Kompose will read input from stdin

Resolves issue #870

for example,

```
$ cat docker-compose.yaml | kompose convert -f -
INFO Kubernetes file "frontend-service.yaml" created
INFO Kubernetes file "redis-master-service.yaml" created
INFO Kubernetes file "redis-slave-service.yaml" created
INFO Kubernetes file "frontend-deployment.yaml" created
INFO Kubernetes file "redis-master-deployment.yaml" created
INFO Kubernetes file "redis-slave-deployment.yaml" created
```

Added integration test for the same.
`

script/test/cmd/.coverprofile

@@ -0,0 +1 @@
+mode: atomic

script/test/cmd/cmd_test.go

@@ -0,0 +1,30 @@
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"testing"
+)
+
+var ProjectPath = "$GOPATH/src/github.com/kubernetes/kompose/"
+var BinaryLocation = os.ExpandEnv(ProjectPath + "kompose")
+
+func Test_stdin(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode.")
+	}
+	kjson := `{"version": "2","services": {"redis": {"image": "redis:3.0","ports": ["6379"]}}}`
+	cmdStr := fmt.Sprintf("%s convert --stdout -j -f - <<EOF\n%s\nEOF\n", BinaryLocation, kjson)
+	subproc := exec.Command("/bin/sh", "-c", cmdStr)
+	output, err := subproc.Output()
+	if err != nil {
+		fmt.Println("error", err)
+	}
+	g, err := ioutil.ReadFile("/tmp/output-k8s.json")
+	if !bytes.Equal(output, g) {
+		t.Errorf("Test Failed")
+	}
+}

script/test/cmd/tests.sh

@@ -663,5 +663,12 @@ cmd="kompose convert --provider=openshift --stdout -j -f $KOMPOSE_ROOT/examples/
 sed -e "s;%VERSION%;$version;g" -e "s;%CMD%;$cmd;g"  $KOMPOSE_ROOT/script/test/fixtures/examples/output-gitlab-os.json > /tmp/output-os.json
 convert::expect_success_and_warning "kompose convert --provider=openshift --stdout -j -f $KOMPOSE_ROOT/examples/docker-gitlab.yaml" "/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
+
+echo -e "\n"
+go test -v github.com/kubernetes/kompose/script/test/cmd
+
 rm /tmp/output-k8s.json /tmp/output-os.json
 exit $EXIT_STATUS

script/test/fixtures/stdin/output.json

@@ -0,0 +1,80 @@
+{
+  "kind": "List",
+  "apiVersion": "v1",
+  "metadata": {},
+  "items": [
+    {
+      "kind": "Service",
+      "apiVersion": "v1",
+      "metadata": {
+        "name": "redis",
+        "creationTimestamp": null,
+        "labels": {
+          "io.kompose.service": "redis"
+        },
+        "annotations": {
+          "kompose.cmd": "%CMD%",
+          "kompose.version": "%VERSION%"
+        }
+      },
+      "spec": {
+        "ports": [
+          {
+            "name": "6379",
+            "port": 6379,
+            "targetPort": 6379
+          }
+        ],
+        "selector": {
+          "io.kompose.service": "redis"
+        }
+      },
+      "status": {
+        "loadBalancer": {}
+      }
+    },
+    {
+      "kind": "Deployment",
+      "apiVersion": "extensions/v1beta1",
+      "metadata": {
+        "name": "redis",
+        "creationTimestamp": null,
+        "labels": {
+          "io.kompose.service": "redis"
+        },
+        "annotations": {
+          "kompose.cmd": "%CMD%",
+          "kompose.version": "%VERSION%"
+        }
+      },
+      "spec": {
+        "replicas": 1,
+        "template": {
+          "metadata": {
+            "creationTimestamp": null,
+            "labels": {
+              "io.kompose.service": "redis"
+            }
+          },
+          "spec": {
+            "containers": [
+              {
+                "name": "redis",
+                "image": "redis:3.0",
+                "ports": [
+                  {
+                    "containerPort": 6379
+                  }
+                ],
+                "resources": {}
+              }
+            ],
+            "restartPolicy": "Always"
+          }
+        },
+        "strategy": {}
+      },
+      "status": {}
+    }
+  ]
+}

script/test_k8s/kubernetes.sh

@@ -117,6 +117,13 @@ test_k8s() {
     ./kompose down -f $f --controller=replicationcontroller
 
   done
+
+  echo -e "\nTesting stdin to kompose\n"
+  echo -e "\n${RED}cat examples/docker-compose.yaml | ./kompose up -f -${NC}\n"
+  cat examples/docker-compose.yaml | ./kompose up -f -
+  sleep 2 # Sleep for k8s to catch up to deployment
+  echo -e "\n${RED}cat examples/docker-compose.yaml | ./kompose down -f - ${NC}\n"
+  cat examples/docker-compose.yaml | ./kompose down -f -
 }
 
 if [[ $1 == "start" ]]; then