deploy: Support invalidating a CloudFront CDN cache

deploy/cloudfront.go

@@ -0,0 +1,51 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// 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 deploy
+
+import (
+	"context"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/cloudfront"
+)
+
+// InvalidateCloudFront invalidates the CloudFront cache for distributionID.
+// It uses the default AWS credentials from the environment.
+func InvalidateCloudFront(ctx context.Context, distributionID string) error {
+	// SharedConfigEnable enables loading "shared config (~/.aws/config) and
+	// shared credentials (~/.aws/credentials) files".
+	// See https://docs.aws.amazon.com/sdk-for-go/api/aws/session/ for more
+	// details.
+	// This is the same codepath used by Go CDK when creating an s3 URL.
+	// TODO: Update this to a Go CDK helper once available
+	// (https://github.com/google/go-cloud/issues/2003).
+	sess, err := session.NewSessionWithOptions(session.Options{SharedConfigState: session.SharedConfigEnable})
+	if err != nil {
+		return err
+	}
+	req := &cloudfront.CreateInvalidationInput{
+		DistributionId: aws.String(distributionID),
+		InvalidationBatch: &cloudfront.InvalidationBatch{
+			CallerReference: aws.String(time.Now().Format("20060102150405")),
+			Paths: &cloudfront.Paths{
+				Items:    []*string{aws.String("/*")},
+				Quantity: aws.Int64(1),
+			},
+		},
+	}
+	_, err = cloudfront.New(sess).CreateInvalidationWithContext(ctx, req)
+	return err
+}