Merge pull request #1079 from urfave/binary-size

Add binary size bounds checking

.github/workflows/cli.yml

@@ -42,10 +42,14 @@ jobs:
         if: matrix.go == 1.13 && matrix.os == 'ubuntu-latest'
         run: test -z $(gofmt -l .)
 
-      - name: Run Tests
+      - name: vet
-        run: |
+        run: go run internal/build/build.go vet
-          go run build.go vet
+
-          go run build.go test
+      - name: test
+        run: go run internal/build/build.go test
+
+      - name: check-binary-size
+        run: go run internal/build/build.go check-binary-size
 
       - name: Upload coverage to Codecov
         if: success() && matrix.go == 1.13 && matrix.os == 'ubuntu-latest'
@@ -91,11 +95,11 @@ jobs:
       - name: Run Tests (v1)
         if: contains(github.base_ref, 'v1')
         run: |
-          go run build.go gfmrun docs/v1/manual.md
+          go run internal/build/build.go gfmrun docs/v1/manual.md
-          go run build.go toc docs/v1/manual.md
+          go run internal/build/build.go toc docs/v1/manual.md
 
       - name: Run Tests (v2)
         if: contains(github.base_ref, 'master')
         run: |
-          go run build.go gfmrun docs/v2/manual.md
+          go run internal/build/build.go gfmrun docs/v2/manual.md
-          go run build.go toc docs/v2/manual.md
+          go run internal/build/build.go toc docs/v2/manual.md

.gitignore

@@ -3,3 +3,5 @@
 node_modules/
 vendor
 .idea
+internal/*/built-example
+coverage.txt

build.go

@@ -1,180 +0,0 @@
-//+build ignore
-
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"os"
-	"os/exec"
-	"strings"
-
-	"github.com/urfave/cli/v2"
-)
-
-var packages = []string{"cli", "altsrc"}
-
-func main() {
-	app := cli.NewApp()
-
-	app.Name = "builder"
-	app.Usage = "Generates a new urfave/cli build!"
-
-	app.Commands = cli.Commands{
-		{
-			Name:   "vet",
-			Action: VetActionFunc,
-		},
-		{
-			Name:   "test",
-			Action: TestActionFunc,
-		},
-		{
-			Name:   "gfmrun",
-			Action: GfmrunActionFunc,
-		},
-		{
-			Name:   "toc",
-			Action: TocActionFunc,
-		},
-	}
-
-	err := app.Run(os.Args)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
-
-func runCmd(arg string, args ...string) error {
-	cmd := exec.Command(arg, args...)
-
-	cmd.Stdin = os.Stdin
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-
-	return cmd.Run()
-}
-
-func VetActionFunc(_ *cli.Context) error {
-	return runCmd("go", "vet")
-}
-
-func TestActionFunc(c *cli.Context) error {
-	for _, pkg := range packages {
-		var packageName string
-
-		if pkg == "cli" {
-			packageName = "github.com/urfave/cli/v2"
-		} else {
-			packageName = fmt.Sprintf("github.com/urfave/cli/v2/%s", pkg)
-		}
-
-		coverProfile := fmt.Sprintf("--coverprofile=%s.coverprofile", pkg)
-
-		err := runCmd("go", "test", "-v", coverProfile, packageName)
-		if err != nil {
-			return err
-		}
-	}
-
-	return testCleanup()
-}
-
-func testCleanup() error {
-	var out bytes.Buffer
-
-	for _, pkg := range packages {
-		file, err := os.Open(fmt.Sprintf("%s.coverprofile", pkg))
-		if err != nil {
-			return err
-		}
-
-		b, err := ioutil.ReadAll(file)
-		if err != nil {
-			return err
-		}
-
-		out.Write(b)
-		err = file.Close()
-		if err != nil {
-			return err
-		}
-
-		err = os.Remove(fmt.Sprintf("%s.coverprofile", pkg))
-		if err != nil {
-			return err
-		}
-	}
-
-	outFile, err := os.Create("coverage.txt")
-	if err != nil {
-		return err
-	}
-
-	_, err = out.WriteTo(outFile)
-	if err != nil {
-		return err
-	}
-
-	err = outFile.Close()
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func GfmrunActionFunc(c *cli.Context) error {
-	filename := c.Args().Get(0)
-	if filename == "" {
-		filename = "README.md"
-	}
-
-	file, err := os.Open(filename)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-
-	var counter int
-	scanner := bufio.NewScanner(file)
-	for scanner.Scan() {
-		if strings.Contains(scanner.Text(), "package main") {
-			counter++
-		}
-	}
-
-	err = file.Close()
-	if err != nil {
-		return err
-	}
-
-	err = scanner.Err()
-	if err != nil {
-		return err
-	}
-
-	return runCmd("gfmrun", "-c", fmt.Sprint(counter), "-s", filename)
-}
-
-func TocActionFunc(c *cli.Context) error {
-	filename := c.Args().Get(0)
-	if filename == "" {
-		filename = "README.md"
-	}
-
-	err := runCmd("markdown-toc", "-i", filename)
-	if err != nil {
-		return err
-	}
-
-	err = runCmd("git", "diff", "--exit-code")
-	if err != nil {
-		return err
-	}
-
-	return nil
-}

