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fix: harden Steam prebuilds #52

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Merged
MarcStdt merged 1 commit into from
Jun 8, 2026
Merged

fix: harden Steam prebuilds #52

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87 changes: 83 additions & 4 deletions scripts/prebuild/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,9 @@ import (
"os/exec"
"path/filepath"
"sort"
"strconv"
"strings"
"syscall"

cp "github.com/otiai10/copy"
"gopkg.in/yaml.v3"
Expand All @@ -23,6 +25,7 @@ type prebuildSpec struct {
Image string
Ports []string
MinDisk string
BuildDisk string
MinRAM string
MinCPU string
Category string
Expand Down Expand Up @@ -84,6 +87,9 @@ func runSpec(spec prebuildSpec) error {
if err := validateRequiredEnv(spec); err != nil {
return err
}
if err := validateBuildDisk(spec); err != nil {
return err
}

root, err := createPrebuildRoot(spec.Target)
if err != nil {
Expand Down Expand Up @@ -226,6 +232,79 @@ func validateRequiredEnv(spec prebuildSpec) error {
return nil
}

func validateBuildDisk(spec prebuildSpec) error {
if spec.BuildDisk == "" {
return nil
}
required, err := parseSizeBytes(spec.BuildDisk)
if err != nil {
return fmt.Errorf("invalid build disk requirement %q: %w", spec.BuildDisk, err)
}
paths := []string{"/var/lib/docker"}
if parent := os.Getenv("PREBUILD_TMP_PARENT"); parent != "" {
paths = append(paths, parent)
} else if cwd, err := os.Getwd(); err == nil {
paths = append(paths, filepath.Join(cwd, ".prebuild-tmp"))
}
for _, path := range paths {
available, err := availableBytes(path)
if err != nil {
return fmt.Errorf("check free disk for %s: %w", path, err)
}
if available < required {
return fmt.Errorf("need at least %s free for %s prebuild at %s, have %s", spec.BuildDisk, spec.Target, path, formatBytes(available))
}
}
return nil
}

func parseSizeBytes(raw string) (uint64, error) {
value := strings.TrimSpace(raw)
if value == "" {
return 0, errors.New("empty size")
}
units := []struct {
suffix string
factor uint64
}{
{"Gi", 1024 * 1024 * 1024},
{"Mi", 1024 * 1024},
{"G", 1000 * 1000 * 1000},
{"M", 1000 * 1000},
}
for _, unit := range units {
if strings.HasSuffix(value, unit.suffix) {
number := strings.TrimSpace(strings.TrimSuffix(value, unit.suffix))
parsed, err := strconv.ParseFloat(number, 64)
if err != nil {
return 0, err
}
return uint64(parsed * float64(unit.factor)), nil
}
}
return strconv.ParseUint(value, 10, 64)
}

func availableBytes(path string) (uint64, error) {
if err := os.MkdirAll(path, 0o755); err != nil {
return 0, err
}
var stat syscall.Statfs_t
if err := syscall.Statfs(path, &stat); err != nil {
return 0, err
}
return stat.Bavail * uint64(stat.Bsize), nil
}

func formatBytes(bytes uint64) string {
const gib = 1024 * 1024 * 1024
if bytes >= gib {
return fmt.Sprintf("%.1fGi", float64(bytes)/gib)
}
const mib = 1024 * 1024
return fmt.Sprintf("%.1fMi", float64(bytes)/mib)
}

