hooks: Order injection by collated JSON filename

We also considered ordering with sort.Strings, but Matthew rejected
that because it uses a byte-by-byte UTF-8 comparison [1] which would
fail many language-specific conventions [2].

There's some more discussion of the localeToLanguage mapping in [3].
Currently language.Parse does not handle either 'C' or 'POSIX',
returning:

  und, language: tag is not well-formed

for both.

[1]: https://github.com/projectatomic/libpod/pull/686#issuecomment-387914358
[2]: https://en.wikipedia.org/wiki/Alphabetical_order#Language-specific_conventions
[3]: https://github.com/golang/go/issues/25340

Signed-off-by: W. Trevor King <wking@tremily.us>

Closes: #686
Approved by: mheon

1 files changed, 38 insertions, 1 deletions

diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index 992c1d07b..1c0bcb07f 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -32,6 +32,7 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/ulule/deepcopier"
 	"golang.org/x/sys/unix"
+	"golang.org/x/text/language"
 )
 
 const (
@@ -39,6 +40,15 @@ const (
 	artifactsDir = "artifacts"
 )
 
+var (
+	// localeToLanguage maps from locale values to language tags.
+	localeToLanguage = map[string]string{
+		"":      "und-u-va-posix",
+		"c":     "und-u-va-posix",
+		"posix": "und-u-va-posix",
+	}
+)
+
 // rootFsSize gets the size of the container's root filesystem
 // A container FS is split into two parts.  The first is the top layer, a
 // mutable layer, and the rest is the RootFS: the set of immutable layers
@@ -1287,7 +1297,34 @@ func (c *Container) setupOCIHooks(ctx context.Context, g *generate.Generator) er
 		return nil
 	}
 
-	manager, err := hooks.New(ctx, []string{c.runtime.config.HooksDir})
+	var locale string
+	var ok bool
+	for _, envVar := range []string{
+		"LC_ALL",
+		"LC_COLLATE",
+		"LANG",
+	} {
+		locale, ok = os.LookupEnv(envVar)
+		if ok {
+			break
+		}
+	}
+
+	langString, ok := localeToLanguage[strings.ToLower(locale)]
+	if !ok {
+		langString = locale
+	}
+
+	lang, err := language.Parse(langString)
+	if err != nil {
+		logrus.Warnf("failed to parse language %q: %s", langString, err)
+		lang, err = language.Parse("und-u-va-posix")
+		if err != nil {
+			return err
+		}
+	}
+
+	manager, err := hooks.New(ctx, []string{c.runtime.config.HooksDir}, lang)
 	if err != nil {
 		if c.runtime.config.HooksDirNotExistFatal || !os.IsNotExist(err) {
 			return err