command/e2etest: an initial test for the primary workflow

This e2etest runs an init, plan, apply, destroy sequence against a test
configuration using the real template and null providers downloaded from
the official repository.

This test _does_ trample a bit on the scope of some already-existing
tests, but this is mainly just to check our assumptions about how
Terraform behaves to ensure that we can reach our main conclusion here:
that the main Terraform workflow commands interact correctly with each
other in real use and we can complete the full workflow.

command/e2etest/primary_test.go

@@ -0,0 +1,123 @@
+package e2etest
+
+import (
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/davecgh/go-spew/spew"
+)
+
+// The tests in this file are for the "primary workflow", which includes
+// variants of the following sequence, with different details:
+// terraform init
+// terraform plan
+// terraform apply
+// terraform destroy
+
+func TestPrimarySeparatePlan(t *testing.T) {
+	t.Parallel()
+
+	// This test reaches out to releases.hashicorp.com to download the
+	// template and null providers, so it can only run if network access is
+	// allowed.
+	skipIfCannotAccessNetwork(t)
+
+	tf := newTerraform("full-workflow-null")
+	defer tf.Close()
+
+	//// INIT
+	stdout, stderr, err := tf.Run("init")
+	if err != nil {
+		t.Fatalf("unexpected init error: %s\nstderr:\n%s", err, stderr)
+	}
+
+	// Make sure we actually downloaded the plugins, rather than picking up
+	// copies that might be already installed globally on the system.
+	if !strings.Contains(stdout, "- Downloading plugin for provider \"template\"") {
+		t.Errorf("template provider download message is missing from init output:\n%s", stdout)
+		t.Logf("(this can happen if you have a copy of the plugin in one of the global plugin search dirs)")
+	}
+	if !strings.Contains(stdout, "- Downloading plugin for provider \"null\"") {
+		t.Errorf("null provider download message is missing from init output:\n%s", stdout)
+		t.Logf("(this can happen if you have a copy of the plugin in one of the global plugin search dirs)")
+	}
+
+	//// PLAN
+	stdout, stderr, err = tf.Run("plan", "-out=tfplan")
+	if err != nil {
+		t.Fatalf("unexpected plan error: %s\nstderr:\n%s", err, stderr)
+	}
+
+	if !strings.Contains(stdout, "1 to add, 0 to change, 0 to destroy") {
+		t.Errorf("incorrect plan tally; want 1 to add:\n%s", stdout)
+	}
+
+	plan, err := tf.Plan("tfplan")
+	if err != nil {
+		t.Fatalf("failed to read plan file: %s", err)
+	}
+
+	stateResources := plan.State.RootModule().Resources
+	diffResources := plan.Diff.RootModule().Resources
+
+	if len(stateResources) != 1 || stateResources["data.template_file.test"] == nil {
+		t.Errorf("incorrect state in plan; want just data.template_file.test to have been rendered, but have:\n%s", spew.Sdump(stateResources))
+	}
+	if len(diffResources) != 1 || diffResources["null_resource.test"] == nil {
+		t.Errorf("incorrect diff in plan; want just null_resource.test to have been rendered, but have:\n%s", spew.Sdump(diffResources))
+	}
+
+	//// APPLY
+	stdout, stderr, err = tf.Run("apply", "tfplan")
+	if err != nil {
+		t.Fatalf("unexpected apply error: %s\nstderr:\n%s", err, stderr)
+	}
+
+	if !strings.Contains(stdout, "Resources: 1 added, 0 changed, 0 destroyed") {
+		t.Errorf("incorrect apply tally; want 1 added:\n%s", stdout)
+	}
+
+	state, err := tf.LocalState()
+	if err != nil {
+		t.Fatalf("failed to read state file: %s", err)
+	}
+
+	stateResources = state.RootModule().Resources
+	var gotResources []string
+	for n := range stateResources {
+		gotResources = append(gotResources, n)
+	}
+	sort.Strings(gotResources)
+
+	wantResources := []string{
+		"data.template_file.test",
+		"null_resource.test",
+	}
+
+	if !reflect.DeepEqual(gotResources, wantResources) {
+		t.Errorf("wrong resources in state\ngot: %#v\nwant: %#v", gotResources, wantResources)
+	}
+
+	//// DESTROY
+	stdout, stderr, err = tf.Run("destroy", "-force")
+	if err != nil {
+		t.Fatalf("unexpected destroy error: %s\nstderr:\n%s", err, stderr)
+	}
+
+	if !strings.Contains(stdout, "Resources: 2 destroyed") {
+		t.Errorf("incorrect destroy tally; want 2 destroyed:\n%s", stdout)
+	}
+
+	state, err = tf.LocalState()
+	if err != nil {
+		t.Fatalf("failed to read state file after destroy: %s", err)
+	}
+
+	stateResources = state.RootModule().Resources
+	if len(stateResources) != 0 {
+		t.Errorf("wrong resources in state after destroy; want none, but still have:%s", spew.Sdump(stateResources))
+	}
+
+}

command/e2etest/test-fixtures/full-workflow-null/main.tf

@@ -0,0 +1,22 @@
+
+variable "name" {
+  default = "world"
+}
+
+data "template_file" "test" {
+  template = "Hello, $${name}"
+
+  vars = {
+    name = "${var.name}"
+  }
+}
+
+resource "null_resource" "test" {
+  triggers = {
+    greeting = "${data.template_file.test.rendered}"
+  }
+}
+
+output "greeting" {
+  value = "${null_resource.test.triggers["greeting"]}"
+}