fix go deployments when missing go.sum

scanner/go.go

@@ -14,19 +14,13 @@ func configureGo(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
 		return nil, nil
 	}
 
-	s := &SourceInfo{
-		Files:  templates("templates/go"),
-		Family: "Go",
-		Port:   8080,
-		Env: map[string]string{
-			"PORT": "8080",
-		},
-		Runtime: plan.RuntimeStruct{Language: "go"},
-	}
+	vars := make(map[string]interface{})
+
+	var skipDeploy bool
 
 	if !absFileExists("go.sum") {
-		s.SkipDeploy = true
-		terminal.Warn("no go.sum file found, please adjust your Dockerfile to remove references to go.sum")
+		vars["skipGoSum"] = true
+		skipDeploy = true
 	}
 
 	gomod, parseErr := parseModfile()
@@ -38,8 +32,18 @@ func configureGo(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
 		version = gomod.Go.Version
 	}
 
-	s.BuildArgs = map[string]string{
-		"GO_VERSION": version,
+	s := &SourceInfo{
+		Files:  templatesExecute("templates/go", vars),
+		Family: "Go",
+		Port:   8080,
+		Env: map[string]string{
+			"PORT": "8080",
+		},
+		Runtime: plan.RuntimeStruct{Language: "go", Version: version},
+		BuildArgs: map[string]string{
+			"GO_VERSION": version,
+		},
+		SkipDeploy: skipDeploy,
 	}
 
 	return s, nil

scanner/templates/go/Dockerfile

@@ -2,7 +2,11 @@ ARG GO_VERSION=1
 FROM golang:${GO_VERSION}-bookworm as builder
 
 WORKDIR /usr/src/app
+{{ if .skipGoSum -}}
+COPY go.mod ./
+{{ else -}}
 COPY go.mod go.sum ./
+{{ end -}}
 RUN go mod download && go mod verify
 COPY . .
 RUN go build -v -o /run-app .

test/deployer/deployer_test.go

@@ -294,6 +294,31 @@ func TestLaunchDjangoBasic(t *testing.T) {
 	require.Contains(t, string(body), "Hello, world. You're at the polls index.")
 }
 
+func TestLaunchGoNoGoSum(t *testing.T) {
+	deploy := testDeployer(t,
+		withFixtureApp("go-no-go-sum"),
+		createRandomApp,
+		testlib.WithoutCustomize,
+		testlib.WithouExtensions,
+		testlib.DeployNow,
+		withWorkDirAppSource,
+		testlib.CleanupBeforeExit,
+	)
+
+	manifest, err := deploy.Output().ArtifactManifest()
+	require.NoError(t, err)
+	require.NotNil(t, manifest)
+
+	require.Equal(t, "go", manifest.Plan.Runtime.Language)
+	require.Equal(t, "1.22.6", manifest.Plan.Runtime.Version)
+
+	appName := deploy.Extra["appName"].(string)
+
+	body, err := testlib.RunHealthCheck(fmt.Sprintf("https://%s.fly.dev/", appName))
+	require.NoError(t, err)
+	require.Contains(t, string(body), "Hello from Go!")
+}
+
 func createRandomApp(d *testlib.DeployTestRun) {
 	appName := d.CreateRandomAppName()
 	require.NotEmpty(d, appName)

test/fixtures/go-no-go-sum/go.mod

@@ -0,0 +1,3 @@
+module example.com/m
+
+go 1.22.6

test/fixtures/go-no-go-sum/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"os"
+)
+
+func main() {
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+
+	}
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Hello from Go!"))
+	})
+
+	log.Println("listening on", port)
+	log.Fatal(http.ListenAndServe(":"+port, nil))
+}