FIX: Topology reservation

Last attempt [0] is doing more harm then good. If testbed is down
but recovered quickly enough (reboot, temporary ssh connectivity
issue, ...) it never gets back into pool making other testbeds
overloaded and queued.

This patch is suppose to partially revert previous behavior until
proper patch will follow.

[0] https://gerrit.fd.io/r/c/csit/+/21148

Signed-off-by: Peter Mikus <pmikus@cisco.com>
Change-Id: I8203946d10d3e7dd51e97519d679246b5dae59e3

1 files changed, 19 insertions, 16 deletions

diff --git a/resources/tools/scripts/topo_reservation.py b/resources/tools/scripts/topo_reservation.py
index 77d84efeba..e7e1ff6bab 100755
--- a/resources/tools/scripts/topo_reservation.py
+++ b/resources/tools/scripts/topo_reservation.py
@@ -28,6 +28,7 @@ from resources.libraries.python.ssh import exec_cmd
 
 
 RESERVATION_DIR = "/tmp/reservation_dir"
+RESERVATION_NODE = "TG"
 
 
 def diag_cmd(node, cmd):
@@ -38,9 +39,9 @@ def diag_cmd(node, cmd):
     :type ssh: dict
     :type cmd: str
     """
-    print "+", cmd
+    print('+ {cmd}'.format(cmd=cmd))
     _, stdout, _ = exec_cmd(node, cmd)
-    print stdout
+    print(stdout)
 
 
 def main():
@@ -88,37 +89,39 @@ def main():
     # we are using it, because testing shows SSH access to DUT
     # during test affects its performance (bursts of lost packets).
     try:
-        tgn = topology["TG"]
+        node = topology[RESERVATION_NODE]
     except KeyError:
-        print "Topology file does not contain 'TG' node"
+        print("Topology file does not contain '{node}' node".
+              format(node=RESERVATION_NODE))
         return 1
 
     # For system reservation we use mkdir it is an atomic operation and we can
     # store additional data (time, client_ID, ..) within reservation directory.
     if args.cancel:
-        ret, _, err = exec_cmd(tgn, "rm -r {}".format(RESERVATION_DIR))
+        ret, _, err = exec_cmd(node, "rm -r {dir}".format(dir=RESERVATION_DIR))
         if ret:
-            print "Cancellation unsuccessful:\n{}".format(err)
+            print("Cancellation unsuccessful:\n{err}".format(err=err))
         return ret
     # Before critical section, output can be outdated already.
     print("Diagnostic commands:")
     # -d and * are to supress "total <size>", see https://askubuntu.com/a/61190
-    diag_cmd(tgn, "ls --full-time -cd '{dir}'/*".format(dir=RESERVATION_DIR))
-    print("Attempting reservation.")
+    diag_cmd(node, "ls --full-time -cd '{dir}'/*".format(dir=RESERVATION_DIR))
+    print("Attempting testbed reservation.")
     # Entering critical section.
-    ret, _, err = exec_cmd(tgn, "mkdir '{dir}'".format(dir=RESERVATION_DIR))
+    ret, _, _ = exec_cmd(node, "mkdir '{dir}'".format(dir=RESERVATION_DIR))
     # Critical section is over.
     if ret:
-        print("Already reserved by another job:\n{}".format(err))
+        _, stdo, _ = exec_cmd(node, "ls '{dir}'/*".format(dir=RESERVATION_DIR))
+        print("Testbed already reserved by:\n{stdo}".format(stdo=stdo))
         return 2
     # Here the script knows it is the only owner of the testbed.
-    print("Success, writing test run info to reservation dir.")
-    ret2, _, err = exec_cmd(
-        tgn, "touch '{dir}/{runtag}'"\
+    print("Reservation success, writing additional info to reservation dir.")
+    ret, _, err = exec_cmd(
+        node, "touch '{dir}/{runtag}'"\
         .format(dir=RESERVATION_DIR, runtag=args.runtag))
-    if ret2:
-        print("Writing test run info failed, but continuing anyway:\n{}".format(
-            err))
+    if ret:
+        print("Writing test run info failed, but continuing anyway:\n{err}".
+              format(err=err))
     return 0