refactor and fix issues #3, #4, camptocamp#8

go.mod

@@ -2,4 +2,7 @@ module github.com/camptocamp/helm-sops
 
 go 1.13
 
-require go.mozilla.org/sops/v3 v3.5.0
+require (
+	go.mozilla.org/sops/v3 v3.6.1
+	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776
+)

helm_wrapper.go

@@ -0,0 +1,203 @@
+package main
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"regexp"
+	"sync"
+	"syscall"
+
+	"go.mozilla.org/sops/v3/decrypt"
+)
+
+type HelmWrapper struct {
+	Errors []error
+	errMutex sync.Mutex
+
+	ExitCode int
+
+	helmBinPath string
+	pipeWriterWaitGroup sync.WaitGroup
+	valuesArgRegexp *regexp.Regexp
+	temporaryDirectory string
+}
+
+func NewHelmWrapper() (*HelmWrapper, error) {
+	c := HelmWrapper{}
+
+	c.Errors = []error{}
+	c.pipeWriterWaitGroup = sync.WaitGroup{}
+	c.valuesArgRegexp = regexp.MustCompile("^(-f|--values)(?:=(.+))?$")
+
+	// Determine the name of the helm binary by examining our binary name
+	helmBinName := "helm"
+	ourBinName := path.Base(os.Args[0])
+	if ourBinName == "helm" || ourBinName == "helm2" || ourBinName == "helm3" {
+		helmBinName = fmt.Sprintf("_%s", ourBinName)
+	}
+
+	var err error
+	c.helmBinPath, err = exec.LookPath(helmBinName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find Helm binary '%s': %s", helmBinName, err)
+	}
+
+	return &c, nil
+}
+
+func (c *HelmWrapper) errorf(msg string, a ...interface{}) error {
+	e := fmt.Errorf(msg, a...)
+	c.errMutex.Lock()
+	c.Errors = append(c.Errors, e)
+	c.errMutex.Unlock()
+	return e
+}
+
+func (c *HelmWrapper) pipeWriter(outPipeName string, data []byte) {
+	c.pipeWriterWaitGroup.Add(1)
+	defer c.pipeWriterWaitGroup.Done()
+
+	cleartextSecretFile, err := os.OpenFile(outPipeName, os.O_WRONLY, 0)
+	if err != nil {
+		c.errorf("failed to open cleartext secret pipe '%s' in pipe writer: %s", outPipeName, err)
+		return
+	}
+	defer func() {
+		err := cleartextSecretFile.Close()
+		if err != nil {
+			c.errorf("failed to close cleartext secret pipe '%s' in pipe writer: %s", outPipeName, err)
+		}
+	}()
+
+	_, err = cleartextSecretFile.Write(data)
+	if err != nil {
+		c.errorf("failed to write cleartext secret to pipe '%s': %s", outPipeName, err)
+	}
+}
+
+func (c *HelmWrapper) valuesArg(args []string) (string, string, error) {
+	valuesArgRegexpMatches := c.valuesArgRegexp.FindStringSubmatch(args[0])
+	if valuesArgRegexpMatches == nil {
+		return "", "", nil
+	}
+
+	var filename string
+	if len(valuesArgRegexpMatches[2]) > 0 {
+		// current arg is in the format --values=filename
+		filename = valuesArgRegexpMatches[2]
+	} else if len(args) > 1 {
+		// arg is in the format "-f filename"
+		filename = args[1]
+	} else {
+		return "", "", c.errorf("missing filename after -f or --values")
+	}
+
+	cleartextSecretFilename := fmt.Sprintf("%s/%x", c.temporaryDirectory, sha256.Sum256([]byte(filename)))
+
+	return filename, cleartextSecretFilename, nil
+}
+
+func (c *HelmWrapper) replaceValueFileArg(args []string, cleartextSecretFilename string) {
+	valuesArgRegexpMatches := c.valuesArgRegexp.FindStringSubmatch(args[0])
+
+	// replace the filename with our pipe
+	if len(valuesArgRegexpMatches[2]) > 0 {
+		args[0] = fmt.Sprintf("%s=%s", valuesArgRegexpMatches[1], cleartextSecretFilename)
+	} else {
+		args[1] = cleartextSecretFilename
+	}
+}
+
+func (c *HelmWrapper) mkTmpDir() (func(), error) {
+	var err error
+	c.temporaryDirectory, err = ioutil.TempDir("", fmt.Sprintf("%s.", path.Base(os.Args[0])))
+	if err != nil {
+		return nil, c.errorf("failed to create temporary directory: %s", err)
+	}
+	return func() {
+		err := os.RemoveAll(c.temporaryDirectory)
+		if err != nil {
+			c.errorf("failed to remove temporary directory '%s': %s", c.temporaryDirectory, err)
+		}
+	}, nil
+}
+
+func (c *HelmWrapper) mkPipe(cleartextSecretFilename string) (func(), error) {
+	err := syscall.Mkfifo(cleartextSecretFilename, 0600)
+	if err != nil {
+		return nil, c.errorf("failed to create cleartext secret pipe '%s': %s", cleartextSecretFilename, err)
+	}
+	return func() {
+		err := os.Remove(cleartextSecretFilename)
+		if err != nil {
+			c.errorf("failed to remove cleartext secret pipe '%s': %s", cleartextSecretFilename, err)
+		}
+	}, nil
+}
+
+func (c *HelmWrapper) RunHelm() {
+	var err error
+	// Setup temporary directory and defer cleanup
+	cleanFn, err := c.mkTmpDir()
+	if err != nil {
+		return
+	}
+	defer cleanFn()
+
+	// Loop through arguments looking for --values or -f.
+	// If we find a values argument, check if file has a sops section indicating it is encrypted.
+	// Setup a named pipe and write the decrypted data into that for helm.
+	for i := range os.Args {
+		args := os.Args[i:]
+
+		filename, cleartextSecretFilename, err := c.valuesArg(args)
+		if err != nil {
+			return
+		}
+		if filename == "" {
+			continue
+		}
+
+		encrypted, err := DetectSopsYaml(filename)
+		if err != nil {
+			c.errorf("error checking if file is encrypted: %s", err)
+			return
+		}
+		if !encrypted {
+			continue
+		}
+
+		c.replaceValueFileArg(args, cleartextSecretFilename)
+
+		cleartextSecrets, err := decrypt.File(filename, "yaml")
+		if err != nil {
+			c.errorf("failed to decrypt secret file '%s': %s", filename, err)
+			return
+		}
+
+		cleanFn, err := c.mkPipe(cleartextSecretFilename)
+		if err != nil {
+			return
+		}
+		defer cleanFn()
+
+		go c.pipeWriter(cleartextSecretFilename, cleartextSecrets)
+	}
+	defer c.pipeWriterWaitGroup.Wait()
+
+	cmd := exec.Command(c.helmBinPath, os.Args[1:]...)
+	cmd.Env = os.Environ()
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	err = cmd.Run()
+	if err != nil {
+		c.ExitCode = cmd.ProcessState.ExitCode()
+		c.errorf("failed to run Helm: %s", err)
+	}
+}

