version-string-driven building of python interpreter builder image

Author: d-w-moore

irods/test/harness/003_compile-specific-python.Dockerfile

@@ -1,7 +1,7 @@
 from ssl-and-pam
 run apt update
-run apt install -y wget build-essential libssl-dev zlib1g-dev
-run apt install wget build-essential
+run apt install -y wget build-essential
+run apt install -y libssl-dev zlib1g-dev libffi-dev libncurses-dev wget build-essential
 arg python_version
 run wget https://www.python.org/ftp/python/${python_version}/Python-${python_version}.tar.xz
 run tar xf Python-${python_version}.tar.xz

irods/test/harness/build-docker.sh

@@ -1,7 +1,10 @@
 #!/usr/bin/env bash
 
-# IRODS_PACKAGE_VERSION if defined is like "4.3.1-0~bionic"
+# environment variables for build
+# IRODS_PACKAGE_VERSION if defined is like "4.3.4" or "5.0.1".
 # (but contains no '~' suffix for irods versions <= 4.2.10)
+# PYTHON_VERSION is usually two dot-separated numbers: example "3.13", but could also have zero, one or three version numbers.
+# (Do not specify the triple form, X.Y.Z, if that release is not known to exist - not counting alphas and release candidates)
 
 BASE=$(basename "$0")
 DIR=$(realpath "$(dirname "$0")")
@@ -15,12 +18,20 @@ fi
 for dockerfile in "${ARGS[@]}"; do 
     image_name=${dockerfile#[0-9]*_}
     image_name=${image_name%.Dockerfile}
-    if [ "$image_name" = "install-irods" ];then
-        package_version_option=${IRODS_PACKAGE_VERSION:+"--build-arg=irods_package_version=$IRODS_PACKAGE_VERSION"}
+    irods_package_version_option=""
+    python_version_option=""
+    if [ "$image_name" = "install-irods" ]; then
+        irods_package_version_option=${IRODS_PACKAGE_VERSION:+"--build-arg=irods_package_version=$IRODS_PACKAGE_VERSION"}
+    elif [ "$image_name" = "compile-specific-python" ]; then
+        temp=$(./most_recent_python.sh $PYTHON_VERSION)
+        if [ -n "$temp" ]; then
+            PYTHON_VERSION="$temp"
+        fi
+        python_version_option=${PYTHON_VERSION:+"--build-arg=python_version=$PYTHON_VERSION"}
     else
         package_version_option=""
     fi
-    $DOCKER build -f $dockerfile -t $image_name . $package_version_option \
+    $DOCKER build -f $dockerfile -t $image_name . $irods_package_version_option $python_version_option \
                                                   ${NO_CACHE+"--no-cache"} || 
                                                   { STATUS=$?; echo "*** Failure while building [$image_name]"; exit $STATUS; }
 done