checkout/src/warpbuild/mirror-cache.ts
2026-07-08 16:51:09 +05:30

321 lines
10 KiB
TypeScript

/* eslint-disable i18n-text/no-en, import/no-unresolved -- upstream conventions; no TS import resolver configured */
import * as core from '@actions/core'
import * as exec from '@actions/exec'
import * as io from '@actions/io'
import * as fs from 'fs'
import * as os from 'os'
import * as path from 'path'
import {Readable} from 'stream'
import {pipeline} from 'stream/promises'
import {IGitSourceSettings} from '../git-source-settings.js'
import * as api from './backend-api.js'
// WarpBuild checkout snapshot cache: SHA-keyed tars of what the stock shallow fetch
// produces. Hit = restore + skip the fetch; miss = upload after checkout. Keys are
// immutable (no expiry). Fail-open: any error degrades to stock behavior.
const DOWNLOAD_TIMEOUT_MS = 15 * 60_000
const UPLOAD_TIMEOUT_MS = 15 * 60_000
// "hit <sha>" | "uploaded <sha>", for e2e assertions.
export const CACHE_STATE_FILE = 'wb-cache-state'
// Logged at debug (normal state outside WarpBuild); other reasons log at info.
export const SKIP_NOT_WARPBUILD =
'not running on a WarpBuild runner (WARPBUILD_* env not present)'
const SHA_PATTERN = /^[0-9a-f]{40}([0-9a-f]{24})?$/
let decision: 'off' | 'miss' = 'off'
// Null = attempt the cache; else a reason to log. Only the default checkout shape
// is served.
export function getMirrorCacheSkipReason(
settings: IGitSourceSettings
): string | null {
if (
!process.env['WARPBUILD_RUNNER_VERIFICATION_TOKEN'] ||
!process.env['WARPBUILD_HOST_URL']
) {
return SKIP_NOT_WARPBUILD
}
const repoKey = process.env['GITHUB_REPOSITORY_ID'] || ''
if (!repoKey) {
return 'GITHUB_REPOSITORY_ID is not set'
}
const checkoutRepo = `${settings.repositoryOwner}/${settings.repositoryName}`
if (checkoutRepo !== process.env['GITHUB_REPOSITORY']) {
return `repository '${checkoutRepo}' is not the workflow repository '${process.env['GITHUB_REPOSITORY']}'`
}
const server = (settings.githubServerUrl || 'https://github.com').replace(
/\/+$/,
''
)
if (server !== 'https://github.com') {
return `server '${server}' is not github.com`
}
if (!settings.commit || !SHA_PATTERN.test(settings.commit)) {
return 'no exact commit sha to key on'
}
if (settings.fetchDepth !== 1) {
return `fetch-depth is ${settings.fetchDepth}, cache only serves fetch-depth 1`
}
if (settings.fetchTags) {
return 'fetch-tags is enabled'
}
if (settings.filter) {
return 'a fetch filter is configured'
}
if (settings.sparseCheckout) {
return 'sparse checkout is configured'
}
if (settings.lfs) {
return 'lfs is enabled (lfs objects are not in the snapshot)'
}
if (settings.ref && computeDestinationRef(settings.ref) === null) {
return `ref '${settings.ref}' has no cacheable destination ref`
}
return null
}
// The local ref the fetch would have created ('' = none needed, null = uncacheable).
export function computeDestinationRef(ref: string): string | null {
if (!ref) {
return ''
}
const upper = ref.toUpperCase()
if (upper.startsWith('REFS/HEADS/')) {
return `refs/remotes/origin/${ref.substring('refs/heads/'.length)}`
}
if (upper.startsWith('REFS/PULL/')) {
return `refs/remotes/pull/${ref.substring('refs/pull/'.length)}`
}
if (upper.startsWith('REFS/TAGS/')) {
return ref
}
return null
}
// Runs right after `git init`; true = restored (caller skips the fetch). Never throws.
export async function setup(settings: IGitSourceSettings): Promise<boolean> {
decision = 'off'
const skipReason = getMirrorCacheSkipReason(settings)
if (skipReason) {
if (skipReason === SKIP_NOT_WARPBUILD) {
core.debug(`WarpBuild snapshot cache skipped: ${skipReason}`)
} else {
core.info(`WarpBuild snapshot cache skipped: ${skipReason}`)
}
return false
}
core.startGroup('WarpBuild: checkout snapshot cache')
try {
return await setupInner(settings)
} catch (error) {
core.warning(
`WarpBuild snapshot cache unavailable, using standard checkout: ${error}`
)
return false
} finally {
core.endGroup()
}
}
async function setupInner(settings: IGitSourceSettings): Promise<boolean> {
const repoKey = process.env['GITHUB_REPOSITORY_ID'] as string
const sha = settings.commit
// The restore/upload paths shell out to `tar`; without it, fall back cleanly.
if (!(await io.which('tar', false))) {
core.info('tar not found on PATH; using standard checkout')
return false
}
const lookup = await api.lookupSnapshot(repoKey, sha)
if (lookup.kind === 'disabled') {
core.info('Snapshot cache is disabled by the backend for this organization')
return false
}
if (lookup.kind === 'error') {
core.info('Snapshot cache backend unavailable; using standard checkout')
return false
}
if (lookup.kind === 'miss') {
core.info(
`Cache miss for ${sha}: the standard fetch will run and its result will be uploaded`
)
decision = 'miss'
return false
}
core.info(
`Cache hit for ${sha}: restoring snapshot (${lookup.info.size_bytes} bytes)`
)
if (!(await restoreSnapshot(settings, lookup.info.url, sha))) {
return false
}
core.info('Snapshot restored; skipping the GitHub fetch entirely')
return true
}
// Runs after checkout; uploads the fetch result on a miss. Failures only warn.
