Support read data from stdin

pkg/loader/compose/compose.go

@@ -18,14 +18,10 @@ package compose
 
 import (
 	"fmt"
-	"io/ioutil"
 	"reflect"
 	"strings"
 
-	yaml "gopkg.in/yaml.v2"
-
-	"bufio"
-	"os"
+	"gopkg.in/yaml.v2"
 
 	"github.com/docker/libcompose/project"
 	"github.com/fatih/structs"
@@ -34,6 +30,9 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+//
+var StdinData []byte
+
 // Compose is docker compose file loader, implements Loader interface
 type Compose struct {
 }
@@ -200,17 +199,11 @@ func getVersionFromFile(file string) (string, error) {
 		Version string `json:"version"` // This affects YAML as well
 	}
 	var version ComposeVersion
-	var loadedFile []byte
-	var err error
-	if file == "-" {
-		data := bufio.NewScanner(os.Stdin)
-		loadedFile = data.Bytes()
-	} else {
-		loadedFile, err = ioutil.ReadFile(file)
+	loadedFile, err := ReadFile(file)
+
 	if err != nil {
 		return "", err
 	}
-	}
 
 	err = yaml.Unmarshal(loadedFile, &version)
 	if err != nil {

pkg/loader/compose/utils.go

@@ -17,6 +17,7 @@ limitations under the License.
 package compose
 
 import (
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -115,3 +116,18 @@ func handleServiceType(ServiceType string) (string, error) {
 func normalizeServiceNames(svcName string) string {
 	return strings.Replace(svcName, "_", "-", -1)
 }
+
+// ReadFile read data from file or stdin
+func ReadFile(fileName string) ([]byte, error) {
+	if fileName == "-" {
+		if StdinData == nil {
+			data, err := ioutil.ReadAll(os.Stdin)
+			StdinData = data
+			return data, err
+		} else {
+			return StdinData, nil
+		}
+	}
+	return ioutil.ReadFile(fileName)
+
+}

pkg/loader/compose/v3.go

@@ -17,7 +17,6 @@ limitations under the License.
 package compose
 
 import (
-	"io/ioutil"
 	"strconv"
 	"strings"
 	"time"
@@ -77,7 +76,7 @@ func parseV3(files []string) (kobject.KomposeObject, error) {
 	var config *types.Config
 	for _, file := range files {
 		// Load and then parse the YAML first!
-		loadedFile, err := ioutil.ReadFile(file)
+		loadedFile, err := ReadFile(file)
 		if err != nil {
 			return kobject.KomposeObject{}, err
 		}

script/test/cmd/tests.sh

@@ -805,8 +805,10 @@ sed -e "s;%VERSION%;$version;g" -e "s;%CMD%;$cmd;g"  $KOMPOSE_ROOT/script/test/f
 convert::expect_success "$cmd" "/tmp/output-os.json"
 
 # Testing stdin feature
-cmd="$KOMPOSE_ROOT/kompose convert --stdout -j -f -"
-sed -e "s;%VERSION%;$version;g" -e "s;%CMD%;$cmd;g"  $KOMPOSE_ROOT/script/test/fixtures/stdin/output.json > /tmp/output-k8s.json
+cmd="kompose convert --stdout -j -f -"
+sed -e "s;%VERSION%;$version;g" -e "s;%CMD%;$cmd;g"  $KOMPOSE_ROOT/script/test/fixtures/stdin/output-k8s.json > /tmp/output-k8s.json
+cat $KOMPOSE_ROOT/script/test/fixtures/stdin/docker-compose.yaml | $cmd | diff /tmp/output-k8s.json -
+EXIT_STATUS=$?
 
 echo -e "\n"
 go test -v github.com/kubernetes/kompose/script/test/cmd

script/test/fixtures/stdin/docker-compose.yaml

@@ -0,0 +1,4 @@
+version: '3'
+services:
+  backend:
+    image: helloworld

script/test/fixtures/stdin/output-k8s.json

@@ -0,0 +1,45 @@
+{
+  "kind": "List",
+  "apiVersion": "v1",
+  "metadata": {},
+  "items": [
+    {
+      "kind": "Deployment",
+      "apiVersion": "extensions/v1beta1",
+      "metadata": {
+        "name": "backend",
+        "creationTimestamp": null,
+        "labels": {
+          "io.kompose.service": "backend"
+        },
+        "annotations": {
+          "kompose.cmd": "%CMD%",
+          "kompose.version": "%VERSION%"
+        }
+      },
+      "spec": {
+        "replicas": 1,
+        "template": {
+          "metadata": {
+            "creationTimestamp": null,
+            "labels": {
+              "io.kompose.service": "backend"
+            }
+          },
+          "spec": {
+            "containers": [
+              {
+                "name": "backend",
+                "image": "helloworld",
+                "resources": {}
+              }
+            ],
+            "restartPolicy": "Always"
+          }
+        },
+        "strategy": {}
+      },
+      "status": {}
+    }
+  ]
+}