pkg: support passing down options for idmap

[NO NEW TESTS NEEDED] the feature is still being worked in crun:

https://github.com/containers/crun/pull/874

also needs: https://github.com/containers/common/pull/927

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

pkg/specgenutil/volumes.go

@@ -356,7 +356,11 @@ func getBindMount(args []string) (spec.Mount, error) {
 			}
 			setOwnership = true
 		case "idmap":
-			newMount.Options = append(newMount.Options, "idmap")
+			if len(kv) > 1 {
+				newMount.Options = append(newMount.Options, fmt.Sprintf("idmap=%s", kv[1]))
+			} else {
+				newMount.Options = append(newMount.Options, "idmap")
+			}
 		case "consistency":
 			// Often used on MACs and mistakenly on Linux platforms.
 			// Since Docker ignores this option so shall we.

pkg/util/mountOpts.go

@@ -45,14 +45,18 @@ func ProcessOptions(options []string, isTmpfs bool, sourcePath string) ([]string
 			}
 		}
 
-		switch splitOpt[0] {
+		if strings.HasPrefix(splitOpt[0], "idmap") {
-		case "O":
-			foundOverlay = true
-		case "idmap":
 			if foundIdmap {
 				return nil, errors.Wrapf(ErrDupeMntOption, "the 'idmap' option can only be set once")
 			}
 			foundIdmap = true
+			newOptions = append(newOptions, opt)
+			continue
+		}
+
+		switch splitOpt[0] {
+		case "O":
+			foundOverlay = true
 		case "exec", "noexec":
 			if foundExec {
 				return nil, errors.Wrapf(ErrDupeMntOption, "only one of 'noexec' and 'exec' can be used")