Check spec directory exists before reading spec files (#709)

* Check spec directory exists before reading spec files
* Fix spec example

examples/spec-example/hello/build.sh

@@ -3,7 +3,7 @@
 set -e
 
 # check syntax
-python -m compileall -l ${SRC_PKG}
+python3 -m compileall -l ${SRC_PKG}
 
 # install deps
-pip install -r ${SRC_PKG}/requirements.txt -t ${SRC_PKG} && cp -r ${SRC_PKG} ${DEPLOY_PKG}
+pip3 install -r ${SRC_PKG}/requirements.txt -t ${SRC_PKG} && cp -r ${SRC_PKG} ${DEPLOY_PKG}

examples/spec-example/specs/env.yaml

@@ -7,6 +7,6 @@ spec:
   version: 2
   builder:
     command: build
-    image: fission/python-build-env-2.7:0.4.0rc
+    image: fission/python-builder
   runtime:
-    image: fission/python-env-2.7:0.4.0rc
+    image: fission/python-env

fission/spec.go

@@ -520,6 +520,12 @@ func (fr *FissionResources) parseYaml(b []byte, loc *location) error {
 // readSpecs reads all specs in the specified directory and returns a parsed set of
 // fission resources.
 func readSpecs(specDir string) (*FissionResources, error) {
+
+	// make sure spec directory exists before continue
+	if _, err := os.Stat(specDir); os.IsNotExist(err) {
+		fatal(fmt.Sprintf("Spec directory %v doesn't exist. Please check directory path or run \"fission spec init\" to create it.", specDir))
+	}
+
 	fr := FissionResources{
 		packages:                make([]crd.Package, 0),
 		functions:               make([]crd.Function, 0),