automated: linux: fix issues with static-delta OTA update

When updating the device using static deltas, the test script has to
wait for aktualizr-lite to complete installation before rebooting.

When there is no static detla available, the test job should end as
incomplete.

This patch also changes how the aklite signal is checked to align with
other OTA testing scripts.

Signed-off-by: Milosz Wasilewski <[email protected]>

automated/linux/ota-update/static-delta.sh

@@ -108,7 +108,7 @@ SIZE_SEARCH_STRING=".[].\"${CURRENT_OSTREE_SHA}\".u_size"
 DELTA_SIZE=$(jq -r "${SIZE_SEARCH_STRING}" delta.json)
 if [ -z "${DELTA_SIZE}" ] || [ "${DELTA_SIZE}" = "null" ]; then
     error_msg "Size of static delta for update from ${CURRENT_OSTREE_SHA} not found"
-    exit 0;
+    exit 1;
 fi
 
 # check how much disk is free
@@ -151,24 +151,21 @@ done
 if [ "${FILL_SIZE}" -gt 100 ]; then
     # no OTA should be performed
     # wait for 'install-post' signal
-    SIGNAL=$(</var/sota/ota.signal)
-    while [ ! "${SIGNAL}" = "install-post" ] && [ ! "${SIGNAL}" = "download-post" ]
+    while ! grep "install-post" /var/sota/ota.signal && ! grep "download-post" /var/sota/ota.signal
     do
         echo "Sleeping 1s"
         sleep 1
         cat /var/sota/ota.signal
-        SIGNAL=$(</var/sota/ota.signal)
-        echo "SIGNAL: ${SIGNAL}."
     done
-    sleep 5
-    if [ "${SIGNAL}" = "download-post" ]; then
+
+    if grep "download-post" /var/sota/ota.signal; then
         if (journalctl --no-pager -u aktualizr-lite | grep "Fetching ostree commit"); then
             report_fail "full-disk-abort-download"
         else
             report_pass "full-disk-abort-download"
         fi
     fi
-    if [ "${SIGNAL}" = "install-post" ]; then
+    if grep "install-post" /var/sota/ota.signal; then
         report_fail "full-disk-abort-download"
     fi
 else
@@ -192,6 +189,12 @@ else
             report_pass "ota-static-delta-update"
         fi
     done
+    while ! grep "install-post" /var/sota/ota.signal
+    do
+        echo "Waiting 1s for aklite to complete installation"
+        sleep 1
+        cat /var/sota/ota.signal
+    done
 fi
 journalctl --no-pager -u aktualizr-lite
 exit 0;