Files
Miloslav Trmač 79583c82ee Vendor c/image after merging c/image#536
... which adds blob info caching

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
2018-12-08 15:31:41 +01:00

64 lines
2.3 KiB
Go
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package blobinfocache
import (
"fmt"
"os"
"path/filepath"
"github.com/containers/image/types"
"github.com/sirupsen/logrus"
)
const (
// blobInfoCacheFilename is the file name used for blob info caches.
// If the format changes in an incompatible way, increase the version number.
blobInfoCacheFilename = "blob-info-cache-v1.boltdb"
// systemBlobInfoCacheDir is the directory containing the blob info cache (in blobInfocacheFilename) for root-running processes.
systemBlobInfoCacheDir = "/var/lib/containers/cache"
)
// blobInfoCacheDir returns a path to a blob info cache appropripate for sys and euid.
// euid is used so that (sudo …) does not write root-owned files into the unprivileged users home directory.
func blobInfoCacheDir(sys *types.SystemContext, euid int) (string, error) {
if sys != nil && sys.BlobInfoCacheDir != "" {
return sys.BlobInfoCacheDir, nil
}
// FIXME? On Windows, os.Geteuid() returns -1. What should we do? Right now we treat it as unprivileged
// and fail (fall back to memory-only) if neither HOME nor XDG_DATA_HOME is set, which is, at least, safe.
if euid == 0 {
if sys != nil && sys.RootForImplicitAbsolutePaths != "" {
return filepath.Join(sys.RootForImplicitAbsolutePaths, systemBlobInfoCacheDir), nil
}
return systemBlobInfoCacheDir, nil
}
// This is intended to mirror the GraphRoot determination in github.com/containers/libpod/pkg/util.GetRootlessStorageOpts.
dataDir := os.Getenv("XDG_DATA_HOME")
if dataDir == "" {
home := os.Getenv("HOME")
if home == "" {
return "", fmt.Errorf("neither XDG_DATA_HOME nor HOME was set non-empty")
}
dataDir = filepath.Join(home, ".local", "share")
}
return filepath.Join(dataDir, "containers", "cache"), nil
}
// DefaultCache returns the default BlobInfoCache implementation appropriate for sys.
func DefaultCache(sys *types.SystemContext) types.BlobInfoCache {
dir, err := blobInfoCacheDir(sys, os.Geteuid())
if err != nil {
logrus.Debugf("Error determining a location for %s, using a memory-only cache", blobInfoCacheFilename)
return NewMemoryCache()
}
path := filepath.Join(dir, blobInfoCacheFilename)
if err := os.MkdirAll(dir, 0700); err != nil {
logrus.Debugf("Error creating parent directories for %s, using a memory-only cache: %v", err)
return NewMemoryCache()
}
logrus.Debugf("Using blob info cache at %s", path)
return NewBoltDBCache(path)
}