ci: Rewrite jobscript creation

Refactor job script creation into its own shell script.
This should improve general readability.

Also use the opportunity and create a dedicated, temporary
home directory for the CI run. This way all files created
in the home directory by the job do not end up in the real
one.

(cherry picked from commit e4ecb3c)

Jenkinsfile

@@ -50,17 +50,11 @@ def jobMatrix(String prefix, String type, List specs) {
             sh "cat ${jobscript}"
             sh "bash ${jobscript}"
           } else {
-            def containercmd = "singularity exec -B/shared ${env.SINGULARITY_CONTAINER_ROOT}/fairroot/${os}.${ver}.sif bash -l -c \\\"${ctestcmd}\\\""
-            sh """\
-              echo \"echo \\\"*** Job started at .......: \\\$(date -R)\\\"\" >> ${jobscript}
-              echo \"echo \\\"*** Job ID ...............: \\\${SLURM_JOB_ID}\\\"\" >> ${jobscript}
-              echo \"echo \\\"*** Compute node .........: \\\$(hostname -f)\\\"\" >> ${jobscript}
-              echo \"unset http_proxy\" >> ${jobscript}
-              echo \"unset HTTP_PROXY\" >> ${jobscript}
-              echo \"${containercmd}\" >> ${jobscript}
-            """
-            sh "cat ${jobscript}"
-            sh "./slurm-submit.sh \"FairRoot \${JOB_BASE_NAME} ${label}\" ${jobscript}"
+            def container = "${os}.${ver}.sif"
+            sh(label: "Create Slurm Job Script", script: """
+              exec test/ci/slurm-create-jobscript.sh "${label}" "${container}" "${jobscript}" ${ctestcmd}
+            """)
+            sh "./test/ci/slurm-submit.sh \"FairRoot \${JOB_BASE_NAME} ${label}\" ${jobscript}"
           }
           if (check == "warnings" || check == "doxygen") {
             discoverGitReferenceBuild()

test/ci/slurm-create-jobscript.sh

@@ -0,0 +1,41 @@
+#! /bin/bash
+
+if [ $# -lt 4 ]
+then
+	echo "*** Please call like: $0 LABEL CONTAINER JOBSH CTEST [CTESTARG ...]"
+	exit 1
+fi
+
+label="$1"; shift
+container="$1"; shift
+jobsh="$1"; shift
+# Convert commandline array into single string, with proper quoting
+ctestcmd="$(printf ' %q' "$@")"
+# Strip leading space
+ctestcmd="${ctestcmd:1}"
+
+echo "*** Creating job script ..: ${jobsh}"
+
+(
+	echo   '# #! /bin/bash'
+	echo   "# export LABEL=${label}"
+	echo   '  echo "*** Job started at .......: $(date -R)"'
+	echo   '  echo "*** Job ID ...............: $SLURM_JOB_ID"'
+	echo   '  echo "*** Compute node .........: $(hostname -f)"'
+	echo   "# source <(sed -e '/^#/d' -e '/^export/!s/^.*=/export &/' /etc/environment)"
+	printf '# ./test/test-start-container.sh %q %q\n' "${container}" "${ctestcmd}"
+	echo   '# retval=$?'
+	echo   '# mkdir -p build'
+	echo   '# echo $retval >"build/${LABEL}-last-exit-code"'
+	echo   '# exit $retval'
+	echo   'newhomedir="$(mktemp --tmpdir -d FairRoot-CI-home.XXXXXX)"'
+	echo   '  echo "*** Temporary homedir ....: $newhomedir"'
+	echo   '  unset http_proxy'
+	echo   '  unset HTTP_PROXY'
+	printf 'singularity exec -B/shared -H "${newhomedir}" %q bash -l -c %q\n' \
+		"${SINGULARITY_CONTAINER_ROOT}/fairroot/${container}" \
+		"${ctestcmd}"
+) >> "$jobsh"
+
+echo "*** Content:"
+sed -e 's/^/    /' "$jobsh"