[JENKINS-73703] Remove UBI 8 + Review Feedback

With the upcoming EOL of Java 11, the UBI 8 image for Jenkins server
will no longer be supported. Creating a UBI 8 image therefore does not
make any sense.

The tag for the base UBI 9 image was converted to a build arg, to
facilitate automatic updates via updatecli. Other minor fixes to
documentation and image metadata also included.

Signed-off-by: Adam Kaplan <[email protected]>
Co-authored-by: Mark Waite <[email protected]>
Co-authored-by: lemeurherveCB <[email protected]>

README_agent.md

@@ -68,7 +68,7 @@ The image has several supported configurations, which can be accessed via the fo
       * `jenkins/agent:rhel-ubi9`
       * `jenkins/agent:rhel-ubi9-jdk17`
       * `jenkins/agent:latest-rhel-ubi9`
-      * `jenkins/agent:latest-rhel-ubi8-jdk17`
+      * `jenkins/agent:latest-rhel-ubi9-jdk17`
   * Java 21:
     * bookworm (Based on `debian:bookworm-${builddate}`):
       * `jenkins/agent:bookworm`
@@ -99,11 +99,6 @@ The image has several supported configurations, which can be accessed via the fo
       * `jenkins/agent:archlinux-jdk11`
       * `jenkins/agent:latest-archlinux`
       * `jenkins/agent:latest-archlinux-jdk11`
-    * rhel-ubi8 (Based on Red Hat Universal Base Image 8)
-      * `jenkins/agent:rhel-ubi8`
-      * `jenkins/agent:rhel-ubi8-jdk11`
-      * `jenkins/agent:latest-rhel-ubi8`
-      * `jenkins/agent:latest-rhel-ubi8-jdk11`
 
 * Windows Images:
   * Java 17 (default):

docker-bake.hcl

@@ -96,6 +96,10 @@ variable "DEBIAN_RELEASE" {
   default = "bookworm-20240904"
 }
 
+variable "UBI9_TAG" {
+  default = "9.4-1214.1726694543"
+}
+
 variable "JAVA11_VERSION" {
   default = "11.0.24_8"
 }
@@ -151,15 +155,8 @@ function "debian_platforms" {
   : ["linux/amd64", "linux/arm64", "linux/ppc64le", "linux/s390x"]))
 }
 
-# Return an array of RHEL UBI 8 platforms to use depending on the jdk passed as parameter
-# Note: Jenkins Docker controller only supports jdk-11 for ubi8
-function "rhel_ubi8_platforms" {
-  params = [jdk]
-  result = ["linux/amd64", "linux/arm64"]
-}
-
-# Return an array of RHEL UBI 8 platforms to use depending on the jdk passed as parameter
-# Note: Jenkins Docker controller only supports jdk-17 and jdk-21 for ubi9
+# Return an array of RHEL UBI 9 platforms to use depending on the jdk passed as parameter
+# Note: Jenkins controller container image only supports jdk17 and jdk21 for ubi9
 function "rhel_ubi9_platforms" {
   params = [jdk]
   result = ["linux/amd64", "linux/arm64", "linux/ppc64le"]
@@ -248,33 +245,6 @@ target "agent_archlinux_jdk11" {
   platforms = ["linux/amd64"]
 }
 
