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-rw-r--r--runsc/cmd/boot.go2
-rw-r--r--runsc/cmd/checkpoint.go2
-rw-r--r--runsc/cmd/create.go2
-rw-r--r--runsc/cmd/gofer.go6
-rw-r--r--runsc/cmd/restore.go2
-rw-r--r--runsc/cmd/run.go2
-rw-r--r--runsc/config/config.go2
-rw-r--r--runsc/config/config_test.go87
-rw-r--r--runsc/config/flags.go36
-rw-r--r--runsc/specutils/BUILD1
-rw-r--r--runsc/specutils/specutils.go21
11 files changed, 152 insertions, 11 deletions
diff --git a/runsc/cmd/boot.go b/runsc/cmd/boot.go
index 357f46517..cd419e1aa 100644
--- a/runsc/cmd/boot.go
+++ b/runsc/cmd/boot.go
@@ -168,7 +168,7 @@ func (b *Boot) Execute(_ context.Context, f *flag.FlagSet, args ...interface{})
// Get the spec from the specFD.
specFile := os.NewFile(uintptr(b.specFD), "spec file")
defer specFile.Close()
- spec, err := specutils.ReadSpecFromFile(b.bundleDir, specFile)
+ spec, err := specutils.ReadSpecFromFile(b.bundleDir, specFile, conf)
if err != nil {
Fatalf("reading spec: %v", err)
}
diff --git a/runsc/cmd/checkpoint.go b/runsc/cmd/checkpoint.go
index db46d509f..8fe0c427a 100644
--- a/runsc/cmd/checkpoint.go
+++ b/runsc/cmd/checkpoint.go
@@ -118,7 +118,7 @@ func (c *Checkpoint) Execute(_ context.Context, f *flag.FlagSet, args ...interfa
Fatalf("setting bundleDir")
}
- spec, err := specutils.ReadSpec(bundleDir)
+ spec, err := specutils.ReadSpec(bundleDir, conf)
if err != nil {
Fatalf("reading spec: %v", err)
}
diff --git a/runsc/cmd/create.go b/runsc/cmd/create.go
index 4d9085244..e76f7ba1d 100644
--- a/runsc/cmd/create.go
+++ b/runsc/cmd/create.go
@@ -91,7 +91,7 @@ func (c *Create) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}
if bundleDir == "" {
bundleDir = getwdOrDie()
}
- spec, err := specutils.ReadSpec(bundleDir)
+ spec, err := specutils.ReadSpec(bundleDir, conf)
if err != nil {
return Errorf("reading spec: %v", err)
}
diff --git a/runsc/cmd/gofer.go b/runsc/cmd/gofer.go
index 7da02c3af..bba00d551 100644
--- a/runsc/cmd/gofer.go
+++ b/runsc/cmd/gofer.go
@@ -100,15 +100,15 @@ func (g *Gofer) Execute(_ context.Context, f *flag.FlagSet, args ...interface{})
return subcommands.ExitUsageError
}
+ conf := args[0].(*config.Config)
+
specFile := os.NewFile(uintptr(g.specFD), "spec file")
defer specFile.Close()
- spec, err := specutils.ReadSpecFromFile(g.bundleDir, specFile)
+ spec, err := specutils.ReadSpecFromFile(g.bundleDir, specFile, conf)
if err != nil {
Fatalf("reading spec: %v", err)
}
- conf := args[0].(*config.Config)
-
if g.setUpRoot {
if err := setupRootFS(spec, conf); err != nil {
Fatalf("Error setting up root FS: %v", err)
diff --git a/runsc/cmd/restore.go b/runsc/cmd/restore.go
index b16975804..096ec814c 100644
--- a/runsc/cmd/restore.go
+++ b/runsc/cmd/restore.go
@@ -88,7 +88,7 @@ func (r *Restore) Execute(_ context.Context, f *flag.FlagSet, args ...interface{
if bundleDir == "" {
bundleDir = getwdOrDie()
}
- spec, err := specutils.ReadSpec(bundleDir)
+ spec, err := specutils.ReadSpec(bundleDir, conf)
if err != nil {
return Errorf("reading spec: %v", err)
}
diff --git a/runsc/cmd/run.go b/runsc/cmd/run.go
index 1161de67a..c48cbe4cd 100644
--- a/runsc/cmd/run.go
+++ b/runsc/cmd/run.go
@@ -75,7 +75,7 @@ func (r *Run) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) s
if bundleDir == "" {
bundleDir = getwdOrDie()
}
- spec, err := specutils.ReadSpec(bundleDir)
+ spec, err := specutils.ReadSpec(bundleDir, conf)
if err != nil {
return Errorf("reading spec: %v", err)
}
diff --git a/runsc/config/config.go b/runsc/config/config.go
index bca27ebf1..df134bb2f 100644
--- a/runsc/config/config.go
+++ b/runsc/config/config.go
@@ -157,6 +157,8 @@ type Config struct {
// Enables FUSE usage.
