cli/connhelper/ssh: use stdlib errors and improve errors

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/connhelper/ssh/ssh.go

@@ -2,9 +2,9 @@
 package ssh
 
 import (
+	"errors"
+	"fmt"
 	"net/url"
-
-	"github.com/pkg/errors"
 )
 
 // ParseURL creates a [Spec] from the given ssh URL. It returns an error if
@@ -13,10 +13,25 @@ import (
 func ParseURL(daemonURL string) (*Spec, error) {
 	u, err := url.Parse(daemonURL)
 	if err != nil {
-		return nil, err
+		var urlErr *url.Error
+		if errors.As(err, &urlErr) {
+			err = urlErr.Unwrap()
+		}
+		return nil, fmt.Errorf("invalid ssh URL: %w", err)
+	}
+	s, err := newSpec(u)
+	if err != nil {
+		return nil, fmt.Errorf("invalid ssh URL: %w", err)
+	}
+	return s, nil
+}
+
+func newSpec(u *url.URL) (*Spec, error) {
+	if u.Scheme == "" {
+		return nil, errors.New("no scheme provided")
 	}
 	if u.Scheme != "ssh" {
-		return nil, errors.Errorf("expected scheme ssh, got %q", u.Scheme)
+		return nil, errors.New("incorrect scheme: " + u.Scheme)
 	}
 
 	var sp Spec
@@ -29,17 +44,18 @@ func ParseURL(daemonURL string) (*Spec, error) {
 	}
 	sp.Host = u.Hostname()
 	if sp.Host == "" {
-		return nil, errors.Errorf("no host specified")
+		return nil, errors.New("hostname is empty")
 	}
 	sp.Port = u.Port()
 	sp.Path = u.Path
 	if u.RawQuery != "" {
-		return nil, errors.Errorf("extra query after the host: %q", u.RawQuery)
+		return nil, fmt.Errorf("query parameters are not allowed: %q", u.RawQuery)
 	}
 	if u.Fragment != "" {
-		return nil, errors.Errorf("extra fragment after the host: %q", u.Fragment)
+		return nil, fmt.Errorf("fragments are not allowed: %q", u.Fragment)
 	}
-	return &sp, err
+
+	return &sp, nil
 }
 
 // Spec of SSH URL

cli/connhelper/ssh/ssh_test.go

@@ -84,30 +84,44 @@ func TestParseURL(t *testing.T) {
 				Path: "/var/run/docker.sock",
 			},
 		},
+		{
+			doc:           "malformed URL",
+			url:           "malformed %%url",
+			expectedError: `invalid ssh URL: invalid URL escape "%%u"`,
+		},
+		{
+			doc:           "URL missing scheme",
+			url:           "no-scheme.example.com",
+			expectedError: "invalid ssh URL: no scheme provided",
+		},
 		{
 			doc:           "invalid URL with password",
 			url:           "ssh://me:passw0rd@example.com",
-			expectedError: "plain-text password is not supported",
+			expectedError: "invalid ssh URL: plain-text password is not supported",
 		},
 		{
 			doc:           "invalid URL with query parameter",
-			url:           "ssh://example.com?bar",
-			expectedError: `extra query after the host: "bar"`,
+			url:           "ssh://example.com?foo=bar&bar=baz",
+			expectedError: `invalid ssh URL: query parameters are not allowed: "foo=bar&bar=baz"`,
 		},
 		{
 			doc:           "invalid URL with fragment",
 			url:           "ssh://example.com#bar",
-			expectedError: `extra fragment after the host: "bar"`,
+			expectedError: `invalid ssh URL: fragments are not allowed: "bar"`,
 		},
 		{
 			doc:           "invalid URL without hostname",
 			url:           "ssh://",
-			expectedError: "no host specified",
+			expectedError: "invalid ssh URL: hostname is empty",
+		},
+		{
+			url:           "ssh:///no-hostname",
+			expectedError: "invalid ssh URL: hostname is empty",
 		},
 		{
 			doc:           "invalid URL with unsupported scheme",
 			url:           "https://example.com",
-			expectedError: `expected scheme ssh, got "https"`,
+			expectedError: `invalid ssh URL: incorrect scheme: https`,
 		},
 	}
 	for _, tc := range testCases {