traefik/provider/file/file.go
2018-03-22 16:14:04 +01:00

220 lines
6 KiB
Go

package file
import (
"fmt"
"io/ioutil"
"os"
"path"
"path/filepath"
"strings"
"text/template"
"github.com/containous/traefik/log"
"github.com/containous/traefik/provider"
"github.com/containous/traefik/safe"
"github.com/containous/traefik/tls"
"github.com/containous/traefik/types"
"gopkg.in/fsnotify.v1"
)
var _ provider.Provider = (*Provider)(nil)
// Provider holds configurations of the provider.
type Provider struct {
provider.BaseProvider `mapstructure:",squash" export:"true"`
Directory string `description:"Load configuration from one or more .toml files in a directory" export:"true"`
}
// Provide allows the file provider to provide configurations to traefik
// using the given configuration channel.
func (p *Provider) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints types.Constraints) error {
configuration, err := p.BuildConfiguration()
if err != nil {
return err
}
if p.Watch {
var watchItem string
if p.Directory != "" {
watchItem = p.Directory
} else {
watchItem = filepath.Dir(p.Filename)
}
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() (*types.Configuration, error) {
if p.Directory != "" {
return p.loadFileConfigFromDirectory(p.Directory, nil)
}
return p.loadFileConfig(p.Filename)
}
func (p *Provider) addWatcher(pool *safe.Pool, directory string, configurationChan chan<- types.ConfigMessage, callback func(chan<- types.ConfigMessage, fsnotify.Event)) error {
watcher, err := fsnotify.NewWatcher()
if err != nil {
return fmt.Errorf("error creating 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 == "" {
_, evtFileName := filepath.Split(evt.Name)
_, confFileName := filepath.Split(p.Filename)
if evtFileName == confFileName {
callback(configurationChan, evt)
}
} else {
callback(configurationChan, evt)
}
case err := <-watcher.Errors:
log.Errorf("Watcher event error: %s", err)
}
}
})
err = watcher.Add(directory)
if err != nil {
return fmt.Errorf("error adding file watcher: %s", err)
}
return nil
}
func (p *Provider) watcherCallback(configurationChan chan<- types.ConfigMessage, event fsnotify.Event) {
watchItem := p.Filename
if p.Directory != "" {
watchItem = p.Directory
}
if _, err := os.Stat(watchItem); err != nil {
log.Debugf("Unable to watch %s : %v", watchItem, err)
return
}
configuration, err := p.BuildConfiguration()
if err != nil {
log.Errorf("Error occurred during watcher callback: %s", err)
return
}
sendConfigToChannel(configurationChan, configuration)
}
func sendConfigToChannel(configurationChan chan<- types.ConfigMessage, configuration *types.Configuration) {
configurationChan <- types.ConfigMessage{
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) (*types.Configuration, error) {
fileContent, err := readFile(filename)
if err != nil {
return nil, fmt.Errorf("error reading configuration file: %s - %s", filename, err)
}
configuration, err := p.CreateConfiguration(fileContent, template.FuncMap{}, false)
if err != nil {
return nil, err
}
if configuration == nil || configuration.Backends == nil && configuration.Frontends == nil && configuration.TLS == nil {
configuration = &types.Configuration{
Frontends: make(map[string]*types.Frontend),
Backends: make(map[string]*types.Backend),
}
}
return configuration, err
}
func (p *Provider) loadFileConfigFromDirectory(directory string, configuration *types.Configuration) (*types.Configuration, error) {
fileList, err := ioutil.ReadDir(directory)
if err != nil {
return configuration, fmt.Errorf("unable to read directory %s: %v", directory, err)
}
if configuration == nil {
configuration = &types.Configuration{
Frontends: make(map[string]*types.Frontend),
Backends: make(map[string]*types.Backend),
}
}
configTLSMaps := make(map[*tls.Configuration]struct{})
for _, item := range fileList {
if item.IsDir() {
configuration, err = p.loadFileConfigFromDirectory(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 *types.Configuration
c, err = p.loadFileConfig(path.Join(directory, item.Name()))
if err != nil {
return configuration, err
}
for backendName, backend := range c.Backends {
if _, exists := configuration.Backends[backendName]; exists {
log.Warnf("Backend %s already configured, skipping", backendName)
} else {
configuration.Backends[backendName] = backend
}
}
for frontendName, frontend := range c.Frontends {
if _, exists := configuration.Frontends[frontendName]; exists {
log.Warnf("Frontend %s already configured, skipping", frontendName)
} else {
configuration.Frontends[frontendName] = frontend
}
}
for _, conf := range c.TLS {
if _, exists := configTLSMaps[conf]; exists {
log.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
}