feat: system prune also cleanup build cache

cmd/nerdctl/system_prune.go

@@ -17,7 +17,11 @@
 package main
 
 import (
+	"bufio"
+	"bytes"
+	"encoding/json"
 	"fmt"
+	"github.com/containerd/nerdctl/pkg/buildkitutil"
 	"strings"
 
 	"github.com/sirupsen/logrus"
@@ -72,6 +76,7 @@ func systemPruneAction(cmd *cobra.Command, args []string) error {
 		}
 		msg += `
   - all images without at least one container associated to them
+  - all build cache
 `
 		msg += "\nAre you sure you want to continue? [y/N] "
 		fmt.Fprintf(cmd.OutOrStdout(), "WARNING! %s", msg)
@@ -99,5 +104,29 @@ func systemPruneAction(cmd *cobra.Command, args []string) error {
 			return err
 		}
 	}
-	return imagePrune(cmd, client, ctx)
+	if err := imagePrune(cmd, client, ctx); err != nil {
+		return err
+	}
+
+	var buf bytes.Buffer
+	outWriter := bufio.NewWriter(&buf)
+	copiedCmd := *cmd
+	copiedCmd.SetOut(outWriter)
+	if err := builderPruneAction(&copiedCmd, args); err != nil {
+		return err
+	}
+	parsedOutput, err := buildkitutil.ParseBuildctlPruneTableOutput(buf.Bytes())
+	if err != nil {
+		return err
+	}
+	// pretty print the output of prune build cache
+	out := cmd.OutOrStdout()
+	for _, row := range parsedOutput.Rows {
+		_, _ = fmt.Fprintf(out, "%s\n", row.ID)
+	}
+	j, _ := json.Marshal(parsedOutput)
+	fmt.Fprintf(out, "%s\n", j)
+
+	fmt.Fprintf(out, "%s", buf.Bytes())
+	return err
 }

pkg/buildkitutil/buildctl_prune_output_parser.go

@@ -0,0 +1,97 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+/*
+   Portions from https://github.com/docker/cli/blob/v20.10.9/cli/command/image/build/context.go
+   Copyright (C) Docker authors.
+   Licensed under the Apache License, Version 2.0
+   NOTICE: https://github.com/docker/cli/blob/v20.10.9/NOTICE
+*/
+
+package buildkitutil
+
+import (
+	"fmt"
+	"github.com/containerd/nerdctl/pkg/tabutil"
+	"strings"
+)
+
+type BuildctlPruneOutput struct {
+	TotalSize string
+	Rows      []BuildctlPruneOutputRow
+}
+
+type BuildctlPruneOutputRow struct {
+	ID           string
+	Reclaimable  string
+	Size         string
+	LastAccessed string
+}
+
+const HeaderID = "ID"
+const HeaderReclaimable = "RECLAIMABLE"
+const HeaderSize = "SIZE"
+const HeaderLastAccessed = "LAST ACCESSED"
+const FinalizerTotal = "Total:"
+
+func ParseBuildctlPruneTableOutput(out []byte) (*BuildctlPruneOutput, error) {
+	tabReader := tabutil.NewReader(fmt.Sprintf("%s\t%s\t%s\t%s", HeaderID, HeaderReclaimable, HeaderSize, HeaderLastAccessed))
+	lines := strings.Split(string(out), "\n")
+
+	totalSize, err := parseTotalSize(lines[len(lines)-2])
+	if err != nil {
+		return nil, err
+	}
+
+	if len(lines) == 2 {
+		return &BuildctlPruneOutput{
+			TotalSize: totalSize,
+			Rows:      nil,
+		}, nil
+	}
+
+	if err := tabReader.ParseHeader(lines[0]); err != nil {
+		return nil, err
+	}
+
+	var rows []BuildctlPruneOutputRow
+
+	for _, line := range lines[1 : len(lines)-2] {
+		// best effort parse row
+		id, _ := tabReader.ReadRow(line, HeaderID)
+		reclaimable, _ := tabReader.ReadRow(line, HeaderReclaimable)
+		size, _ := tabReader.ReadRow(line, HeaderSize)
+		lastAccessed, _ := tabReader.ReadRow(line, HeaderLastAccessed)
+		rows = append(rows, BuildctlPruneOutputRow{
+			ID:           id,
+			Reclaimable:  reclaimable,
+			Size:         size,
+			LastAccessed: lastAccessed,
+		})
+	}
+
+	return &BuildctlPruneOutput{
+		TotalSize: totalSize,
+		Rows:      rows,
+	}, nil
+}
+
+func parseTotalSize(line string) (string, error) {
+	if strings.HasPrefix(line, FinalizerTotal) {
+		return strings.TrimSpace(line[len(FinalizerTotal):]), nil
+	}
+	return "", fmt.Errorf("parse total size from buildctl prune command ouput, unexpected line, does not contains total size: %s", line)
+}

