This image contains the Java Runtime Environment (JRE) 21 from the Eclipse Temurin project, which in this case is a compilation of the OpenJDK project.
This carefully crafted Docker image delivers a pristine and lightweight installation of JRE 21. It is built upon Sourcemation’s optimized Debian 13 Slim base, ensuring a minimal footprint and enhanced security.
This image was built to be a drop-in replacement for the Temurin JRE 21 image.
To run the base image without any additional configuration, you can use the following:
docker run -it --rm --name jre21 sourcemation/jre-21
This will start a shell inside a container with JRE 21 installed and ready to use.
Running a Java Application
The following Dockerfile demonstrates how to run a Java application using the JRE 21 image:
from sourcemation/jre-21
# Copy your Java application JAR file into the image
COPY your-application.jar /app/your-application.jar
# Set the working directory
WORKDIR /app
# Run the Java application
CMD ["java", "-jar", "your-application.jar"]
You can also run a Java application directly from the command line by mounting the volume:
docker run -it --rm -v /path/to/your/application:/app sourcemation/jre-21
java -jar /app/your-application.jar
Lastly, to add custom CA certificates, you can mount a volume (or copy it to the image during the Containerfile/Dockerfile build) and set the USE_SYSTEM_CA_CERTS environment variable to 1:
docker run -v /home/dev/mycerts:/certificates/ -e USE_SYSTEM_CA_CERTS=1 sourcemation/jre-21
FROM sourcemation/jre-21
# Copy your CA certificates into the image
COPY mycerts /certificates/
# Set the environment variable to use system CA certificates
ENV USE_SYSTEM_CA_CERTS=1
# Set the working directory
WORKDIR /app
# Run the Java application
CMD ["java", "-jar", "your-application.jar"]
To enhance security, it is recommended to run your Java application as a non-root user. To create a new user and run your application as that user, you can use the following dockerfile
FROM sourcemation/jre-21
# Create a new user
RUN useradd -m -s /bin/bash myuser
# Copy your Java application JAR file into the image
COPY your-application.jar /app/your-application.jar
# Set the working directory
WORKDIR /app
# Change ownership of the application files
RUN chown -R myuser:myuser /app
# Switch to the new user
USER myuser
# Run the Java application
CMD ["java", "-jar", "your-application.jar"]
Standard encoding is set to en_US.UTF-8, and other locale variables default to en_US. JAVA_VERSION can help you identify the Java version, and JAVA_HOME is set to /opt/java/openjdk.
JAVA_VERSION=jdk-21.0.7+6 # or a newer version depending on the build
JAVA_HOME=/opt/java/openjdk
PATH=$JAVA_HOME/bin:$PATH
# Encoding
LANG='en_US.UTF-8'
LANGUAGE='en_US:en'
LC_ALL='en_US.UTF-8'
This image was created with the intention of being a drop-in replacement for the Temurin JRE 21 image. This image runs as the root user! You should extend it to run your application as a non-root user.
We welcome your contributions! If you have new feature requests, want to report a bug, or wish to submit a pull request with your code or an image request, you can do so via the Sourcemation GitHub repository for this image.
Sourcemation offers a range of open-source projects and Docker images with extensive risk assessment of open-source software. We are committed to providing high-quality images. Comprehensive risk analysis reports for selected images are available on the Sourcemation platform.
The OpenJDK project is licensed under the GNU General Public License, version 2, with the Classpath Exception.
Content type
Image
Digest
sha256:013b4a22a…
Size
101.6 MB
Last updated
14 days ago
docker pull sourcemation/jre-21