FUSE bool `flag:"fuse"`
+ AllowFlagOverride bool `flag:"allow-flag-override"`
+
// TestOnlyAllowRunAsCurrentUserWithoutChroot should only be used in
// tests. It allows runsc to start the sandbox process as the current
// user, and without chrooting the sandbox process. This can be
diff --git a/runsc/config/config_test.go b/runsc/config/config_test.go
index af7867a2a..fb162b7eb 100644
--- a/runsc/config/config_test.go
+++ b/runsc/config/config_test.go
@@ -183,3 +183,90 @@ func TestValidationFail(t *testing.T) {
})
}
}
+
+func TestOverride(t *testing.T) {
+ c, err := NewFromFlags()
+ if err != nil {
+ t.Fatal(err)
+ }
+ c.AllowFlagOverride = true
+
+ t.Run("string", func(t *testing.T) {
+ c.RootDir = "foobar"
+ if err := c.Override("root", "bar"); err != nil {
+ t.Fatalf("Override(root, bar) failed: %v", err)
+ }
+ defer setDefault("root")
+ if c.RootDir != "bar" {
+ t.Errorf("Override(root, bar) didn't work: %+v", c)
+ }
+ })
+
+ t.Run("bool", func(t *testing.T) {
+ c.Debug = true
+ if err := c.Override("debug", "false"); err != nil {
+ t.Fatalf("Override(debug, false) failed: %v", err)
+ }
+ defer setDefault("debug")
+ if c.Debug {
+ t.Errorf("Override(debug, false) didn't work: %+v", c)
+ }
+ })
+
+ t.Run("enum", func(t *testing.T) {
+ c.FileAccess = FileAccessShared
+ if err := c.Override("file-access", "exclusive"); err != nil {
+ t.Fatalf("Override(file-access, exclusive) failed: %v", err)
+ }
+ defer setDefault("file-access")
+ if c.FileAccess != FileAccessExclusive {
+ t.Errorf("Override(file-access, exclusive) didn't work: %+v", c)
+ }
+ })
+}
+
+func TestOverrideDisabled(t *testing.T) {
+ c, err := NewFromFlags()
+ if err != nil {
+ t.Fatal(err)
+ }
+ const errMsg = "flag override disabled"
+ if err := c.Override("root", "path"); err == nil || !strings.Contains(err.Error(), errMsg) {
+ t.Errorf("Override() wrong error: %v", err)
+ }
+}
+
+func TestOverrideError(t *testing.T) {
+ c, err := NewFromFlags()
+ if err != nil {
+ t.Fatal(err)
+ }
+ c.AllowFlagOverride = true
+ for _, tc := range []struct {
+ name string
+ value string
+ error string
+ }{
+ {
+ name: "invalid",
+ value: "valid",
+ error: `flag "invalid" not found`,
+ },
+ {
+ name: "debug",
+ value: "invalid",
+ error: "error setting flag debug",
+ },
+ {
+ name: "file-access",
+ value: "invalid",
+ error: "invalid file access type",
+ },
+ } {
+ t.Run(tc.name, func(t *testing.T) {
+ if err := c.Override(tc.name, tc.value); err == nil || !strings.Contains(err.Error(), tc.error) {
+ t.Errorf("Override(%q, %q) wrong error: %v", tc.name, tc.value, err)
+ }
+ })
+ }
+}
diff --git a/runsc/config/flags.go b/runsc/config/flags.go
index 488a4b9fb..eff46e938 100644
--- a/runsc/config/flags.go
+++ b/runsc/config/flags.go
@@ -48,6 +48,7 @@ func RegisterFlags() {
flag.Bool("log-packets", false, "enable network packet logging.")
flag.String("debug-log-format", "text", "log format: text (default), json, or json-k8s.")
flag.Bool("alsologtostderr", false, "send log messages to stderr.")
+ flag.Bool("allow-flag-override", false, "allow OCI annotations (dev.gvisor.flag.<name>) to override flags for debugging.")
// Debugging flags: strace related
flag.Bool("strace", false, "enable strace.")
@@ -149,6 +150,41 @@ func (c *Config) ToFlags() []string {
return rv
}
+// Override writes a new value to a flag.
