traefik/pkg/provider/file/file.go
Ludovic Fernandez 8d7eccad5d New static configuration loading system.
Co-authored-by: Mathieu Lonjaret <mathieu.lonjaret@gmail.com>
2019-06-17 11:48:05 +02:00

370 lines
10 KiB
Go

package file
import (
"bytes"
"context"
"errors"
"fmt"
"io/ioutil"
"os"
"path"
"path/filepath"
"strings"
"text/template"
"github.com/BurntSushi/toml"
"github.com/Masterminds/sprig"
"github.com/containous/traefik/pkg/config"
"github.com/containous/traefik/pkg/log"
"github.com/containous/traefik/pkg/provider"
"github.com/containous/traefik/pkg/safe"
"github.com/containous/traefik/pkg/tls"
"gopkg.in/fsnotify.v1"
)
const providerName = "file"
var _ provider.Provider = (*Provider)(nil)
// Provider holds configurations of the provider.
type Provider struct {
Directory string `description:"Load configuration from one or more .toml files in a directory." export:"true"`
Watch bool `description:"Watch provider." export:"true"`
Filename string `description:"Override default configuration template. For advanced users :)" export:"true"`
DebugLogGeneratedTemplate bool `description:"Enable debug logging of generated configuration template." export:"true"`
TraefikFile string `description:"-"`
}
// SetDefaults sets the default values.
func (p *Provider) SetDefaults() {
p.Watch = true
p.Filename = ""
}
// Init the provider
func (p *Provider) Init() error {
return nil
}
// Provide allows the file provider to provide configurations to traefik
// using the given configuration channel.
func (p *Provider) Provide(configurationChan chan<- config.Message, pool *safe.Pool) error {
configuration, err := p.BuildConfiguration()
if err != nil {
return err
}
if p.Watch {
var watchItem string
switch {
case len(p.Directory) > 0:
watchItem = p.Directory
case len(p.Filename) > 0:
watchItem = filepath.Dir(p.Filename)
default:
watchItem = filepath.Dir(p.TraefikFile)
}
if err := p.addWatcher(pool, watchItem, configurationChan, p.watcherCallback); err != nil {
return err
}
}
sendConfigToChannel(configurationChan, configuration)
return nil
}
// BuildConfiguration loads configuration either from file or a directory specified by 'Filename'/'Directory'
// and returns a 'Configuration' object
func (p *Provider) BuildConfiguration() (*config.Configuration, error) {
ctx := log.With(context.Background(), log.Str(log.ProviderName, providerName))
if len(p.Directory) > 0 {
return p.loadFileConfigFromDirectory(ctx, p.Directory, nil)
}
if len(p.Filename) > 0 {
return p.loadFileConfig(p.Filename, true)
}
if len(p.TraefikFile) > 0 {
return p.loadFileConfig(p.TraefikFile, false)
}
return nil, errors.New("error using file configuration backend, no filename defined")
}
func (p *Provider) addWatcher(pool *safe.Pool, directory string, configurationChan chan<- config.Message, callback func(chan<- config.Message, fsnotify.Event)) error {
watcher, err := fsnotify.NewWatcher()
if err != nil {
return fmt.Errorf("error creating file watcher: %s", err)
}
err = watcher.Add(directory)
if err != nil {
return fmt.Errorf("error adding file watcher: %s", err)
}
// Process events
pool.Go(func(stop chan bool) {
defer watcher.Close()
for {
select {
case <-stop:
return
case evt := <-watcher.Events:
if p.Directory == "" {
var filename string
if len(p.Filename) > 0 {
filename = p.Filename
} else {
filename = p.TraefikFile
}
_, evtFileName := filepath.Split(evt.Name)
_, confFileName := filepath.Split(filename)
if evtFileName == confFileName {
callback(configurationChan, evt)
}
} else {
callback(configurationChan, evt)
}
case err := <-watcher.Errors:
log.WithoutContext().WithField(log.ProviderName, providerName).Errorf("Watcher event error: %s", err)
}
}
})
return nil
}
func (p *Provider) watcherCallback(configurationChan chan<- config.Message, event fsnotify.Event) {
watchItem := p.TraefikFile
if len(p.Directory) > 0 {
watchItem = p.Directory
} else if len(p.Filename) > 0 {
watchItem = p.Filename
}
logger := log.WithoutContext().WithField(log.ProviderName, providerName)
if _, err := os.Stat(watchItem); err != nil {
logger.Errorf("Unable to watch %s : %v", watchItem, err)
return
}
configuration, err := p.BuildConfiguration()
if err != nil {
logger.Errorf("Error occurred during watcher callback: %s", err)
return
}
sendConfigToChannel(configurationChan, configuration)
}
func sendConfigToChannel(configurationChan chan<- config.Message, configuration *config.Configuration) {
configurationChan <- config.Message{
ProviderName: "file",
Configuration: configuration,
}
}
func readFile(filename string) (string, error) {
if len(filename) > 0 {
buf, err := ioutil.ReadFile(filename)
if err != nil {
return "", err
}
return string(buf), nil
}
return "", fmt.Errorf("invalid filename: %s", filename)
}
func (p *Provider) loadFileConfig(filename string, parseTemplate bool) (*config.Configuration, error) {
