Automate execution of go mod download for pulumi new Go templates (#4353)

CHANGELOG.md

@@ -38,6 +38,9 @@ CHANGELOG
 - Add additional overloads to Deployment.RunAsync in .NET API.
   [#4286](https://github.com/pulumi/pulumi/pull/4286)
 
+- Automate execution of `go mod download` for `pulumi new` Go templates
+  [#4353](https://github.com/pulumi/pulumi/pull/4353)
+
 ## 1.14.0 (2020-04-01)
 - Fix error related to side-by-side versions of `@pulumi/pulumi`.
   [#4235](https://github.com/pulumi/pulumi/pull/4235)

pkg/cmd/pulumi/new.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"runtime"
 	"sort"
@@ -42,6 +43,7 @@ import (
 	"github.com/pulumi/pulumi/sdk/go/common/tokens"
 	"github.com/pulumi/pulumi/sdk/go/common/util/cmdutil"
 	"github.com/pulumi/pulumi/sdk/go/common/util/contract"
+	"github.com/pulumi/pulumi/sdk/go/common/util/executable"
 	"github.com/pulumi/pulumi/sdk/go/common/util/logging"
 	"github.com/pulumi/pulumi/sdk/go/common/workspace"
 )
@@ -567,6 +569,11 @@ func installDependencies(proj *workspace.Project, root string) error {
 		}
 	} else if strings.EqualFold(proj.Runtime.Name(), "dotnet") {
 		return dotnetInstallDependenciesAndBuild(proj, root)
+	} else if strings.EqualFold(proj.Runtime.Name(), "go") {
+		if err := goInstallDependencies(); err != nil {
+			return errors.Wrapf(err, "`go mod download` failed to install dependencies; rerun manually to try again, "+
+				"then run 'pulumi up' to perform an initial deployment")
+		}
 	}
 
 	return nil
@@ -616,6 +623,30 @@ func dotnetInstallDependenciesAndBuild(proj *workspace.Project, root string) err
 	return nil
 }
 
+// goInstallDependencies will install dependencies for the project by running `go mod download`
+func goInstallDependencies() error {
+	fmt.Println("Installing dependencies...")
+	fmt.Println()
+
+	gobin, err := executable.FindExecutable("go")
+	if err != nil {
+		return err
+	}
+
+	cmd := exec.Command(gobin, "mod", "download")
+	cmd.Env = os.Environ()
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	fmt.Println("Finished installing dependencies")
+	fmt.Println()
+
+	return nil
+}
+
 // printNextSteps prints out a series of commands that the user needs to run before their stack is able to be updated.
 func printNextSteps(proj *workspace.Project, originalCwd, cwd string, generateOnly bool, opts display.Options) {
 	var commands []string

sdk/go/common/util/executable/executable.go

@@ -0,0 +1,51 @@
+package executable
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/pulumi/pulumi/sdk/go/common/util/logging"
+)
+
+const unableToFindProgramTemplate = "unable to find program: %s"
+
+// FindExecutable attempts to find the needed executable in various locations on the
+// filesystem, eventually resorting to searching in $PATH.
+func FindExecutable(program string) (string, error) {
+	if runtime.GOOS == "windows" && !strings.HasSuffix(program, ".exe") {
+		program = fmt.Sprintf("%s.exe", program)
+	}
+	// look in the same directory
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "", errors.Wrap(err, "unable to get current working directory")
+	}
+
+	cwdProgram := filepath.Join(cwd, program)
+	if fileInfo, err := os.Stat(cwdProgram); !os.IsNotExist(err) && !fileInfo.Mode().IsDir() {
+		logging.V(5).Infof("program %s found in CWD", program)
+		return cwdProgram, nil
+	}
+
+	// look in $GOPATH/bin
+	if goPath := os.Getenv("GOPATH"); len(goPath) > 0 {
+		goPathProgram := filepath.Join(goPath, "bin", program)
+		if fileInfo, err := os.Stat(goPathProgram); !os.IsNotExist(err) && !fileInfo.Mode().IsDir() {
+			logging.V(5).Infof("program %s found in $GOPATH/bin", program)
+			return goPathProgram, nil
+		}
+	}
+
+	// look in the $PATH somewhere
+	if fullPath, err := exec.LookPath(program); err == nil {
+		logging.V(5).Infof("program %s found in $PATH", program)
+		return fullPath, nil
+	}
+
+	return "", errors.Errorf(unableToFindProgramTemplate, program)
+}

sdk/go/pulumi-language-go/main.go

@@ -24,7 +24,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"runtime"
 	"strings"
 	"syscall"
 
