add podman remote system df

Signed-off-by: Brent Baude <bbaude@redhat.com>

cmd/podman/system/df.go

@@ -37,7 +37,7 @@ var (
 
 func init() {
 	registry.Commands = append(registry.Commands, registry.CliCommand{
-		Mode:    []entities.EngineMode{entities.ABIMode},
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
 		Command: dfSystemCommand,
 		Parent:  systemCmd,
 	})

pkg/api/handlers/libpod/system.go

@@ -7,6 +7,7 @@ import (
 	"github.com/containers/libpod/pkg/api/handlers/compat"
 	"github.com/containers/libpod/pkg/api/handlers/utils"
 	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/containers/libpod/pkg/domain/infra/abi"
 	"github.com/gorilla/schema"
 	"github.com/pkg/errors"
 )
@@ -79,3 +80,15 @@ func SystemReset(w http.ResponseWriter, r *http.Request) {
 	}
 	utils.WriteResponse(w, http.StatusOK, nil)
 }
+
+func DiskUsage(w http.ResponseWriter, r *http.Request) {
+	// Options are only used by the CLI
+	options := entities.SystemDfOptions{}
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	ic := abi.ContainerEngine{Libpod: runtime}
+	response, err := ic.SystemDf(r.Context(), options)
+	if err != nil {
+		utils.InternalServerError(w, err)
+	}
+	utils.WriteResponse(w, http.StatusOK, response)
+}

pkg/api/server/register_system.go

@@ -12,7 +12,7 @@ func (s *APIServer) registerSystemHandlers(r *mux.Router) error {
 	r.Handle(VersionedPath("/system/df"), s.APIHandler(compat.GetDiskUsage)).Methods(http.MethodGet)
 	// Added non version path to URI to support docker non versioned paths
 	r.Handle("/system/df", s.APIHandler(compat.GetDiskUsage)).Methods(http.MethodGet)
-	// Swagger:operation POST /libpod/system/prune libpod pruneSystem
+	// swagger:operation POST /libpod/system/prune libpod pruneSystem
 	// ---
 	// tags:
 	//   - system
@@ -41,5 +41,19 @@ func (s *APIServer) registerSystemHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.Handle(VersionedPath("/libpod/system/reset"), s.APIHandler(libpod.SystemReset)).Methods(http.MethodPost)
+	// swagger:operation GET /libpod/system/df libpod df
+	// ---
+	// tags:
+	//   - system
+	// summary: Show disk usage
+	// description: Return information about disk usage for containers, images, and volumes
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     $ref: '#/responses/SystemDiskUse'
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.Handle(VersionedPath("/libpod/system/df"), s.APIHandler(libpod.DiskUsage)).Methods(http.MethodGet)
 	return nil
 }

pkg/api/server/swagger.go

@@ -190,3 +190,21 @@ type swagVersion struct {
 		entities.SystemVersionReport
 	}
 }
+
+// Disk usage
+// swagger:response SystemDiskUse
+type swagDiskUseResponse struct {
+	// in:body
+	Body struct {
+		entities.SystemDfReport
+	}
+}
+
+// Prune report
+// swagger:response SystemPruneReport
+type swagSystemPruneReport struct {
+	// in:body
+	Body struct {
+		entities.SystemPruneReport
+	}
+}

pkg/bindings/system/system.go

@@ -134,3 +134,18 @@ func Reset(ctx context.Context) error {
 	}
 	return response.Process(response)
 }
+
+// DiskUsage returns information about image, container, and volume disk
+// consumption
+func DiskUsage(ctx context.Context) (*entities.SystemDfReport, error) {
+	var report entities.SystemDfReport
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+	response, err := conn.DoRequest(nil, http.MethodGet, "/system/df", nil)
+	if err != nil {
+		return nil, err
+	}
+	return &report, response.Process(&report)
+}

pkg/domain/infra/tunnel/system.go

@@ -33,7 +33,7 @@ func (ic *SystemEngine) Reset(ctx context.Context) error {
 }
 
 func (ic *ContainerEngine) SystemDf(ctx context.Context, options entities.SystemDfOptions) (*entities.SystemDfReport, error) {
-	panic(errors.New("system df is not supported on remote clients"))
+	return system.DiskUsage(ic.ClientCxt)
 }
 
 func (ic *ContainerEngine) Unshare(ctx context.Context, args []string) error {