Cloud migrations: create snapshot files (#89693)

* Cloud migrations: create snapshot and store it on disk

* fix merge conflicts

* implement StartSnapshot for gms client

* pass snapshot directory as argument to snapshot builder

* ensure snapshot folder is set

* make swagger-gen

* remove Test_ExecuteAsyncWorkflow

* pass signed in user to buildSnapshot method / use github.com/grafana/grafana-cloud-migration-snapshot to create snapshot files

* fix FakeServiceImpl.CreateSnapshot

* remove new line

pkg/services/cloudmigration/slicesext/slicesext.go

@@ -0,0 +1,33 @@
+package slicesext
+
+import "math"
+
+// Partitions the input into slices where the length is <= chunkSize.
+//
+// Example:
+//
+// Chunks(2, []int{1, 2, 3, 4})
+// => [][]int{{1, 2}, {3, 4}}
+func Chunks[T any](chunkSize int, xs []T) [][]T {
+	if chunkSize < 0 {
+		panic("chunk size must be greater than or equal to 0")
+	}
+	if chunkSize == 0 {
+		return [][]T{}
+	}
+
+	out := make([][]T, 0, int(math.Ceil(float64(len(xs))/float64(chunkSize))))
+
+	for i := 0; i < len(xs); i += chunkSize {
+		var chunk []T
+		if i+chunkSize < len(xs) {
+			chunk = xs[i : i+chunkSize]
+		} else {
+			chunk = xs[i:]
+		}
+
+		out = append(out, chunk)
+	}
+
+	return out
+}

pkg/services/cloudmigration/slicesext/slicesext_test.go

@@ -0,0 +1,80 @@
+package slicesext
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestChunks(t *testing.T) {
+	t.Parallel()
+
+	t.Run("chunkSize must be greater than 0", func(t *testing.T) {
+		t.Parallel()
+
+		assert.PanicsWithValue(t, "chunk size must be greater than or equal to 0", func() {
+			Chunks(-1, []string{})
+		})
+	})
+
+	t.Run("basic", func(t *testing.T) {
+		t.Parallel()
+
+		cases := []struct {
+			description string
+			chunkSize   int
+			input       []int
+			expected    [][]int
+		}{
+			{
+				description: "empty slice",
+				chunkSize:   2,
+				input:       []int{},
+				expected:    [][]int{},
+			},
+			{
+				description: "nil slice",
+				chunkSize:   2,
+				input:       nil,
+				expected:    [][]int{},
+			},
+			{
+				description: "chunk size is 0",
+				chunkSize:   0,
+				input:       []int{1, 2, 3},
+				expected:    [][]int{},
+			},
+			{
+				description: "chunk size is greater than slice length",
+				chunkSize:   3,
+				input:       []int{1},
+				expected:    [][]int{{1}},
+			},
+			{
+				description: "chunk size is 1",
+				chunkSize:   1,
+				input:       []int{1, 2, 3},
+				expected:    [][]int{{1}, {2}, {3}},
+			},
+			{
+				description: "chunk size is 2 and slice length is 3",
+				chunkSize:   2,
+				input:       []int{1, 2, 3},
+				expected:    [][]int{{1, 2}, {3}},
+			},
+			{
+				description: "chunk size is 2 and slice length is 6",
+				chunkSize:   2,
+				input:       []int{1, 2, 3, 4, 5, 6},
+				expected:    [][]int{{1, 2}, {3, 4}, {5, 6}},
+			},
+		}
+
+		for _, tt := range cases {
+			t.Run(tt.description, func(t *testing.T) {
+				result := Chunks(tt.chunkSize, tt.input)
+				assert.Equal(t, tt.expected, result)
+			})
+		}
+	})
+}