Files
headscale/tools/capver/main.go
Kristoffer Dalby 251e16d772 tools/capver: regenerate from docker tags
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2025-12-18 10:02:23 +01:00

486 lines
14 KiB
Go

package main
//go:generate go run main.go
import (
"context"
"encoding/json"
"errors"
"fmt"
"go/format"
"io"
"log"
"net/http"
"os"
"regexp"
"slices"
"sort"
"strconv"
"strings"
xmaps "golang.org/x/exp/maps"
"tailscale.com/tailcfg"
)
const (
ghcrTokenURL = "https://ghcr.io/token?service=ghcr.io&scope=repository:tailscale/tailscale:pull" //nolint:gosec
ghcrTagsURL = "https://ghcr.io/v2/tailscale/tailscale/tags/list?n=10000"
rawFileURL = "https://github.com/tailscale/tailscale/raw/refs/tags/%s/tailcfg/tailcfg.go"
outputFile = "../../hscontrol/capver/capver_generated.go"
testFile = "../../hscontrol/capver/capver_test_data.go"
fallbackCapVer = 90
maxTestCases = 4
supportedMajorMinorVersions = 10
filePermissions = 0o600
semverMatchGroups = 4
latest3Count = 3
latest2Count = 2
)
var errUnexpectedStatusCode = errors.New("unexpected status code")
// GHCRTokenResponse represents the response from GHCR token endpoint.
type GHCRTokenResponse struct {
Token string `json:"token"`
}
// GHCRTagsResponse represents the response from GHCR tags list endpoint.
type GHCRTagsResponse struct {
Name string `json:"name"`
Tags []string `json:"tags"`
}
// getGHCRToken fetches an anonymous token from GHCR for accessing public container images.
func getGHCRToken(ctx context.Context) (string, error) {
client := &http.Client{}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, ghcrTokenURL, nil)
if err != nil {
return "", fmt.Errorf("error creating token request: %w", err)
}
resp, err := client.Do(req)
if err != nil {
return "", fmt.Errorf("error fetching GHCR token: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return "", fmt.Errorf("%w: %d", errUnexpectedStatusCode, resp.StatusCode)
}
body, err := io.ReadAll(resp.Body)
if err != nil {
return "", fmt.Errorf("error reading token response: %w", err)
}
var tokenResp GHCRTokenResponse
err = json.Unmarshal(body, &tokenResp)
if err != nil {
return "", fmt.Errorf("error parsing token response: %w", err)
}
return tokenResp.Token, nil
}
// getGHCRTags fetches all available tags from GHCR for tailscale/tailscale.
func getGHCRTags(ctx context.Context) ([]string, error) {
token, err := getGHCRToken(ctx)
if err != nil {
return nil, fmt.Errorf("failed to get GHCR token: %w", err)
}
client := &http.Client{}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, ghcrTagsURL, nil)
if err != nil {
return nil, fmt.Errorf("error creating tags request: %w", err)
}
req.Header.Set("Authorization", "Bearer "+token)
resp, err := client.Do(req)
if err != nil {
return nil, fmt.Errorf("error fetching tags: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%w: %d", errUnexpectedStatusCode, resp.StatusCode)
}
body, err := io.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("error reading tags response: %w", err)
}
var tagsResp GHCRTagsResponse
err = json.Unmarshal(body, &tagsResp)
if err != nil {
return nil, fmt.Errorf("error parsing tags response: %w", err)
}
return tagsResp.Tags, nil
}
// semverRegex matches semantic version tags like v1.90.0 or v1.90.1.
var semverRegex = regexp.MustCompile(`^v(\d+)\.(\d+)\.(\d+)$`)
// parseSemver extracts major, minor, patch from a semver tag.
// Returns -1 for all values if not a valid semver.
func parseSemver(tag string) (int, int, int) {
matches := semverRegex.FindStringSubmatch(tag)
if len(matches) != semverMatchGroups {
return -1, -1, -1
}
major, _ := strconv.Atoi(matches[1])
minor, _ := strconv.Atoi(matches[2])
patch, _ := strconv.Atoi(matches[3])
return major, minor, patch
}
// getMinorVersionsFromTags processes container tags and returns a map of minor versions
// to the first available patch version for each minor.
// For example: {"v1.90": "v1.90.0", "v1.92": "v1.92.0"}.
func getMinorVersionsFromTags(tags []string) map[string]string {
// Map minor version (e.g., "v1.90") to lowest patch version available
minorToLowestPatch := make(map[string]struct {
patch int
fullVer string
})
for _, tag := range tags {
major, minor, patch := parseSemver(tag)
if major < 0 {
continue // Not a semver tag
}
minorKey := fmt.Sprintf("v%d.%d", major, minor)
existing, exists := minorToLowestPatch[minorKey]
if !exists || patch < existing.patch {
minorToLowestPatch[minorKey] = struct {
patch int
fullVer string
}{
patch: patch,
fullVer: tag,
}
}
}
// Convert to simple map
result := make(map[string]string)
for minorVer, info := range minorToLowestPatch {
result[minorVer] = info.fullVer
}
return result
}
// getCapabilityVersions fetches container tags from GHCR, identifies minor versions,
// and fetches the capability version for each from the Tailscale source.
