|
| 1 | +package acme |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "context" |
| 6 | + "encoding/json" |
| 7 | + "fmt" |
| 8 | + "io" |
| 9 | + "net" |
| 10 | + "net/http" |
| 11 | + "net/url" |
| 12 | + "strings" |
| 13 | + "time" |
| 14 | + |
| 15 | + "github.com/rs/zerolog/log" |
| 16 | + |
| 17 | + "gosuda.org/portal/types" |
| 18 | +) |
| 19 | + |
| 20 | +const ( |
| 21 | + cfAPIBase = "https://api.cloudflare.com/client/v4" |
| 22 | + publicIPURL = "https://api4.ipify.org" |
| 23 | + dnsHTTPTimeout = 15 * time.Second |
| 24 | + dnsAutoTTL = 1 // Cloudflare "automatic" TTL |
| 25 | +) |
| 26 | + |
| 27 | +// Cloudflare API response types. |
| 28 | + |
| 29 | +type cfError struct { |
| 30 | + Code int `json:"code"` |
| 31 | + Message string `json:"message"` |
| 32 | +} |
| 33 | + |
| 34 | +type cfZone struct { |
| 35 | + ID string `json:"id"` |
| 36 | + Name string `json:"name"` |
| 37 | +} |
| 38 | + |
| 39 | +type cfDNSRecord struct { |
| 40 | + ID string `json:"id"` |
| 41 | + Type string `json:"type"` |
| 42 | + Name string `json:"name"` |
| 43 | + Content string `json:"content"` |
| 44 | + TTL int `json:"ttl"` |
| 45 | + Proxied bool `json:"proxied"` |
| 46 | +} |
| 47 | + |
| 48 | +type cfZonesResult struct { |
| 49 | + Success bool `json:"success"` |
| 50 | + Errors []cfError `json:"errors"` |
| 51 | + Result []cfZone `json:"result"` |
| 52 | +} |
| 53 | + |
| 54 | +type cfRecordsResult struct { |
| 55 | + Success bool `json:"success"` |
| 56 | + Errors []cfError `json:"errors"` |
| 57 | + Result []cfDNSRecord `json:"result"` |
| 58 | +} |
| 59 | + |
| 60 | +type cfRecordResult struct { |
| 61 | + Success bool `json:"success"` |
| 62 | + Errors []cfError `json:"errors"` |
| 63 | + Result cfDNSRecord `json:"result"` |
| 64 | +} |
| 65 | + |
| 66 | +// EnsureDNSRecords creates or updates Cloudflare A records for the base domain |
| 67 | +// and its wildcard subdomain, pointing to the server's detected public IP. |
| 68 | +// Skips silently when baseDomain is empty, localhost, or cloudflareToken is missing. |
| 69 | +func EnsureDNSRecords(ctx context.Context, baseDomain, cloudflareToken string) error { |
| 70 | + baseDomain = strings.TrimSpace(baseDomain) |
| 71 | + cloudflareToken = strings.TrimSpace(cloudflareToken) |
| 72 | + |
| 73 | + if baseDomain == "" || cloudflareToken == "" || types.IsLocalhost(baseDomain) { |
| 74 | + return nil |
| 75 | + } |
| 76 | + |
| 77 | + ctx, cancel := context.WithTimeout(ctx, 30*time.Second) |
| 78 | + defer cancel() |
| 79 | + |
| 80 | + publicIP, err := detectPublicIP(ctx) |
| 81 | + if err != nil { |
| 82 | + return fmt.Errorf("detect public IP: %w", err) |
| 83 | + } |
| 84 | + |
| 85 | + log.Info(). |
| 86 | + Str("public_ip", publicIP). |
| 87 | + Str("base_domain", baseDomain). |
| 88 | + Msg("[DNS] detected server public IP") |
| 89 | + |
| 90 | + zoneID, err := findZoneID(ctx, cloudflareToken, baseDomain) |
| 91 | + if err != nil { |
| 92 | + return fmt.Errorf("find Cloudflare zone for %s: %w", baseDomain, err) |
| 93 | + } |
| 94 | + |
| 95 | + targets := []string{baseDomain, "*." + baseDomain} |
| 96 | + for _, name := range targets { |
| 97 | + if err := ensureARecord(ctx, cloudflareToken, zoneID, name, publicIP); err != nil { |
| 98 | + return fmt.Errorf("ensure A record for %s: %w", name, err) |
| 99 | + } |
| 100 | + } |
| 101 | + |
| 102 | + return nil |
| 103 | +} |
| 104 | + |
| 105 | +// detectPublicIP fetches the server's public IPv4 address from an external service. |
| 106 | +func detectPublicIP(ctx context.Context) (string, error) { |
| 107 | + ctx, cancel := context.WithTimeout(ctx, dnsHTTPTimeout) |
| 108 | + defer cancel() |
| 109 | + |
| 110 | + req, err := http.NewRequestWithContext(ctx, http.MethodGet, publicIPURL, nil) |
| 111 | + if err != nil { |
