SSH connections are left dangling after use (#668)

Bumps [github.com/nicholas-fedor/shoutrrr](https://github.com/nicholas-fedor/shoutrrr) from 0.11.0 to 0.11.1.
- [Release notes](https://github.com/nicholas-fedor/shoutrrr/releases)
- [Commits](https://github.com/nicholas-fedor/shoutrrr/compare/v0.11.0...v0.11.1)

---
updated-dependencies:
- dependency-name: github.com/nicholas-fedor/shoutrrr
  dependency-version: 0.11.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

cmd/backup/script.go

@@ -177,10 +177,20 @@ func (s *script) init() error {
 			IdentityPassphrase: s.c.SSHIdentityPassphrase,
 			RemotePath:         s.c.SSHRemotePath,
 		}
-		sshBackend, err := ssh.NewStorageBackend(sshConfig, logFunc)
+
+		sshBackend, closeSSHConnection, err := ssh.NewStorageBackend(sshConfig, logFunc)
+
+		s.registerHook(hookLevelPlumbing, func(err error) error {
+			if err := closeSSHConnection(); err != nil {
+				return errwrap.Wrap(err, "failed to close ssh connection")
+			}
+			return nil
+		})
+
 		if err != nil {
 			return errwrap.Wrap(err, "error creating ssh storage backend")
 		}
+
 		s.storages = append(s.storages, sshBackend)
 	}
 

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/klauspost/compress v1.18.1
 	github.com/leekchan/timeutil v0.0.0-20150802142658-28917288c48d
 	github.com/minio/minio-go/v7 v7.0.95
-	github.com/nicholas-fedor/shoutrrr v0.11.0
+	github.com/nicholas-fedor/shoutrrr v0.11.1
 	github.com/offen/envconfig v1.5.0
 	github.com/otiai10/copy v1.14.1
 	github.com/pkg/sftp v1.13.10
@@ -23,7 +23,7 @@ require (
 	golang.org/x/crypto v0.43.0
 	golang.org/x/oauth2 v0.32.0
 	golang.org/x/sync v0.17.0
-	google.golang.org/api v0.253.0
+	google.golang.org/api v0.254.0
 	mvdan.cc/sh/v3 v3.12.0
 )
 
@@ -72,7 +72,7 @@ require (
 	go.opentelemetry.io/proto/otlp v1.7.0 // indirect
 	golang.org/x/term v0.36.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251022142026-3a174f9686a8 // indirect
 	google.golang.org/grpc v1.76.0 // indirect
 	google.golang.org/protobuf v1.36.10 // indirect
 )