+func (c *Config) Override(name string, value string) error {
+ if !c.AllowFlagOverride {
+ return fmt.Errorf("flag override disabled, use --allow-flag-override to enable it")
+ }
+
+ obj := reflect.ValueOf(c).Elem()
+ st := obj.Type()
+ for i := 0; i < st.NumField(); i++ {
+ f := st.Field(i)
+ fieldName, ok := f.Tag.Lookup("flag")
+ if !ok || fieldName != name {
+ // Not a flag field, or flag name doesn't match.
+ continue
+ }
+ fl := flag.CommandLine.Lookup(name)
+ if fl == nil {
+ // Flag must exist if there is a field match above.
+ panic(fmt.Sprintf("Flag %q not found", name))
+ }
+
+ // Use flag to convert the string value to the underlying flag type, using
+ // the same rules as the command-line for consistency.
+ if err := fl.Value.Set(value); err != nil {
+ return fmt.Errorf("error setting flag %s=%q: %w", name, value, err)
+ }
+ x := reflect.ValueOf(flag.Get(fl.Value))
+ obj.Field(i).Set(x)
+
+ // Validates the config again to ensure it's left in a consistent state.
+ return c.validate()
+ }
+ return fmt.Errorf("flag %q not found. Cannot set it to %q", name, value)
+}
+
func getVal(field reflect.Value) string {
if str, ok := field.Addr().Interface().(fmt.Stringer); ok {
return str.String()
diff --git a/runsc/specutils/BUILD b/runsc/specutils/BUILD
index 43851a22f..679d8bc8e 100644
--- a/runsc/specutils/BUILD
+++ b/runsc/specutils/BUILD
@@ -16,6 +16,7 @@ go_library(
"//pkg/bits",
"//pkg/log",
"//pkg/sentry/kernel/auth",
+ "//runsc/config",
"@com_github_cenkalti_backoff//:go_default_library",
"@com_github_mohae_deepcopy//:go_default_library",
"@com_github_opencontainers_runtime_spec//specs-go:go_default_library",
diff --git a/runsc/specutils/specutils.go b/runsc/specutils/specutils.go
index 5015c3a84..a2275398a 100644
--- a/runsc/specutils/specutils.go
+++ b/runsc/specutils/specutils.go
@@ -35,6 +35,7 @@ import (
"gvisor.dev/gvisor/pkg/bits"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/runsc/config"
)
// ExePath must point to runsc binary, which is normally the same binary. It's
@@ -161,18 +162,18 @@ func OpenSpec(bundleDir string) (*os.File, error) {
// ReadSpec reads an OCI runtime spec from the given bundle directory.
// ReadSpec also normalizes all potential relative paths into absolute
// path, e.g. spec.Root.Path, mount.Source.
-func ReadSpec(bundleDir string) (*specs.Spec, error) {
+func ReadSpec(bundleDir string, conf *config.Config) (*specs.Spec, error) {
specFile, err := OpenSpec(bundleDir)
if err != nil {
return nil, fmt.Errorf("error opening spec file %q: %v", filepath.Join(bundleDir, "config.json"), err)
}
defer specFile.Close()
- return ReadSpecFromFile(bundleDir, specFile)
+ return ReadSpecFromFile(bundleDir, specFile, conf)
}
// ReadSpecFromFile reads an OCI runtime spec from the given File, and
// normalizes all relative paths into absolute by prepending the bundle dir.
-func ReadSpecFromFile(bundleDir string, specFile *os.File) (*specs.Spec, error) {
+func ReadSpecFromFile(bundleDir string, specFile *os.File, conf *config.Config) (*specs.Spec, error) {
if _, err := specFile.Seek(0, os.SEEK_SET); err != nil {
return nil, fmt.Errorf("error seeking to beginning of file %q: %v", specFile.Name(), err)
}
@@ -195,6 +196,20 @@ func ReadSpecFromFile(bundleDir string, specFile *os.File) (*specs.Spec, error)
m.Source = absPath(bundleDir, m.Source)
}
}
+
+ // Override flags using annotation to allow customization per sandbox
+ // instance.
+ for annotation, val := range spec.Annotations {
+ const flagPrefix = "dev.gvisor.flag."
+ if strings.HasPrefix(annotation, flagPrefix) {
+ name := annotation[len(flagPrefix):]
+ log.Infof("Overriding flag: %s=%q", name, val)
+ if err := conf.Override(name, val); err != nil {
+ return nil, err
+ }
+ }
+ }
+
return &spec, nil
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 07:25:30 +0000