VictoriaMetrics/app/vmalert/config/fs.go
Roman Khavronenko d66bae212b
app/vmalert: log number of configration files found for each specified -rule (#3936)
The change also introduces `List` method to `FS` interface.
The `List` method can be used for wildcard support in object storage FS.

Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Nikolay <nik@victoriametrics.com>
2023-03-09 14:46:19 +01:00

109 lines
2.7 KiB
Go

package config
import (
"fmt"
"strings"
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/config/fslocal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
)
// FS represent a file system abstract for reading files.
type FS interface {
// Init initializes FS.
Init() error
// String must return human-readable representation of FS.
String() string
// List returns the list of file names which will be read via Read fn
List() ([]string, error)
// Read returns a list of read files in form of a map
// where key is a file name and value is a content of read file.
// Read must be called only after the successful Init call.
Read(files []string) (map[string][]byte, error)
}
var (
fsRegistryMu sync.Mutex
fsRegistry = make(map[string]FS)
)
// readFromFS parses the given path list and inits FS for each item.
// Once inited, readFromFS will try to read and return files from each FS.
// readFromFS returns an error if at least one FS failed to init.
// The function can be called multiple times but each unique path
// will be inited only once.
// If silent == true, readFromFS will not emit any logs.
//
// It is allowed to mix different FS types in path list.
func readFromFS(paths []string, silent bool) (map[string][]byte, error) {
var err error
result := make(map[string][]byte)
for _, path := range paths {
fsRegistryMu.Lock()
fs, ok := fsRegistry[path]
if !ok {
fs, err = newFS(path)
if err != nil {
fsRegistryMu.Unlock()
return nil, fmt.Errorf("error while parsing path %q: %w", path, err)
}
if err := fs.Init(); err != nil {
fsRegistryMu.Unlock()
return nil, fmt.Errorf("error while initializing path %q: %w", path, err)
}
fsRegistry[path] = fs
}
fsRegistryMu.Unlock()
list, err := fs.List()
if err != nil {
return nil, fmt.Errorf("failed to list files from %q", fs)
}
if !silent {
logger.Infof("found %d files to read from %q", len(list), fs)
}
if len(list) < 1 {
continue
}
files, err := fs.Read(list)
if err != nil {
return nil, fmt.Errorf("error while reading files from %q: %w", fs, err)
}
for k, v := range files {
if _, ok := result[k]; ok {
return nil, fmt.Errorf("duplicate found for file name %q: file names must be unique", k)
}
result[k] = v
}
}
return result, nil
}
// newFS creates FS based on the give path.
// Supported file systems are: fs
func newFS(path string) (FS, error) {
scheme := "fs"
n := strings.Index(path, "://")
if n >= 0 {
scheme = path[:n]
path = path[n+len("://"):]
}
if len(path) == 0 {
return nil, fmt.Errorf("path cannot be empty")
}
switch scheme {
case "fs":
return &fslocal.FS{Pattern: path}, nil
default:
return nil, fmt.Errorf("unsupported scheme %q", scheme)
}
}