Add a unit test for S3Path.RenderTerraform

Unfortunately it needs to be in a different package to avoid a rather complex import loop: terraform -> kops api -> vfs -> terraform

util/pkg/vfs/tests/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+
+go_test(
+    name = "go_default_test",
+    srcs = ["s3fs_test.go"],
+    deps = [
+        "//upup/pkg/fi/cloudup/awsup:go_default_library",
+        "//upup/pkg/fi/cloudup/terraform:go_default_library",
+        "//util/pkg/vfs:go_default_library",
+        "//vendor/github.com/stretchr/testify/assert:go_default_library",
+    ],
+)

util/pkg/vfs/tests/s3fs_test.go

@@ -0,0 +1,117 @@
+/*
+Copyright 2021 The Kubernetes 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.
+*/
+
+package tests
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"k8s.io/kops/upup/pkg/fi/cloudup/awsup"
+	"k8s.io/kops/upup/pkg/fi/cloudup/terraform"
+	"k8s.io/kops/util/pkg/vfs"
+)
+
+func TestS3RenderTerraform(t *testing.T) {
+	content := "hello world"
+	grid := []struct {
+		expectedPath string
+		s3Path       string
+		s3Object     string
+		expectedJSON string
+	}{
+		{
+			s3Path:   "s3://foo/bar",
+			s3Object: "bar",
+			expectedJSON: `
+			{
+				"acl": "bucket-owner-full-control",
+				"bucket": "foo",
+				"content": "${file(\"${path.module}/data/aws_s3_bucket_object_bar_content\")}",
+				"key": "bar",
+				"provider": "${aws.files}",
+				"server_side_encryption": "AES256"
+			}
+			`,
+		},
+	}
+	origEndpoint := os.Getenv("S3_ENDPOINT")
+	os.Setenv("S3_ENDPOINT", "foo.s3.amazonaws.com")
+	defer os.Setenv("S3_ENDPOINT", origEndpoint)
+
+	origACL := os.Getenv("KOPS_STATE_S3_ACL")
+	os.Setenv("KOPS_STATE_S3_ACL", "bucket-owner-full-control")
+	defer os.Setenv("KOPS_STATE_S3_ACL", origACL)
+	for _, tc := range grid {
+
+		t.Run(tc.s3Path, func(t *testing.T) {
+			cloud := awsup.BuildMockAWSCloud("us-east-1", "a")
+			path, err := vfs.Context.BuildVfsPath(tc.s3Path)
+			if err != nil {
+				t.Fatalf("error building VFS path: %v", err)
+				t.FailNow()
+			}
+
+			vfsProvider, err := path.(vfs.TerraformPath).TerraformProvider()
+			if err != nil {
+				t.Fatalf("error building VFS Terraform provider: %v", err)
+				t.FailNow()
+			}
+			target := terraform.NewTerraformTarget(cloud, "", vfsProvider, "/dev/null", nil)
+
+			err = path.(*vfs.S3Path).RenderTerraform(
+				&target.TerraformWriter, tc.s3Object, strings.NewReader(content), vfs.S3Acl{},
+			)
+			if err != nil {
+				t.Fatalf("error rendering terraform %v", err)
+				t.FailNow()
+			}
+			res, err := target.GetResourcesByType()
+			if err != nil {
+				t.Fatalf("error fetching terraform resources: %v", err)
+				t.FailNow()
+			}
+			if objs := res["aws_s3_bucket_object"]; objs == nil {
+				t.Fatalf("aws_s3_bucket_object resources not found: %v", res)
+				t.FailNow()
+			}
+			if obj := res["aws_s3_bucket_object"][tc.s3Object]; obj == nil {
+				t.Fatalf("aws_s3_bucket_object object not found: %v", res["aws_s3_bucket_object"])
+				t.FailNow()
+			}
+			obj, err := json.Marshal(res["aws_s3_bucket_object"][tc.s3Object])
+			if err != nil {
+				t.Fatalf("error marshaling s3 object: %v", err)
+				t.FailNow()
+			}
+			if !assert.JSONEq(t, tc.expectedJSON, string(obj), "JSON representation of terraform resource did not match") {
+				t.FailNow()
+			}
+			if objs := target.TerraformWriter.Files[fmt.Sprintf("data/aws_s3_bucket_object_%v_content", tc.s3Object)]; objs == nil {
+				t.Fatalf("aws_s3_bucket_object content file not found: %v", target.TerraformWriter.Files)
+				t.FailNow()
+			}
+			actualContent := string(target.TerraformWriter.Files[fmt.Sprintf("data/aws_s3_bucket_object_%v_content", tc.s3Object)])
+			if !assert.Equal(t, content, actualContent, "aws_s3_bucket_object content did not match") {
+				t.FailNow()
+			}
+		})
+	}
+}