[Techinal Debt] Cleanup ABI vs. Tunnel CLI commands

[NO TESTS NEEDED]

This commit cleans up two issues:
* Most commands support all EngineModes so default to that. Let
  outlayers declare their intent.
* Use cobra.Annotations to set supported EngineMode. This simplies
  instantiating commands as there is now one method to communicate a
  commands requirements rather than two.
* Combined aliased commands into one file
* Fixed aliased commands where Args field did not match
* Updated examples in README.md for writing commands
* Remove redundant flag DisableFlagsInUseLine in cobra.Command
  initialization.

Signed-off-by: Jhon Honce <jhonce@redhat.com>

2 files changed, 12 insertions, 2 deletions

diff --git a/cmd/podman/registry/config.go b/cmd/podman/registry/config.go
index 3ce6e3899..25139a3de 100644
--- a/cmd/podman/registry/config.go
+++ b/cmd/podman/registry/config.go
@@ -15,14 +15,25 @@ import (
 )
 
 const (
-	ParentNSRequired  = "ParentNSRequired"
+	// ParentNSRequired used as cobra.Annotation when command requires root access
+	ParentNSRequired = "ParentNSRequired"
+
+	// UnshareNSRequired used as cobra.Annotation when command requires modified user namespace
 	UnshareNSRequired = "UnshareNSRequired"
+
+	// EngineMode used as cobra.Annotation when command supports a limited number of Engines
+	EngineMode = "EngineMode"
 )
 
 var (
 	podmanOptions entities.PodmanConfig
 	podmanSync    sync.Once
 	abiSupport    = false
+
+	// ABIMode used in cobra.Annotations registry.EngineMode when command only supports ABIMode
+	ABIMode = entities.ABIMode.String()
+	// TunnelMode used in in cobra.Annotations registry.EngineMode when command only supports TunnelMode
+	TunnelMode = entities.TunnelMode.String()
 )
 
 // PodmanConfig returns an entities.PodmanConfig built up from
diff --git a/cmd/podman/registry/registry.go b/cmd/podman/registry/registry.go
index 0b1d9293a..607ef6d8e 100644
--- a/cmd/podman/registry/registry.go
+++ b/cmd/podman/registry/registry.go
@@ -19,7 +19,6 @@ const DefaultRootAPIPath = "/run/podman/podman.sock"
 const DefaultRootAPIAddress = "unix:" + DefaultRootAPIPath
 
 type CliCommand struct {
-	Mode    []entities.EngineMode
 	Command *cobra.Command
 	Parent  *cobra.Command
 }