rebuilds/kernel: better logging of disk space

Trying to report situations where rebuild fails of low disk space.

plans/build-gating.fmf

@@ -46,3 +46,11 @@ adjust+:
       - how: fmf
         filter: "tag:gate-build"
         test: '^/tests/rebuilds/kernel$'
+
+    provision:
+      - how: virtual
+        hardware:
+          disk:
+            - size: ">= 120 GiB"
+          cpu:
+            processors: ">= 8"

tests/rebuilds/kernel/test.sh

@@ -61,6 +61,24 @@ REBOOTCOUNT="${REBOOTCOUNT:-0}"
 
 unset ARCH
 
+
+function log_disk_space () {
+    rlLogInfo 'Disk space:'
+
+    df -h | while read line; do
+        rlLogInfo "    $line"
+    done
+}
+
+function log_rpms () {
+    rlLogInfo 'Installed packages:'
+
+    rpm -qa | sort | while read line; do
+        rlLogInfo "    $line"
+    done
+}
+
+
 rlJournalStart
     rlPhaseStartSetup
         buTestHeader
@@ -71,22 +89,6 @@ rlJournalStart
         rlLogInfo "REBOOTCOUNT=$REBOOTCOUNT"
         rlLogInfo "RPM_BUILD_ID=$RPM_BUILD_ID"
 
-        # We'll use a lot of disk space (tens of GBs at least). The root FS
-        # often is the most beefy one in CI environemnts. Let's use it but also
-        # let's log what's actually available.
-        export TMPDIR=/test_tmp_root
-        rlRun "mkdir -p $TMPDIR"
-        rlLogInfo "TMPDIR=$TMPDIR"
-        rlLogInfo 'Disk space:'
-        df -h | while read line; do
-            rlLogInfo "    $line"
-        done
-
-        rlLogInfo 'Installed packages:'
-        rpm -qa | sort | while read line; do
-            rlLogInfo "    $line"
-        done
-
         rlRun "AFTER_REBOOT=no"
 
         if [ "$REBOOTCOUNT" != "0" ]; then
@@ -107,6 +109,9 @@ rlJournalStart
             rlRun "rngd -r /dev/hwrandom || rngd -r /dev/urandom"
 
             buPrepareSRPM "$KERNEL" "--nobest"
+
+            log_disk_space
+            log_rpms
         fi
     rlPhaseEnd
 
@@ -128,6 +133,9 @@ rlJournalStart
             else
                 rlLogInfo "rpmbuild kernel failed"
                 rlRun "RPMBUILD_OK=no"
+
+                log_disk_space
+                log_rpms
             fi
             rlBundleLogs "Build-log" BUILD_LOG
         rlPhaseEnd
@@ -153,6 +161,9 @@ rlJournalStart
                 else
                     rlRun "grub2-set-default 2"
                 fi
+
+                log_disk_space
+                log_rpms
             rlPhaseEnd
 
             rlPhaseStartTest "Reboot"