package provider import ( "bytes" "strings" "text/template" "github.com/BurntSushi/toml" "github.com/Masterminds/sprig" "github.com/containous/traefik/config" "github.com/containous/traefik/log" "github.com/containous/traefik/types" ) // BaseProvider should be inherited by providers. type BaseProvider struct { Watch bool `description:"Watch provider" export:"true"` Filename string `description:"Override default configuration template. For advanced users :)" export:"true"` Constraints types.Constraints `description:"Filter services by constraint, matching with Traefik tags." export:"true"` Trace bool `description:"Display additional provider logs (if available)." export:"true"` DebugLogGeneratedTemplate bool `description:"Enable debug logging of generated configuration template." export:"true"` } // Init for compatibility reason the BaseProvider implements an empty Init. func (p *BaseProvider) Init() error { return nil } // MatchConstraints must match with EVERY single constraint // returns first constraint that do not match or nil. func (p *BaseProvider) MatchConstraints(tags []string) (bool, *types.Constraint) { // if there is no tags and no constraints, filtering is disabled if len(tags) == 0 && len(p.Constraints) == 0 { return true, nil } for _, constraint := range p.Constraints { // xor: if ok and constraint.MustMatch are equal, then no tag is currently matching with the constraint if ok := constraint.MatchConstraintWithAtLeastOneTag(tags); ok != constraint.MustMatch { return false, constraint } } // If no constraint or every constraints matching return true, nil } // CreateConfiguration creates a provider configuration from content using templating. func (p *BaseProvider) CreateConfiguration(tmplContent string, funcMap template.FuncMap, templateObjects interface{}) (*config.Configuration, error) { var defaultFuncMap = sprig.TxtFuncMap() // tolower is deprecated in favor of sprig's lower function defaultFuncMap["tolower"] = strings.ToLower defaultFuncMap["normalize"] = Normalize defaultFuncMap["split"] = split for funcID, funcElement := range funcMap { defaultFuncMap[funcID] = funcElement } tmpl := template.New(p.Filename).Funcs(defaultFuncMap) _, err := tmpl.Parse(tmplContent) if err != nil { return nil, err } var buffer bytes.Buffer err = tmpl.Execute(&buffer, templateObjects) if err != nil { return nil, err } var renderedTemplate = buffer.String() if p.DebugLogGeneratedTemplate { log.Debugf("Template content: %s", tmplContent) log.Debugf("Rendering results: %s", renderedTemplate) } return p.DecodeConfiguration(renderedTemplate) } // DecodeConfiguration Decodes a *types.Configuration from a content. func (p *BaseProvider) DecodeConfiguration(content string) (*config.Configuration, error) { configuration := new(config.Configuration) if _, err := toml.Decode(content, configuration); err != nil { return nil, err } return configuration, nil } func split(sep, s string) []string { return strings.Split(s, sep) }