feat(osctl): add df command (#569)

Signed-off-by: Andrew Rynhard <andrew@andrewrynhard.com>

cmd/osctl/cmd/df.go

@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// nolint: dupl,golint
+package cmd
+
+import (
+	"github.com/spf13/cobra"
+	"github.com/talos-systems/talos/cmd/osctl/pkg/client"
+	"github.com/talos-systems/talos/cmd/osctl/pkg/helpers"
+	"github.com/talos-systems/talos/internal/pkg/constants"
+)
+
+// dfCmd represents the df command.
+var dfCmd = &cobra.Command{
+	Use:   "df",
+	Short: "List disk usage",
+	Long:  ``,
+	Run: func(cmd *cobra.Command, args []string) {
+		creds, err := client.NewDefaultClientCredentials(talosconfig)
+		if err != nil {
+			helpers.Fatalf("error getting client credentials: %s", err)
+		}
+		if target != "" {
+			creds.Target = target
+		}
+		c, err := client.NewClient(constants.OsdPort, creds)
+		if err != nil {
+			helpers.Fatalf("error constructing client: %s", err)
+		}
+
+		if err := c.DF(); err != nil {
+			helpers.Fatalf("error getting df: %s", err)
+		}
+	},
+}
+
+func init() {
+	dfCmd.Flags().StringVarP(&target, "target", "t", "", "target the specificed node")
+	rootCmd.AddCommand(dfCmd)
+}

cmd/osctl/pkg/client/client.go

@@ -13,6 +13,7 @@ import (
 	"encoding/gob"
 	"fmt"
 	"io"
+	"math"
 	"os"
 	"text/tabwriter"
 
@@ -271,3 +272,28 @@ func (c *Client) Top() (pl []proc.ProcessList, err error) {
 	err = dec.Decode(&pl)
 	return
 }
+
+// DF implements the proto.OSDClient interface.
+func (c *Client) DF() (err error) {
+	ctx := context.Background()
+	reply, err := c.client.DF(ctx, &empty.Empty{})
+	if err != nil {
+		fmt.Printf("one or more error encountered: %+v", err)
+	}
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', 0)
+	fmt.Fprintln(w, "FILESYSTEM\tSIZE(GB)\tUSED(GB)\tAVAILABLE(GB)\tPERCENT USED\tMOUNTED ON")
+	for _, r := range reply.Stats {
+		percentAvailable := 100.0 - 100.0*(float64(r.Available)/float64(r.Size))
+
+		if math.IsNaN(percentAvailable) {
+			continue
+		}
+
+		fmt.Fprintf(w, "%s\t%.02f\t%.02f\t%.02f\t%.02f%%\t%s\n", r.Filesystem, float64(r.Size)*1e-9, float64(r.Size-r.Available)*1e-9, float64(r.Available)*1e-9, percentAvailable, r.MountedOn)
+	}
+	if err := w.Flush(); err != nil {
+		return err
+	}
+
+	return nil
+}

internal/app/osd/internal/reg/reg.go

@@ -5,12 +5,14 @@
 package reg
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"encoding/gob"
 	"io/ioutil"
 	"log"
 	"os"
+	"strings"
 
 	"github.com/containerd/cgroups"
 	"github.com/containerd/containerd"
@@ -19,6 +21,7 @@ import (
 	"github.com/containerd/containerd/oci"
 	"github.com/containerd/typeurl"
 	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/hashicorp/go-multierror"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/talos-systems/talos/internal/app/init/pkg/system/events"
@@ -399,3 +402,68 @@ func (r *Registrator) Top(ctx context.Context, in *empty.Empty) (reply *proto.To
 	reply = &proto.TopReply{ProcessList: p}
 	return
 }
+
+// DF implements the proto.OSDServer interface.
+func (r *Registrator) DF(ctx context.Context, in *empty.Empty) (reply *proto.DFReply, err error) {
+	file, err := os.Open("/proc/mounts")
+	if err != nil {
+		return nil, err
+	}
+	// nolint: errcheck
+	defer file.Close()
+
+	var (
+		stat     unix.Statfs_t
+		multiErr *multierror.Error
+	)
+
+	stats := []*proto.DFStat{}
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+
+		if len(fields) < 2 {
+			continue
+		}
+
+		filesystem := fields[0]
+		mountpoint := fields[1]
+
+		f, err := os.Stat(mountpoint)
+		if err != nil {
+			multiErr = multierror.Append(multiErr, err)
+			continue
+		}
+
+		if mode := f.Mode(); !mode.IsDir() {
+			continue
+		}
+
+		if err := unix.Statfs(mountpoint, &stat); err != nil {
+			multiErr = multierror.Append(multiErr, err)
+			continue
+		}
+
+		totalSize := uint64(stat.Bsize) * stat.Blocks
+		totalAvail := uint64(stat.Bsize) * stat.Bavail
+
+		stat := &proto.DFStat{
+			Filesystem: filesystem,
+			Size:       totalSize,
+			Available:  totalAvail,
+			MountedOn:  mountpoint,
+		}
+
+		stats = append(stats, stat)
+	}
+
+	if err := scanner.Err(); err != nil {
+		multiErr = multierror.Append(multiErr, err)
+	}
+
+	reply = &proto.DFReply{
+		Stats: stats,
+	}
+
+	return reply, multiErr.ErrorOrNil()
+}

internal/app/osd/proto/api.proto

@@ -17,6 +17,7 @@ service OSD {
   rpc Routes(google.protobuf.Empty) returns (RoutesReply) {}
   rpc Stats(StatsRequest) returns (StatsReply) {}
   rpc Top(google.protobuf.Empty) returns (TopReply) {}
+  rpc DF(google.protobuf.Empty) returns (DFReply) {}
   rpc Version(google.protobuf.Empty) returns (Data) {}
 }
 
@@ -89,3 +90,14 @@ message TopRequest {}
 message TopReply { ProcessList process_list = 1; }
 
 message ProcessList { bytes bytes = 1; }
+
+// The response message containing the requested df stats.
+message DFReply { repeated DFStat stats = 1; }
+
+// The response message containing the requested processes.
+message DFStat {
+  string filesystem = 1;
+  uint64 size = 2;
+  uint64 available = 3;
+  string mounted_on = 4;
+}