helm_wrapper_test.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"os"
+    "testing"
+)
+
+var g_hw *HelmWrapper
+
+func init() {
+    g_hw, _ = NewHelmWrapper()
+}
+
+func TestNewHelmWrapper(t *testing.T) {
+	// TODO
+}
+
+func TestErrorf(t *testing.T) {
+	g_hw.Errors = []error{}
+	err := g_hw.errorf("test %s %d %t", "a", 1, true)
+	if g_hw.Errors[0] != err {
+		t.Errorf("errorf(test %%s %%d %%t, a, 1, true) = %s; want %s",  g_hw.Errors[0], err)
+	}
+}
+
+func TestPipeWriter(t *testing.T) {
+	// TODO
+}
+
+func TestValuesArg(t *testing.T) {
+	res, _, err := g_hw.valuesArg([]string{"-f", "cat.yaml"})
+	if res != "cat.yaml" || err != nil {
+		t.Errorf("valuesArg([]string{\"-f\", \"cat.yaml\"}) = %s, %s; want cat.yaml, <nil>",  res, "cat.yaml")
+	}
+
+	res, _, err = g_hw.valuesArg([]string{"--values", "cat.yaml"})
+	if res != "cat.yaml" || err != nil {
+		t.Errorf("valuesArg([]string{\"--valuse\", \"cat.yaml\"}) = %s, %s; want cat.yaml, <nil>",  res, "cat.yaml")
+	}
+
+	res, _, err = g_hw.valuesArg([]string{"--values=cat.yaml"})
+	if res != "cat.yaml" || err != nil {
+		t.Errorf("valuesArg([]string{\"--values=cat.yaml\"}) = %s, %s; want cat.yaml, <nil>",  res, "cat.yaml")
+	}
+}
+
+func TestReplaceValueFileArg(t *testing.T) {
+	args := []string{"-f", "cat.yaml"}
+	g_hw.replaceValueFileArg(args, "dog.yaml")
+	if args[1] != "dog.yaml" {
+		t.Errorf("args[1] = %s; want dog.yaml", args[1])
+	}
+
+	args = []string{"--values", "cat.yaml"}
+	g_hw.replaceValueFileArg(args, "dog.yaml")
+	if args[1] != "dog.yaml" {
+		t.Errorf("args[1] = %s; want dog.yaml", args[1])
+	}
+
+	args = []string{"--values=cat.yaml"}
+	g_hw.replaceValueFileArg(args, "dog.yaml")
+	if args[0] != "--values=dog.yaml" {
+		t.Errorf("args[1] = %s; want --values=dog.yaml", args[1])
+	}
+}
+
+func TestMkTmpDir(t *testing.T) {
+	// ensure no errors
+	cleanFn, err := g_hw.mkTmpDir()
+	if err != nil {
+		t.Errorf("mkTmpDir error: %s", err)
+	}
+
+	// dir exists
+	if _, err = os.Stat(g_hw.temporaryDirectory); err != nil {
+		t.Errorf("mkTmpDir stat error: %s", err)
+	}
+
+	// ensure dir is deleted
+	cleanFn()
+	if _, err = os.Stat(g_hw.temporaryDirectory); err == nil {
+		t.Errorf("mkTmpDir cleanup func did not work")
+	} else if !os.IsNotExist(err) {
+		t.Errorf("mkTmpDir cleanup something went wrong: %s", err)
+	}
+}
+
+func TestMkPipe(t *testing.T) {
+	// ensure no errors
+	cleanFn, err := g_hw.mkPipe("cat.yaml")
+	if err != nil {
+		t.Errorf("mkPipe error: %s", err)
+	}
+
+	// file exists
+	if _, err = os.Stat("cat.yaml"); err != nil {
+		t.Errorf("mkPipe stat error: %s", err)
+	}
+
+	// ensure file is deleted
+	cleanFn()
+	if _, err = os.Stat("cat.yaml"); err == nil {
+		t.Errorf("mkPipe cleanup func did not work")
+	} else if !os.IsNotExist(err) {
+		t.Errorf("mkPipe cleanup something went wrong: %s", err)
+	}
+}
+
+func TestRunHelm(t *testing.T) {
+	// TODO
+}