func getCapabilityVersions(ctx context.Context) (map[string]tailcfg.CapabilityVersion, error) {
// Fetch container tags from GHCR
tags, err := getGHCRTags(ctx)
if err != nil {
return nil, fmt.Errorf("failed to get container tags: %w", err)
}
log.Printf("Found %d container tags", len(tags))
// Get minor versions with their representative patch versions
minorVersions := getMinorVersionsFromTags(tags)
log.Printf("Found %d minor versions", len(minorVersions))
// Regular expression to find the CurrentCapabilityVersion line
re := regexp.MustCompile(`const CurrentCapabilityVersion CapabilityVersion = (\d+)`)
versions := make(map[string]tailcfg.CapabilityVersion)
client := &http.Client{}
for minorVer, patchVer := range minorVersions {
// Fetch the raw Go file for the patch version
rawURL := fmt.Sprintf(rawFileURL, patchVer)
req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil) //nolint:gosec
if err != nil {
log.Printf("Warning: failed to create request for %s: %v", patchVer, err)
continue
}
resp, err := client.Do(req)
if err != nil {
log.Printf("Warning: failed to fetch %s: %v", patchVer, err)
continue
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
log.Printf("Warning: got status %d for %s", resp.StatusCode, patchVer)
continue
}
body, err := io.ReadAll(resp.Body)
if err != nil {
log.Printf("Warning: failed to read response for %s: %v", patchVer, err)
continue
}
// Find the CurrentCapabilityVersion
matches := re.FindStringSubmatch(string(body))
if len(matches) > 1 {
capabilityVersionStr := matches[1]
capabilityVersion, _ := strconv.Atoi(capabilityVersionStr)
versions[minorVer] = tailcfg.CapabilityVersion(capabilityVersion)
log.Printf(" %s (from %s): capVer %d", minorVer, patchVer, capabilityVersion)
}
}
return versions, nil
}
func calculateMinSupportedCapabilityVersion(versions map[string]tailcfg.CapabilityVersion) tailcfg.CapabilityVersion {
// Since we now store minor versions directly, just sort and take the oldest of the latest N
minorVersions := xmaps.Keys(versions)
sort.Strings(minorVersions)
supportedCount := min(len(minorVersions), supportedMajorMinorVersions)
if supportedCount == 0 {
return fallbackCapVer
}
// The minimum supported version is the oldest of the latest 10
oldestSupportedMinor := minorVersions[len(minorVersions)-supportedCount]
return versions[oldestSupportedMinor]
}
func writeCapabilityVersionsToFile(versions map[string]tailcfg.CapabilityVersion, minSupportedCapVer tailcfg.CapabilityVersion) error {
// Generate the Go code as a string
var content strings.Builder
content.WriteString("package capver\n\n")
content.WriteString("// Generated DO NOT EDIT\n\n")
content.WriteString(`import "tailscale.com/tailcfg"`)
content.WriteString("\n\n")
content.WriteString("var tailscaleToCapVer = map[string]tailcfg.CapabilityVersion{\n")
sortedVersions := xmaps.Keys(versions)
sort.Strings(sortedVersions)
for _, version := range sortedVersions {
fmt.Fprintf(&content, "\t\"%s\": %d,\n", version, versions[version])
}
content.WriteString("}\n")
content.WriteString("\n\n")
content.WriteString("var capVerToTailscaleVer = map[tailcfg.CapabilityVersion]string{\n")
capVarToTailscaleVer := make(map[tailcfg.CapabilityVersion]string)
for _, v := range sortedVersions {
capabilityVersion := versions[v]
// If it is already set, skip and continue,
// we only want the first tailscale version per
// capability version.
