Add docker plugin upgrade

This allows a plugin to be upgraded without requiring to
uninstall/reinstall a plugin.
Since plugin resources (e.g. volumes) are tied to a plugin ID, this is
important to ensure resources aren't lost.

The plugin must be disabled while upgrading (errors out if enabled).
This does not add any convenience flags for automatically
disabling/re-enabling the plugin during before/after upgrade.

Since an upgrade may change requested permissions, the user is required
to accept permissions just like `docker plugin install`.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

interface.go

@@ -113,6 +113,7 @@ type PluginAPIClient interface {
 	PluginEnable(ctx context.Context, name string, options types.PluginEnableOptions) error
 	PluginDisable(ctx context.Context, name string, options types.PluginDisableOptions) error
 	PluginInstall(ctx context.Context, name string, options types.PluginInstallOptions) (io.ReadCloser, error)
+	PluginUpgrade(ctx context.Context, name string, options types.PluginInstallOptions) (io.ReadCloser, error)
 	PluginPush(ctx context.Context, name string, registryAuth string) (io.ReadCloser, error)
 	PluginSet(ctx context.Context, name string, args []string) error
 	PluginInspectWithRaw(ctx context.Context, name string) (*types.Plugin, []byte, error)

plugin_install.go

@@ -20,43 +20,15 @@ func (cli *Client) PluginInstall(ctx context.Context, name string, options types
 	}
 	query.Set("remote", options.RemoteRef)
 
-	resp, err := cli.tryPluginPrivileges(ctx, query, options.RegistryAuth)
+	privileges, err := cli.checkPluginPermissions(ctx, query, options)
-	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {
-		// todo: do inspect before to check existing name before checking privileges
-		newAuthHeader, privilegeErr := options.PrivilegeFunc()
-		if privilegeErr != nil {
-			ensureReaderClosed(resp)
-			return nil, privilegeErr
-		}
-		options.RegistryAuth = newAuthHeader
-		resp, err = cli.tryPluginPrivileges(ctx, query, options.RegistryAuth)
-	}
-	if err != nil {
-		ensureReaderClosed(resp)
-		return nil, err
-	}
-
-	var privileges types.PluginPrivileges
-	if err := json.NewDecoder(resp.body).Decode(&privileges); err != nil {
-		ensureReaderClosed(resp)
-		return nil, err
-	}
-	ensureReaderClosed(resp)
-
-	if !options.AcceptAllPermissions && options.AcceptPermissionsFunc != nil && len(privileges) > 0 {
-		accept, err := options.AcceptPermissionsFunc(privileges)
 	if err != nil {
 		return nil, err
 	}
-		if !accept {
-			return nil, pluginPermissionDenied{options.RemoteRef}
-		}
-	}
 
 	// set name for plugin pull, if empty should default to remote reference
 	query.Set("name", name)
 
-	resp, err = cli.tryPluginPull(ctx, query, privileges, options.RegistryAuth)
+	resp, err := cli.tryPluginPull(ctx, query, privileges, options.RegistryAuth)
 	if err != nil {
 		return nil, err
 	}
@@ -103,3 +75,39 @@ func (cli *Client) tryPluginPull(ctx context.Context, query url.Values, privileg
 	headers := map[string][]string{"X-Registry-Auth": {registryAuth}}
 	return cli.post(ctx, "/plugins/pull", query, privileges, headers)
 }
+
+func (cli *Client) checkPluginPermissions(ctx context.Context, query url.Values, options types.PluginInstallOptions) (types.PluginPrivileges, error) {
+	resp, err := cli.tryPluginPrivileges(ctx, query, options.RegistryAuth)
+	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {
+		// todo: do inspect before to check existing name before checking privileges
+		newAuthHeader, privilegeErr := options.PrivilegeFunc()
+		if privilegeErr != nil {
+			ensureReaderClosed(resp)
+			return nil, privilegeErr
+		}
+		options.RegistryAuth = newAuthHeader
+		resp, err = cli.tryPluginPrivileges(ctx, query, options.RegistryAuth)
+	}
+	if err != nil {
+		ensureReaderClosed(resp)
+		return nil, err
+	}
+
+	var privileges types.PluginPrivileges
+	if err := json.NewDecoder(resp.body).Decode(&privileges); err != nil {
+		ensureReaderClosed(resp)
+		return nil, err
+	}
+	ensureReaderClosed(resp)
+
+	if !options.AcceptAllPermissions && options.AcceptPermissionsFunc != nil && len(privileges) > 0 {
+		accept, err := options.AcceptPermissionsFunc(privileges)
+		if err != nil {
+			return nil, err
+		}
+		if !accept {
+			return nil, pluginPermissionDenied{options.RemoteRef}
+		}
+	}
+	return privileges, nil
+}

plugin_upgrade.go

@@ -0,0 +1,37 @@
+package client
+
+import (
+	"fmt"
+	"io"
+	"net/url"
+
+	"github.com/docker/distribution/reference"
+	"github.com/docker/docker/api/types"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+)
+
+// PluginUpgrade upgrades a plugin
+func (cli *Client) PluginUpgrade(ctx context.Context, name string, options types.PluginInstallOptions) (rc io.ReadCloser, err error) {
+	query := url.Values{}
+	if _, err := reference.ParseNamed(options.RemoteRef); err != nil {
+		return nil, errors.Wrap(err, "invalid remote reference")
+	}
+	query.Set("remote", options.RemoteRef)
+
+	privileges, err := cli.checkPluginPermissions(ctx, query, options)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := cli.tryPluginUpgrade(ctx, query, privileges, name, options.RegistryAuth)
+	if err != nil {
+		return nil, err
+	}
+	return resp.body, nil
+}
+
+func (cli *Client) tryPluginUpgrade(ctx context.Context, query url.Values, privileges types.PluginPrivileges, name, registryAuth string) (serverResponse, error) {
+	headers := map[string][]string{"X-Registry-Auth": {registryAuth}}
+	return cli.post(ctx, fmt.Sprintf("/plugins/%s/upgrade", name), query, privileges, headers)
+}