Only run zero downtime push when app name provided and app exists.

Signed-off-by: Damien Le Berrigaud <damien@itsdamo.com>

out/assets/erroringCf

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+./$(dirname $0)/cf $*
+
+exit 1

out/cloud_foundry.go

@@ -54,13 +54,13 @@ func (cf *CloudFoundry) PushApp(
 	noStart bool,
 ) error {
 
-	if currentAppName == "" {
-		return cf.simplePush(manifest, path, currentAppName, vars, varsFiles, dockerUser, noStart)
-	} else {
+	if zdt.CanPush(cf.cf, currentAppName) {
 		pushFunction := func() error {
 			return cf.simplePush(manifest, path, currentAppName, vars, varsFiles, dockerUser, noStart)
 		}
 		return zdt.Push(cf.cf, currentAppName, pushFunction, showLogs)
+	} else {
+		return cf.simplePush(manifest, path, currentAppName, vars, varsFiles, dockerUser, noStart)
 	}
 }
 

out/zdt/push.go

@@ -5,6 +5,21 @@ import (
 	"os/exec"
 )
 
+func CanPush(
+	cf func(args ...string) *exec.Cmd,
+	currentAppName string,
+) bool {
+
+	if currentAppName == "" {
+		return false
+	}
+
+	findErr := cf("app", currentAppName).Run()
+	appExists := findErr == nil
+
+	return appExists
+}
+
 func Push(
 	cf func(args ...string) *exec.Cmd,
 	currentAppName string,

out/zdt/push_test.go

@@ -1,4 +1,4 @@
-package zdt
+package zdt_test
 
 import (
 	"errors"
@@ -7,20 +7,54 @@ import (
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	"github.com/onsi/gomega/gbytes"
+
+	"github.com/concourse/cf-resource/out/zdt"
 )
 
-var _ = Describe("BuildActions", func() {
-	stdout := gbytes.NewBuffer()
+var stdout *gbytes.Buffer
 
-	cf := func(args ...string) *exec.Cmd {
-		cmd := exec.Command("assets/cf", args...)
+func cli(path string) func(args ...string) *exec.Cmd {
+	return func(args ...string) *exec.Cmd {
+		cmd := exec.Command(path, args...)
 		cmd.Stdout = stdout
 		return cmd
 	}
+}
+
+var _ = Describe("CanPush", func() {
+	cf := cli("assets/cf")
+	errCf := cli("assets/erroringCf")
+
+	BeforeEach(func() {
+		stdout = gbytes.NewBuffer()
+	})
+
+	It("needs a currentAppName", func() {
+		Expect(zdt.CanPush(cf, "")).To(BeFalse())
+		Expect(stdout.Contents()).To(BeEmpty())
+	})
+
+	It("needs the app to exist", func() {
+		Expect(zdt.CanPush(errCf, "my-app")).To(BeFalse())
+		Expect(stdout).To(gbytes.Say("cf app my-app"))
+	})
+
+	It("is ok when app exists", func() {
+		Expect(zdt.CanPush(cf, "my-app")).To(BeTrue())
+		Expect(stdout).To(gbytes.Say("cf app my-app"))
+	})
+})
+
+var _ = Describe("Push", func() {
+	cf := cli("assets/cf")
+
+	BeforeEach(func() {
+		stdout = gbytes.NewBuffer()
+	})
 
 	It("pushes an app with zero downtime", func() {
 		pushFunction := func() error { return cf("push", "my-app").Run() }
-		err := Push(cf, "my-app", pushFunction, false)
+		err := zdt.Push(cf, "my-app", pushFunction, false)
 
 		Expect(err).NotTo(HaveOccurred())
 		Expect(stdout).To(gbytes.Say("cf rename my-app my-app-venerable"))
@@ -34,7 +68,7 @@ var _ = Describe("BuildActions", func() {
 			_ = cf("push", "my-app").Run()
 			return pushErr
 		}
-		err := Push(cf, "my-app", pushFunction, false)
+		err := zdt.Push(cf, "my-app", pushFunction, false)
 
 		Expect(err).To(Equal(pushErr))
 		Expect(stdout).To(gbytes.Say("cf rename my-app my-app-venerable"))
@@ -49,7 +83,7 @@ var _ = Describe("BuildActions", func() {
 			_ = cf("push", "my-app").Run()
 			return errors.New("push failed")
 		}
-		err := Push(cf, "my-app", pushFunction, true)
+		err := zdt.Push(cf, "my-app", pushFunction, true)
 
 		Expect(err).To(HaveOccurred())
 		Expect(stdout).To(gbytes.Say("cf rename my-app my-app-venerable"))

out/zdt/zdt_suite_test.go

@@ -0,0 +1,12 @@
+package zdt_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"testing"
+)
+
+func TestOut(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Zdt Suite")
+}