obmcutil: Add wait/timeout option

The option to block/wait for a state transition to complete has
been added. The transition is expected to occur within a set
timeout window and will terminate if the desired state has not
been observed within that window. It may be possible for the
state transition to complete outside this window, but it is
assumed to be a failure.

Change-Id: Icb9ff29f51b8712469fd9957b7e4b287704cb314
Signed-off-by: Anthony Wilson <wilsonan@us.ibm.com>

1 files changed, 79 insertions, 3 deletions

diff --git a/obmcutil b/obmcutil
index 26fd760..ed5dbc6 100644
--- a/obmcutil
+++ b/obmcutil
@@ -5,7 +5,7 @@ set -euo pipefail
 OPTS="bmcstate,bootprogress,chassisoff,chassison,chassisstate,hoststate,\
 power,poweroff,poweron,state,status"
 
-USAGE="Usage: obmcutil [-h]
+USAGE="Usage: obmcutil [-h] [--wait]
                 {$OPTS}"
 
 INTERFACE_ROOT=xyz.openbmc_project
@@ -14,6 +14,23 @@ STATE_INTERFACE=$INTERFACE_ROOT.State
 OBJECT_ROOT=/xyz/openbmc_project
 STATE_OBJECT=$OBJECT_ROOT/state
 
+## NOTE: The following global variables are used only in the run_timeout cmd.
+## By declaring these globally instead of passing them through the
+## intermediary functions, which may not be "best practice", the readability
+## and cleanliness of the code should at least be increased.
+
+# The command passed in to be executed (e.g. poweron/off, status, etc.)
+# This will be be used in some instances of error reporting
+G_ORIG_CMD=
+# The state an interface should be in after executing the requested command.
+G_REQUESTED_STATE=
+# The query to run during a poweron/off or chassison/off to check that
+# the requested state (G_REQUESTED_STATE) of the interface has been reached.
+G_QUERY=
+# Wait the set period of time for state transitions to be successful before
+# continuing on with the program or reporting an error if timeout reached.
+G_WAIT=
+
 print_help ()
 {
     echo "$USAGE"
@@ -23,17 +40,63 @@ print_help ()
     echo ""
     echo "optional arguments:"
     echo "  -h, --help          show this help message and exit"
+    echo "  -w, --wait          block until state transition succeeds or fails"
     exit 0
 }
 
+run_timeout ()
+{
+    local timeout="$1"; shift
+    local cmd="$@"
+
+    $cmd
+
+    # Run a background query for the transition to the expected state
+    # This will be killed if the transition doesn't succeed within
+    # a timeout period.
+    (
+        while ! grep -q $G_REQUESTED_STATE <<< $(handle_cmd $G_QUERY) ; do
+            sleep 1
+        done
+    ) &
+    child=$!
+
+    # Could be bad if process is killed before 'timeout' occurs if
+    # transition doesn't succeed.
+    trap -- "" SIGTERM
+
+    # Workaround for lack of 'timeout' command.
+    (
+        sleep $timeout
+        kill $child
+    ) > /dev/null 2>&1 &
+
+    if ! wait $child; then
+        echo "Unable to confirm '$G_ORIG_CMD' success" \
+        "within timeout period (${timeout}s)"
+    fi
+}
+
+run_cmd ()
+{
+    local cmd="$@";
+
+    if [ -n "$G_WAIT" ]; then
+        run_timeout $G_WAIT "$cmd"
+    else
+        $cmd
+    fi
+}
+
 set_property ()
 {
-    busctl set-property "$@"
+    run_cmd busctl set-property "$@"
 }
 
 get_property ()
 {
-    busctl get-property "$@"
+    G_WAIT=""
+    run_cmd busctl get-property "$@"
 }
 
 state_query ()
@@ -58,6 +121,8 @@ handle_cmd ()
             INTERFACE=$STATE_INTERFACE.Chassis
             PROPERTY=RequestedPowerTransition
             VALUE=$INTERFACE.Transition.Off
+            G_REQUESTED_STATE=$INTERFACE.PowerState.Off
+            G_QUERY="chassisstate"
             set_property $SERVICE $OBJECT $INTERFACE $PROPERTY "s" $VALUE
             ;;
         chassison)
@@ -66,6 +131,8 @@ handle_cmd ()
             INTERFACE=$STATE_INTERFACE.Chassis
             PROPERTY=RequestedPowerTransition
             VALUE=$INTERFACE.Transition.On
+            G_REQUESTED_STATE=$INTERFACE.PowerState.On
+            G_QUERY="chassisstate"
             set_property $SERVICE $OBJECT $INTERFACE $PROPERTY "s" $VALUE
             ;;
         poweroff)
@@ -74,6 +141,8 @@ handle_cmd ()
             INTERFACE=$STATE_INTERFACE.Host
             PROPERTY=RequestedHostTransition
             VALUE=$INTERFACE.Transition.Off
+            G_REQUESTED_STATE=$INTERFACE.HostState.Off
+            G_QUERY="hoststate"
             set_property $SERVICE $OBJECT $INTERFACE $PROPERTY "s" $VALUE
             ;;
         poweron)
@@ -82,6 +151,8 @@ handle_cmd ()
             INTERFACE=$STATE_INTERFACE.Host
             PROPERTY=RequestedHostTransition
             VALUE=$INTERFACE.Transition.On
+            G_REQUESTED_STATE=$INTERFACE.HostState.Running
+            G_QUERY="hoststate"
             set_property $SERVICE $OBJECT $INTERFACE $PROPERTY "s" $VALUE
             ;;
         bmcstate)
@@ -141,6 +212,10 @@ handle_cmd ()
 
 for arg in "$@"; do
     case $arg in
+        -w|--wait)
+            G_WAIT=30
+            continue
+            ;;
         -h|--help)
             print_help
             ;;
@@ -148,6 +223,7 @@ for arg in "$@"; do
             print_usage_err "Unknown option: $arg"
             ;;
         *)
+            G_ORIG_CMD=$arg
             handle_cmd $arg
             break
             ;;