internal/build/build.go

@@ -0,0 +1,292 @@
+// local build script file, similar to a makefile or collection of bash scripts in other projects
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"math"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/urfave/cli/v2"
+)
+
+var packages = []string{"cli", "altsrc"}
+
+func main() {
+	app := cli.NewApp()
+
+	app.Name = "builder"
+	app.Usage = "Generates a new urfave/cli build!"
+
+	app.Commands = cli.Commands{
+		{
+			Name:   "vet",
+			Action: VetActionFunc,
+		},
+		{
+			Name:   "test",
+			Action: TestActionFunc,
+		},
+		{
+			Name:   "gfmrun",
+			Action: GfmrunActionFunc,
+		},
+		{
+			Name:   "toc",
+			Action: TocActionFunc,
+		},
+		{
+			Name:   "check-binary-size",
+			Action: checkBinarySizeActionFunc,
+		},
+	}
+
+	err := app.Run(os.Args)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func runCmd(arg string, args ...string) error {
+	cmd := exec.Command(arg, args...)
+
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}
+
+func VetActionFunc(_ *cli.Context) error {
+	return runCmd("go", "vet")
+}
+
+func TestActionFunc(c *cli.Context) error {
+	for _, pkg := range packages {
+		var packageName string
+
+		if pkg == "cli" {
+			packageName = "github.com/urfave/cli/v2"
+		} else {
+			packageName = fmt.Sprintf("github.com/urfave/cli/v2/%s", pkg)
+		}
+
+		coverProfile := fmt.Sprintf("--coverprofile=%s.coverprofile", pkg)
+
+		err := runCmd("go", "test", "-v", coverProfile, packageName)
+		if err != nil {
+			return err
+		}
+	}
+
+	return testCleanup()
+}
+
+func testCleanup() error {
+	var out bytes.Buffer
+
+	for _, pkg := range packages {
+		file, err := os.Open(fmt.Sprintf("%s.coverprofile", pkg))
+		if err != nil {
+			return err
+		}
+
+		b, err := ioutil.ReadAll(file)
+		if err != nil {
+			return err
+		}
+
+		out.Write(b)
+		err = file.Close()
+		if err != nil {
+			return err
+		}
+
+		err = os.Remove(fmt.Sprintf("%s.coverprofile", pkg))
+		if err != nil {
+			return err
+		}
+	}
+
+	outFile, err := os.Create("coverage.txt")
+	if err != nil {
+		return err
+	}
+
+	_, err = out.WriteTo(outFile)
+	if err != nil {
+		return err
+	}
+
+	err = outFile.Close()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func GfmrunActionFunc(c *cli.Context) error {
+	filename := c.Args().Get(0)
+	if filename == "" {
+		filename = "README.md"
+	}
+
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	var counter int
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		if strings.Contains(scanner.Text(), "package main") {
+			counter++
+		}
+	}
+
+	err = file.Close()
+	if err != nil {
+		return err
+	}
+
+	err = scanner.Err()
+	if err != nil {
+		return err
+	}
+
+	return runCmd("gfmrun", "-c", fmt.Sprint(counter), "-s", filename)
+}
+
+func TocActionFunc(c *cli.Context) error {
+	filename := c.Args().Get(0)
+	if filename == "" {
+		filename = "README.md"
+	}
+
+	err := runCmd("markdown-toc", "-i", filename)
+	if err != nil {
+		return err
+	}
+
+	err = runCmd("git", "diff", "--exit-code")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// checkBinarySizeActionFunc checks the size of an example binary to ensure that we are keeping size down
+// this was originally inspired by https://github.com/urfave/cli/issues/1055, and followed up on as a part
+// of https://github.com/urfave/cli/issues/1057
+func checkBinarySizeActionFunc(c *cli.Context) (err error) {
+	const (
+		cliSourceFilePath    = "./internal/example-cli/example-cli.go"
+		cliBuiltFilePath     = "./internal/example-cli/built-example"
+		helloSourceFilePath  = "./internal/example-hello-world/example-hello-world.go"
+		helloBuiltFilePath   = "./internal/example-hello-world/built-example"
+		desiredMinBinarySize = 2.0
+		desiredMaxBinarySize = 2.1
+		badNewsEmoji         = "🚨"
+		goodNewsEmoji        = "✨"
+		checksPassedEmoji    = "✅"
+		mbStringFormatter    = "%.1fMB"
+	)
+
+	// get cli example size
+	cliSize, err := getSize(cliSourceFilePath, cliBuiltFilePath)
+	if err != nil {
+		return err
+	}
+
+	// get hello world size
