Add support for setting DATABASE_URL from vcap services

- This is replicating behavior that exists in buildpack app lifecycle

Signed-off-by: Tom Kennedy <tom.kennedy@broadcom.com>

Author: tomkennedy513

cmd/builder/cli/cli.go

@@ -13,6 +13,7 @@ import (
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/archive"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/buildpacks"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/credhub"
+	"code.cloudfoundry.org/cnbapplifecycle/pkg/databaseuri"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/errors"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/keychain"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/log"
@@ -54,7 +55,6 @@ var (
 	systemBuildpacksDir       string
 	extensionsDir             string
 	downloadCacheDir          string
-	err                       error
 	credhubConnectionAttempts int
 	credhubRetryDelay         time.Duration
 )
@@ -95,7 +95,20 @@ var builderCmd = &cobra.Command{
 
 		if err := credhub.InterpolateServiceRefs(credhubConnectionAttempts, credhubRetryDelay); err != nil {
 			logger.Error(err.Error())
-			return errors.ErrLaunching
+			return errors.ErrGenericBuild
+		}
+
+		databaseUrl, err := databaseuri.ParseDatabaseURI(os.Getenv("VCAP_SERVICES"))
+		if err != nil {
+			logger.Errorf("failed to parse database URI, error: %s\n", err.Error())
+			return errors.ErrGenericBuild
+		}
+		if databaseUrl != "" {
+			err = os.Setenv("DATABASE_URL", databaseUrl)
+			if err != nil {
+				logger.Errorf("Unable to set DATABASE_URL envirionment variable: %v", err)
+				return errors.ErrGenericBuild
+			}
 		}
 
 		tempDirs := map[string]*string{

cmd/launcher/cli/cli.go

@@ -17,6 +17,7 @@ import (
 
 	builderCli "code.cloudfoundry.org/cnbapplifecycle/cmd/builder/cli"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/credhub"
+	"code.cloudfoundry.org/cnbapplifecycle/pkg/databaseuri"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/errors"
 	"code.cloudfoundry.org/cnbapplifecycle/pkg/log"
 )
@@ -93,6 +94,19 @@ func Launch(osArgs []string, theLauncher TheLauncher) error {
 		return errors.ErrLaunching
 	}
 
+	databaseUrl, err := databaseuri.ParseDatabaseURI(os.Getenv("VCAP_SERVICES"))
+	if err != nil {
+		logger.Errorf("failed to parse database URI, error: %s\n", err.Error())
+		return errors.ErrLaunching
+	}
+	if databaseUrl != "" {
+		err = os.Setenv("DATABASE_URL", databaseUrl)
+		if err != nil {
+			logger.Errorf("Unable to set DATABASE_URL envirionment variable: %v", err)
+			return errors.ErrLaunching
+		}
+	}
+
 	var self string
 	var isSidecar bool
 	if len(osArgs) > 1 {

pkg/databaseuri/databaseuri.go

@@ -0,0 +1,48 @@
+package databaseuri
+
+import (
+	"encoding/json"
+	"net/url"
+)
+
+func ParseDatabaseURI(services string) (string, error) {
+	if services == "" {
+		return "", nil
+	}
+
+	data := map[string][]struct {
+		Credentials struct {
+			Uri string `json:"uri"`
+		} `json:"credentials"`
+	}{}
+	if err := json.Unmarshal([]byte(services), &data); err != nil {
+		return "", err
+	}
+
+	var creds []string
+	for _, v1 := range data {
+		for _, v2 := range v1 {
+			if v2.Credentials.Uri != "" {
+				creds = append(creds, v2.Credentials.Uri)
+			}
+		}
+	}
+
+	schemes := map[string]string{
+		"mysql":      "mysql2",
+		"mysql2":     "",
+		"postgres":   "",
+		"postgresql": "postgres",
+	}
+	for _, service_uri := range creds {
+		if uri, err := url.Parse(service_uri); err == nil {
+			if val, ok := schemes[uri.Scheme]; ok {
+				if val != "" {
+					uri.Scheme = val
+				}
+				return uri.String(), nil
+			}
+		}
+	}
+	return "", nil
+}

pkg/databaseuri/databaseuri_test.go

@@ -0,0 +1,110 @@
+package databaseuri_test
+
+import (
+	"testing"
+
+	"code.cloudfoundry.org/cnbapplifecycle/pkg/databaseuri"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestDatabaseuri(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Databaseuri Suite")
+}
+
+var _ = Describe("ParseDatabaseURI", func() {
+	It("ignores services without credentials.uri", func() {
+		services := `{"eg":[{}]}`
+		uri, err := databaseuri.ParseDatabaseURI(services)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(uri).To(BeEmpty())
+	})
+
+	It("returns empty when there are non relational database services", func() {
+		services := `{"eg":[{"credentials":{"uri":"sendgrid://foo:bar@host/db"}}]}`
+		uri, err := databaseuri.ParseDatabaseURI(services)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(uri).To(BeEmpty())
+	})
+
+	It("returns empty when there are no services", func() {
+		services := "{}"
+		uri, err := databaseuri.ParseDatabaseURI(services)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(uri).To(BeEmpty())
+	})
+
+	It("returns empty when services are empty", func() {
+		services := ""
+		uri, err := databaseuri.ParseDatabaseURI(services)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(uri).To(BeEmpty())
+	})
+
+	Context("when there are relational database services", func() {
+		Context("with a mysql URI", func() {
+			It("changes the scheme to mysql2", func() {
+				services := `{"eg":[{"credentials":{"uri":"mysql://username:password@host/db"}}]}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal("mysql2://username:password@host/db"))
+			})
+		})
+		Context("with a mysql2 URI", func() {
+			It("returns the URI unchanged", func() {
+				services := `{"eg":[{"credentials":{"uri":"mysql2://username:password@host/db"}}]}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal("mysql2://username:password@host/db"))
+			})
+		})
+		Context("with a postgres URI", func() {
+			It("returns the URI unchanged", func() {
+				services := `{"eg":[{"credentials":{"uri":"postgres://username:password@host/db"}}]}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal("postgres://username:password@host/db"))
+			})
+		})
+		Context("with a postgresql URI", func() {
+			It("changes the scheme to postgres", func() {
+				services := `{"eg":[{"credentials":{"uri":"postgresql://username:password@host/db"}}]}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal("postgres://username:password@host/db"))
+			})
+		})
+		Context("with multiple relational database URIs", func() {
+			It("returns the first one found", func() {
+				services := `{
+					"abc":[{"credentials":{"uri":"postgres://username:password@host/db1"}}],
+					"def":[{"credentials":{"uri":"postgres://username:password@host/db2"}}]
+				}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal("postgres://username:password@host/db1"))
+			})
+		})
+		Context("with an invalid URI", func() {
+			It("returns an empty string", func() {
+				services := `{"eg":[{"credentials":{"uri":"postgresql://invalid:password@host/%a"}}]}`
+				uri, err := databaseuri.ParseDatabaseURI(services)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(uri).To(Equal(""))
+			})
+		})
+	})
+
+	It("handles multiple services correctly", func() {
+		services := `{
+			"abc":[{"credentials":{"uri":"u1"}}],
+			"def":[{"other":"data"}],
+			"ghi":[{"credentials":{"other":"data"}}],
+			"jkl":[{},{"credentials":{"uri":"mysql://username:password@host/db"}}]
+		}`
+		uri, err := databaseuri.ParseDatabaseURI(services)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(uri).To(Equal("mysql2://username:password@host/db"))
+	})
+})