Embed version information into Docker containers and display on startup

[Copilot]

Containers now display the exact Git version at startup, enabling users to identify which code version was used in a run.

Changes

• Dockerfiles (sim/Dockerfile, endpoint/Dockerfile):

  • Added ARG VERSION=unknown build argument
  • Persist version to /version.txt during build

• Startup scripts (sim/run.sh, endpoint/run_endpoint.sh):

  • Display version at startup: QUIC Network Simulator version: <version>

• GitHub Actions (.github/workflows/build-docker-images.yml):

  • Extract Git version: git describe --tags --always --dirty (fallback: git rev-parse --short HEAD)
  • Pass as VERSION build arg to both images

Example output

QUIC Network Simulator version: 30a49c7
Using scenario: simple-p2p --delay=15ms --bandwidth=10Mbps

Version format: tags (v1.0.0), commit hashes (30a49c7), or unknown if not provided during build.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>embed version information into the Docker container, output it when starting up</issue_title> <issue_description>This way, we could exactly see which code version was used in a run.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes quic-interop/quic-network-simulator#138

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.