package provider import ( "bytes" "io/ioutil" "strings" "text/template" "unicode" "github.com/BurntSushi/toml" "github.com/Masterminds/sprig" "github.com/containous/traefik/autogen/gentemplates" "github.com/containous/traefik/log" "github.com/containous/traefik/safe" "github.com/containous/traefik/types" ) // Provider defines methods of a provider. type Provider interface { // Provide allows the provider to provide configurations to traefik // using the given configuration channel. Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool) error Init(constraints types.Constraints) error } // 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(constraints types.Constraints) error { p.Constraints = append(p.Constraints, constraints...) 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 } // GetConfiguration return the provider configuration from default template (file or content) or overrode template file func (p *BaseProvider) GetConfiguration(defaultTemplate string, funcMap template.FuncMap, templateObjects interface{}) (*types.Configuration, error) { tmplContent, err := p.getTemplateContent(defaultTemplate) if err != nil { return nil, err } return p.CreateConfiguration(tmplContent, funcMap, templateObjects) } // CreateConfiguration create a provider configuration from content using templating func (p *BaseProvider) CreateConfiguration(tmplContent string, funcMap template.FuncMap, templateObjects interface{}) (*types.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 Decode a *types.Configuration from a content func (p *BaseProvider) DecodeConfiguration(content string) (*types.Configuration, error) { configuration := new(types.Configuration) if _, err := toml.Decode(content, configuration); err != nil { return nil, err } return configuration, nil } func (p *BaseProvider) getTemplateContent(defaultTemplateFile string) (string, error) { if len(p.Filename) > 0 { buf, err := ioutil.ReadFile(p.Filename) if err != nil { return "", err } return string(buf), nil } if strings.HasSuffix(defaultTemplateFile, ".tmpl") { buf, err := gentemplates.Asset(defaultTemplateFile) if err != nil { return "", err } return string(buf), nil } return defaultTemplateFile, nil } func split(sep, s string) []string { return strings.Split(s, sep) } // Normalize transform a string that work with the rest of traefik // Replace '.' with '-' in quoted keys because of this issue https://github.com/BurntSushi/toml/issues/78 func Normalize(name string) string { fargs := func(c rune) bool { return !unicode.IsLetter(c) && !unicode.IsNumber(c) } // get function return strings.Join(strings.FieldsFunc(name, fargs), "-") } // ReverseStringSlice invert the order of the given slice of string func ReverseStringSlice(slice *[]string) { for i, j := 0, len(*slice)-1; i < j; i, j = i+1, j-1 { (*slice)[i], (*slice)[j] = (*slice)[j], (*slice)[i] } }