rootless: support a custom arg to the new process

let the process running as euid != 0 pass down an argument to the
process running in the user namespace.  This will be useful for
commands like rm -a that needs to join different namespaces, so that
we can re-exec separately for each of them.

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

1 files changed, 9 insertions, 0 deletions

diff --git a/pkg/rootless/rootless.go b/pkg/rootless/rootless.go
new file mode 100644
index 000000000..a531e43ce
--- /dev/null
+++ b/pkg/rootless/rootless.go
@@ -0,0 +1,9 @@
+package rootless
+
+// Opts allows to customize how re-execing to a rootless process is done
+type Opts struct {
+	// Argument overrides the arguments on the command line
+	// for the re-execed process.  The process in the namespace
+	// must use rootless.Argument() to read its value.
+	Argument string
+}