ubuntu/jre Docker Image

ubuntu/jre is a rock for jre maintained by https://canonical.com/.

OpenJDK is the official reference implementation of Java Platform, Standard Edition (Java SE), since version 7. This image packs the Java Runtime Environment, coming from the https://www.openjdk.org/, a free and open source implementation of the Java Platform, Standard Edition (Java SE).

Java is a registered trademark of Oracle and/or its affiliates.

\https://openjdk.org/\]

Tags and Architectures

NOTE: These tags follow a specific naming convention that respects the concept of channels.

Get started

This rock's entrypoint is Pebble, a container-optimized init process that enables the orchestration of a collection of local service processes as an organized set.

\https://documentation.ubuntu.com/pebble/\]

Inspect

To view the https://documentation.ubuntu.com/rockcraft/en/latest/reference/rockcraft-yaml/#services and https://documentation.ubuntu.com/rockcraft/latest/reference/rockcraft-yaml/#checks defined in this rock:

sh
docker run --rm ubuntu/jre:25-26.04_stable plan

sh
docker inspect --format='{{.Config.Entrypoint}} {{.Config.Cmd}}' ubuntu/jre:25-26.04_stable

Run

To run this rock, use any of the usual container runtimes, for example, docker:

sh
docker run --name jre-container \
    --rm \
    ubuntu/jre:25-26.04_stable \
    exec java

The container logs will simply show the OpenJRE help message. This is because the container expects a compiled Java application to be given.

Let's use the following Hello World application as an example:

java
// HelloWorld.java

class HelloWorld
{
    public static void main(String args[])
    {
        System.out.println("Hello, World");
    }
}

You can build and package the above Hello World application with ***led Ubuntu 24.04 using the following example Dockerfile.

docker
FROM ubuntu:24.04 AS builder
RUN apt-get update && apt-get install -y openjdk-8-jdk
WORKDIR /app
ADD HelloWorld.java .

RUN javac -source 8 -target 8 HelloWorld.java -d .

FROM ubuntu/jre:21-24.04_edge

COPY --from=builder /app/HelloWorld.class .

CMD [ "exec", "java", "-cp", "/", "HelloWorld" ]

sh
docker run --name jre-container \
    --rm \
    ubuntu/jre:25-26.04_stable

docker
FROM ubuntu:22.04 AS builder
RUN apt-get update && apt-get install -y openjdk-8-jdk
WORKDIR /app
ADD HelloWorld.java .

RUN javac -source 8 -target 8 HelloWorld.java -d .

FROM ubuntu/jre:8-22.04_edge

WORKDIR /
COPY --from=builder /app/HelloWorld.class .

CMD [ "HelloWorld" ]
java [options] <mainclass> [args...]
...

Get logs

To view the logs of the running container, run:

sh
docker exec jre-container pebble logs

Or, for a specific service:

sh
docker exec jre-container pebble logs <service>

sh
docker logs jre-container

Monitor health checks

Rocks may have predefined health checks that you can list by running:

sh
docker exec jre-container pebble checks

The overall health of your container can be inspected via:

sh
docker exec jre-container pebble health

Configuration

Environment variables

Volumes

Application parameters

Other configuration options

\https://github.com/canonical/jre-rock/issues\] \https://github.com/canonical/jdk-rock\]

Canonical is the provider of this container image. It is the user's responsibility to ensure that any use of this image complies with any relevant licenses for all software contained within, as well as with https://canonical.com/legal/intellectual-property-policy.