TT#69504 Support specific version usage of grml2usb/grml2iso

This is a *partial* cherry-pick from commit c3d753562, excluding all the
testing related changes and keeping only viable and safe changes.

Relevant changes included here:

* Stick grml2usb version to v0.17.0, instead of relying on the grml2usb
  version available on the host system (being 0.14.14 on Debian/stretch as
  present on our current build hosts). For arbitrary addon file names we
  need grml2iso (which uses grml2usb underneath) from grml2usb >=0.17.0.
  FTR, grml2iso and grml2usb can be executed from within the git repository,
  assuming all relevant tools are present

* No longer invoke isohybrid on the resulting ISO, instead rely on
  grml2iso behaviour (which also checks for EFI support and enables
  according switches as needed)

* Fix usage instructions in t/Dockerfile (it's "deployment-iso-buster" and not
  "lua-ngcp-kamailio-buster")

This is in preparation for backporting/cherry-pick commit 608dd0367
("TT#73210 Use grml2usb v0.14.14 when handling grml64-small_2018.04.11-efi.iso")
to use a specific grml2usb version when dealing with special
case ISO grml64-small_2018.04.11-efi.iso for mr6.5 release.

Change-Id: I67e3f85bbe86bd1b3ee709161504b5250ca5d7fe
(*partially* cherry picked from commit c3d753562d)

build_iso.sh

@@ -75,10 +75,17 @@ echo "*** Copying isolinux.cfg to syslinux.cfg for grml2usb support ***"
 cp ${TEMPLATES}/boot/isolinux/isolinux.cfg ${TEMPLATES}/boot/isolinux/syslinux.cfg
 
 echo "*** Generating Sipwise ISO ***"
-sudo /usr/sbin/grml2iso -c ./${TEMPLATES} -o "${SIPWISE_ISO}" "${GRML_ISO}"
 
-echo "*** Generating dd-able ISO ***"
-sudo /usr/bin/isohybrid "${SIPWISE_ISO}"
+if [[ ! -d grml2usb.git ]] ; then
+  GRML2USB_VERSION='v0.17.0'
+  if ! git clone -b "${GRML2USB_VERSION}" --single-branch --depth 1 https://github.com/grml/grml2usb grml2usb.git ; then
+    echo "Cloning grml2usb from github failed, falling back to git.grml.org"
+    git clone -b "${GRML2USB_VERSION}" --single-branch --depth 1 git://git.grml.org/grml2usb.git
+  fi
+fi
+GRML2USB_DIR=$(pwd)/grml2usb.git
+
+sudo GRML2USB="${GRML2USB_DIR}/grml2usb" "${GRML2USB_DIR}/grml2iso" -c ./${TEMPLATES} -o "${SIPWISE_ISO}" "${GRML_ISO}"
 
 sudo implantisomd5 "${SIPWISE_ISO}"
 

t/Dockerfile

@@ -19,13 +19,13 @@ WORKDIR /code/
 # When you want to build the base image from scratch
 # jump to the next section if you don't want to build yourself!:
 #
-# % docker build --tag="lua-ngcp-kamailio-stretch" -f t/Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:rw lua-ngcp-kamailio-stretch:latest bash
+# % docker build --tag="deployment-iso-buster" -f t/Dockerfile .
+# % docker run --rm -i -t -v $(pwd):/code:rw deployment-iso-buster:latest bash
 #
 # Use the existing docker image:
-# % docker pull docker.mgm.sipwise.com/lua-ngcp-kamailio-stretch
+# % docker pull docker.mgm.sipwise.com/deployment-iso-buster
 # NOTE: run the following command from root folder of git repository:
-# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/lua-ngcp-kamailio-stretch:latest bash
+# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/deployment-iso-buster:latest bash
 #
 # Inside docker (the command is in history, just press UP button):
 #   ./t/testrunner