pkg/buildkitutil/buildctl_prune_output_parser_test.go

@@ -0,0 +1,148 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+/*
+   Portions from https://github.com/docker/cli/blob/v20.10.9/cli/command/image/build/context.go
+   Copyright (C) Docker authors.
+   Licensed under the Apache License, Version 2.0
+   NOTICE: https://github.com/docker/cli/blob/v20.10.9/NOTICE
+*/
+
+package buildkitutil
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParseBuildctlPruneOutput(t *testing.T) {
+	type args struct {
+		out []byte
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    *BuildctlPruneOutput
+		wantErr bool
+	}{
+		{
+			name: "builtctl prune frees several spaces",
+			args: args{out: []byte(`ID									RECLAIMABLE	SIZE	LAST ACCESSED
+4kaw6aqapf3qvmqj3jskct89r                                              	true       	0B	
+i0ys2vka15idnu952zc3le36o*                                             	true       	0B	
+zn1cxnxqyxa18mzi5u2bnnqqk*                                             	true       	4.10kB	
+x43clde10rasyy42vvzwo5w1r                                              	true       	156B	
+kt007lnewdnssgukycqux8rcc                                              	true       	0B	
+th54xgnz12r1rsgaoy55pfla1                                              	true       	0B	
+66b6kbtv4iul87bzibzxwgo51                                              	true       	0B	
+nlanvxjtqluiipuwva3uwfwvk                                              	true       	0B	
+yh3oha6crdq9y34lmi2jshwhb                                              	true       	0B	
+hai2h463u7o8xuybj0339e139                                              	true       	0B	
+Total:	4.25kB
+`)},
+			want: &BuildctlPruneOutput{
+				TotalSize: "584.31MB",
+				Rows: []BuildctlPruneOutputRow{
+					{
+						ID:           "4kaw6aqapf3qvmqj3jskct89r",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "i0ys2vka15idnu952zc3le36o*",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "zn1cxnxqyxa18mzi5u2bnnqqk*",
+						Reclaimable:  "true",
+						Size:         "4.10kB",
+						LastAccessed: "",
+					},
+					{
+						ID:           "x43clde10rasyy42vvzwo5w1r",
+						Reclaimable:  "true",
+						Size:         "156B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "kt007lnewdnssgukycqux8rcc",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "th54xgnz12r1rsgaoy55pfla1",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "66b6kbtv4iul87bzibzxwgo51",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "nlanvxjtqluiipuwva3uwfwvk",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "yh3oha6crdq9y34lmi2jshwhb",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+					{
+						ID:           "hai2h463u7o8xuybj0339e139",
+						Reclaimable:  "true",
+						Size:         "0B",
+						LastAccessed: "",
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "buildctl prune frees no spaces",
+			args: args{
+				out: []byte(`Total:	0B
+`),
+			},
+			want: &BuildctlPruneOutput{
+				TotalSize: "0B",
+				Rows:      nil,
+			},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ParseBuildctlPruneTableOutput(tt.args.out)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseBuildctlPruneTableOutput() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("ParseBuildctlPruneTableOutput() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

pkg/tabutil/tabutil.go

@@ -61,11 +61,21 @@ func (r *TabReader) ReadRow(row, key string) (string, bool) {
 	if !ok {
 		return "", false
 	}
+	if idx.start > len(row) {
+		return "", false
+	}
 	var value string
 	if idx.end == -1 {
 		value = row[idx.start:]
 	} else {
-		value = row[idx.start:idx.end]
+		end := min(idx.end, len(row))
+		value = row[idx.start:end]
 	}
 	return strings.TrimSpace(value), true
 }
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

pkg/tabutil/tabutil_test.go

@@ -44,3 +44,37 @@ func TestTabReader(t *testing.T) {
 	value, _ = reader.ReadRow(tabRows[2], "b")
 	assert.Equal(t, value, "456")
 }
+
+func TestTabReaderParseTrimmedRow(t *testing.T) {
+	// for example, row 2 and row 3 are trimmed because they do not contain value for the header c
+	tabRows := strings.Split(`a    b    c
+1    2
+123  456`, "\n")
+	reader := NewReader("a\tb\tc\t")
+
+	err := reader.ParseHeader(tabRows[0])
+	assert.NilError(t, err)
+
+	var (
+		value string
+		ok    bool
+	)
+	value, ok = reader.ReadRow(tabRows[1], "a")
+	assert.Equal(t, value, "1")
+	assert.Equal(t, ok, true)
+	value, ok = reader.ReadRow(tabRows[1], "b")
+	assert.Equal(t, value, "2")
+	assert.Equal(t, ok, true)
+	value, ok = reader.ReadRow(tabRows[1], "c")
+	assert.Equal(t, value, "")
+	assert.Equal(t, ok, false)
+	value, ok = reader.ReadRow(tabRows[2], "a")
+	assert.Equal(t, value, "123")
+	assert.Equal(t, ok, true)
+	value, ok = reader.ReadRow(tabRows[2], "b")
+	assert.Equal(t, value, "456")
+	assert.Equal(t, ok, true)
+	value, ok = reader.ReadRow(tabRows[2], "c")
+	assert.Equal(t, value, "")
+	assert.Equal(t, ok, false)
+}