Add experimental Void guest workflow and vsock agent

Make iterating on a Firecracker-friendly Void guest practical without replacing the Debian default image path.

Add local Void rootfs build/register/verify plumbing, a language-agnostic dev package baseline, and guest SSH/work-disk hardening so new images use the runtime bundle key, keep a normal root bash environment, and repair stale nested /root layouts on restart.

Replace the guest PING/PONG responder with an HTTP /healthz agent over vsock, rename the runtime bundle and config surface from ping helper to agent while still accepting the legacy keys, and route the post-SSH reminder through the new vm.health path.

Validated with GOCACHE=/tmp/banger-gocache go test ./..., make build, bash -n customize.sh make-rootfs-void.sh, and git diff --check.
This commit is contained in:
Thales Maciel 2026-03-19 14:51:25 -03:00
parent c8d9a122f9
commit 3ed78fdcfc
No known key found for this signature in database
GPG key ID: 33112E6833C34679
42 changed files with 2222 additions and 388 deletions

View file

@ -22,6 +22,7 @@ type fileConfig struct {
SSHKeyPath string `toml:"ssh_key_path"`
NamegenPath string `toml:"namegen_path"`
CustomizeScript string `toml:"customize_script"`
VSockAgent string `toml:"vsock_agent_path"`
VSockPingHelper string `toml:"vsock_ping_helper_path"`
DefaultWorkSeed string `toml:"default_work_seed"`
DefaultImageName string `toml:"default_image_name"`
@ -83,17 +84,16 @@ func Load(layout paths.Layout) (model.DaemonConfig, error) {
if file.LogLevel != "" {
cfg.LogLevel = file.LogLevel
}
if file.SSHKeyPath != "" {
cfg.SSHKeyPath = file.SSHKeyPath
}
if file.NamegenPath != "" {
cfg.NamegenPath = file.NamegenPath
}
if file.CustomizeScript != "" {
cfg.CustomizeScript = file.CustomizeScript
}
if file.VSockPingHelper != "" {
cfg.VSockPingHelperPath = file.VSockPingHelper
if file.VSockAgent != "" {
cfg.VSockAgentPath = file.VSockAgent
} else if file.VSockPingHelper != "" {
cfg.VSockAgentPath = file.VSockPingHelper
}
if file.DefaultWorkSeed != "" {
cfg.DefaultWorkSeed = file.DefaultWorkSeed
@ -197,7 +197,7 @@ func applyBundleMetadataDefaults(cfg *model.DaemonConfig, runtimeDir string, met
cfg.SSHKeyPath = defaultRuntimePath(cfg.SSHKeyPath, runtimeDir, meta.SSHKeyPath)
cfg.NamegenPath = defaultRuntimePath(cfg.NamegenPath, runtimeDir, meta.NamegenPath)
cfg.CustomizeScript = defaultRuntimePath(cfg.CustomizeScript, runtimeDir, meta.CustomizeScript)
cfg.VSockPingHelperPath = defaultRuntimePath(cfg.VSockPingHelperPath, runtimeDir, meta.VSockPingHelperPath)
cfg.VSockAgentPath = defaultRuntimePath(cfg.VSockAgentPath, runtimeDir, meta.VSockAgentPath)
cfg.DefaultWorkSeed = defaultRuntimePath(cfg.DefaultWorkSeed, runtimeDir, meta.DefaultWorkSeed)
cfg.DefaultKernel = defaultRuntimePath(cfg.DefaultKernel, runtimeDir, meta.DefaultKernel)
cfg.DefaultInitrd = defaultRuntimePath(cfg.DefaultInitrd, runtimeDir, meta.DefaultInitrd)
@ -212,7 +212,10 @@ func applyLegacyRuntimeDefaults(cfg *model.DaemonConfig) {
cfg.SSHKeyPath = defaultRuntimePath(cfg.SSHKeyPath, cfg.RuntimeDir, "id_ed25519")
cfg.NamegenPath = defaultRuntimePath(cfg.NamegenPath, cfg.RuntimeDir, "namegen")
cfg.CustomizeScript = defaultRuntimePath(cfg.CustomizeScript, cfg.RuntimeDir, "customize.sh")
cfg.VSockPingHelperPath = defaultRuntimePath(cfg.VSockPingHelperPath, cfg.RuntimeDir, "banger-vsock-pingd")
cfg.VSockAgentPath = firstExistingRuntimePath(
defaultRuntimePath(cfg.VSockAgentPath, cfg.RuntimeDir, "banger-vsock-agent"),
filepath.Join(cfg.RuntimeDir, "banger-vsock-pingd"),
)
cfg.DefaultWorkSeed = defaultRuntimePath(cfg.DefaultWorkSeed, cfg.RuntimeDir, "rootfs-docker.work-seed.ext4")
cfg.DefaultKernel = defaultRuntimePath(cfg.DefaultKernel, cfg.RuntimeDir, "wtf/root/boot/vmlinux-6.8.0-94-generic")
cfg.DefaultInitrd = defaultRuntimePath(cfg.DefaultInitrd, cfg.RuntimeDir, "wtf/root/boot/initrd.img-6.8.0-94-generic")

