Follow symlinks and ignore target directories. (#3137)

* Follow symlinks and ignore target directories.

Signed-off-by: Peter Štibraný <[email protected]>

* CHANGELOG.md

Signed-off-by: Peter Štibraný <[email protected]>

Author: pstibrany

CHANGELOG.md

@@ -53,6 +53,7 @@
 * [ENHANCEMENT] Add `DELETE api/v1/rules/{namespace}` to the Ruler. It allows all the rule groups of a namespace to be deleted. #3120
 * [ENHANCEMENT] Experimental Delete Series: Retry processing of Delete requests during failures. #2926
 * [ENHANCEMENT] Modules included in "All" target are now visible in output of `-modules` CLI flag. #3155
+* [BUGFIX] Ruler: when loading rules from "local" storage, check for directory after resolving symlink. #3137
 * [BUGFIX] Query-frontend: Fixed rounding for incoming query timestamps, to be 100% Prometheus compatible. #2990
 * [BUGFIX] Querier: Merge results from chunks and blocks ingesters when using streaming of results. #3013
 * [BUGFIX] Querier: query /series from ingesters regardless the `-querier.query-ingesters-within` setting. #3035

pkg/ruler/rules/local/local.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
@@ -48,16 +49,27 @@ func (l *Client) ListAllRuleGroups(ctx context.Context) (map[string]rules.RuleGr
 	}
 
 	for _, info := range infos {
+		// After resolving link, info.Name() may be different than user, so keep original name.
+		user := info.Name()
+
+		if info.Mode()&os.ModeSymlink != 0 {
+			// ioutil.ReadDir only returns result of LStat. Calling Stat resolves symlink.
+			info, err = os.Stat(filepath.Join(root, info.Name()))
+			if err != nil {
+				return nil, err
+			}
+		}
+
 		if !info.IsDir() {
 			continue
 		}
 
-		list, err := l.listAllRulesGroupsForUser(ctx, info.Name())
+		list, err := l.listAllRulesGroupsForUser(ctx, user)
 		if err != nil {
-			return nil, errors.Wrapf(err, "failed to list rule groups for user %s", info.Name())
+			return nil, errors.Wrapf(err, "failed to list rule groups for user %s", user)
 		}
 
-		lists[info.Name()] = list
+		lists[user] = list
 	}
 
 	return lists, nil
@@ -102,13 +114,24 @@ func (l *Client) listAllRulesGroupsForUser(ctx context.Context, userID string) (
 	}
 
 	for _, info := range infos {
+		// After resolving link, info.Name() may be different than namespace, so keep original name.
+		namespace := info.Name()
+
+		if info.Mode()&os.ModeSymlink != 0 {
+			// ioutil.ReadDir only returns result of LStat. Calling Stat resolves symlink.
+			info, err = os.Stat(filepath.Join(root, info.Name()))
+			if err != nil {
+				return nil, err
+			}
+		}
+
 		if info.IsDir() {
 			continue
 		}
 
-		list, err := l.listAllRulesGroupsForUserAndNamespace(ctx, userID, info.Name())
+		list, err := l.listAllRulesGroupsForUserAndNamespace(ctx, userID, namespace)
 		if err != nil {
-			return nil, errors.Wrapf(err, "failed to list rule group for user %s and namespace %s", userID, info.Name())
+			return nil, errors.Wrapf(err, "failed to list rule group for user %s and namespace %s", userID, namespace)
 		}
 
 		allLists = append(allLists, list...)

pkg/ruler/rules/local/local_test.go

@@ -17,8 +17,11 @@ import (
 )
 
 func TestClient_ListAllRuleGroups(t *testing.T) {
-	user := "user"
-	namespace := "ns"
+	user1 := "user"
+	user2 := "second-user"
+
+	namespace1 := "ns"
+	namespace2 := "z-another" // This test relies on the fact that ioutil.ReadDir() returns files sorted by name.
 
 	dir, err := ioutil.TempDir("", "")
 	require.NoError(t, err)
@@ -42,10 +45,25 @@ func TestClient_ListAllRuleGroups(t *testing.T) {
 	b, err := yaml.Marshal(ruleGroups)
 	require.NoError(t, err)
 
-	err = os.MkdirAll(path.Join(dir, user), 0777)
+	err = os.MkdirAll(path.Join(dir, user1), 0777)
+	require.NoError(t, err)
+
+	// Link second user to first.
+	err = os.Symlink(user1, path.Join(dir, user2))
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(path.Join(dir, user1, namespace1), b, 0777)
 	require.NoError(t, err)
 
-	err = ioutil.WriteFile(path.Join(dir, user, namespace), b, 0777)
+	const ignoredDir = "ignored-dir"
+	err = os.Mkdir(path.Join(dir, user1, ignoredDir), os.ModeDir|0644)
+	require.NoError(t, err)
+
+	err = os.Symlink(ignoredDir, path.Join(dir, user1, "link-to-dir"))
+	require.NoError(t, err)
+
+	// Link second namespace to first.
+	err = os.Symlink(namespace1, path.Join(dir, user1, namespace2))
 	require.NoError(t, err)
 
 	client, err := NewLocalRulesClient(Config{
@@ -57,13 +75,13 @@ func TestClient_ListAllRuleGroups(t *testing.T) {
 	userMap, err := client.ListAllRuleGroups(ctx)
 	require.NoError(t, err)
 
-	actual, found := userMap[user]
-	require.True(t, found)
-
-	require.Equal(t, len(ruleGroups.Groups), len(actual))
-	for i, actualGroup := range actual {
-		expected := rules.ToProto(user, namespace, ruleGroups.Groups[i])
+	for _, u := range []string{user1, user2} {
+		actual, found := userMap[u]
+		require.True(t, found)
 
-		require.Equal(t, expected, actualGroup)
+		require.Equal(t, 2, len(actual))
+		// We rely on the fact that files are parsed in alphabetical order, and our namespace1 < namespace2.
+		require.Equal(t, rules.ToProto(u, namespace1, ruleGroups.Groups[0]), actual[0])
+		require.Equal(t, rules.ToProto(u, namespace2, ruleGroups.Groups[0]), actual[1])
 	}
 }