rootfs: Add support for rootfs-overlay and bump to buildah v1.22.1-0.202108

Allows users to specify a readonly rootfs with :O, in exchange podman will create a writable overlay.

bump builah to v1.22.1-0.20210823173221-da2b428c56ce

[NO TESTS NEEDED]

Signed-off-by: flouthoc <flouthoc.git@gmail.com>

vendor/github.com/containers/buildah/run.go

@@ -5,6 +5,7 @@ import (
 	"io"
 
 	"github.com/containers/buildah/define"
+	"github.com/containers/buildah/pkg/sshagent"
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/sirupsen/logrus"
 )
@@ -139,7 +140,19 @@ type RunOptions struct {
 	Devices define.ContainerDevices
 	// Secrets are the available secrets to use in a RUN
 	Secrets map[string]string
+	// SSHSources is the available ssh agents to use in a RUN
+	SSHSources map[string]*sshagent.Source `json:"-"`
 	// RunMounts are mounts for this run. RunMounts for this run
 	// will not show up in subsequent runs.
 	RunMounts []string
 }
+
+// RunMountArtifacts are the artifacts created when using a run mount.
+type runMountArtifacts struct {
+	// RunMountTargets are the run mount targets inside the container
+	RunMountTargets []string
+	// Agents are the ssh agents started
+	Agents []*sshagent.AgentServer
+	// SSHAuthSock is the path to the ssh auth sock inside the container
+	SSHAuthSock string
+}