headplane/app/server/headscale/config-loader.ts

423 lines
10 KiB
TypeScript

import { constants, access, readFile, writeFile } from 'node:fs/promises';
import { exit } from 'node:process';
import { setTimeout } from 'node:timers/promises';
import { type } from 'arktype';
import { Document, parseDocument } from 'yaml';
import log from '~/utils/log';
import { DNSRecord, HeadscaleDNSConfig, loadHeadscaleDNS } from './config-dns';
import { headscaleConfig } from './config-schema';
interface PatchConfig {
path: string;
value: unknown;
}
// We need a class for the config because we need to be able to
// support retrieving it via a getter but also be able to
// patch it and to query it for its mode
class HeadscaleConfig {
private config?: typeof headscaleConfig.infer;
private document?: Document;
private access: 'rw' | 'ro' | 'no';
private path?: string;
private writeLock = false;
private dns?: HeadscaleDNSConfig;
constructor(
access: 'rw' | 'ro' | 'no',
dns?: HeadscaleDNSConfig,
config?: typeof headscaleConfig.infer,
document?: Document,
path?: string,
) {
this.access = access;
this.config = config;
this.document = document;
this.path = path;
this.dns = dns;
}
readable() {
return this.access !== 'no';
}
writable() {
return this.access === 'rw';
}
get c() {
return this.config;
}
get d() {
if (this.dns) {
return this.dns.r;
}
return this.config?.dns.extra_records ?? [];
}
async patch(patches: PatchConfig[]) {
if (!this.path || !this.document || !this.readable() || !this.writable()) {
return;
}
log.debug('config', 'Patching Headscale configuration');
for (const patch of patches) {
const { path, value } = patch;
log.debug('config', 'Patching %s with %o', path, value);
// If the key is something like `test.bar."foo.bar"`, then we treat
// the foo.bar as a single key, and not as two keys, so that needs
// to be split correctly.
// Iterate through each character, and if we find a dot, we check if
// the next character is a quote, and if it is, we skip until the next
// quote, and then we skip the next character, which should be a dot.
// If it's not a quote, we split it.
const key = [];
let current = '';
let quote = false;
for (const char of path) {
if (char === '"') {
quote = !quote;
}
if (char === '.' && !quote) {
key.push(current);
current = '';
continue;
}
current += char;
}
key.push(current.replaceAll('"', ''));
if (value === null) {
this.document.deleteIn(key);
continue;
}
this.document.setIn(key, value);
}
// Revalidate our configuration and update the config
// object with the new configuration
log.info('config', 'Revalidating Headscale configuration');
const config = validateConfig(this.document.toJSON());
if (!config) {
return;
}
log.debug(
'config',
'Writing updated Headscale configuration to %s',
this.path,
);
// We need to lock the writeLock so that we don't try to write
// to the file while we're already writing to it
while (this.writeLock) {
await setTimeout(100);
}
this.writeLock = true;
await writeFile(this.path, this.document.toString(), 'utf8');
this.config = config;
this.writeLock = false;
return;
}
/**
* Adds a DNS record to the Headscale configuration.
* Differentiates between the file mode and config mode automatically.
* @param record The DNS record to add.
* @returns True if we need to restart the integration.
*/
async addDNS(record: DNSRecord) {
if (this.dns) {
if (!this.dns.readable() || !this.dns.writable()) {
log.debug('config', 'DNS config is not writable');
return;
}
const records = this.dns.r;
if (
records.some((i) => i.name === record.name && i.type === record.type)
) {
log.debug('config', 'DNS record already exists');
return;
}
return this.dns.patch([...records, record]);
}
// If we get here, we need to add to the main config instead of
// a separate file (which requires an integration restart)
const existing = this.config?.dns.extra_records ?? [];
if (
existing.some((i) => i.name === record.name && i.type === record.type)
) {
log.debug('config', 'DNS record already exists');
return;
}
await this.patch([
{
path: 'dns.extra_records',
value: Array.from(new Set([...existing, record])),
},
]);
return true;
}
/**
* Removes a DNS record from the Headscale configuration.
* Differentiates between the file mode and config mode automatically.
* @param records The DNS record to remove.
* @returns True if we need to restart the integration.
*/
async removeDNS(record: DNSRecord) {
// In this case we need to check both the main config and the DNS config
// to see if the record exists, and if it does, we need to remove it
// from both places.
