add support for streaming to cmd stdin

internal/command/command.go

@@ -32,9 +32,11 @@ type Command struct {
 	Env				[]string                 `json:"env" yaml:"env"`
 	Split     bool                     `json:"split" yaml:"split"`
 	FailOnError bool                   `json:"failonerror" yaml:"failonerror"`
+	StdinAvailable bool                `json:"stdinavailable,omitempty" yaml:"stdinavailable,omitempty"`
 	Executor  CommandExecutor          `json:"-" yaml:"-"`
 	Extractor CommandExtractAttributes `json:"-" yaml:"-"`
 	CommandExists CommandExists        `json:"-" yaml:"-"`
+	stdin io.Reader                    `json:"-" yaml:"-"`
 }
 
 func NewCommand() *Command {
@@ -60,6 +62,10 @@ func (c *Command) Defaults() {
 		cmd := exec.Command(c.Path, args...)
 		c.SetCmdEnv(cmd)
 	
+		if c.stdin != nil {
+			cmd.Stdin = c.stdin
+		}
+
 		slog.Info("execute() - cmd", "path", c.Path, "args", args)
 		output, stdoutPipeErr := cmd.StdoutPipe()
 		if stdoutPipeErr != nil {
@@ -78,11 +84,18 @@ func (c *Command) Defaults() {
 		slog.Info("execute() - start", "cmd", cmd)
 		stdOutOutput, _ := io.ReadAll(output)
 		stdErrOutput, _ := io.ReadAll(stderr)
-
-		slog.Info("execute() - io", "stdout", string(stdOutOutput), "stderr", string(stdErrOutput))
+		if len(stdOutOutput) > 100 {
+			slog.Info("execute() - io", "stdout", string(stdOutOutput[:100]), "stderr", string(stdErrOutput))
+		} else {
+			slog.Info("execute() - io", "stdout", string(stdOutOutput), "stderr", string(stdErrOutput))
+		}
 		waitErr := cmd.Wait()
 
-		slog.Info("execute()", "path", c.Path, "args", args, "output", string(stdOutOutput), "error", string(stdErrOutput))
+		if len(stdOutOutput) > 100 {
+			slog.Info("execute()", "path", c.Path, "args", args, "output", string(stdOutOutput[:100]), "error", string(stdErrOutput))
+		} else {
+			slog.Info("execute()", "path", c.Path, "args", args, "output", string(stdOutOutput), "error", string(stdErrOutput))
+		}
 
 		if len(stdErrOutput) > 0 && c.FailOnError {
 			return stdOutOutput, fmt.Errorf("%w %s", waitErr, string(stdErrOutput))
@@ -103,6 +116,12 @@ func (c *Command) SetCmdEnv(cmd *exec.Cmd) {
 	cmd.Env = append(os.Environ(), c.Env...)
 }
 
+func (c *Command) SetStdinReader(r io.Reader) {
+	if c.StdinAvailable {
+		c.stdin = r
+	}
+}
+
 func (c *Command) Exists() bool {
 	return c.CommandExists() == nil
 }

internal/command/command_test.go

@@ -9,6 +9,7 @@ _	"fmt"
 _	"os"
 _	"strings"
 	"testing"
+	"bytes"
 )
 
 func TestNewCommand(t *testing.T) {
@@ -58,3 +59,25 @@ args:
 	assert.Nil(t, err)
 	assert.Greater(t, len(out), 0)
 }
+
+func TestCommandStdin(t *testing.T) {
+	var expected string = "stdin test data"
+	var stdinBuffer bytes.Buffer
+	stdinBuffer.WriteString(expected)
+
+	c := NewCommand()
+	assert.NotNil(t, c)
+
+	decl := `
+path: cat
+stdinavailable: true
+`
+
+	assert.Nil(t, c.LoadDecl(decl))
+	assert.Equal(t, "cat", c.Path)
+	
+	c.SetStdinReader(&stdinBuffer)
+	out, err := c.Execute(nil)
+	assert.Nil(t, err)
+	assert.Equal(t, expected, string(out))
+}