From 8340912a28c23afda18abb2943bc0c012d450b8f Mon Sep 17 00:00:00 2001
From: Diptanu Choudhury <diptanuc@gmail.com>
Date: Mon, 28 Mar 2016 12:25:16 -0700
Subject: [PATCH] Added support for interpolation in check cmd and args

---
 client/driver/executor/executor.go      |  8 +++++++-
 client/driver/executor/executor_test.go | 16 +++++++++++++---
 nomad/mock/mock.go                      | 14 +++++++++++++-
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/client/driver/executor/executor.go b/client/driver/executor/executor.go
index e9a45e2d5..2136eef49 100644
--- a/client/driver/executor/executor.go
+++ b/client/driver/executor/executor.go
@@ -545,11 +545,17 @@ func (e *UniversalExecutor) createCheck(check *structs.ServiceCheck, checkID str
 	return nil, fmt.Errorf("couldn't create check for %v", check.Name)
 }
 
-// interpolateServices interpolates tags in a service with values from the
+// interpolateServices interpolates tags in a service and checks with values from the
 // task's environment.
 func (e *UniversalExecutor) interpolateServices(task *structs.Task) {
 	e.ctx.TaskEnv.Build()
 	for _, service := range task.Services {
+		for _, check := range service.Checks {
+			if check.Type == structs.ServiceCheckScript {
+				check.Cmd = e.ctx.TaskEnv.ReplaceEnv(check.Cmd)
+				check.Args = e.ctx.TaskEnv.ParseAndReplace(check.Args)
+			}
+		}
 		service.Tags = e.ctx.TaskEnv.ParseAndReplace(service.Tags)
 	}
 }
diff --git a/client/driver/executor/executor_test.go b/client/driver/executor/executor_test.go
index 0dc91e17c..f5322d0b3 100644
--- a/client/driver/executor/executor_test.go
+++ b/client/driver/executor/executor_test.go
@@ -278,8 +278,18 @@ func TestExecutorInterpolateServices(t *testing.T) {
 
 	executor.(*UniversalExecutor).ctx = ctx
 	executor.(*UniversalExecutor).interpolateServices(task)
-	expected := []string{"pci:true", "datacenter:dc1"}
-	if !reflect.DeepEqual(task.Services[0].Tags, expected) {
-		t.Fatalf("expected: %v, actual: %v", expected, task.Services[0].Tags)
+	expectedTags := []string{"pci:true", "datacenter:dc1"}
+	if !reflect.DeepEqual(task.Services[0].Tags, expectedTags) {
+		t.Fatalf("expected: %v, actual: %v", expectedTags, task.Services[0].Tags)
+	}
+
+	expectedCheckCmd := "/usr/local/check-table-mysql"
+	expectedCheckArgs := []string{"5.6"}
+	if !reflect.DeepEqual(task.Services[0].Checks[0].Cmd, expectedCheckCmd) {
+		t.Fatalf("expected: %v, actual: %v", expectedCheckCmd, task.Services[0].Checks[0].Cmd)
+	}
+
+	if !reflect.DeepEqual(task.Services[0].Checks[0].Args, expectedCheckArgs) {
+		t.Fatalf("expected: %v, actual: %v", expectedCheckArgs, task.Services[0].Checks[0].Args)
 	}
 }
diff --git a/nomad/mock/mock.go b/nomad/mock/mock.go
index 432917c80..24ea87f20 100644
--- a/nomad/mock/mock.go
+++ b/nomad/mock/mock.go
@@ -47,7 +47,9 @@ func Node() *structs.Node {
 			"consul": "foobar.dc1",
 		},
 		Meta: map[string]string{
-			"pci-dss": "true",
+			"pci-dss":  "true",
+			"database": "mysql",
+			"version":  "5.6",
 		},
 		NodeClass: "linux-medium-pci",
 		Status:    structs.NodeStatusReady,
@@ -97,6 +99,16 @@ func Job() *structs.Job {
 								Name:      "${TASK}-frontend",
 								PortLabel: "http",
 								Tags:      []string{"pci:${meta.pci-dss}", "datacenter:${node.datacenter}"},
+								Checks: []*structs.ServiceCheck{
+									{
+										Name:     "check-table",
+										Type:     structs.ServiceCheckScript,
+										Cmd:      "/usr/local/check-table-${meta.database}",
+										Args:     []string{"${meta.version}"},
+										Interval: 30 * time.Second,
+										Timeout:  5 * time.Second,
+									},
+								},
 							},
 							{
 								Name:      "${TASK}-admin",