: Install matching or newer JRE version:
FROM alpine:3.19 RUN apk add --no-cache openjdk17-jre Create app user RUN addgroup -g 1000 -S appuser && adduser -u 1000 -S appuser -G appuser linux java runtime environment
sudo useradd -r -s /bin/false javauser sudo chown -R javauser:javauser /opt/myapp sudo -u javauser java -jar /opt/myapp/app.jar 10.1 "java: command not found" Cause : JRE not installed or PATH not set. : Install matching or newer JRE version: FROM alpine:3
USER appuser WORKDIR /app CMD ["java", "-XX:+UseContainerSupport", "-XX:MaxRAMPercentage=75.0", "-jar", "myapp.jar"] 55 = Java 11
# Check JAR's required version javap -verbose MyClass.class | grep "major version" # 52 = Java 8, 55 = Java 11, 61 = Java 17, 65 = Java 21 Minimal Dockerfile using Alpine + OpenJDK JRE :
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