| 112 | + return "", err |
| 113 | + } |
| 114 | + |
| 115 | + resp, err := http.DefaultClient.Do(req) |
| 116 | + if err != nil { |
| 117 | + return "", err |
| 118 | + } |
| 119 | + defer resp.Body.Close() |
| 120 | + |
| 121 | + body, err := io.ReadAll(io.LimitReader(resp.Body, 256)) |
| 122 | + if err != nil { |
| 123 | + return "", err |
| 124 | + } |
| 125 | + |
| 126 | + ip := strings.TrimSpace(string(body)) |
| 127 | + parsed := net.ParseIP(ip) |
| 128 | + if parsed == nil { |
| 129 | + return "", fmt.Errorf("invalid IP address: %q", ip) |
| 130 | + } |
| 131 | + if parsed.To4() == nil { |
| 132 | + return "", fmt.Errorf("expected IPv4 address, got: %q", ip) |
| 133 | + } |
| 134 | + |
| 135 | + return ip, nil |
| 136 | +} |
| 137 | + |
| 138 | +// findZoneID looks up the Cloudflare zone ID by progressively stripping |
| 139 | +// subdomain labels from the given domain (e.g., portal.example.com → example.com). |
| 140 | +func findZoneID(ctx context.Context, token, domain string) (string, error) { |
| 141 | + parts := strings.Split(domain, ".") |
| 142 | + for i := range len(parts) - 1 { |
| 143 | + candidate := strings.Join(parts[i:], ".") |
| 144 | + |
| 145 | + zones, err := cfListZones(ctx, token, candidate) |
| 146 | + if err != nil { |
| 147 | + return "", err |
| 148 | + } |
| 149 | + for _, z := range zones { |
| 150 | + if strings.EqualFold(z.Name, candidate) { |
| 151 | + log.Debug(). |
| 152 | + Str("zone", z.Name). |
| 153 | + Str("zone_id", z.ID). |
| 154 | + Msg("[DNS] found Cloudflare zone") |
| 155 | + return z.ID, nil |
| 156 | + } |
| 157 | + } |
| 158 | + } |
| 159 | + |
| 160 | + return "", fmt.Errorf("no Cloudflare zone found for domain %s", domain) |
| 161 | +} |
| 162 | + |
| 163 | +// ensureARecord creates or updates a single A record. |
| 164 | +// If the record exists with the correct IP and proxy-off, it is left untouched. |
| 165 | +func ensureARecord(ctx context.Context, token, zoneID, name, ip string) error { |
| 166 | + records, err := cfListDNSRecords(ctx, token, zoneID, name, "A") |
| 167 | + if err != nil { |
| 168 | + return err |
| 169 | + } |
| 170 | + |
| 171 | + for _, r := range records { |
| 172 | + if !strings.EqualFold(r.Name, name) { |
| 173 | + continue |
| 174 | + } |
| 175 | + if r.Content == ip && !r.Proxied { |
| 176 | + log.Info(). |
| 177 | + Str("name", name). |
| 178 | + Str("ip", ip). |
| 179 | + Msg("[DNS] A record already up to date") |
| 180 | + return nil |
| 181 | + } |
| 182 | + // Record exists but IP or proxy status differs — update it. |
| 183 | + return cfUpdateDNSRecord(ctx, token, zoneID, r.ID, name, ip) |
| 184 | + } |
| 185 | + |
| 186 | + return cfCreateDNSRecord(ctx, token, zoneID, name, ip) |
| 187 | +} |
| 188 | + |
| 189 | +// ── Cloudflare API helpers ────────────────────────────────────────── |
| 190 | + |
| 191 | +func cfListZones(ctx context.Context, token, name string) ([]cfZone, error) { |
| 192 | + u, _ := url.Parse(cfAPIBase + "/zones") |
| 193 | + q := u.Query() |
| 194 | + q.Set("name", name) |
| 195 | + u.RawQuery = q.Encode() |
| 196 | + |
| 197 | + var out cfZonesResult |
| 198 | + if err := cfGet(ctx, token, u.String(), &out); err != nil { |
| 199 | + return nil, err |
| 200 | + } |
| 201 | + if !out.Success { |
| 202 | + return nil, cfErrs(out.Errors) |
| 203 | + } |
| 204 | + return out.Result, nil |
| 205 | +} |
| 206 | + |
| 207 | +func cfListDNSRecords(ctx context.Context, token, zoneID, name, recordType string) ([]cfDNSRecord, error) { |
| 208 | + u, _ := url.Parse(fmt.Sprintf("%s/zones/%s/dns_records", cfAPIBase, zoneID)) |
| 209 | + q := u.Query() |
| 210 | + q.Set("name", name) |
| 211 | + q.Set("type", recordType) |
| 212 | + u.RawQuery = q.Encode() |
| 213 | + |
| 214 | + var out cfRecordsResult |
| 215 | + if err := cfGet(ctx, token, u.String(), &out); err != nil { |