go.sum

@@ -304,16 +304,16 @@ github.com/moby/term v0.0.0-20200312100748-672ec06f55cd h1:aY7OQNf2XqY/JQ6qREWam
 github.com/moby/term v0.0.0-20200312100748-672ec06f55cd/go.mod h1:DdlQx2hp0Ss5/fLikoLlEeIYiATotOjgB//nb973jeo=
 github.com/morikuni/aec v1.0.0 h1:nP9CBfwrvYnBRgY6qfDQkygYDmYwOilePFkwzv4dU8A=
 github.com/morikuni/aec v1.0.0/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7PXmsc=
-github.com/nicholas-fedor/shoutrrr v0.11.0 h1:hAMv2uM8OfFXkMHVP977elkP3Wgw5/YpVX5GxXQwiWA=
-github.com/nicholas-fedor/shoutrrr v0.11.0/go.mod h1:0kRF9ral22xUn/0BlxfhLQUeJDTySCPsuNvaclyagb4=
+github.com/nicholas-fedor/shoutrrr v0.11.1 h1:DND1gW8UM8GYG8c0bUZ5fPFAnm3id8noPdfaFBUmezk=
+github.com/nicholas-fedor/shoutrrr v0.11.1/go.mod h1:RZuSZSEaSimS47zTOLXb6HJDwLjDHiuJ9SrzxsDcWaQ=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/offen/envconfig v1.5.0 h1:LHL4wYIDVeoGxSDI40MShmWfss3gYUlCdstfSiSq4Fk=
 github.com/offen/envconfig v1.5.0/go.mod h1:L7ny7R+4JWH3VVnZ+ARHvZysWUiZ2eQcm3L0imU9ACY=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.12.0 h1:Iw5WCbBcaAAd0fpRb1c9r5YCylv4XDoCSigm1zLevwU=
 github.com/onsi/ginkgo v1.12.0/go.mod h1:oUhWkIvk5aDxtKvDDuw8gItl8pKl42LzjC9KZE0HfGg=
-github.com/onsi/ginkgo/v2 v2.27.1 h1:0LJC8MpUSQnfnp4n/3W3GdlmJP3ENGF0ZPzjQGLPP7s=
-github.com/onsi/ginkgo/v2 v2.27.1/go.mod h1:wmy3vCqiBjirARfVhAqFpYt8uvX0yaFe+GudAqqcCqA=
+github.com/onsi/ginkgo/v2 v2.27.2 h1:LzwLj0b89qtIy6SSASkzlNvX6WktqurSHwkk2ipF/Ns=
+github.com/onsi/ginkgo/v2 v2.27.2/go.mod h1:ArE1D/XhNXBXCBkKOLkbsb2c81dQHCRcF5zwn/ykDRo=
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/onsi/gomega v1.9.0/go.mod h1:Ho0h+IUsWyvy1OpqCwxlQ/21gkhVunqlU8fDGcoTdcA=
 github.com/onsi/gomega v1.38.2 h1:eZCjf2xjZAqe+LeWvKb5weQ+NcPwX84kqJ0cZNxok2A=
@@ -423,8 +423,6 @@ go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mx
 go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
 go.opentelemetry.io/proto/otlp v1.7.0 h1:jX1VolD6nHuFzOYso2E73H85i92Mv8JQYk0K9vz09os=
 go.opentelemetry.io/proto/otlp v1.7.0/go.mod h1:fSKjH6YJ7HDlwzltzyMj036AJ3ejJLCgCSHGj4efDDo=
-go.uber.org/automaxprocs v1.6.0 h1:O3y2/QNTOdbF+e/dpXNNW7Rx2hZ4sTIPyybbxyNqTUs=
-go.uber.org/automaxprocs v1.6.0/go.mod h1:ifeIMSnPZuznNm6jmdzmU3/bfk01Fe2fotchwEFJ8r8=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -637,8 +635,8 @@ google.golang.org/api v0.24.0/go.mod h1:lIXQywCXRcnZPGlsd8NbLnOjtAoL6em04bJ9+z0M
 google.golang.org/api v0.28.0/go.mod h1:lIXQywCXRcnZPGlsd8NbLnOjtAoL6em04bJ9+z0MncE=
 google.golang.org/api v0.29.0/go.mod h1:Lcubydp8VUV7KeIHD9z2Bys/sm/vGKnG1UHuDBSrHWM=
 google.golang.org/api v0.30.0/go.mod h1:QGmEvQ87FHZNiUVJkT14jQNYJ4ZJjdRF23ZXz5138Fc=
-google.golang.org/api v0.253.0 h1:apU86Eq9Q2eQco3NsUYFpVTfy7DwemojL7LmbAj7g/I=
-google.golang.org/api v0.253.0/go.mod h1:PX09ad0r/4du83vZVAaGg7OaeyGnaUmT/CYPNvtLCbw=
+google.golang.org/api v0.254.0 h1:jl3XrGj7lRjnlUvZAbAdhINTLbsg5dbjmR90+pTQvt4=
+google.golang.org/api v0.254.0/go.mod h1:5BkSURm3D9kAqjGvBNgf0EcbX6Rnrf6UArKkwBzAyqQ=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
@@ -678,8 +676,8 @@ google.golang.org/genproto v0.0.0-20250603155806-513f23925822 h1:rHWScKit0gvAPuO
 google.golang.org/genproto v0.0.0-20250603155806-513f23925822/go.mod h1:HubltRL7rMh0LfnQPkMH4NPDFEWp0jw3vixw7jEM53s=
 google.golang.org/genproto/googleapis/api v0.0.0-20250804133106-a7a43d27e69b h1:ULiyYQ0FdsJhwwZUwbaXpZF5yUE3h+RA+gxvBu37ucc=
 google.golang.org/genproto/googleapis/api v0.0.0-20250804133106-a7a43d27e69b/go.mod h1:oDOGiMSXHL4sDTJvFvIB9nRQCGdLP1o/iVaqQK8zB+M=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f h1:1FTH6cpXFsENbPR5Bu8NQddPSaUUE6NA2XdZdDSAJK4=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251022142026-3a174f9686a8 h1:M1rk8KBnUsBDg1oPGHNCxG4vc1f49epmTO7xscSajMk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251022142026-3a174f9686a8/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
 google.golang.org/grpc v1.0.5/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=

