Look for plugins in a non-conflicting location

When we do plugin discovery, don't look in places that would cause our
plugins to be mixed up with docker's or vice-versa.  Drop plugin
management, since we don't talk to remote anything.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

plugins/discovery.go

@@ -15,8 +15,8 @@ import (
 var (
 	// ErrNotFound plugin not found
 	ErrNotFound = errors.New("plugin not found")
-	socketsPath = "/run/docker/plugins"
+	socketsPath = "/run/oci-storage/plugins"
-	specsPaths  = []string{"/etc/docker/plugins", "/usr/lib/docker/plugins"}
+	specsPaths  = []string{"/etc/oci-storage/plugins", "/usr/lib/oci-storage/plugins"}
 )
 
 // localRegistry defines a registry that is local (using unix socket).

plugins/discovery_test.go

@@ -33,8 +33,8 @@ func TestFileSpecPlugin(t *testing.T) {
 		fail bool
 	}{
 		// TODO Windows: Factor out the unix:// variants.
-		{filepath.Join(tmpdir, "echo.spec"), "echo", "unix://var/lib/docker/plugins/echo.sock", false},
+		{filepath.Join(tmpdir, "echo.spec"), "echo", "unix://var/lib/oci-storage/plugins/echo.sock", false},
-		{filepath.Join(tmpdir, "echo", "echo.spec"), "echo", "unix://var/lib/docker/plugins/echo.sock", false},
+		{filepath.Join(tmpdir, "echo", "echo.spec"), "echo", "unix://var/lib/oci-storage/plugins/echo.sock", false},
 		{filepath.Join(tmpdir, "foo.spec"), "foo", "tcp://localhost:8080", false},
 		{filepath.Join(tmpdir, "foo", "foo.spec"), "foo", "tcp://localhost:8080", false},
 		{filepath.Join(tmpdir, "bar.spec"), "bar", "localhost:8080", true}, // unknown transport
@@ -79,11 +79,11 @@ func TestFileJSONSpecPlugin(t *testing.T) {
 	p := filepath.Join(tmpdir, "example.json")
 	spec := `{
   "Name": "plugin-example",
-  "Addr": "https://example.com/docker/plugin",
+  "Addr": "https://example.com/oci-storage/plugin",
   "TLSConfig": {
-    "CAFile": "/usr/shared/docker/certs/example-ca.pem",
+    "CAFile": "/usr/shared/oci-storage/certs/example-ca.pem",
-    "CertFile": "/usr/shared/docker/certs/example-cert.pem",
+    "CertFile": "/usr/shared/oci-storage/certs/example-cert.pem",
-    "KeyFile": "/usr/shared/docker/certs/example-key.pem"
+    "KeyFile": "/usr/shared/oci-storage/certs/example-key.pem"
 	}
 }`
 
@@ -101,19 +101,19 @@ func TestFileJSONSpecPlugin(t *testing.T) {
 		t.Fatalf("Expected plugin `plugin-example`, got %s\n", plugin.Name)
 	}
 
-	if plugin.Addr != "https://example.com/docker/plugin" {
+	if plugin.Addr != "https://example.com/oci-storage/plugin" {
-		t.Fatalf("Expected plugin addr `https://example.com/docker/plugin`, got %s\n", plugin.Addr)
+		t.Fatalf("Expected plugin addr `https://example.com/oci-storage/plugin`, got %s\n", plugin.Addr)
 	}
 
-	if plugin.TLSConfig.CAFile != "/usr/shared/docker/certs/example-ca.pem" {
+	if plugin.TLSConfig.CAFile != "/usr/shared/oci-storage/certs/example-ca.pem" {
-		t.Fatalf("Expected plugin CA `/usr/shared/docker/certs/example-ca.pem`, got %s\n", plugin.TLSConfig.CAFile)
+		t.Fatalf("Expected plugin CA `/usr/shared/oci-storage/certs/example-ca.pem`, got %s\n", plugin.TLSConfig.CAFile)
 	}
 
-	if plugin.TLSConfig.CertFile != "/usr/shared/docker/certs/example-cert.pem" {
+	if plugin.TLSConfig.CertFile != "/usr/shared/oci-storage/certs/example-cert.pem" {
-		t.Fatalf("Expected plugin Certificate `/usr/shared/docker/certs/example-cert.pem`, got %s\n", plugin.TLSConfig.CertFile)
+		t.Fatalf("Expected plugin Certificate `/usr/shared/oci-storage/certs/example-cert.pem`, got %s\n", plugin.TLSConfig.CertFile)
 	}
 
-	if plugin.TLSConfig.KeyFile != "/usr/shared/docker/certs/example-key.pem" {
+	if plugin.TLSConfig.KeyFile != "/usr/shared/oci-storage/certs/example-key.pem" {
-		t.Fatalf("Expected plugin Key `/usr/shared/docker/certs/example-key.pem`, got %s\n", plugin.TLSConfig.KeyFile)
+		t.Fatalf("Expected plugin Key `/usr/shared/oci-storage/certs/example-key.pem`, got %s\n", plugin.TLSConfig.KeyFile)
 	}
 }

plugins/plugins.go

@@ -1,17 +1,18 @@
 // Package plugins provides structures and helper functions to manage Docker
 // plugins.
 //
-// Docker discovers plugins by looking for them in the plugin directory whenever
+// Storage discovers plugins by looking for them in the plugin directory whenever
 // a user or container tries to use one by name. UNIX domain socket files must
-// be located under /run/docker/plugins, whereas spec files can be located
+// be located under /run/oci-storage/plugins, whereas spec files can be located
-// either under /etc/docker/plugins or /usr/lib/docker/plugins. This is handled
+// either under /etc/oci-storage/plugins or /usr/lib/oci-storage/plugins. This
-// by the Registry interface, which lets you list all plugins or get a plugin by
+// is handled by the Registry interface, which lets you list all plugins or get
-// its name if it exists.
+// a plugin by its name if it exists.
 //
 // The plugins need to implement an HTTP server and bind this to the UNIX socket
 // or the address specified in the spec files.
 // A handshake is send at /Plugin.Activate, and plugins are expected to return
-// a Manifest with a list of of Docker subsystems which this plugin implements.
+// a Manifest with a list of subsystems which this plugin implements.  As of
+// this writing, the known subsystem is "GraphDriver".
 //
 // In order to use a plugins, you can use the ``Get`` with the name of the
 // plugin and the subsystem it implements.
@@ -52,7 +53,7 @@ type Manifest struct {
 	Implements []string
 }
 
-// Plugin is the definition of a docker plugin.
+// Plugin is the definition of a storage plugin.
 type Plugin struct {
 	// Name of the plugin
 	name string