-target "rhel_ubi8" {
-  matrix = {
-    type = ["agent", "inbound-agent"]
-    jdk  = [11]
-  }
-  name       = "${type}_rhel_ubi8_jdk${jdk}"
-  target     = type
-  dockerfile = "rhel/ubi8/Dockerfile"
-  context    = "."
-  args = {
-    VERSION        = REMOTING_VERSION
-    JAVA_VERSION   = "${javaversion(jdk)}"
-  }
-  tags = [
-    # If there is a tag, add versioned tag suffixed by the jdk
-    equal(ON_TAG, "true") ? "${REGISTRY}/${orgrepo(type)}:${REMOTING_VERSION}-${BUILD_NUMBER}-rhel-ubi8-jdk${jdk}" : "",
-    # If there is a tag and if the jdk is the default one, add versioned short tag
-    equal(ON_TAG, "true") ? (is_default_jdk(jdk) ? "${REGISTRY}/${orgrepo(type)}:${REMOTING_VERSION}-${BUILD_NUMBER}-rhel-ubi8" : "") : "",
-    # If the jdk is the default one, add rhel and latest short tags
-    is_default_jdk(jdk) ? "${REGISTRY}/${orgrepo(type)}:rhel-ubi8" : "",
-    is_default_jdk(jdk) ? "${REGISTRY}/${orgrepo(type)}:latest-rhel-ubi8" : "",
-    "${REGISTRY}/${orgrepo(type)}:rhel-ubi8-jdk${jdk}",
-    "${REGISTRY}/${orgrepo(type)}:latest-rhel-ubi8-jdk${jdk}",
-  ]
-  platforms = rhel_ubi8_platforms(jdk)
-}
-
 target "rhel_ubi9" {
   matrix = {
     type = ["agent", "inbound-agent"]
@@ -285,6 +255,7 @@ target "rhel_ubi9" {
   dockerfile = "rhel/ubi9/Dockerfile"
   context    = "."
   args = {
+    UBI9_TAG       = UBI9_TAG
     VERSION        = REMOTING_VERSION
     JAVA_VERSION   = "${javaversion(jdk)}"
   }

rhel/ubi9/Dockerfile

@@ -1,4 +1,5 @@
-FROM registry.access.redhat.com/ubi9/ubi:9.4-1214 as jre-build
+ARG UBI9_TAG="9.4-1214.1726694543"
+FROM registry.access.redhat.com/ubi9/ubi:"${UBI9_TAG}" AS jre-build
 SHELL ["/bin/bash", "-e", "-u", "-o", "pipefail", "-c"]
 
 # This Build ARG is populated by Docker
@@ -38,7 +39,7 @@ RUN case "$(jlink --version 2>&1)" in \
       --no-header-files \
       --output /javaruntime
 
-FROM registry.access.redhat.com/ubi9/ubi:9.4-1214 AS agent
+FROM registry.access.redhat.com/ubi9/ubi:"${UBI9_TAG}" AS agent
 
 ARG user=jenkins
 ARG group=jenkins
@@ -52,7 +53,7 @@ ARG AGENT_WORKDIR=/home/"${user}"/agent
 ENV TZ=Etc/UTC
 
 RUN dnf install --disableplugin=subscription-manager --setopt=install_weak_deps=0 --setopt=tsflags=nodocs -y \
-      ca-certificates \   
+      ca-certificates \
       fontconfig \
       git \
       git-lfs \
@@ -65,17 +66,17 @@ ARG VERSION=3261.v9c670a_4748a_9
 ADD --chown="${user}":"${group}" "https://repo.jenkins-ci.org/public/org/jenkins-ci/main/remoting/${VERSION}/remoting-${VERSION}.jar" /usr/share/jenkins/agent.jar
 RUN chmod 0644 /usr/share/jenkins/agent.jar \
     && ln -sf /usr/share/jenkins/agent.jar /usr/share/jenkins/slave.jar
-    
+
 ENV LANG C.UTF-8
-    
+
 ENV JAVA_HOME=/opt/java/openjdk
 COPY --from=jre-build /javaruntime "$JAVA_HOME"
 ENV PATH="${JAVA_HOME}/bin:${PATH}"
-    
+
 USER "${user}"
 ENV AGENT_WORKDIR=${AGENT_WORKDIR}
 RUN mkdir -p /home/"${user}"/.jenkins && mkdir -p "${AGENT_WORKDIR}"
-    
+
 VOLUME /home/"${user}"/.jenkins
 VOLUME "${AGENT_WORKDIR}"
 WORKDIR /home/"${user}"
@@ -88,7 +89,7 @@ LABEL \
   org.opencontainers.image.url="https://www.jenkins.io/" \
   org.opencontainers.image.source="https://github.com/jenkinsci/docker-agent" \
   org.opencontainers.image.licenses="MIT"
-    
+
 ## Inbound Agent image target
 FROM agent AS inbound-agent