[Bug]: Post-hook script not triggered when stopping custom Docker container via Testcontainers due to trap signal not being invoked

[gurubabujampala]

Module

Core

Testcontainers version

1.20.6

Using the latest Testcontainers version?

Yes

Host OS

Windows

Host Arch

x86

Docker version

Client:
 Version:           27.5.1-rd
 API version:       1.45 (downgraded from 1.47)
 Go version:        go1.22.11
 Git commit:        0c97515
 Built:             Thu Jan 23 18:14:31 2025
 OS/Arch:           windows/amd64
 Context:           default

Server:
 Engine:
  Version:          26.1.5
  API version:      1.45 (minimum version 1.24)
  Go version:       go1.22.5
  Git commit:       411e817ddf710ff8e08fa193da80cb78af708191
  Built:            Fri Jul 26 17:51:06 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.7.17
  GitCommit:        3a4de459a68952ffb703bbe7f2290861a75b6b67
 runc:
  Version:          1.1.14
  GitCommit:        2c9f5602f0ba3d9da1c2596322dfc4e156844890
 docker-init:
  Version:          0.19.0
  GitCommit:

What happened?

I’ve implemented pre-hook and post-hook scripts for a custom Docker image. The intention is for the pre-hook to execute when the container starts, and the post-hook to run when the container stops. When I manually start and stop the container using the docker run command and terminate it with Ctrl+C, both hooks function correctly. However, when I run the same Docker image using Testcontainers, the post-hook doesn’t get triggered. I’ve configured a trap to catch SIGTERM, SIGINT, and EXIT signals to invoke the on_shutdown function as the post-hook, but it doesn’t appear to execute in the Testcontainers environment.
How can we make test container trap any SIGNAL to make post hook executed?

Relevant log output

Additional Information

`#!/bin/bash

MODE="$1"

Trap shutdown to send metrics

function on_shutdown() {
echo "🔌 $MODE container ..."
echo "📊 Logging to New Relic logs $MODE container..."
echo "✅ Post-hook complete."
}

-------- PRE-HOOK: TaaS Authentication --------

echo "🔐 Validating TaaS authentication for $MODE container."
echo "✅ Authentication successful for $MODE container."

if [ "$MODE" == "test" ] || [ "$MODE" == "stub" ]; then
trap on_shutdown SIGTERM SIGINT EXIT

echo "Running in $MODE mode..."
echo "🚀 Executing Specmatic with args : $@"
exec java -jar /app.jar "$@"
exit_code=$?
echo "Exiting with code: $exit_code"
else
echo "Unknown MODE: $MODE. Use 'test' or 'stub'."
exit 1
fi

Below is the Dockerfile configuration:
FROM myapp_image:latest
RUN apk add --no-cache tini bash
COPY script.sh /entrypoint-wrapper.sh
RUN chmod +x /entrypoint-wrapper.sh
ENTRYPOINT ["/sbin/tini", "--", "/entrypoint-wrapper.sh"]

Below is Container configuration in my SpringBoot application
GenericContainer<?> specmaticProductStubContainer = new FixedHostPortGenericContainer<>("myapp_image:latest")
.withLabel("name", "product-stub-container")
.withCommand("stub", "--examples=examples", "--port=" + PRODUCT_STUB_PORT)
.withFixedExposedPort(PRODUCT_STUB_PORT, PRODUCT_STUB_PORT)
.withLogConsumer(outputFrame -> System.out.print(outputFrame.getUtf8String()))
.waitingFor(Wait.forListeningPort())
.withStartupTimeout(Duration.ofSeconds(30));
`