Add Connection.User() to lookup user associated with the connection

connection.go

@@ -0,0 +1,49 @@
+package netstat
+
+import (
+	"net"
+	"os/user"
+)
+
+// Connection contains the gathered information about an open network connection.
+type Connection struct {
+	// Exe contains the path to the process.
+	// Exe is empty if there was an error reading /proc/pid/exe.
+	Exe string
+	// Cmdline contains the complete command line for the process split by \000. Trailing \000 removed.
+	// Returns an empty array if /proc/pid/cmdline can't be read.
+	Cmdline []string
+	// Pid contains the pid of the process. Is zero if open connection can't be assigned to a pid.
+	Pid int
+
+	// UserID represents the user account id of the user owning the socket.
+	// On Linux systems it is usually a uint32.
+	// Type string was chosen because os/user.LookupId() wants a string.
+	UserID string
+
+	// Inode contains the inode for the open connection.
+	Inode uint64
+
+	// IP holds the local IP for the connection.
+	IP net.IP
+	// Port holds the local port for the connection.
+	Port int
+	// RemoteIP holds the remote IP for the connection.
+	RemoteIP net.IP
+	// RemotePort holds the remote port for the connection.
+	RemotePort int
+	// State represents the state of a TCP connection. The UDP 'states' shown
+	// are recycled from TCP connection states and have a slightly different meaning.
+	State TCPState
+
+	// TransmitQueue is the outgoing data queue in terms of kernel memory usage in bytes.
+	TransmitQueue uint64
+	// ReceiveQueue is the incoming data queue in terms of kernel memory usage in bytes.
+	ReceiveQueue uint64
+}
+
+// User looks up the user owning the socket.
+// If the user cannot be found, the returned error is of type UnknownUserIdError.
+func (c *Connection) User() (*user.User, error) {
+	return user.LookupId(c.UserID)
+}

connection_test.go

@@ -0,0 +1,20 @@
+package netstat_test
+
+import (
+	"os/user"
+	"testing"
+
+	"gotest.tools/assert"
+
+	"github.com/bastjan/netstat"
+)
+
+func TestConnectionUser(t *testing.T) {
+	validUser, _ := user.Current()
+	subject := &netstat.Connection{UserID: validUser.Uid}
+
+	expectedUser, expectedErr := user.LookupId(validUser.Uid)
+	user, err := subject.User()
+	assert.DeepEqual(t, expectedUser, user)
+	assert.DeepEqual(t, expectedErr, err)
+}

netstat.go

@@ -29,42 +29,6 @@ type Netstat struct {
 	RelPath string
 }
 
-// Connection contains the gathered information about an open network connection.
-type Connection struct {
-	// Exe contains the path to the process.
-	// Exe is empty if there was an error reading /proc/pid/exe.
-	Exe string
-	// Cmdline contains the complete command line for the process split by \000. Trailing \000 removed.
-	// Returns an empty array if /proc/pid/cmdline can't be read.
-	Cmdline []string
-	// Pid contains the pid of the process. Is zero if open connection can't be assigned to a pid.
-	Pid int
-
-	// UserID represents a user account id. On Linux systems it is usually a uint32.
-	// Type string was chosen because os/user.LookupId() wants a string.
-	UserID string
-
-	// Inode contains the inode for the open connection.
-	Inode uint64
-
-	// IP holds the local IP for the connection.
-	IP net.IP
-	// Port holds the local port for the connection.
-	Port int
-	// RemoteIP holds the remote IP for the connection.
-	RemoteIP net.IP
-	// RemotePort holds the remote port for the connection.
-	RemotePort int
-	// State represents the state of a TCP connection. The UDP 'states' shown
-	// are recycled from TCP connection states and have a slightly different meaning.
-	State TCPState
-
-	// TransmitQueue is the outgoing data queue in terms of kernel memory usage in bytes.
-	TransmitQueue uint64
-	// ReceiveQueue is the incoming data queue in terms of kernel memory usage in bytes.
-	ReceiveQueue uint64
-}
-
 // ProcRoot should point to the root of the proc file system
 var ProcRoot = "/proc"