functionality will work.java.lang.RuntimeException: The server did not start, got FailedToOpenBspConnection
    at bloop.launcher.LauncherMain.failPromise$1(Launcher.scala:92)
    at bloop.launcher.LauncherMain.runLauncher(Launcher.scala:119)

I'm not particularly running any command, I was hoping the "extensions":['scalameta.metals'] in the .devcontainer.json would be enough to start the bsp server.

tanishiking — Today at 3:53 PM
Are you trying to run Metals in container? I've never tried devcontainer feature, but do you see any logs from the container? 

Tin — Today at 3:57 PM
Yes, ideally want to have metals running in the workspace without having to install it manually in every new environment. I can't find any relevant logs inside the container all I see is the metals.log that gets mounted from the workspace into the container

Tomasz Godzik — Today at 3:59 PM
Is there anything in the logs after the exception?
Maybe you could specify java home explicitly in the metals settings?
That should not be needed but I am not sure why we would be getting the exception
Looks like we are unable to start the process of the build server

tanishiking — Today at 4:01 PM
I guess something has failed (downloading something, or launching something) in container, and there's log from the container, but not sure

Tin — Today at 4:02 PM
No, the exception is the last thing. From the FAQ that exception was either by missing the Java home or not having Java in the PATH so I made sure they were there.
Where would I find such a log?

tanishiking — Today at 4:03 PM
I'm not sure how you setup the container, but something like docker logs
Maybe I wanna challenge myself setting up Metals using devcontainer 💪

Tin — Today at 4:09 PM
ok, found the container log but nothing relevant seems to be going on in there
[40098 ms] [05:52:17] Extension installed successfully: scala-lang.scala
[40099 ms] [05:52:17] Extension installed successfully: scalameta.metals
[40100 ms] Extension 'scalameta.metals' v1.19.0 was successfully installed.

tanishiking — Today at 4:13 PM
is it possible to share Dockerfile, docker-compose.yml, and devcontainer.json ? 
Tin — Today at 4:16 PM
devcontainer is pretty short:
{
  "name": "Test",
  "build": {
    "dockerfile": "Dockerfile"
  },
    "remoteUser": "dev",
  "mounts": [
    "type=bind,source=${localEnv:HOME}/.ivy2,target=/root/.ivy2",
    "type=bind,source=${localEnv:HOME}/.sbt,target=/root/.sbt"
  ],
  "extensions": [
    "scalameta.metals"
  ],
  "forwardPorts": [3000, 8080, 9040],
    "settings": {
        "terminal.integrated.defaultProfile.linux": "zsh"
    }
}
dockerfile:
FROM eclipse-temurin:11-alpine

ARG USERNAME=dev
ARG USER_UID=1000
ARG USER_GID=$USER_UID
COPY library-scripts/*.sh library-scripts/*.env /tmp/library-scripts/
RUN apk update && ash /tmp/library-scripts/common-alpine.sh "${INSTALL_ZSH}" "${USERNAME}" "${USER_UID}" "${USER_GID}" \
    && rm -rf /tmp/library-scripts

ARG SCALA_VERSION=2.12.4
ARG SBT_VERSION=1.7.1

ENV SCALA_HOME=/usr/share/scala

RUN cd /opt/ && \
    wget -O sbt-$SBT_VERSION.tgz https://github.com/sbt/sbt/releases/download/v$SBT_VERSION/sbt-$SBT_VERSION.tgz && \
    tar -xvzf sbt-$SBT_VERSION.tgz && \
    chmod +x sbt/bin/sbt && \
    ln -s /opt/sbt/bin/sbt /usr/local/bin/ && \
    echo "DONE"

USER dev

tanishiking — Today at 4:23 PM
Thanks! let me try setting up devcontainer, but it may take some time (maybe try in my weekend) so hold tight.
~One thing I noticed was the SCALA_VERSION is pretty old, what happens if you update it to 2.12.16? ~~nevermind, it looks unused 

[tanishiking]

I wanted to try devcontainer this weekend but didn't have time

[tanishiking]

I found a good example repository for setting up devcontainer for Scala (Metals)
https://github.com/yokra9/vscode-dev-containers-scala-sbt/tree/master/sample Also, here's a blog post explaining it (Japanese, but can read it with Google translate:+1:) kudos to @yokra9