fileContent, err := readFile(filename)
if err != nil {
return nil, fmt.Errorf("error reading configuration file: %s - %s", filename, err)
}
var configuration *config.Configuration
if parseTemplate {
configuration, err = p.CreateConfiguration(fileContent, template.FuncMap{}, false)
} else {
configuration, err = p.DecodeConfiguration(fileContent)
}
if err != nil {
return nil, err
}
var tlsConfigs []*tls.Configuration
for _, conf := range configuration.TLS {
bytes, err := conf.Certificate.CertFile.Read()
if err != nil {
log.Error(err)
continue
}
conf.Certificate.CertFile = tls.FileOrContent(string(bytes))
bytes, err = conf.Certificate.KeyFile.Read()
if err != nil {
log.Error(err)
continue
}
conf.Certificate.KeyFile = tls.FileOrContent(string(bytes))
tlsConfigs = append(tlsConfigs, conf)
}
configuration.TLS = tlsConfigs
return configuration, nil
}
func (p *Provider) loadFileConfigFromDirectory(ctx context.Context, directory string, configuration *config.Configuration) (*config.Configuration, error) {
logger := log.FromContext(ctx)
fileList, err := ioutil.ReadDir(directory)
if err != nil {
return configuration, fmt.Errorf("unable to read directory %s: %v", directory, err)
}
if configuration == nil {
configuration = &config.Configuration{
HTTP: &config.HTTPConfiguration{
Routers: make(map[string]*config.Router),
Middlewares: make(map[string]*config.Middleware),
Services: make(map[string]*config.Service),
},
TCP: &config.TCPConfiguration{
Routers: make(map[string]*config.TCPRouter),
Services: make(map[string]*config.TCPService),
},
}
}
configTLSMaps := make(map[*tls.Configuration]struct{})
for _, item := range fileList {
if item.IsDir() {
configuration, err = p.loadFileConfigFromDirectory(ctx, filepath.Join(directory, item.Name()), configuration)
if err != nil {
return configuration, fmt.Errorf("unable to load content configuration from subdirectory %s: %v", item, err)
}
continue
} else if !strings.HasSuffix(item.Name(), ".toml") && !strings.HasSuffix(item.Name(), ".tmpl") {
continue
}
var c *config.Configuration
c, err = p.loadFileConfig(path.Join(directory, item.Name()), true)
if err != nil {
return configuration, err
}
for name, conf := range c.HTTP.Routers {
if _, exists := configuration.HTTP.Routers[name]; exists {
logger.WithField(log.RouterName, name).Warn("HTTP router already configured, skipping")
} else {
configuration.HTTP.Routers[name] = conf
}
}
for name, conf := range c.HTTP.Middlewares {
if _, exists := configuration.HTTP.Middlewares[name]; exists {
logger.WithField(log.MiddlewareName, name).Warn("HTTP middleware already configured, skipping")
} else {
configuration.HTTP.Middlewares[name] = conf
}
}
for name, conf := range c.HTTP.Services {
if _, exists := configuration.HTTP.Services[name]; exists {
logger.WithField(log.ServiceName, name).Warn("HTTP service already configured, skipping")
} else {
configuration.HTTP.Services[name] = conf
}
}
for name, conf := range c.TCP.Routers {
if _, exists := configuration.TCP.Routers[name]; exists {
logger.WithField(log.RouterName, name).Warn("TCP router already configured, skipping")
} else {
configuration.TCP.Routers[name] = conf
}
}
for name, conf := range c.TCP.Services {
if _, exists := configuration.TCP.Services[name]; exists {
logger.WithField(log.ServiceName, name).Warn("TCP service already configured, skipping")
} else {
configuration.TCP.Services[name] = conf
}
}
for _, conf := range c.TLS {
if _, exists := configTLSMaps[conf]; exists {
logger.Warnf("TLS configuration %v already configured, skipping", conf)
} else {
configTLSMaps[conf] = struct{}{}
}
}
}
for conf := range configTLSMaps {
configuration.TLS = append(configuration.TLS, conf)
}
return configuration, nil
}
// CreateConfiguration creates a provider configuration from content using templating.
func (p *Provider) CreateConfiguration(tmplContent string, funcMap template.FuncMap, templateObjects interface{}) (*config.Configuration, error) {
var defaultFuncMap = sprig.TxtFuncMap()
defaultFuncMap["normalize"] = provider.Normalize
defaultFuncMap["split"] = strings.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 *Provider) DecodeConfiguration(content string) (*config.Configuration, error) {
configuration := &config.Configuration{
HTTP: &config.HTTPConfiguration{
Routers: make(map[string]*config.Router),
Middlewares: make(map[string]*config.Middleware),
Services: make(map[string]*config.Service),
},
TCP: &config.TCPConfiguration{
Routers: make(map[string]*config.TCPRouter),
Services: make(map[string]*config.TCPService),
},
TLS: make([]*tls.Configuration, 0),
TLSStores: make(map[string]tls.Store),
TLSOptions: make(map[string]tls.TLS),
}
if _, err := toml.Decode(content, configuration); err != nil {
return nil, err
}
return configuration, nil
}