| 216 | + return nil, err |
| 217 | + } |
| 218 | + if !out.Success { |
| 219 | + return nil, cfErrs(out.Errors) |
| 220 | + } |
| 221 | + return out.Result, nil |
| 222 | +} |
| 223 | + |
| 224 | +func cfCreateDNSRecord(ctx context.Context, token, zoneID, name, ip string) error { |
| 225 | + endpoint := fmt.Sprintf("%s/zones/%s/dns_records", cfAPIBase, zoneID) |
| 226 | + |
| 227 | + body := map[string]any{ |
| 228 | + "type": "A", |
| 229 | + "name": name, |
| 230 | + "content": ip, |
| 231 | + "ttl": dnsAutoTTL, |
| 232 | + "proxied": false, |
| 233 | + } |
| 234 | + |
| 235 | + var out cfRecordResult |
| 236 | + if err := cfMutate(ctx, http.MethodPost, token, endpoint, body, &out); err != nil { |
| 237 | + return err |
| 238 | + } |
| 239 | + if !out.Success { |
| 240 | + return cfErrs(out.Errors) |
| 241 | + } |
| 242 | + |
| 243 | + log.Info(). |
| 244 | + Str("name", name). |
| 245 | + Str("ip", ip). |
| 246 | + Msg("[DNS] created A record") |
| 247 | + return nil |
| 248 | +} |
| 249 | + |
| 250 | +func cfUpdateDNSRecord(ctx context.Context, token, zoneID, recordID, name, ip string) error { |
| 251 | + endpoint := fmt.Sprintf("%s/zones/%s/dns_records/%s", cfAPIBase, zoneID, recordID) |
| 252 | + |
| 253 | + body := map[string]any{ |
| 254 | + "type": "A", |
| 255 | + "name": name, |
| 256 | + "content": ip, |
| 257 | + "ttl": dnsAutoTTL, |
| 258 | + "proxied": false, |
| 259 | + } |
| 260 | + |
| 261 | + var out cfRecordResult |
| 262 | + if err := cfMutate(ctx, http.MethodPut, token, endpoint, body, &out); err != nil { |
| 263 | + return err |
| 264 | + } |
| 265 | + if !out.Success { |
| 266 | + return cfErrs(out.Errors) |
| 267 | + } |
| 268 | + |
| 269 | + log.Info(). |
| 270 | + Str("name", name). |
| 271 | + Str("ip", ip). |
| 272 | + Msg("[DNS] updated A record") |
| 273 | + return nil |
| 274 | +} |
| 275 | + |
| 276 | +// ── HTTP transport ────────────────────────────────────────────────── |
| 277 | + |
| 278 | +func cfGet(ctx context.Context, token, rawURL string, out any) error { |
| 279 | + req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil) |
| 280 | + if err != nil { |
| 281 | + return err |
| 282 | + } |
| 283 | + req.Header.Set("Authorization", "Bearer "+token) |
| 284 | + req.Header.Set("Content-Type", "application/json") |
| 285 | + |
| 286 | + resp, err := http.DefaultClient.Do(req) |
| 287 | + if err != nil { |
| 288 | + return err |
| 289 | + } |
| 290 | + defer resp.Body.Close() |
| 291 | + |
| 292 | + return json.NewDecoder(resp.Body).Decode(out) |
| 293 | +} |
| 294 | + |
| 295 | +func cfMutate(ctx context.Context, method, token, rawURL string, body any, out any) error { |
| 296 | + payload, err := json.Marshal(body) |
| 297 | + if err != nil { |
| 298 | + return err |
| 299 | + } |
| 300 | + |
| 301 | + req, err := http.NewRequestWithContext(ctx, method, rawURL, bytes.NewReader(payload)) |
| 302 | + if err != nil { |
| 303 | + return err |
| 304 | + } |
| 305 | + req.Header.Set("Authorization", "Bearer "+token) |
| 306 | + req.Header.Set("Content-Type", "application/json") |
| 307 | + |
| 308 | + resp, err := http.DefaultClient.Do(req) |
| 309 | + if err != nil { |
| 310 | + return err |
| 311 | + } |
| 312 | + defer resp.Body.Close() |
| 313 | + |
| 314 | + return json.NewDecoder(resp.Body).Decode(out) |
| 315 | +} |
| 316 | + |
| 317 | +func cfErrs(errs []cfError) error { |
| 318 | + if len(errs) == 0 { |
| 319 | + return fmt.Errorf("cloudflare API request failed") |
| 320 | + } |
| 321 | + msgs := make([]string, 0, len(errs)) |
| 322 | + for _, e := range errs { |
| 323 | + msgs = append(msgs, fmt.Sprintf("[%d] %s", e.Code, e.Message)) |
| 324 | + } |
| 325 | + return fmt.Errorf("cloudflare API: %s", strings.Join(msgs, "; ")) |
| 326 | +} |
0 commit comments