support create via stdin '-'

Signed-off-by: Jeeva Kandasamy <[email protected]>

cmd/command/create.go

@@ -2,10 +2,12 @@ package command
 
 import (
 	"fmt"
+	"io/ioutil"
 
 	jenkins "github.com/jkandasa/jenkinsctl/pkg/jenkins"
 	cliML "github.com/jkandasa/jenkinsctl/pkg/model/cli"
 	"github.com/jkandasa/jenkinsctl/pkg/utils"
+	stdinUtils "github.com/jkandasa/jenkinsctl/pkg/utils/read_stdin"
 	"github.com/spf13/cobra"
 )
 
@@ -27,14 +29,34 @@ var createResource = &cobra.Command{
 	Short: "Create a resource from a file",
 	Example: `  # create a build using the date in yaml file
   jenkinsctl create -f my_build.yaml
+
+  # create a build based on the YAML passed into stdin.
+  cat my_build.yaml | jenkinsctl create -f -
 	`,
 	Run: func(cmd *cobra.Command, args []string) {
 		if CONFIG.JobContext == "" {
 			fmt.Fprintf(ioStreams.ErrOut, "job context not set")
 			return
 		}
 
-		resourceInterface, err := utils.GetResource(resourceFile)
+		var data []byte
+		if resourceFile == "-" { // process's standard input
+			stdinData, err := stdinUtils.ReadStdIn()
+			if err != nil {
+				fmt.Fprintln(ioStreams.ErrOut, err)
+				return
+			}
+			data = stdinData
+		} else {
+			bytes, err := ioutil.ReadFile(resourceFile)
+			if err != nil {
+				fmt.Fprintln(ioStreams.ErrOut, err)
+				return
+			}
+			data = bytes
+		}
+
+		resourceInterface, err := utils.GetResource(data)
 		if err != nil {
 			fmt.Fprintln(ioStreams.ErrOut, err)
 			return

pkg/utils/read_stdin/utils.go

@@ -0,0 +1,50 @@
+package utils
+
+import (
+	"bufio"
+	"io"
+	"os"
+)
+
+type lineIterator struct {
+	reader *bufio.Reader
+}
+
+func newLineIterator(rd io.Reader) *lineIterator {
+	return &lineIterator{
+		reader: bufio.NewReader(rd),
+	}
+}
+
+func (ln *lineIterator) next() ([]byte, error) {
+	var bytes []byte
+	for {
+		line, isPrefix, err := ln.reader.ReadLine()
+		if err != nil {
+			return nil, err
+		}
+		bytes = append(bytes, line...)
+		if !isPrefix {
+			break
+		}
+	}
+	return bytes, nil
+}
+
+func ReadStdIn() ([]byte, error) {
+	ln := newLineIterator(os.Stdin)
+	lines := make([]byte, 0)
+	for {
+		line, err := ln.next()
+		if err != nil {
+			if err == io.EOF {
+				break
+			} else {
+				return nil, err
+			}
+		}
+		lines = append(lines, line...)
+		lines = append(lines, '\n')
+	}
+	return []byte(lines), nil
+}

pkg/utils/utils.go

@@ -23,9 +23,9 @@ func FileToStruct(filename string, out interface{}) error {
 	return yaml.Unmarshal(bytes, out)
 }
 
-func GetResource(filename string) (interface{}, error) {
+func GetResource(bytes []byte) (interface{}, error) {
 	kindData := &cliML.Kind{}
-	err := FileToStruct(filename, kindData)
+	err := yaml.Unmarshal(bytes, kindData)
 	if err != nil {
 		return nil, err
 	}
@@ -43,7 +43,7 @@ func GetResource(filename string) (interface{}, error) {
 		return nil, fmt.Errorf("unknown kind:%s", kindData.Kind)
 	}
 
-	if err = FileToStruct(filename, resource); err != nil {
+	if err = yaml.Unmarshal(bytes, resource); err != nil {
 		return nil, err
 	}
 	return resource, nil