func isShell(value string) bool {
base := filepath.Base(value)
return base == "sh" || base == "bash"
Expand Down Expand Up @@ -567,11 +646,11 @@ func allSpecs() []prebuildSpec {
{Target: "untserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:untserver-prebuild", Source: "./scrolls/lgsm/untserver", Image: steamImage, Ports: []string{"main=27015/udp", "mainv6=27016"}, MinDisk: "7Gi", MinRAM: "1Gi", MinCPU: "0.5", Category: "unturned", Smart: true, PackMeta: true},
{Target: "sdtdserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:sdtdserver-prebuild", Source: "./scrolls/lgsm/sdtdserver", Image: steamImage, Ports: []string{"query=26900/udp", "main=26900/udp", "main2=26902/udp", "maintcp=26900"}, MinDisk: "20Gi", MinRAM: "2Gi", MinCPU: "0.5", Category: "7days", PackMeta: true},
{Target: "gmodserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:gmodserver-prebuild", Source: "./scrolls/lgsm/gmodserver", Image: steamImage, Ports: []string{"query=27005/udp", "main=27015/udp", "sourcetv=27020/udp", "steam=27015"}, MinDisk: "8Gi", MinRAM: "512Mi", MinCPU: "0.25", Category: "gmod", Smart: true, PackMeta: true},
{Target: "cs2server", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:cs2server-prebuild", Source: "./scrolls/lgsm/cs2server", Image: steamImage, Ports: []string{"main=27015/udp", "rcon=27015"}, MinDisk: "38Gi", MinRAM: "1Gi", MinCPU: "0.5", Category: "cs2", Smart: true, PackMeta: true},
{Target: "cs2server", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:cs2server-prebuild", Source: "./scrolls/lgsm/cs2server", Image: steamImage, Ports: []string{"main=27015/udp", "rcon=27015"}, MinDisk: "38Gi", BuildDisk: "95Gi", MinRAM: "1Gi", MinCPU: "0.5", Category: "cs2", Smart: true, PackMeta: true},
{Target: "pzserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:pzserver-prebuild", Source: "./scrolls/lgsm/pzserver", Image: steamImage, Ports: []string{"main=16261/udp", "main2=16262/udp", "maintcp=16261"}, MinDisk: "3Gi", MinRAM: "512Mi", MinCPU: "0.25", Category: "zomboid", Smart: true, PackMeta: true},
{Target: "csgoserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:csgoserver-prebuild", Source: "./scrolls/lgsm/csgoserver", Image: steamImage, Ports: []string{"query=27005/udp", "main=27015/udp", "sourcetv=27020/udp", "steam=27015"}, Category: "csgo", Smart: true, PackMeta: true},
{Target: "rust-vanilla", Artifact: "artifacts.druid.gg/druid-team/scroll-rust-vanilla:latest-prebuild", Source: "./scrolls/rust/rust-vanilla/latest", Image: steamImage, Ports: []string{"main=/udp", "query=/udp", "rcon", "rustplus"}, MinDisk: "10Gi", MinRAM: "6Gi", MinCPU: "1", Category: "rust", Smart: true},
{Target: "rust-oxide", Artifact: "artifacts.druid.gg/druid-team/scroll-rust-oxide:latest-prebuild", Source: "./scrolls/rust/rust-oxide/latest", Image: steamImage, Ports: []string{"main=/udp", "query=/udp", "rcon", "rustplus"}, MinDisk: "10Gi", MinRAM: "6Gi", MinCPU: "1", Category: "rust", Smart: true},
{Target: "csgoserver", Artifact: "artifacts.druid.gg/druid-team/scroll-lgsm:csgoserver-prebuild", Source: "./scrolls/lgsm/csgoserver", Image: steamImage, Ports: []string{"query=27005/udp", "main=27015/udp", "sourcetv=27020/udp", "steam=27015"}, BuildDisk: "45Gi", Category: "csgo", Smart: true, PackMeta: true},
{Target: "rust-vanilla", Artifact: "artifacts.druid.gg/druid-team/scroll-rust-vanilla:latest-prebuild", Source: "./scrolls/rust/rust-vanilla/latest", Image: steamImage, Ports: []string{"main=28015/udp", "query=28017/udp", "rcon=28016", "rustplus=28082"}, MinDisk: "10Gi", BuildDisk: "25Gi", MinRAM: "6Gi", MinCPU: "1", Category: "rust", Smart: true},
{Target: "rust-oxide", Artifact: "artifacts.druid.gg/druid-team/scroll-rust-oxide:latest-prebuild", Source: "./scrolls/rust/rust-oxide/latest", Image: steamImage, Ports: []string{"main=28015/udp", "query=28017/udp", "rcon=28016", "rustplus=28082"}, MinDisk: "10Gi", BuildDisk: "25Gi", MinRAM: "6Gi", MinCPU: "1", Category: "rust", Smart: true},
}
sort.Slice(specs, func(i, j int) bool { return specs[i].Target < specs[j].Target })
return specs
Expand Down
25 changes: 25 additions & 0 deletions scripts/prebuild/main_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,20 @@ func TestDayZPrebuildRequiresSteamCredentials(t *testing.T) {
}
}

func TestRustPrebuildPortsAreConcrete(t *testing.T) {
specs, err := selectSpecs("rust-vanilla,rust-oxide")
if err != nil {
t.Fatal(err)
}
for _, spec := range specs {
for _, port := range spec.Ports {
if port == "main=/udp" || port == "query=/udp" || port == "rcon" || port == "rustplus" {
t.Fatalf("%s has non-concrete port %q", spec.Target, port)
}
}
}
}

func TestValidateRequiredEnvFailsBeforePrebuild(t *testing.T) {
t.Setenv("PREBUILD_TEST_REQUIRED", "")
err := validateRequiredEnv(prebuildSpec{Target: "test", RequiredEnv: []string{"PREBUILD_TEST_REQUIRED"}})
Expand All @@ -97,6 +111,17 @@ func TestValidateRequiredEnvFailsBeforePrebuild(t *testing.T) {
}
}

func TestParseSizeBytesSupportsBinaryUnits(t *testing.T) {
got, err := parseSizeBytes("1.5Gi")
if err != nil {
t.Fatal(err)
}
want := uint64(1610612736)
if got != want {
t.Fatalf("bytes = %d, want %d", got, want)
}
}

func TestValidateRequiredEnvAcceptsPresentEnv(t *testing.T) {
t.Setenv("PREBUILD_TEST_REQUIRED", "present")
if err := validateRequiredEnv(prebuildSpec{Target: "test", RequiredEnv: []string{"PREBUILD_TEST_REQUIRED"}}); err != nil {
Expand Down
3 changes: 2 additions & 1 deletion scrolls/lgsm/.build/vars.json
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Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,8 @@
"lua_query_folder": "csgo",
"lua_query_map": "server idle",
"lua_query_servername": "Druid.gg Server (idle) - join to start",
"main_port_protocol": "udp",
"lua_query_port": "main",
"lua_query_start_on_unknown_packet": "yes",
"ppm": "600",
"lua_steam_app_id": "730",
"dependencies": "bc;binutils;bzip2;cpio;file;jq;pkgsi686Linux.gcc;netcat;pigz;python3;tmux;unzip;util-linux;moreutils;iproute2"
Expand Down
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