Externalize build properties.

See #1629.

ci/pipeline.properties

@@ -0,0 +1,19 @@
+# Java versions
+java.main.tag=17.0.2_8-jdk
+
+# Docker container images - standard
+docker.java.main.image=eclipse-temurin:${java.main.tag}
+
+# Supported versions of MongoDB
+docker.mongodb.4.4.version=4.4.4
+docker.mongodb.5.0.version=5.0.3
+
+# Supported versions of Redis
+docker.redis.6.version=6.2.4
+
+# Supported versions of Cassandra
+docker.cassandra.3.version=3.11.11
+
+# Docker environment settings
+docker.java.inside.basic=-v $HOME:/tmp/jenkins-home
+docker.java.inside.docker=-u root -v /var/run/docker.sock:/var/run/docker.sock -v /usr/bin/docker:/usr/bin/docker -v $HOME:/tmp/jenkins-home