internal/storage/ssh/ssh.go

@@ -36,8 +36,10 @@ type Config struct {
 	RemotePath         string
 }
 
+var noop = func() error { return nil }
+
 // NewStorageBackend creates and initializes a new SSH storage backend.
-func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error) {
+func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, func() error, error) {
 	var authMethods []ssh.AuthMethod
 
 	if opts.Password != "" {
@@ -47,20 +49,20 @@ func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error
 	if _, err := os.Stat(opts.IdentityFile); err == nil {
 		key, err := os.ReadFile(opts.IdentityFile)
 		if err != nil {
-			return nil, errwrap.Wrap(nil, "error reading the private key")
+			return nil, noop, errwrap.Wrap(nil, "error reading the private key")
 		}
 
 		var signer ssh.Signer
 		if opts.IdentityPassphrase != "" {
 			signer, err = ssh.ParsePrivateKeyWithPassphrase(key, []byte(opts.IdentityPassphrase))
 			if err != nil {
-				return nil, errwrap.Wrap(nil, "error parsing the encrypted private key")
+				return nil, noop, errwrap.Wrap(nil, "error parsing the encrypted private key")
 			}
 			authMethods = append(authMethods, ssh.PublicKeys(signer))
 		} else {
 			signer, err = ssh.ParsePrivateKey(key)
 			if err != nil {
-				return nil, errwrap.Wrap(nil, "error parsing the private key")
+				return nil, noop, errwrap.Wrap(nil, "error parsing the private key")
 			}
 			authMethods = append(authMethods, ssh.PublicKeys(signer))
 		}
@@ -72,13 +74,12 @@ func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error
 		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
 	}
 	sshClient, err := ssh.Dial("tcp", fmt.Sprintf("%s:%s", opts.HostName, opts.Port), sshClientConfig)
-
-	if err != nil {
-		return nil, errwrap.Wrap(err, "error creating ssh client")
+	if err != nil || sshClient == nil {
+		return nil, noop, errwrap.Wrap(err, "error creating ssh client")
 	}
 	_, _, err = sshClient.SendRequest("keepalive", false, nil)
 	if err != nil {
-		return nil, err
+		return nil, sshClient.Close, err
 	}
 
 	sftpClient, err := sftp.NewClient(sshClient,
@@ -87,7 +88,7 @@ func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error
 		sftp.MaxConcurrentRequestsPerFile(64),
 	)
 	if err != nil {
-		return nil, errwrap.Wrap(err, "error creating sftp client")
+		return nil, sshClient.Close, errwrap.Wrap(err, "error creating sftp client")
 	}
 
 	return &sshStorage{
@@ -98,7 +99,7 @@ func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error
 		client:     sshClient,
 		sftpClient: sftpClient,
 		hostName:   opts.HostName,
-	}, nil
+	}, sshClient.Close, nil
 }
 