if _, ok := capVarToTailscaleVer[capabilityVersion]; ok {
continue
}
capVarToTailscaleVer[capabilityVersion] = v
}
capsSorted := xmaps.Keys(capVarToTailscaleVer)
slices.Sort(capsSorted)
for _, capVer := range capsSorted {
fmt.Fprintf(&content, "\t%d:\t\t\"%s\",\n", capVer, capVarToTailscaleVer[capVer])
}
content.WriteString("}\n\n")
// Add the SupportedMajorMinorVersions constant
content.WriteString("// SupportedMajorMinorVersions is the number of major.minor Tailscale versions supported.\n")
fmt.Fprintf(&content, "const SupportedMajorMinorVersions = %d\n\n", supportedMajorMinorVersions)
// Add the MinSupportedCapabilityVersion constant
content.WriteString("// MinSupportedCapabilityVersion represents the minimum capability version\n")
content.WriteString("// supported by this Headscale instance (latest 10 minor versions)\n")
fmt.Fprintf(&content, "const MinSupportedCapabilityVersion tailcfg.CapabilityVersion = %d\n", minSupportedCapVer)
// Format the generated code
formatted, err := format.Source([]byte(content.String()))
if err != nil {
return fmt.Errorf("error formatting Go code: %w", err)
}
// Write to file
err = os.WriteFile(outputFile, formatted, filePermissions)
if err != nil {
return fmt.Errorf("error writing file: %w", err)
}
return nil
}
func writeTestDataFile(versions map[string]tailcfg.CapabilityVersion, minSupportedCapVer tailcfg.CapabilityVersion) error {
// Sort minor versions
minorVersions := xmaps.Keys(versions)
sort.Strings(minorVersions)
// Take latest N
supportedCount := min(len(minorVersions), supportedMajorMinorVersions)
latest10 := minorVersions[len(minorVersions)-supportedCount:]
latest3 := minorVersions[len(minorVersions)-min(latest3Count, len(minorVersions)):]
latest2 := minorVersions[len(minorVersions)-min(latest2Count, len(minorVersions)):]
// Generate test data file content
var content strings.Builder
content.WriteString("package capver\n\n")
content.WriteString("// Generated DO NOT EDIT\n\n")
content.WriteString("import \"tailscale.com/tailcfg\"\n\n")
// Generate complete test struct for TailscaleLatestMajorMinor
content.WriteString("var tailscaleLatestMajorMinorTests = []struct {\n")
content.WriteString("\tn int\n")
content.WriteString("\tstripV bool\n")
content.WriteString("\texpected []string\n")
content.WriteString("}{\n")
// Latest 3 with v prefix
content.WriteString("\t{3, false, []string{")
for i, version := range latest3 {
content.WriteString(fmt.Sprintf("\"%s\"", version))
if i < len(latest3)-1 {
content.WriteString(", ")
}
}
content.WriteString("}},\n")
// Latest 2 without v prefix
content.WriteString("\t{2, true, []string{")
for i, version := range latest2 {
// Strip v prefix for this test case
verNoV := strings.TrimPrefix(version, "v")
content.WriteString(fmt.Sprintf("\"%s\"", verNoV))
if i < len(latest2)-1 {
content.WriteString(", ")
}
}
content.WriteString("}},\n")
// Latest N without v prefix (all supported)
content.WriteString(fmt.Sprintf("\t{%d, true, []string{\n", supportedMajorMinorVersions))
for _, version := range latest10 {
verNoV := strings.TrimPrefix(version, "v")
content.WriteString(fmt.Sprintf("\t\t\"%s\",\n", verNoV))
}
content.WriteString("\t}},\n")
// Empty case
content.WriteString("\t{0, false, nil},\n")
content.WriteString("}\n\n")
// Build capVerToTailscaleVer for test data
capVerToTailscaleVer := make(map[tailcfg.CapabilityVersion]string)
sortedVersions := xmaps.Keys(versions)
sort.Strings(sortedVersions)
for _, v := range sortedVersions {
capabilityVersion := versions[v]
if _, ok := capVerToTailscaleVer[capabilityVersion]; !ok {
capVerToTailscaleVer[capabilityVersion] = v
}
}
// Generate complete test struct for CapVerMinimumTailscaleVersion
content.WriteString("var capVerMinimumTailscaleVersionTests = []struct {\n")
content.WriteString("\tinput tailcfg.CapabilityVersion\n")
content.WriteString("\texpected string\n")
content.WriteString("}{\n")
// Add minimum supported version
minVersionString := capVerToTailscaleVer[minSupportedCapVer]
content.WriteString(fmt.Sprintf("\t{%d, \"%s\"},\n", minSupportedCapVer, minVersionString))
// Add a few more test cases
capsSorted := xmaps.Keys(capVerToTailscaleVer)
slices.Sort(capsSorted)
testCount := 0
for _, capVer := range capsSorted {
if testCount >= maxTestCases {
break
}
if capVer != minSupportedCapVer { // Don't duplicate the min version test
version := capVerToTailscaleVer[capVer]
content.WriteString(fmt.Sprintf("\t{%d, \"%s\"},\n", capVer, version))
testCount++
}
}
// Edge cases
content.WriteString("\t{9001, \"\"}, // Test case for a version higher than any in the map\n")
content.WriteString("\t{60, \"\"}, // Test case for a version lower than any in the map\n")
content.WriteString("}\n")
// Format the generated code
formatted, err := format.Source([]byte(content.String()))
if err != nil {
return fmt.Errorf("error formatting test data Go code: %w", err)
}
// Write to file
err = os.WriteFile(testFile, formatted, filePermissions)
if err != nil {
return fmt.Errorf("error writing test data file: %w", err)
}
return nil
}
func main() {
ctx := context.Background()
versions, err := getCapabilityVersions(ctx)
if err != nil {
log.Println("Error:", err)
return
}
// Calculate the minimum supported capability version
minSupportedCapVer := calculateMinSupportedCapabilityVersion(versions)
err = writeCapabilityVersionsToFile(versions, minSupportedCapVer)
if err != nil {
log.Println("Error writing to file:", err)
return
}
err = writeTestDataFile(versions, minSupportedCapVer)
if err != nil {
log.Println("Error writing test data file:", err)
return
}
log.Println("Capability versions written to", outputFile)
}