From baa65b8155aa21468650f5859c4dc42ece478a6b Mon Sep 17 00:00:00 2001 From: Benjamin Porter Date: Wed, 3 Jan 2024 13:55:43 -0700 Subject: [PATCH] Add tini as PID 1 handler in container image This PR adds `tini` to the container image and uses it as PID 1 when starting the container. This ensures that proper PID 1 signal-handling is implemented and passed to the underlying node.js process, thereby ensuring that the ABS process has a chance to receive and handle signals other than `SIGKILL`, such as the important `SIGINT`. This is somewhat related to #2445 . Without this, the signal handled by 2445 won't be received when running in a container. Some background: In linux, PID 1 has special duties involving signal handling that are different than other processes. Node doesn't properly handle these signals, which can lead to a number of problems ranging from annoying to disruptive. PID 1 also has reaping duties that can lead to resource exhaustion if not properly handled. For example, the container ignores `SIGINT` (Ctrl+C) as well as `docker stop`, which can be annoying in development as you have to kill or wait for the timeout to be reached. In a production environment (such as Kubernetes) this can lead to signal escalation and unnecessarily adds delays to deployments and restarts as K8s has to wait for the timeout to be reached before sending `SIGKILL`. At best this is annoying and unnecessarily adds delays. At worst this can lead to file/data corruption as the process doesn't get a chance to clean anything up when it is sent `SIGKILL`. Without a proper PID 1 to forward signals, only SIGKILL can be used to terminate the running process. --- Dockerfile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Dockerfile b/Dockerfile index 25472000..943fc567 100644 --- a/Dockerfile +++ b/Dockerfile @@ -18,7 +18,8 @@ RUN apk update && \ ffmpeg \ make \ python3 \ - g++ + g++ \ + tini COPY --from=tone /usr/local/bin/tone /usr/local/bin/ COPY --from=build /client/dist /client/dist @@ -31,4 +32,5 @@ RUN apk del make python3 g++ EXPOSE 80 +ENTRYPOINT ["tini", "--"] CMD ["node", "index.js"]