From 07a7652535d2e97239c4d4c02ae27089712e9450 Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Wed, 16 Sep 2015 16:20:19 -0700
Subject: [PATCH] command: easier exit codes, check if eval is already finished

---
 command/eval_monitor.go |  5 ++---
 command/monitor.go      | 28 +++++++++++++++++-----------
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/command/eval_monitor.go b/command/eval_monitor.go
index b7bcb0117..78b84e5ac 100644
--- a/command/eval_monitor.go
+++ b/command/eval_monitor.go
@@ -22,9 +22,8 @@ Usage: nomad eval-monitor [options] <evaluation>
   real-time to the terminal.
 
   The command will exit when the given evaluation reaches a terminal
-  state (completed or failed). The exit status will reflect the
-  result of the evaluation (0 on success, 1 on failure). Exit code
-  1 may also be encountered for client connectivity errors.
+  state (completed or failed). The exit code indicates the status
+  of the monitoring only; it does not reflect the evaluation status.
 
 General Options:
 
diff --git a/command/monitor.go b/command/monitor.go
index 6ad2f9c8f..4ecd8c625 100644
--- a/command/monitor.go
+++ b/command/monitor.go
@@ -129,10 +129,23 @@ func (m *monitor) update(eval *api.Evaluation, allocs []*api.AllocationListStub)
 
 // monitor is used to start monitoring the given evaluation ID. It
 // writes output directly to the monitor's ui, and returns the
-// exit code for the command. The return code is 0 if monitoring
-// succeeded and exited successfully, or 1 if an error was encountered
-// or the eval status was returned as failed.
+// exit code for the command. The return code indicates monitoring
+// success or failure ONLY. It is no indication of the outcome of
+// the evaluation, since conflating these values obscures things.
 func (m *monitor) monitor(evalID string) int {
+	// Check if the eval has already completed and fast-path it.
+	eval, _, err := m.client.Evaluations().Info(evalID, nil)
+	if err != nil {
+		m.ui.Error(fmt.Sprintf("Error reading evaluation: %s", err))
+		return 1
+	}
+	switch eval.Status {
+	case structs.EvalStatusComplete, structs.EvalStatusFailed:
+		m.ui.Info(fmt.Sprintf("Evaluation %q already finished with status %q",
+			evalID, eval.Status))
+		return 0
+	}
+
 	m.ui.Info(fmt.Sprintf("Monitoring evaluation %q", evalID))
 	for {
 		// Check the current state of things
@@ -165,14 +178,7 @@ func (m *monitor) monitor(evalID string) int {
 		if eval.NextEval != "" {
 			return m.monitor(eval.NextEval)
 		}
-
-		// Check if the eval is complete
-		switch eval.Status {
-		case structs.EvalStatusComplete:
-			return 0
-		case structs.EvalStatusFailed:
-			return 1
-		}
+		break
 	}
 
 	return 0