Update Ubuntu to 26.04 / Resolute and Java 25

Keep Java 21 for the purpose of installing the Gerrit package which
isn't able to detect Java 25 properly yet.

Change-Id: Id407dc640ea6c5dd5515a80af7732ad90eec33db

build_multiplatform.sh

diff --git a/build_multiplatform.sh b/build_multiplatform.sh
index 7318dd4..93a7891 100755
--- a/build_multiplatform.sh
+++ b/build_multiplatform.sh
@@ -71,7 +71,7 @@
 
 echo
 echo "### Building ubuntu multi-platform: [$PLATFORMS] iamges"
-(cd ubuntu/24 && docker buildx build --platform "$PLATFORMS" --no-cache -t "$DOCKER_USER:${VERSION}-ubuntu24" "$DESTINATION" .)
+(cd ubuntu/26 && docker buildx build --platform "$PLATFORMS" --no-cache -t "$DOCKER_USER:${VERSION}-ubuntu26" "$DESTINATION" .)
 
 echo
 echo "### Removing multi-platform builder"

ubuntu/26/.dockerignore

diff --git a/ubuntu/24/.dockerignore b/ubuntu/26/.dockerignore
similarity index 100%
rename from ubuntu/24/.dockerignore
rename to ubuntu/26/.dockerignore

ubuntu/26/Dockerfile

diff --git a/ubuntu/24/Dockerfile b/ubuntu/26/Dockerfile
similarity index 67%
rename from ubuntu/24/Dockerfile
rename to ubuntu/26/Dockerfile
index c2c5047..9bbc2f6 100644
--- a/ubuntu/24/Dockerfile
+++ b/ubuntu/26/Dockerfile
@@ -1,29 +1,34 @@
-FROM eclipse-temurin:21.0.10_7-jdk-noble
+FROM eclipse-temurin:25.0.3_9-jdk-resolute
 LABEL org.opencontainers.image.authors="luca.milanesio@gmail.com"
 
 # Add Gerrit packages repository
 RUN apt-get update && \
     apt-get -y install gnupg2
-RUN echo "deb mirror://mirrorlist.gerritforge.com/bionic gerrit contrib" > /etc/apt/sources.list.d/GerritForge.list
-RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 55787ed781304950
+
+RUN gpg --keyserver keyserver.ubuntu.com --recv-keys 55787ed781304950 && \
+    gpg --export 55787ed781304950 | tee /etc/apt/keyrings/gerritforge.gpg > /dev/null && \
+    chmod 644 /etc/apt/keyrings/gerritforge.gpg
+RUN echo "deb [signed-by=/etc/apt/keyrings/gerritforge.gpg] mirror://mirrorlist.gerritforge.com/bionic gerrit contrib" > /etc/apt/sources.list.d/GerritForge.list
 
 RUN apt-get update
-RUN apt-key update
 RUN apt-get -y install sudo
 
 ADD entrypoint.sh /
 
-# Note that temurin does everything that is needed in order to install JDK but doesn't
-# update alternatives for java which is detected during the gerrit install step
-# hence it is the only extra step that had to be added
-RUN update-alternatives --install /usr/bin/java java $(which java) 2222 && \
+RUN apt-get -y install openjdk-21-jdk && \
     apt-get -y upgrade && \
     apt-get -y install gerrit=3.14.1-1 && \
+    apt-get -y remove openjdk-21-jdk && \
     apt-mark hold gerrit && \
     /entrypoint.sh init && \
     bash -c 'rm -f /var/gerrit/etc/{ssh,secure}* && rm -Rf /var/gerrit/{static,index,logs,data,index,cache,git,db,tmp}/*' && \
     chown -R gerrit:gerrit /var/gerrit
 
+# Note that temurin does everything that is needed in order to install JDK but doesn't
+# update alternatives for java which is detected during the gerrit install step
+# hence it is the only extra step that had to be added
+RUN update-alternatives --install /usr/bin/java java $(which java) 2222
+
 USER gerrit
 
 ENV CANONICAL_WEB_URL=

ubuntu/26/Dockerfile-dev

diff --git a/ubuntu/24/Dockerfile-dev b/ubuntu/26/Dockerfile-dev
similarity index 96%
rename from ubuntu/24/Dockerfile-dev
rename to ubuntu/26/Dockerfile-dev
index 2e4d283..8d96c6c 100644
--- a/ubuntu/24/Dockerfile-dev
+++ b/ubuntu/26/Dockerfile-dev
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:21.0.10_7-jdk-noble
+FROM eclipse-temurin:25.0.3_9-jdk-resolute
 LABEL org.opencontainers.image.authors="luca.milanesio@gmail.com"
 
 # Install OpenJDK and Git and allow remote connectivity and sudo

ubuntu/26/entrypoint.sh

diff --git a/ubuntu/24/entrypoint.sh b/ubuntu/26/entrypoint.sh
similarity index 100%
rename from ubuntu/24/entrypoint.sh
rename to ubuntu/26/entrypoint.sh