✨ Support dash as short for stdin (#434)

* Support dash as short for stdin

Signed-off-by: Raffael Sahli <raffael.sahli@doodle.com>

* document dash stdin

Signed-off-by: Raffael Sahli <raffael.sahli@doodle.com>

README.md

@@ -213,7 +213,7 @@ Auditors can also be run individually.
 | :---- | :----------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------- |
 |       | --format           | The output format to use (one of "pretty", "logrus", "json") (default is "pretty")                                                                     |
 | -c    | --kubeconfig       | Path to local Kubernetes config file. Only used in local mode (default is `$HOME/.kube/config`)                                                        |
-| -f    | --manifest         | Path to the yaml configuration to audit. Only used in manifest mode.                                                                                   |
+| -f    | --manifest         | Path to the yaml configuration to audit. Only used in manifest mode. You may use `-` to read from stdin.                                               |
 | -n    | --namespace        | Only audit resources in the specified namespace. Not currently supported in manifest mode.                                                             |
 | -g    | --includegenerated | Include generated resources in scan  (such as Pods generated by deployments). If you would like kubeaudit to produce results for generated resources (for example if you have custom resources or want to catch orphaned resources where the owner resource no longer exists) you can use this flag. |
 | -m    | --minseverity      | Set the lowest severity level to report (one of "error", "warning", "info") (default "info")                                                           |

cmd/commands/root.go

@@ -17,12 +17,12 @@ import (
 var rootConfig rootFlags
 
 type rootFlags struct {
-	format      string
-	kubeConfig  string
-	manifest    string
-	namespace   string
-	minSeverity string
-	exitCode    int
+	format           string
+	kubeConfig       string
+	manifest         string
+	namespace        string
+	minSeverity      string
+	exitCode         int
 	includeGenerated bool
 }
 
@@ -91,11 +91,19 @@ func getReport(auditors ...kubeaudit.Auditable) *kubeaudit.Report {
 	auditor := initKubeaudit(auditors...)
 
 	if rootConfig.manifest != "" {
-		manifest, err := os.Open(rootConfig.manifest)
-		if err != nil {
-			log.WithError(err).Fatal("Error opening manifest file")
+		var f *os.File
+		if rootConfig.manifest == "-" {
+			f = os.Stdin
+		} else {
+			manifest, err := os.Open(rootConfig.manifest)
+			if err != nil {
+				log.WithError(err).Fatal("Error opening manifest file")
+			}
+
+			f = manifest
 		}
-		report, err := auditor.AuditManifest(manifest)
+
+		report, err := auditor.AuditManifest(f)
 		if err != nil {
 			log.WithError(err).Fatal("Error auditing manifest")
 		}