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Move avoidable daemon shell-outs into Go

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Reduce the control plane's dependency on helper scripts while keeping the hard Linux integration points in the approved shell-out layer.

Replace the bash-driven image build path with a native Go builder that clones and optionally resizes the rootfs, boots a temporary Firecracker VM, provisions the guest over SSH, installs packages and modules, and preserves the package-manifest sidecar.

Also replace a few small convenience shell-outs with Go helpers: read process stats from /proc, use os.Truncate for ext4 image growth, add file-clone and normalized-line helpers, drop the sh -c work-disk flattening path, and launch Firecracker via a direct sudo command.

Add tests for the new SSH/archive and system helpers, plus a policy test that keeps os/exec imports confined to cli/firecracker/system. Update the docs to describe customize.sh as a manual helper rather than the daemon's image-build backend.

Validated with go mod tidy, go test ./..., and make build.
This commit is contained in:
Thales Maciel 2026-03-17 17:13:07 -03:00
parent 0a0b0b617b
commit 942d242c03
No known key found for this signature in database
GPG key ID: 33112E6833C34679
17 changed files with 936 additions and 145 deletions
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38
internal/daemon/preflight.go
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@ -13,7 +13,7 @@ func (d *Daemon) validateStartPrereqs(ctx context.Context, vm model.VMRecord, im
checks := system.NewPreflight()
hint := paths.RuntimeBundleHint()
for _, command := range []string{"sudo", "ip", "dmsetup", "losetup", "blockdev", "truncate", "pgrep", "ps", "chown", "chmod", "kill", "e2cp", "e2rm", "debugfs"} {
for _, command := range []string{"sudo", "ip", "dmsetup", "losetup", "blockdev", "truncate", "pgrep", "chown", "chmod", "kill", "e2cp", "e2rm", "debugfs"} {
checks.RequireCommand(command, toolHint(command))
}
checks.RequireExecutable(d.config.FirecrackerBin, "firecracker binary", hint)
@ -33,22 +33,34 @@ func (d *Daemon) validateStartPrereqs(ctx context.Context, vm model.VMRecord, im
return checks.Err("vm start preflight failed")
}
func (d *Daemon) validateImageBuildPrereqs(ctx context.Context, baseRootfs, kernelPath, initrdPath, modulesDir string) error {
func (d *Daemon) validateImageBuildPrereqs(ctx context.Context, baseRootfs, kernelPath, initrdPath, modulesDir, sizeSpec string) error {
checks := system.NewPreflight()
hint := paths.RuntimeBundleHint()
for _, command := range []string{"bash", "sudo", "ip", "curl", "ssh", "jq", "sha256sum", "e2fsck", "resize2fs"} {
for _, command := range []string{"sudo", "ip", "pgrep", "chown", "chmod", "kill"} {
checks.RequireCommand(command, toolHint(command))
}
checks.RequireExecutable(d.config.CustomizeScript, "customize.sh helper", hint)
checks.RequireExecutable(d.config.FirecrackerBin, "firecracker binary", hint)
checks.RequireFile(d.config.SSHKeyPath, "ssh private key", `set "ssh_key_path" or refresh the runtime bundle`)
checks.RequireFile(baseRootfs, "base rootfs image", `pass --base-rootfs or set "default_base_rootfs"`)
checks.RequireFile(kernelPath, "kernel image", `pass --kernel or set "default_kernel"`)
checks.RequireFile(d.config.DefaultPackagesFile, "package manifest", `set "default_packages_file" or refresh the runtime bundle`)
if strings.TrimSpace(initrdPath) != "" {
checks.RequireFile(initrdPath, "initrd image", `pass --initrd or set "default_initrd"`)
}
if strings.TrimSpace(modulesDir) != "" {
checks.RequireDir(modulesDir, "modules directory", `pass --modules or set "default_modules_dir"`)
}
if strings.TrimSpace(d.config.DefaultPackagesFile) != "" {
if _, err := system.ReadNormalizedLines(d.config.DefaultPackagesFile); err != nil {
checks.Addf("package manifest at %s is invalid: %v", d.config.DefaultPackagesFile, err)
}
}
if strings.TrimSpace(sizeSpec) != "" {
checks.RequireCommand("e2fsck", toolHint("e2fsck"))
checks.RequireCommand("resize2fs", toolHint("resize2fs"))
}
d.addNATPrereqs(ctx, checks)
return checks.Err("image build preflight failed")
}
@ -63,7 +75,11 @@ func (d *Daemon) validateWorkDiskResizePrereqs() error {
func (d *Daemon) addNATPrereqs(ctx context.Context, checks *system.Preflight) {
checks.RequireCommand("iptables", toolHint("iptables"))
checks.RequireCommand("sysctl", toolHint("sysctl"))
out, err := d.runner.Run(ctx, "ip", "route", "show", "default")
runner := d.runner
if runner == nil {
runner = system.NewRunner()
}
out, err := runner.Run(ctx, "ip", "route", "show", "default")
if err != nil {
checks.Addf("failed to inspect the default route for NAT: %v", err)
return
@ -83,7 +99,7 @@ func toolHint(command string) string {
return "install util-linux"
case "dmsetup":
return "install device-mapper"
case "pgrep", "ps", "kill":
case "pgrep", "kill":
return "install procps"
case "chown", "chmod", "cp", "truncate":
return "install coreutils"
@ -91,16 +107,6 @@ func toolHint(command string) string {
return "install e2fsprogs"
case "e2cp", "e2rm":
return "install e2tools"
case "curl":
return "install curl"
case "jq":
return "install jq"
case "sha256sum":
return "install coreutils"
case "ssh":
return "install openssh-client"
case "bash":
return "install bash"
case "sudo":
return "install sudo"
default: