pkg/compose: explicitly map AuthConfig fields instead of a direct cast

Commit [cli@27b2797] forked the AuthConfig type from the API, and changed
existing code to do a direct cast / convert of the forked type to the API
type. This can cause issues if the API types diverges, such as the removal
of the Email field.

This patch explicitly maps each field to the corresponding API type, but
adds some TODOs, because various code-paths only included a subset of the
fields, which may be intentional for fields that were meant to be handled
on the daemon / registry-client only.

We should evaluate these conversions to make sure these fields should
be sent from the client or not (and possibly even removed from the API
type).

[cli@27b2797]: 27b2797f7d

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

pkg/compose/build_classic.go

@@ -154,8 +154,17 @@ func (s *composeService) doBuildClassic(ctx context.Context, project *types.Proj
 		return "", err
 	}
 	authConfigs := make(map[string]registry.AuthConfig, len(creds))
-	for k, auth := range creds {
-		authConfigs[k] = registry.AuthConfig(auth)
+	for k, authConfig := range creds {
+		authConfigs[k] = registry.AuthConfig{
+			Username:      authConfig.Username,
+			Password:      authConfig.Password,
+			ServerAddress: authConfig.ServerAddress,
+
+			// TODO(thaJeztah): Are these expected to be included? See https://github.com/docker/cli/pull/6516#discussion_r2387586472
+			Auth:          authConfig.Auth,
+			IdentityToken: authConfig.IdentityToken,
+			RegistryToken: authConfig.RegistryToken,
+		}
 	}
 	buildOptions := imageBuildOptions(s.dockerCli, project, service, options)
 	imageName := api.GetImageNameOrDefault(service, project.Name)