View file

@ -13,24 +13,24 @@ import (
func TestLoadDerivesArtifactPathsFromRuntimeDir(t *testing.T) {
runtimeDir := t.TempDir()
meta := runtimebundle.BundleMetadata{
FirecrackerBin: "bin/firecracker",
SSHKeyPath: "keys/id_ed25519",
NamegenPath: "bin/namegen",
CustomizeScript: "scripts/customize.sh",
VSockPingHelperPath: "bin/banger-vsock-pingd",
DefaultPackages: "config/packages.apt",
DefaultRootfs: "images/rootfs-docker.ext4",
DefaultWorkSeed: "images/rootfs-docker.work-seed.ext4",
DefaultKernel: "kernels/vmlinux",
DefaultInitrd: "kernels/initrd.img",
DefaultModulesDir: "modules/current",
FirecrackerBin: "bin/firecracker",
SSHKeyPath: "keys/id_ed25519",
NamegenPath: "bin/namegen",
CustomizeScript: "scripts/customize.sh",
VSockAgentPath: "bin/banger-vsock-agent",
DefaultPackages: "config/packages.apt",
DefaultRootfs: "images/rootfs-docker.ext4",
DefaultWorkSeed: "images/rootfs-docker.work-seed.ext4",
DefaultKernel: "kernels/vmlinux",
DefaultInitrd: "kernels/initrd.img",
DefaultModulesDir: "modules/current",
}
for _, rel := range []string{
meta.FirecrackerBin,
meta.SSHKeyPath,
meta.NamegenPath,
meta.CustomizeScript,
meta.VSockPingHelperPath,
meta.VSockAgentPath,
meta.DefaultPackages,
meta.DefaultRootfs,
meta.DefaultWorkSeed,
@ -75,8 +75,8 @@ func TestLoadDerivesArtifactPathsFromRuntimeDir(t *testing.T) {
if cfg.CustomizeScript != filepath.Join(runtimeDir, meta.CustomizeScript) {
t.Fatalf("CustomizeScript = %q", cfg.CustomizeScript)
}
if cfg.VSockPingHelperPath != filepath.Join(runtimeDir, meta.VSockPingHelperPath) {
t.Fatalf("VSockPingHelperPath = %q", cfg.VSockPingHelperPath)
if cfg.VSockAgentPath != filepath.Join(runtimeDir, meta.VSockAgentPath) {
t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
}
if cfg.DefaultRootfs != filepath.Join(runtimeDir, meta.DefaultRootfs) {
t.Fatalf("DefaultRootfs = %q", cfg.DefaultRootfs)
@ -108,7 +108,7 @@ func TestLoadFallsBackToLegacyRuntimeLayoutWithoutBundleMetadata(t *testing.T) {
"id_ed25519",
"namegen",
"customize.sh",
"banger-vsock-pingd",
"banger-vsock-agent",
"packages.apt",
"rootfs-docker.ext4",
"rootfs-docker.work-seed.ext4",
@ -134,8 +134,8 @@ func TestLoadFallsBackToLegacyRuntimeLayoutWithoutBundleMetadata(t *testing.T) {
if cfg.FirecrackerBin != filepath.Join(runtimeDir, "firecracker") {
t.Fatalf("FirecrackerBin = %q", cfg.FirecrackerBin)
}
if cfg.VSockPingHelperPath != filepath.Join(runtimeDir, "banger-vsock-pingd") {
t.Fatalf("VSockPingHelperPath = %q", cfg.VSockPingHelperPath)
if cfg.VSockAgentPath != filepath.Join(runtimeDir, "banger-vsock-agent") {
t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
}
if cfg.DefaultWorkSeed != filepath.Join(runtimeDir, "rootfs-docker.work-seed.ext4") {
t.Fatalf("DefaultWorkSeed = %q", cfg.DefaultWorkSeed)
@ -167,3 +167,125 @@ func TestLoadDefaultsLogLevelToInfo(t *testing.T) {
t.Fatalf("LogLevel = %q, want info", cfg.LogLevel)
}
}
func TestLoadIgnoresConfigSSHKeyOverrideForGuestAccess(t *testing.T) {
runtimeDir := t.TempDir()
meta := runtimebundle.BundleMetadata{
FirecrackerBin: "bin/firecracker",
SSHKeyPath: "keys/id_ed25519",
NamegenPath: "bin/namegen",
CustomizeScript: "scripts/customize.sh",