@@ -35,6 +34,7 @@ import (
 
 	"github.com/pulumi/pulumi/sdk/go/common/util/buildutil"
 	"github.com/pulumi/pulumi/sdk/go/common/util/cmdutil"
+	"github.com/pulumi/pulumi/sdk/go/common/util/executable"
 	"github.com/pulumi/pulumi/sdk/go/common/util/logging"
 	"github.com/pulumi/pulumi/sdk/go/common/util/rpcutil"
 	"github.com/pulumi/pulumi/sdk/go/common/version"
@@ -42,48 +42,12 @@ import (
 	pulumirpc "github.com/pulumi/pulumi/sdk/proto/go"
 )
 
-// findExecutable attempts to find the needed executable in various locations on the
-// filesystem, eventually resorting to searching in $PATH.
-func findExecutable(program string) (string, error) {
-	if runtime.GOOS == "windows" && !strings.HasSuffix(program, ".exe") {
-		program = fmt.Sprintf("%s.exe", program)
-	}
-	// look in the same directory
-	cwd, err := os.Getwd()
-	if err != nil {
-		return "", errors.Wrap(err, "unable to get current working directory")
-	}
-
-	cwdProgram := filepath.Join(cwd, program)
-	if fileInfo, err := os.Stat(cwdProgram); !os.IsNotExist(err) && !fileInfo.Mode().IsDir() {
-		logging.V(5).Infof("program %s found in CWD", program)
-		return cwdProgram, nil
-	}
-
-	// look in $GOPATH/bin
-	if goPath := os.Getenv("GOPATH"); len(goPath) > 0 {
-		goPathProgram := filepath.Join(goPath, "bin", program)
-		if fileInfo, err := os.Stat(goPathProgram); !os.IsNotExist(err) && !fileInfo.Mode().IsDir() {
-			logging.V(5).Infof("program %s found in $GOPATH/bin", program)
-			return goPathProgram, nil
-		}
-	}
-
-	// look in the $PATH somewhere
-	if fullPath, err := exec.LookPath(program); err == nil {
-		logging.V(5).Infof("program %s found in $PATH", program)
-		return fullPath, nil
-	}
-
-	return "", errors.Errorf("unable to find program: %s", program)
-}
-
 func findProgram(binary string) (*exec.Cmd, error) {
 	// we default to execution via `go run`
 	// the user can explicitly opt in to using a binary executable by specifying
 	// runtime.options.binary in the Pulumi.yaml
 	if binary != "" {
-		program, err := findExecutable(binary)
+		program, err := executable.FindExecutable(binary)
 		if err != nil {
 			return nil, errors.Wrap(err, "expected to find prebuilt executable")
 		}
@@ -92,7 +56,7 @@ func findProgram(binary string) (*exec.Cmd, error) {
 
 	// Fall back to 'go run' style executions
 	logging.V(5).Infof("No prebuilt executable specified, attempting invocation via 'go run'")
-	program, err := findExecutable("go")
+	program, err := executable.FindExecutable("go")
 	if err != nil {
 		return nil, errors.Wrap(err, "problem executing program (could not run language executor)")
 	}
@@ -221,7 +185,7 @@ func (host *goLanguageHost) GetRequiredPlugins(ctx context.Context,
 
 	logging.V(5).Infof("GetRequiredPlugins: Determining pulumi packages")
 
-	gobin, err := findExecutable("go")
+	gobin, err := executable.FindExecutable("go")
 	if err != nil {
 		return nil, errors.Wrap(err, "couldn't find go binary")
 	}