if (this.dns) {
if (!this.dns.readable() || !this.dns.writable()) {
log.debug('config', 'DNS config is not writable');
return;
}
const records = this.dns.r.filter(
(i) => i.name !== record.name || i.type !== record.type,
);
return this.dns.patch(records);
}
// If we get here, we need to remove from the main config instead of
// a separate file (which requires an integration restart)
const existing = this.config?.dns.extra_records ?? [];
const filtered = existing.filter(
(i) => i.name !== record.name || i.type !== record.type,
);
// If the length of the existing records is the same as the filtered
// records, then we don't need to do anything
if (existing.length === filtered.length) {
return;
}
await this.patch([
{
path: 'dns.extra_records',
value: existing.filter(
(i) => i.name !== record.name || i.type !== record.type,
),
},
]);
return true;
}
}
export async function loadHeadscaleConfig(
path?: string,
strict = true,
dnsPath?: string,
) {
if (!path) {
log.debug('config', 'No Headscale configuration file was provided');
return new HeadscaleConfig('no');
}
log.debug('config', 'Loading Headscale configuration file: %s', path);
const { r, w } = await validateConfigPath(path);
if (!r) {
return new HeadscaleConfig('no');
}
const document = await loadConfigFile(path);
if (!document) {
return new HeadscaleConfig('no');
}
if (!strict) {
return new HeadscaleConfig(
w ? 'rw' : 'ro',
new HeadscaleDNSConfig('no'),
augmentUnstrictConfig(document.toJSON()),
document,
path,
);
}
const config = validateConfig(document.toJSON());
if (!config) {
return new HeadscaleConfig('no');
}
if (config.dns.extra_records && config.dns.extra_records_path) {
log.warn(
'config',
'Both extra_records and extra_records_path are set, Headscale will crash',
);
log.warn('config', 'Please remove one of them from the configuration file');
return new HeadscaleConfig('no');
}
const dns = await loadHeadscaleDNS(dnsPath);
if (dns && !config.dns.extra_records_path) {
log.error(
'config',
'Using separate DNS config file but dns.extra_records_path is not set in Headscale config',
);
log.error(
'config',
'Please set `dns.extra_records_path` in the Headscale config',
);
log.error(
'config',
'Or remove `headscale.dns_records_path` from the Headplane config',
);
exit(1);
}
return new HeadscaleConfig(w ? 'rw' : 'ro', dns, config, document, path);
}
async function validateConfigPath(path: string) {
try {
await access(path, constants.F_OK | constants.R_OK);
log.info(
'config',
'Found a valid Headscale configuration file at %s',
path,
);
} catch (error) {
log.error(
'config',
'Unable to read a Headscale configuration file at %s',
path,
);
log.error('config', '%s', error);
return { w: false, r: false };
}
try {
await access(path, constants.F_OK | constants.W_OK);
return { w: true, r: true };
} catch (error) {
log.warn(
'config',
'Headscale configuration file at %s is not writable',
path,
);
return { w: false, r: true };
}
}
async function loadConfigFile(path: string) {
log.debug('config', 'Reading Headscale configuration file at %s', path);
try {
const data = await readFile(path, 'utf8');
const configYaml = parseDocument(data);
if (configYaml.errors.length > 0) {
log.error(
'config',
'Cannot parse Headscale configuration file at %s',
path,
);
for (const error of configYaml.errors) {
log.error('config', ` - ${error.toString()}`);
}
return false;
}
return configYaml;
} catch (e) {
log.error(
'config',
'Error reading Headscale configuration file at %s',
path,
);
log.error('config', '%s', e);
return false;
}
}
export function validateConfig(config: unknown) {
log.debug('config', 'Validating Headscale configuration');
const result = headscaleConfig(config);
if (result instanceof type.errors) {
log.error('config', 'Error validating Headscale configuration:');
for (const [number, error] of result.entries()) {
log.error('config', ` - (${number}): ${error.toString()}`);
}
return;
}
return result;
}
// If config_strict is false, we set the defaults and disable
// the schema checking for the values that are not present
function augmentUnstrictConfig(loaded: Partial<typeof headscaleConfig.infer>) {
log.debug('config', 'Augmenting Headscale configuration in non-strict mode');
const config = {
...loaded,
tls_letsencrypt_cache_dir:
loaded.tls_letsencrypt_cache_dir ?? '/var/www/cache',
tls_letsencrypt_challenge_type:
loaded.tls_letsencrypt_challenge_type ?? 'HTTP-01',
grpc_listen_addr: loaded.grpc_listen_addr ?? ':50443',
grpc_allow_insecure: loaded.grpc_allow_insecure ?? false,
randomize_client_port: loaded.randomize_client_port ?? false,
unix_socket: loaded.unix_socket ?? '/var/run/headscale/headscale.sock',
unix_socket_permission: loaded.unix_socket_permission ?? '0770',
log: loaded.log ?? {
level: 'info',
format: 'text',
},
logtail: loaded.logtail ?? {
enabled: false,
},
prefixes: loaded.prefixes ?? {
allocation: 'sequential',
v4: '',
v6: '',
},
dns: loaded.dns ?? {
nameservers: {
global: [],
split: {},
},
search_domains: [],
extra_records: [],
magic_dns: false,
base_domain: 'headscale.net',
},
};
log.warn('config', 'Headscale configuration was loaded in non-strict mode');
log.warn('config', 'This is very dangerous and comes with a few caveats:');
log.warn('config', ' - Headplane could very easily crash');
log.warn('config', ' - Headplane could break your Headscale installation');
log.warn(
'config',
' - The UI could throw random errors/show incorrect data',
);
return config as typeof headscaleConfig.infer;
}