 // Name returns the name of the storage backend

test/no-restart/docker-compose.yml

@@ -1,16 +1,10 @@
 services:
   backup:
     image: offen/docker-volume-backup:${TEST_VERSION:-canary}
-    hostname: hostnametoken
     restart: always
     environment:
-      BACKUP_FILENAME_EXPAND: 'true'
-      BACKUP_FILENAME: test-$$HOSTNAME.tar.gz
-      BACKUP_LATEST_SYMLINK: test-$$HOSTNAME.latest.tar.gz.gpg
+      BACKUP_FILENAME: test.tar.gz
       BACKUP_CRON_EXPRESSION: 0 0 5 31 2 ?
-      BACKUP_RETENTION_DAYS: ${BACKUP_RETENTION_DAYS:-7}
-      BACKUP_PRUNING_LEEWAY: 5s
-      BACKUP_PRUNING_PREFIX: test
     volumes:
       - app_data:/backup/app_data:ro
       - /var/run/docker.sock:/var/run/docker.sock:ro

test/no-restart/run.sh

@@ -11,9 +11,6 @@ export LOCAL_DIR=$(mktemp -d)
 docker compose up -d --quiet-pull
 sleep 5
 
-# A symlink for a known file in the volume is created so the test can check
-# whether symlinks are preserved on backup.
-docker compose exec offen ln -s /var/opt/offen/offen.db /var/opt/offen/db.link
 docker compose exec backup backup
 
 sleep 5
@@ -21,56 +18,7 @@ sleep 5
 expect_running_containers "1"
 
 tmp_dir=$(mktemp -d)
-tar -xvf "$LOCAL_DIR/test-hostnametoken.tar.gz" -C $tmp_dir
+tar -xvf "$LOCAL_DIR/test.tar.gz" -C $tmp_dir
 if [ ! -f "$tmp_dir/backup/app_data/offen.db" ]; then
   fail "Could not find expected file in untared archive."
 fi
-rm -f "$LOCAL_DIR/test-hostnametoken.tar.gz"
-
-if [ ! -L "$tmp_dir/backup/app_data/db.link" ]; then
-  fail "Could not find expected symlink in untared archive."
-fi
-
-pass "Found relevant files in decrypted and untared local backup."
-
-if [ ! -L "$LOCAL_DIR/test-hostnametoken.latest.tar.gz.gpg" ]; then
-  fail "Could not find symlink to latest version."
-fi
-
-pass "Found symlink to latest version in local backup."
-
-# The second part of this test checks if backups get deleted when the retention
-# is set to 0 days (which it should not as it would mean all backups get deleted)
-BACKUP_RETENTION_DAYS="0" docker compose up -d
-sleep 5
-
-docker compose exec backup backup
-
-if [ "$(find "$LOCAL_DIR" -type f | wc -l)" != "1" ]; then
-  fail "Backups should not have been deleted, instead seen: "$(find "$local_dir" -type f)""
-fi
-pass "Local backups have not been deleted."
-
-# The third part of this test checks if old backups get deleted when the retention
-# is set to 7 days (which it should)
-
-BACKUP_RETENTION_DAYS="7" docker compose up -d
-sleep 5
-
-info "Create first backup with no prune"
-docker compose exec backup backup
-
-touch -r "$LOCAL_DIR/test-hostnametoken.tar.gz" -d "14 days ago" "$LOCAL_DIR/test-hostnametoken-old.tar.gz"
-
-info "Create second backup and prune"
-docker compose exec backup backup
-
-if [ -f "$LOCAL_DIR/test-hostnametoken-old.tar.gz" ]; then
-  fail "Backdated file has not been deleted."
-fi
-
-if [ ! -f "$LOCAL_DIR/test-hostnametoken.tar.gz" ]; then
-  fail "Recent file has been deleted."
-fi
-
-pass "Old remote backup has been pruned, new one is still present."