build: Add per-step CPU and memory resource limits

Port of moby/buildkit#6569 to buildx. Adds --memory, --memory-swap,
--cpu-shares, --cpu-period, --cpu-quota, --cpuset-cpus, and --cpuset-mems
flags to build, plus the equivalent bake target attributes and compose
x-bake fields.

Signed-off-by: Jiří Moravčík <jiri.moravcik@gmail.com>

build/utils_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	dockeropts "github.com/docker/cli/opts"
 	"github.com/stretchr/testify/require"
 )
 
@@ -150,3 +151,109 @@ func TestToBuildkitExtraHosts(t *testing.T) {
 		})
 	}
 }
+
+func TestAddResourceLimits(t *testing.T) {
+	mustMemSwap := func(v string) dockeropts.MemSwapBytes {
+		var m dockeropts.MemSwapBytes
+		require.NoError(t, m.Set(v))
+		return m
+	}
+
+	tests := []struct {
+		name     string
+		limits   ResourceLimits
+		expected map[string]string
+	}{
+		{
+			name:     "empty",
+			limits:   ResourceLimits{},
+			expected: map[string]string{},
+		},
+		{
+			name: "all",
+			limits: ResourceLimits{
+				Memory:     dockeropts.MemBytes(2 * 1024 * 1024 * 1024),
+				MemorySwap: mustMemSwap("4g"),
+				CPUShares:  1024,
+				CPUPeriod:  100000,
+				CPUQuota:   50000,
+				CPUSetCPUs: "0-3",
+				CPUSetMems: "0,1",
+			},
+			expected: map[string]string{
+				"memory":     "2147483648",
+				"memswap":    "4294967296",
+				"cpushares":  "1024",
+				"cpuperiod":  "100000",
+				"cpuquota":   "50000",
+				"cpusetcpus": "0-3",
+				"cpusetmems": "0,1",
+			},
+		},
+		{
+			name:   "unlimited swap",
+			limits: ResourceLimits{MemorySwap: mustMemSwap("-1")},
+			expected: map[string]string{
+				"memswap": "-1",
+			},
+		},
+		{
+			name:   "partial",
+			limits: ResourceLimits{Memory: dockeropts.MemBytes(512 * 1024 * 1024)},
+			expected: map[string]string{
+				"memory": "536870912",
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			attrs := map[string]string{}
+			addResourceLimits(tc.limits, attrs)
+			require.Equal(t, tc.expected, attrs)
+		})
+	}
+}
+
+func TestParseResourceLimits(t *testing.T) {
+	t.Run("all", func(t *testing.T) {
+		rl, err := ParseResourceLimits([]string{
+			"memory=2g",
+			"memory-swap=4g",
+			"cpu-shares=1024",
+			"cpu-period=100000",
+			"cpu-quota=50000",
+			"cpuset-cpus=0-3",
+			"cpuset-mems=0,1",
+		})
+		require.NoError(t, err)
+		require.Equal(t, int64(2*1024*1024*1024), rl.Memory.Value())
+		require.Equal(t, int64(4*1024*1024*1024), rl.MemorySwap.Value())
+		require.Equal(t, int64(1024), rl.CPUShares)
+		require.Equal(t, int64(100000), rl.CPUPeriod)
+		require.Equal(t, int64(50000), rl.CPUQuota)
+		require.Equal(t, "0-3", rl.CPUSetCPUs)
+		require.Equal(t, "0,1", rl.CPUSetMems)
+	})
+
+	t.Run("unlimited swap", func(t *testing.T) {
+		rl, err := ParseResourceLimits([]string{"memory-swap=-1"})
+		require.NoError(t, err)
+		require.Equal(t, int64(-1), rl.MemorySwap.Value())
+	})
+
+	t.Run("missing value", func(t *testing.T) {
+		_, err := ParseResourceLimits([]string{"memory"})
+		require.Error(t, err)
+	})
+
+	t.Run("unknown key", func(t *testing.T) {
+		_, err := ParseResourceLimits([]string{"bogus=1"})
+		require.Error(t, err)
+	})
+
+	t.Run("invalid int", func(t *testing.T) {
+		_, err := ParseResourceLimits([]string{"cpu-shares=notanumber"})
+		require.Error(t, err)
+	})
+}