+	helloSize, err := getSize(helloSourceFilePath, helloBuiltFilePath)
+	if err != nil {
+		return err
+	}
+
+	// The CLI size diff is the number we are interested in.
+	// This tells us how much our CLI package contributes to the binary size.
+	cliSizeDiff := cliSize - helloSize
+
+	// get human readable size, in MB with one decimal place.
+	// example output is: 35.2MB. (note: this simply an example)
+	// that output is much easier to reason about than the `35223432`
+	// that you would see output without the rounding
+	fileSizeInMB := float64(cliSizeDiff) / float64(1000000)
+	roundedFileSize := math.Round(fileSizeInMB*10) / 10
+	roundedFileSizeString := fmt.Sprintf(mbStringFormatter, roundedFileSize)
+
+	// check against bounds
+	isLessThanDesiredMin := roundedFileSize < desiredMinBinarySize
+	isMoreThanDesiredMax := roundedFileSize > desiredMaxBinarySize
+	desiredMinSizeString := fmt.Sprintf(mbStringFormatter, desiredMinBinarySize)
+	desiredMaxSizeString := fmt.Sprintf(mbStringFormatter, desiredMaxBinarySize)
+
+	// show guidance
+	fmt.Println(fmt.Sprintf("\n%s is the current binary size", roundedFileSizeString))
+	// show guidance for min size
+	if isLessThanDesiredMin {
+		fmt.Println(fmt.Sprintf("  %s %s is the target min size", goodNewsEmoji, desiredMinSizeString))
+		fmt.Println("") // visual spacing
+		fmt.Println("     The binary is smaller than the target min size, which is great news!")
+		fmt.Println("     That means that your changes are shrinking the binary size.")
+		fmt.Println("     You'll want to go into ./internal/build/build.go and decrease")
+		fmt.Println("     the desiredMinBinarySize, and also probably decrease the ")
+		fmt.Println("     desiredMaxBinarySize by the same amount. That will ensure that")
+		fmt.Println("     future PRs will enforce the newly shrunk binary sizes.")
+		fmt.Println("") // visual spacing
+		os.Exit(1)
+	} else {
+		fmt.Println(fmt.Sprintf("  %s %s is the target min size", checksPassedEmoji, desiredMinSizeString))
+	}
+	// show guidance for max size
+	if isMoreThanDesiredMax {
+		fmt.Println(fmt.Sprintf("  %s %s is the target max size", badNewsEmoji, desiredMaxSizeString))
+		fmt.Println("") // visual spacing
+		fmt.Println("     The binary is larger than the target max size.")
+		fmt.Println("     That means that your changes are increasing the binary size.")
+		fmt.Println("     The first thing you'll want to do is ask your yourself")
+		fmt.Println("     Is this change worth increasing the binary size?")
+		fmt.Println("     Larger binary sizes for this package can dissuade its use.")
+		fmt.Println("     If this change is worth the increase, then we can up the")
+		fmt.Println("     desired max binary size. To do that you'll want to go into")
+		fmt.Println("     ./internal/build/build.go and increase the desiredMaxBinarySize,")
+		fmt.Println("     and increase the desiredMinBinarySize by the same amount.")
+		fmt.Println("") // visual spacing
+		os.Exit(1)
+	} else {
+		fmt.Println(fmt.Sprintf("  %s %s is the target max size", checksPassedEmoji, desiredMaxSizeString))
+	}
+
+	return nil
+}
+
+func getSize(sourcePath string, builtPath string) (size int64, err error) {
+	// build example binary
+	err = runCmd("go", "build", "-o", builtPath, "-ldflags", "-s -w", sourcePath)
+	if err != nil {
+		fmt.Println("issue getting size for example binary")
+		return 0, err
+	}
+
+	// get file info
+	fileInfo, err := os.Stat(builtPath)
+	if err != nil {
+		fmt.Println("issue getting size for example binary")
+		return 0, err
+	}
+
+	// size!
+	size = fileInfo.Size()
+
+	return size, nil
+}

internal/example-cli/example-cli.go

@@ -0,0 +1,11 @@
+// minimal example CLI used for binary size checking
+
+package main
+
+import (
+	"github.com/urfave/cli/v2"
+)
+
+func main() {
+	(&cli.App{}).Run([]string{})
+}

internal/example-hello-world/example-hello-world.go

@@ -0,0 +1,9 @@
+// example hello world used for binary size checking
+
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world")
+}