Consolidate tool Dockerfiles into a single multi-stage Dockerfile

[Copilot]

Each tool's Dockerfile independently ran a full Maven build, preventing Docker from caching shared build work across tools.

Changes

• New root-level Dockerfile with the following stages:

  • mavenbuilder – single mvn clean install -Pall over the entire services/ directory; all tool service stages copy from this one cached layer
  • staticbuild-{emf,emfatic,ocl,conversion,xtext} – per-tool npm/webpack frontend builds
  • toolservice-{emf,emfatic,ocl,conversion,xtext} – final runtime images (nginx or tomcat) pulling from the shared Maven stage and the tool-specific static build; each stage copies only the Maven module folders required for that tool

• Removed old per-tool Dockerfiles (static.emf/Dockerfile, static.emfatic/Dockerfile, static.ocl/Dockerfile, static.conversion/Dockerfile, xtext/Dockerfile, xtext/static.xtext/Dockerfile) — these are now superseded by the central Dockerfile

• Updated README.md with a new "Building Tool Docker Images" section documenting how to build each tool service using --target

Usage

Target the relevant stage when building, e.g.:

docker build --target toolservice-emf      -t emf-tool      .
docker build --target toolservice-emfatic  -t emfatic-tool  .
docker build --target toolservice-ocl      -t ocl-tool      .
docker build --target toolservice-conversion -t conversion-tool .
docker build --target toolservice-xtext    -t xtext-tool    .

The central Dockerfile requires the build context to be the repository root. Updating the main docker-compose to target these stages is a follow-up in a separate repository.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Improve tool Docker file performance</issue_title>
<issue_description>The docker files for the various tools (/static.xxx/Dockerfile) re-run Maven repeatedly. The way this is currently written, docker has no way to identify that parts of this build are redundant.

Instead, we should have just one staged-build Dockerfile for all tool services. This would start with a stage that builds all tools in one Maven call and then we would have separate stages for building each tool, copying the required information as and when. In the main docker-compose file, we then call the appropriate stage in this central Dockerfile instead of using a separate Dockerfile for each tool.

This way, Maven has to run once and the results can then be cached by Docker across all tools. </issue_description>

<agent_instructions>Make a first refactoring of all the relevant Dockerfiles into one central Dockerfile. Ignore the comment about the central docker-compose file, which is in a separate repository and needs a separate PR there.</agent_instructions>

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

• Fixes Improve tool Docker file performance #110

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[Copilot]

Pull request overview

This PR introduces a single root-level multi-stage Dockerfile that centralizes the Maven build for all tool services and then produces separate final images per tool by targeting different stages.

Changes:

• Adds a root Dockerfile with a shared mavenbuilder stage that builds all tool modules with -Pall.
• Adds per-tool frontend build stages (EMF, Emfatic, OCL, Conversion, Xtext) and per-tool final service stages.
• Updates service stages to copy only the Maven module folders needed for each tool (mirroring the original per-tool profile module sets).

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[szschaler]

Works in principle (tested on staging via mdenet/educationplatform-docker#83). Outstanding tasks before merge:

• Carefully compare old dockerfiles with new dockerfile to ensure nothing was lost in the transition
  • Conversion tools
  • Emfatic
  • OCL
  • EMF
  • Xtext
• Remove old dockerfiles
• Consider Copilot suggestions and either move to separate issue/PR or implement directly
• Update README file to document how to build tools

[szschaler]

@copilot draft an update to the readme file and add it to this PR.

[Copilot]

@copilot draft an update to the readme file and add it to this PR.

Done in 01cbd13. The README now has a "Building Tool Docker Images" section documenting the docker build --target <stage> commands for each tool, noting that the repository root must be the build context, and including the optional build args for the Xtext stage.

Works in principle (tested on staging via mdenet/educationplatform-docker#83). Outstanding tasks before merge:

• Carefully compare old dockerfiles with new dockerfile to...

Done in 01cbd13:

• Compared old Dockerfiles with the new one — all behaviour is preserved (module sets, install commands, start scripts, env vars)
• Removed all old per-tool Dockerfiles (static.emf, static.emfatic, static.ocl, static.conversion, xtext/Dockerfile, xtext/static.xtext/Dockerfile)
• Updated README with build instructions

The Copilot reviewer suggestions (Node EOL, npm ci, && chaining, SHASUM verification) are noted — I'll leave those for a follow-up PR as they are independent improvements.

[szschaler]

While doing this, might as well update the GitHub actions to move away from Node 20 Actions, which will deprecate in June 2026.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 6 comments.

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[szschaler]

Works on staging...