Hardened Java 8 on CentOS Stream 9 Latest (LVM)

Charges for this image cover the security hardening, optimization, and pre-integration work Hanwei performs on top of the upstream OpenJDK 8 and CentOS Stream 9 projects. OpenJDK 8 is installed during the image build and java and javac are on PATH at first boot. Unlike a partition-based layout, the root filesystem is XFS on an LVM logical volume, so root storage can be grown online as the workload needs it. The operating system underneath is configured to a fixed hardened and tuned baseline and validated on EC2 before publication.

What Hanwei Adds to Upstream OpenJDK 8

• Toolchain installed at build time: the OpenJDK 8 development kit is installed rather than the runtime alone, so java, javac and jar are present on PATH.
• Root filesystem on LVM: / is XFS on logical volume lvroot in volume group centos, while /boot stays on a plain partition. Capacity can be added online by attaching an EBS volume and running pvcreate, vgextend, lvextend and xfs_growfs, or by enlarging the root volume and growing the partition, physical volume and logical volume in turn, without a reboot.
• Build dependencies preinstalled: gcc, pkgconf and the OpenSSL development headers are present, so native libraries reached through JNI and build plugins that compile native code work without further setup.
• Tuning baseline applied identically across the catalogue: the file descriptor limit goes from 1024 to 65536 and the memory-map ceiling from 65530 to 262144; the device receive backlog goes from 1000 to 16384 and the TCP SYN backlog from 128 to 8192, so bursts queue instead of being dropped; socket buffer maxima reach 16 MB for larger autotuned windows; connections keep their congestion window across idle periods; and the journal is capped at 500 MB. The profile raises ceilings only and does not alter protocol semantics or application behaviour.
• Applied hardening beyond the distribution default: SSH is limited to a vetted cipher, key exchange and MAC list, X11 forwarding is off, the login grace period is shortened and verbose authentication logging is on; auditd runs a base rule set for privileged command execution; the kernel drops ICMP redirects on IPv4 and IPv6, logs martian packets, filters reverse paths in loose mode, restricts dmesg, disables setuid core dumps and turns off sysrq.
• AWS operational integration: the SSM Agent is installed and enabled for Session Manager and Patch Manager without an inbound SSH rule; chrony points at the Amazon Time Sync Service; and growpart and the LVM tools are present for resizing root storage after the volume is enlarged.
• Patch level and repeatable build: packages come from official upstream repositories at the newest level published when the image was built, and each version is launched and exercised on EC2 before release.

Access and Security Posture

• SELinux runs in enforcing mode and auditd records activity against a base rule set.
• Sign in as 'ec2-user' with the key pair selected at launch, then use 'sudo su -' for a root shell. Session Manager is available as an alternative that needs no inbound port.
• Direct root login over SSH is disabled and password authentication is not accepted.
• No authorized keys and no SSH private keys are embedded in the image.

Operational Impact on EC2

• Launch-to-first-build time is reduced to a single boot cycle, and root storage can grow without re-imaging the instance.
• Every instance starts from an identical configuration, removing drift between development, staging and production hosts.
• Network services need no per-host limit or backlog adjustment before handling load.
• Clock accuracy comes from the Amazon Time Sync Service, which matters for log correlation and request signing.
• Post-launch patching effort is lower because the package set is current at release.

Where This Image Fits

• Java 8 application servers whose data or log footprint grows and must be extended online.
• Build and CI hosts that compile projects targeting Java SE 8 with Maven, Gradle or Ant.
• Environments whose storage standards require LVM-managed root volumes.
• Hosts that must keep a Java 8 runtime while running on a CentOS Stream 9 base.

About OpenJDK 8 and CentOS Stream 9

OpenJDK 8 is the open source implementation of Java SE 8. It introduced lambda expressions, the Stream API, default methods on interfaces and the java.time date and time API, and a large body of enterprise applications, libraries and build tooling is still compiled against this release. Packages in this image come from the CentOS Stream 9 AppStream repository.

CentOS Stream 9 is a Linux distribution that tracks the development stream of Red Hat Enterprise Linux 9. Packages land in CentOS Stream before they appear in a RHEL minor release, so it stays close to the RHEL package set and toolchain while remaining freely redistributable. It uses dnf, systemd and SELinux, which makes it a predictable base for server workloads that need RHEL compatibility.