fail early when cache folder does not exist

acceptance.bats

@@ -202,3 +202,17 @@
   [ "$status" -eq 0 ]
   [ "$output" = "Summary: 1 resource found in 1 file - Valid: 1, Invalid: 0, Errors: 0, Skipped: 0" ]
 }
+
+@test "Pass when parsing a valid Kubernetes config YAML file and store cache" {
+  run mkdir cache
+  run bin/kubeconform -cache cache -summary fixtures/valid.yaml
+  [ "$status" -eq 0 ]
+  [ "$output" = "Summary: 1 resource found in 1 file - Valid: 1, Invalid: 0, Errors: 0, Skipped: 0" ]
+  [ "`ls cache/ | wc -l`" -eq 1 ]
+}
+
+@test "Fail when cache folder does not exist" {
+  run bin/kubeconform -cache cache_does_not_exist -summary fixtures/valid.yaml
+  [ "$status" -eq 1 ]
+  [ "$output" = "failed opening cache folder cache_does_not_exist: stat cache_does_not_exist: no such file or directory" ]
+}

pkg/registry/http.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/yannh/kubeconform/pkg/cache"
@@ -22,7 +23,7 @@ type SchemaRegistry struct {
 	strict             bool
 }
 
-func newHTTPRegistry(schemaPathTemplate string, cacheFolder string, strict bool, skipTLS bool) *SchemaRegistry {
+func newHTTPRegistry(schemaPathTemplate string, cacheFolder string, strict bool, skipTLS bool) (*SchemaRegistry, error) {
 	reghttp := &http.Transport{
 		MaxIdleConns:       100,
 		IdleConnTimeout:    3 * time.Second,
@@ -35,6 +36,14 @@ func newHTTPRegistry(schemaPathTemplate string, cacheFolder string, strict bool,
 
 	var filecache cache.Cache = nil
 	if cacheFolder != "" {
+		fi, err := os.Stat(cacheFolder)
+		if err != nil {
+			return nil, fmt.Errorf("failed opening cache folder %s: %s", cacheFolder, err)
+		}
+		if !fi.IsDir() {
+			return nil, fmt.Errorf("cache folder %s is not a directory", err)
+		}
+
 		filecache = cache.NewOnDiskCache(cacheFolder)
 	}
 
@@ -43,7 +52,7 @@ func newHTTPRegistry(schemaPathTemplate string, cacheFolder string, strict bool,
 		schemaPathTemplate: schemaPathTemplate,
 		cache:              filecache,
 		strict:             strict,
-	}
+	}, nil
 }
 
 // DownloadSchema downloads the schema for a particular resource from an HTTP server

pkg/registry/local.go

@@ -12,11 +12,11 @@ type LocalRegistry struct {
 }
 
 // NewLocalSchemas creates a new "registry", that will serve schemas from files, given a list of schema filenames
-func newLocalRegistry(pathTemplate string, strict bool) *LocalRegistry {
+func newLocalRegistry(pathTemplate string, strict bool) (*LocalRegistry, error) {
 	return &LocalRegistry{
 		pathTemplate,
 		strict,
-	}
+	}, nil
 }
 
 // DownloadSchema retrieves the schema from a file for the resource

pkg/registry/registry.go

@@ -90,8 +90,8 @@ func New(schemaLocation string, cache string, strict bool, skipTLS bool) (Regist
 	}
 
 	if strings.HasPrefix(schemaLocation, "http") {
-		return newHTTPRegistry(schemaLocation, cache, strict, skipTLS), nil
+		return newHTTPRegistry(schemaLocation, cache, strict, skipTLS)
 	}
 
-	return newLocalRegistry(schemaLocation, strict), nil
+	return newLocalRegistry(schemaLocation, strict)
 }