export async function contribute(settings: IGitSourceSettings): Promise<void> {
if (decision !== 'miss') {
return
}
core.startGroup('WarpBuild: uploading checkout snapshot')
try {
await uploadSnapshot(settings)
} catch (error) {
core.warning(`Snapshot upload skipped: ${error}`)
} finally {
core.endGroup()
}
}
// Refuse any tar member outside objects/ or shallow, absolute, or with a `..`
// component — the tar is remote and extracted into .git, so a crafted member could
// escape (e.g. hooks/, ../) and run code during checkout.
export async function assertSafeTarMembers(tar: string): Promise<void> {
let listing = ''
await exec.exec('tar', ['-tf', tar], {
silent: true,
listeners: {stdout: (d: Buffer) => (listing += d.toString())}
})
for (const raw of listing.split('\n')) {
const member = raw.trim()
if (!member) {
continue
}
const top = member.replace(/^\.\//, '').split('/')[0]
if (
member.startsWith('/') ||
member.split('/').includes('..') ||
(top !== 'objects' && top !== 'shallow')
) {
throw new Error(`unexpected snapshot tar member: ${member}`)
}
}
}
async function restoreSnapshot(
settings: IGitSourceSettings,
url: string,
sha: string
): Promise<boolean> {
const gitDir = path.join(settings.repositoryPath, '.git')
const tmpTar = path.join(os.tmpdir(), `wb-snapshot-${process.pid}.tar`)
try {
const res = await fetch(url, {
signal: AbortSignal.timeout(DOWNLOAD_TIMEOUT_MS)
})
if (!res.ok || !res.body) {
throw new Error(`snapshot download answered ${res.status}`)
}
await pipeline(
Readable.fromWeb(res.body as import('stream/web').ReadableStream),
fs.createWriteStream(tmpTar)
)
await assertSafeTarMembers(tmpTar)
await exec.exec('tar', ['-xf', tmpTar, '-C', gitDir])
const check = await exec.exec(
'git',
['-C', settings.repositoryPath, 'cat-file', '-e', `${sha}^{commit}`],
{ignoreReturnCode: true}
)
if (check !== 0) {
throw new Error(`restored snapshot does not contain ${sha}`)
}
// The ref the skipped fetch would have created; upstream's verification needs it.
const dstRef = computeDestinationRef(settings.ref)
if (dstRef) {
await exec.exec('git', [
'-C',
settings.repositoryPath,
'update-ref',
dstRef,
sha
])
}
await fs.promises.writeFile(
path.join(gitDir, CACHE_STATE_FILE),
`hit ${sha}\n`
)
return true
} catch (error) {
core.warning(`Snapshot restore failed: ${error}`)
// Reset .git to its freshly-init state.
await fs.promises.rm(path.join(gitDir, 'objects'), {
recursive: true,
force: true
})
await fs.promises.rm(path.join(gitDir, 'shallow'), {force: true})
await fs.promises.mkdir(path.join(gitDir, 'objects', 'info'), {
recursive: true
})
await fs.promises.mkdir(path.join(gitDir, 'objects', 'pack'), {
recursive: true
})
return false
} finally {
await fs.promises.rm(tmpTar, {force: true})
}
}
async function uploadSnapshot(settings: IGitSourceSettings): Promise<void> {
const repoKey = process.env['GITHUB_REPOSITORY_ID'] as string
const sha = settings.commit
const gitDir = path.join(settings.repositoryPath, '.git')
const tmpTar = path.join(os.tmpdir(), `wb-snapshot-up-${process.pid}.tar`)
try {
const members = ['objects']
if (fs.existsSync(path.join(gitDir, 'shallow'))) {
members.push('shallow')
}
await exec.exec('tar', ['-cf', tmpTar, '-C', gitDir, ...members])
const size = (await fs.promises.stat(tmpTar)).size
const upload = await api.requestUploadURL(repoKey, sha)
if (upload.kind !== 'ok') {
core.info(
upload.kind === 'locked'
? 'Another job is already uploading this snapshot; skipping'
: upload.kind === 'disabled'
? 'Snapshot cache is disabled by the backend; not uploading'
: 'Snapshot cache backend unavailable; not uploading'
)
return
}
const init: RequestInit & {duplex: 'half'} = {
method: 'PUT',
headers: {
'content-length': String(size),
'content-type': 'application/x-tar'
},
body: Readable.toWeb(
fs.createReadStream(tmpTar)
) as unknown as ReadableStream,
duplex: 'half',
signal: AbortSignal.timeout(UPLOAD_TIMEOUT_MS)
}
const res = await fetch(upload.url, init)
if (!res.ok) {
throw new Error(`snapshot upload answered ${res.status}`)
}
await fs.promises.writeFile(
path.join(gitDir, CACHE_STATE_FILE),
`uploaded ${sha}\n`
)
core.info(
`Snapshot uploaded (${size} bytes); jobs checking out ${sha} will skip the GitHub fetch`
)
} finally {
await fs.promises.rm(tmpTar, {force: true})
}
}