From 7079ad0c42c4223cc98643a1b863cca4e604b281 Mon Sep 17 00:00:00 2001
From: Michael Schurter <schmichael@hashicorp.com>
Date: Tue, 25 Jul 2017 10:28:50 -0700
Subject: [PATCH 1/4] Mention env templates in nomad init

---
 command/init.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/command/init.go b/command/init.go
index b83c7cea9..b9e7ac43e 100644
--- a/command/init.go
+++ b/command/init.go
@@ -337,6 +337,15 @@ job "example" {
       #   change_signal = "SIGHUP"
       # }
 
+      # The "template" stanza can also be used to create env vars for tasks
+      # that prefer those to config files.
+      #
+      # template {
+      #   data        = "KEY={{ key \"service/my-key\" }}"
+      #   destination = "local/file.env"
+      #   env         = true
+      # }
+
       # The "vault" stanza instructs the Nomad client to acquire a token from
       # a HashiCorp Vault server. The Nomad servers must be configured and
       # authorized to communicate with Vault. By default, Nomad will inject

From 58d5cd140d41bf5b3f728bbe2d0889ed578a2fed Mon Sep 17 00:00:00 2001
From: Michael Schurter <schmichael@hashicorp.com>
Date: Tue, 25 Jul 2017 16:26:42 -0700
Subject: [PATCH 2/4] Mention restart

---
 command/init.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/command/init.go b/command/init.go
index b9e7ac43e..771b54f93 100644
--- a/command/init.go
+++ b/command/init.go
@@ -337,8 +337,9 @@ job "example" {
       #   change_signal = "SIGHUP"
       # }
 
-      # The "template" stanza can also be used to create env vars for tasks
-      # that prefer those to config files.
+      # The "template" stanza can also be used to create environment variables
+      # for tasks that prefer those to config files. The task will be restarted
+      # when data pulled from Consul or Vault changes.
       #
       # template {
       #   data        = "KEY={{ key \"service/my-key\" }}"

From e76d1e56ec1183e83ec3a88e99076b5540ea66c1 Mon Sep 17 00:00:00 2001
From: Michael Schurter <schmichael@hashicorp.com>
Date: Tue, 25 Jul 2017 16:34:41 -0700
Subject: [PATCH 3/4] Prevent using env templates with signals

---
 nomad/structs/structs.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nomad/structs/structs.go b/nomad/structs/structs.go
index 4e220c018..0cd56096c 100644
--- a/nomad/structs/structs.go
+++ b/nomad/structs/structs.go
@@ -3338,6 +3338,9 @@ func (t *Template) Validate() error {
 		if t.ChangeSignal == "" {
 			multierror.Append(&mErr, fmt.Errorf("Must specify signal value when change mode is signal"))
 		}
+		if t.Envvars {
+			multierror.Append(&mErr, fmt.Errorf("cannot use signals with env var templates"))
+		}
 	default:
 		multierror.Append(&mErr, TemplateChangeModeInvalidError)
 	}

From 99f97627878b12015a604ac8efbfd823bdb2069e Mon Sep 17 00:00:00 2001
From: Michael Schurter <schmichael@hashicorp.com>
Date: Tue, 25 Jul 2017 20:27:18 -0700
Subject: [PATCH 4/4] Test for template envvar validation

---
 nomad/structs/structs_test.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/nomad/structs/structs_test.go b/nomad/structs/structs_test.go
index 115447efc..462de13d7 100644
--- a/nomad/structs/structs_test.go
+++ b/nomad/structs/structs_test.go
@@ -1167,6 +1167,22 @@ func TestTask_Validate_Template(t *testing.T) {
 	if !strings.Contains(err.Error(), "same destination as") {
 		t.Fatalf("err: %s", err)
 	}
+
+	// Env templates can't use signals
+	task.Templates = []*Template{
+		{
+			Envvars:    true,
+			ChangeMode: "signal",
+		},
+	}
+
+	err = task.Validate(ephemeralDisk)
+	if err == nil {
+		t.Fatalf("expected error from Template.Validate")
+	}
+	if expected := "cannot use signals"; !strings.Contains(err.Error(), expected) {
+		t.Errorf("expected to find %q but found %v", expected, err)
+	}
 }
 
 func TestTemplate_Validate(t *testing.T) {