Deprecate secrets (#4235)

pipeline/frontend/yaml/linter/linter.go

@@ -265,6 +265,21 @@ func (l *Linter) lintDeprecations(config *WorkflowConfig) (err error) {
 		return err
 	}
 
+	for _, container := range parsed.Steps.ContainerList {
+		if len(container.Secrets) > 0 {
+			err = multierr.Append(err, &errorTypes.PipelineError{
+				Type:    errorTypes.PipelineErrorTypeDeprecation,
+				Message: "Secrets are deprecated, use environment with from_secret",
+				Data: errors.DeprecationErrorData{
+					File:  config.File,
+					Field: fmt.Sprintf("steps.%s.secrets", container.Name),
+					Docs:  "https://woodpecker-ci.org/docs/usage/secrets#usage",
+				},
+				IsWarning: true,
+			})
+		}
+	}
+
 	return nil
 }
 

pipeline/frontend/yaml/types/container.go

@@ -47,9 +47,11 @@ type (
 		Ports          []string           `yaml:"ports,omitempty"`
 		DependsOn      base.StringOrSlice `yaml:"depends_on,omitempty"`
 
-		Secrets     []string       `yaml:"secrets,omitempty"`
 		Environment map[string]any `yaml:"environment,omitempty"`
 
+		// Deprecated
+		Secrets []string `yaml:"secrets,omitempty"`
+
 		// Docker and Kubernetes Specific
 		Privileged bool `yaml:"privileged,omitempty"`