Make it possible to supply a glob for matching files to remove from S3

go.mod

@@ -2,6 +2,7 @@ module github.com/drone-plugins/drone-s3
 
 require (
 	github.com/aws/aws-sdk-go v1.16.17
+	github.com/bmatcuk/doublestar v1.1.1
 	github.com/joho/godotenv v1.3.0
 	github.com/mattn/go-zglob v0.0.1
 	github.com/sirupsen/logrus v1.3.0

go.sum

@@ -1,5 +1,7 @@
 github.com/aws/aws-sdk-go v1.16.17 h1:hHRKZhoB4qEY17aGNp71UxQFyYpx6WZXGMUzx9y/A4w=
 github.com/aws/aws-sdk-go v1.16.17/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
+github.com/bmatcuk/doublestar v1.1.1 h1:YroD6BJCZBYx06yYFEWvUuKVWQn3vLLQAVmDmvTSaiQ=
+github.com/bmatcuk/doublestar v1.1.1/go.mod h1:UD6OnuiIn0yFxxA2le/rnRU1G4RaI4UvFv1sNto9p6w=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af h1:pmfjZENx5imkbgOkpRUYLnmbU7UEFbjtDA2hxJ1ichM=

main.go

@@ -98,6 +98,11 @@ func main() {
 			Name:  "env-file",
 			Usage: "source env file",
 		},
+		cli.StringFlag{
+			Name:   "target-remove",
+			Usage:  "glob for which files to remove from target",
+			EnvVar: "PLUGIN_TARGET_REMOVE",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -125,6 +130,7 @@ func run(c *cli.Context) error {
 		CacheControl: c.String("cache-control"),
 		PathStyle:    c.Bool("path-style"),
 		DryRun:       c.Bool("dry-run"),
+		TargetRemove: c.String("target-remove"),
 	}
 
 	return plugin.Exec()

plugin.go

@@ -10,6 +10,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/bmatcuk/doublestar"
 	"github.com/mattn/go-zglob"
 	log "github.com/sirupsen/logrus"
 )
@@ -74,6 +75,8 @@ type Plugin struct {
 	PathStyle bool
 	// Dry run without uploading/
 	DryRun bool
+	// Glob for which files to remove from target
+	TargetRemove string
 }
 
 // Exec runs the plugin
@@ -114,6 +117,83 @@ func (p *Plugin) Exec() error {
 		return err
 	}
 
+	if len(p.TargetRemove) != 0 {
+
+		log.WithFields(log.Fields{
+			"glob": p.TargetRemove,
+		}).Info("Deleting files according to glob")
+
+		log.Info("Listing files in bucket")
+		list_input := &s3.ListObjectsInput{
+			Bucket: &p.Bucket,
+		}
+
+		s3_objects, list_err := client.ListObjects(list_input)
+		if list_err != nil {
+			log.WithFields(log.Fields{
+				"error": list_err,
+			}).Error("Error listing objects from bucket")
+			return list_err
+		}
+
+		var to_remove []string
+		for _, object := range s3_objects.Contents {
+			filename := object.Key
+
+			globmatch, globerr := doublestar.PathMatch(p.TargetRemove, *filename)
+
+			if globerr != nil {
+				log.WithFields(log.Fields{
+					"error": globerr,
+					"glob":  p.TargetRemove,
+				}).Error("Error with provided glob")
+				return globerr
+			}
+
+			if globmatch {
+				to_remove = append(to_remove, *filename)
+			}
+		}
+
+		if len(to_remove) > 0 {
+			log.WithFields(log.Fields{
+				"num_files": len(to_remove),
+			}).Info("Deleting files from bucket")
+
+			var remove_identifiers []*s3.ObjectIdentifier
+			for _, key := range to_remove {
+				id := s3.ObjectIdentifier{
+					Key: aws.String(key),
+				}
+				remove_identifiers = append(remove_identifiers, &id)
+			}
+
+			delete_input := &s3.DeleteObjectsInput{
+				Bucket: &p.Bucket,
+				Delete: &s3.Delete{
+					Objects: remove_identifiers,
+					Quiet:   aws.Bool(false),
+				},
+			}
+
+			// when executing a dry-run we skip this step because we don't actually
+			// want to remove files from S3.
+			if !p.DryRun {
+				log.WithFields(log.Fields{
+					"num_files": len(remove_identifiers),
+				}).Info("Attempting to delete files")
+				_, delete_err := client.DeleteObjects(delete_input)
+
+				if delete_err != nil {
+					log.WithFields(log.Fields{
+						"error": delete_err,
+					}).Error("Error deleting objects from S3")
+					return delete_err
+				}
+			}
+		}
+	}
+
 	for _, match := range matches {
 
 		stat, err := os.Stat(match)