docker-images

Production-oriented container images for the Galaxio team.

Images

This repo does not build a standalone minimal/distroless base image. The root of the image hierarchy, galaxioteam/galaxio, is built externally in galax-io/galaxio-cli and always tracks latest; the Dockerfiles below build on top of it.

java.Dockerfile

Hardened Java 21 JDK image:

• full JDK copied from Eclipse Temurin
• non-root by default
• UTF-8 defaults baked in

Build:

docker build -f java.Dockerfile -t galaxioteam/java:local .

gatling-sbt-builder.Dockerfile

Builder image for Scala Gatling projects:

• based on sbtscala/scala-sbt
• warms sbt and Coursier caches
• installs galaxio-cli
• warms dependencies by rendering gatling/scala-sbt from the Galaxio template registry
• keeps gatling-picatinny in the generated warmup project
• keeps shell tooling because it is a CI/builder image, not a production runtime

Build:

docker build -f gatling-sbt-builder.Dockerfile -t galaxioteam/gatling-sbt-builder:local .

Build arguments

Argument	Default	Description
GALAXIO_CLI_VERSION	0.6.1	Version of galaxio-cli to download.
GALAXIO_CLI_CHECKSUM	(see Dockerfile)	SHA256 checksum of the galaxio-cli release tarball. Used to verify the download before extraction.

GALAXIO_CLI_CHECKSUM — how to find and use it:

1. Open the release page for the target version: https://github.com/galax-io/galaxio-cli/releases/tag/v<VERSION>
2. Download checksums.txt from the release assets and locate the line for galaxio_<VERSION>_linux_amd64.tar.gz.
3. Pass the hash at build time:

docker build \
  --build-arg GALAXIO_CLI_VERSION=0.6.1 \
  --build-arg GALAXIO_CLI_CHECKSUM=711075adfa5bd7fc188326ee4200177cfd13d997082ecc27b304e405ae035fea \
  -f gatling-sbt-builder.Dockerfile \
  -t galaxioteam/gatling-sbt-builder:local .

If GALAXIO_CLI_CHECKSUM does not match the downloaded file, the build will fail at the sha256sum -c step before any binary is extracted.

gatling-maven-builder.Dockerfile

Builder image for Gatling Maven projects:

• based on official Maven + Temurin
• warms the local .m2 repository with Gatling 3.13 dependencies
• intended for Java/Kotlin/Scala Maven projects

Build:

docker build -f gatling-maven-builder.Dockerfile -t galaxioteam/gatling-maven-builder:local .

gatling-gradle-builder.Dockerfile

Builder image for Gatling Gradle projects:

• based on official Gradle + JDK 21
• warms the Gradle cache with Gatling 3.13 dependencies
• intended for Java/Kotlin/Scala Gradle projects

Build:

docker build -f gatling-gradle-builder.Dockerfile -t galaxioteam/gatling-gradle-builder:local .

gatling-runtime.Dockerfile

Hardened Gatling 3.13 runtime image:

• distroless final image
• non-root user
• offline Maven cache warmed at build time
• tiny BusyBox userspace instead of a full Debian/Ubuntu userspace

Why not fully distroless-only?

Gatling 3.13.x ships as a Maven-wrapper-based bundle. Running the official bundle requires a shell and a few POSIX utilities because mvnw is a shell script. The runtime image therefore uses:

• tiny BusyBox userspace instead of a full Debian/Ubuntu userspace

Build runtime:

docker build -f gatling-runtime.Dockerfile -t galaxioteam/gatling-runtime:local .

gatling-debug.Dockerfile

Debug-friendly Gatling 3.13 image:

• shell, git, jq, curl, netcat, procps
• meant only for troubleshooting and ad-hoc inspection

Build:

docker build -f gatling-debug.Dockerfile -t galaxioteam/gatling-debug:local .

Run bundled sample simulation:

docker run --rm galaxioteam/gatling-runtime:local

Override the Maven/Gatling goal:

docker run --rm galaxioteam/gatling-runtime:local test gatling:test -Dgatling.simulationClass=computerdatabase.BasicSimulation

Production guidance

For production and CI usage, prefer the following split:

1. Use gatling-sbt-builder, gatling-maven-builder, and gatling-gradle-builder only as builder images.
2. Use gatling-runtime as the smallest safe image when you need the official 3.13 bundle workflow.
3. Use gatling-debug only for troubleshooting.
4. Run containers with:
   • read-only root filesystem
   • dropped Linux capabilities
   • allowPrivilegeEscalation=false
   • seccomp=RuntimeDefault
5. Pin upstream base images by digest in CI/CD before publishing to production registries.

Main improvements versus the previous setup

• removed apt-get upgrade from image builds
• stopped copying a near-complete Ubuntu userspace into a distroless image
• made the base image truly minimal
• made Java runtime images non-root by default
• split Gatling images by builder tool: sbt, maven, gradle
• separated production and debug concerns
• switched sbt warmup from g8 to galaxio-cli
• updated Picatinny in sbt warmup to the latest verified version
• fixed SBT_OPTS handling in the sbt builder

Docker Hub: galaxioteam

Image sizes are not currently published here. The versioned image tags this table would query were never actually pushed to Docker Hub, a symptom of the release-tagging bug fixed in #129 — see #132 for details. Sizes are no longer generated into this README; see Docker Hub for current image tags and their sizes.