VSockAgentPath: "bin/banger-vsock-agent",
DefaultPackages: "config/packages.apt",
DefaultRootfs: "images/rootfs.ext4",
DefaultWorkSeed: "images/rootfs.work-seed.ext4",
DefaultKernel: "kernels/vmlinux",
DefaultModulesDir: "modules/current",
}
for _, rel := range []string{
meta.FirecrackerBin,
meta.SSHKeyPath,
meta.NamegenPath,
meta.CustomizeScript,
meta.VSockAgentPath,
meta.DefaultPackages,
meta.DefaultRootfs,
meta.DefaultWorkSeed,
meta.DefaultKernel,
filepath.Join(meta.DefaultModulesDir, "modules.dep"),
} {
path := filepath.Join(runtimeDir, rel)
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
}
if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
t.Fatalf("write %s: %v", path, err)
}
}
data, err := json.Marshal(meta)
if err != nil {
t.Fatalf("Marshal: %v", err)
}
if err := os.WriteFile(filepath.Join(runtimeDir, runtimebundle.BundleMetadataFile), data, 0o644); err != nil {
t.Fatalf("write bundle metadata: %v", err)
}
configDir := t.TempDir()
if err := os.WriteFile(filepath.Join(configDir, "config.toml"), []byte("ssh_key_path = \"/tmp/override-key\"\n"), 0o644); err != nil {
t.Fatalf("write config.toml: %v", err)
}
t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
cfg, err := Load(paths.Layout{ConfigDir: configDir})
if err != nil {
t.Fatalf("Load: %v", err)
}
want := filepath.Join(runtimeDir, meta.SSHKeyPath)
if cfg.SSHKeyPath != want {
t.Fatalf("SSHKeyPath = %q, want runtime key %q", cfg.SSHKeyPath, want)
}
}
func TestLoadAcceptsLegacyBundleVsockPingHelperPath(t *testing.T) {
runtimeDir := t.TempDir()
meta := runtimebundle.BundleMetadata{
FirecrackerBin: "bin/firecracker",
SSHKeyPath: "keys/id_ed25519",
NamegenPath: "bin/namegen",
CustomizeScript: "scripts/customize.sh",
VSockPingHelperPath: "bin/banger-vsock-pingd",
DefaultPackages: "config/packages.apt",
DefaultRootfs: "images/rootfs.ext4",
DefaultKernel: "kernels/vmlinux",
}
for _, rel := range []string{
meta.FirecrackerBin,
meta.SSHKeyPath,
meta.NamegenPath,
meta.CustomizeScript,
meta.VSockPingHelperPath,
meta.DefaultPackages,
meta.DefaultRootfs,
meta.DefaultKernel,
} {
path := filepath.Join(runtimeDir, rel)
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
}
if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
t.Fatalf("write %s: %v", path, err)
}
}
data, err := json.Marshal(meta)
if err != nil {
t.Fatalf("Marshal: %v", err)
}
if err := os.WriteFile(filepath.Join(runtimeDir, runtimebundle.BundleMetadataFile), data, 0o644); err != nil {
t.Fatalf("write bundle metadata: %v", err)
}
t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.VSockAgentPath != filepath.Join(runtimeDir, meta.VSockPingHelperPath) {
t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
}
}
func TestLoadAcceptsLegacyConfigVsockPingHelperPath(t *testing.T) {
configDir := t.TempDir()
if err := os.WriteFile(filepath.Join(configDir, "config.toml"), []byte("vsock_ping_helper_path = \"/tmp/legacy-agent\"\n"), 0o644); err != nil {
t.Fatalf("write config.toml: %v", err)
}
cfg, err := Load(paths.Layout{ConfigDir: configDir})
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.VSockAgentPath != "/tmp/legacy-agent" {
t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
}
}