2023-10-20 01:35:16 -07:00

476 lines
14 KiB
TypeScript

import {
DAEMON_PB_IDLE_TTL,
mkAppUrl,
mkDocUrl,
PUBLIC_MOTHERSHIP_NAME,
} from '$constants'
import {
clientService,
InstanceLogger,
pocketbaseService,
port,
proxyService,
} from '$services'
import { mkInternalUrl, now } from '$util'
import {
assertTruthy,
CLEANUP_PRIORITY_LAST,
createCleanupManager,
createTimerManager,
InstanceFields,
InstanceId,
InstanceStatus,
mkSingleton,
safeCatch,
SingletonBaseConfig,
} from '@pockethost/common'
import { map, values } from '@s-libs/micro-dash'
import Bottleneck from 'bottleneck'
import { ClientResponseError } from 'pocketbase'
import { AsyncReturnType } from 'type-fest'
enum InstanceApiStatus {
Starting = 'starting',
Healthy = 'healthy',
ShuttingDown = 'shutdown',
}
type InstanceApi = {
status: () => InstanceApiStatus
internalUrl: () => string
startRequest: () => () => void
shutdown: (reason?: Error) => Promise<void>
}
export type InstanceServiceConfig = SingletonBaseConfig & {
instanceApiTimeoutMs: number
instanceApiCheckIntervalMs: number
}
export type InstanceServiceApi = AsyncReturnType<typeof instanceService>
export const instanceService = mkSingleton(
async (config: InstanceServiceConfig) => {
const { logger, instanceApiTimeoutMs, instanceApiCheckIntervalMs } = config
const instanceServiceLogger = logger.create('InstanceService')
const { dbg, raw, error, warn } = instanceServiceLogger
const { client } = await clientService()
const pbService = await pocketbaseService()
const instanceApis: { [_: InstanceId]: InstanceApi } = {}
client.resetInstances().catch(error)
const getInstanceApi = (instance: InstanceFields): Promise<InstanceApi> => {
const _logger = instanceServiceLogger.create(`getInstanceApi`)
const { id, subdomain, version } = instance
_logger.breadcrumb(`${subdomain}:${id}:${version}`)
const { dbg, trace } = _logger
return new Promise<InstanceApi>((resolve, reject) => {
let maxTries = instanceApiTimeoutMs / instanceApiCheckIntervalMs
const retry = (interval = instanceApiCheckIntervalMs) => {
maxTries--
if (maxTries <= 0) {
reject(new Error(`Timeout obtaining instance API.`))
return
}
dbg(`${maxTries} tries remaining. Retrying in ${interval}ms`)
setTimeout(_check, interval)
}
const _check = () => {
dbg(`Checking for existing instance API`)
const instanceApi = instanceApis[id]
if (!instanceApi) {
dbg(`No API found, creating`)
createInstanceApi(instance)
retry(0)
return
}
try {
if (instanceApi.status() === InstanceApiStatus.Healthy) {
dbg(`API found and healthy, returning`)
resolve(instanceApi)
return
}
} catch (e) {
dbg(`Instance is in an error state, returning error`)
reject(e)
return
}
dbg(`API found but not healthy, waiting`)
retry()
}
_check()
})
}
const createInstanceApi = (instance: InstanceFields): InstanceApi => {
const { id, subdomain, version } = instance
const systemInstanceLogger = instanceServiceLogger.create(
`${subdomain}:${id}:${version}`,
)
const { dbg, warn, error, info } = systemInstanceLogger
if (instanceApis[id]) {
throw new Error(
`Attempted to create an instance API when one is already available for ${id}`,
)
}
/*
Initialize shutdown manager
*/
const shutdownManager = createCleanupManager()
shutdownManager.add(async () => {
dbg(`Deleting from cache`)
delete instanceApis[id]
dbg(`There are ${values(instanceApis).length} still in cache`)
}, CLEANUP_PRIORITY_LAST) // Make this the very last thing that happens
shutdownManager.add(async () => {
dbg(`Shutting down`)
status = InstanceApiStatus.ShuttingDown
})
info(`Starting`)
let status = InstanceApiStatus.Starting
let internalUrl = ''
let startRequest: InstanceApi['startRequest'] = () => {
throw new Error(`Not ready yet`)
}
/*
Initialize API
*/
let _shutdownReason: Error | undefined
const api: InstanceApi = {
status: () => {
if (_shutdownReason) throw _shutdownReason
return status
},
internalUrl: () => {
if (status !== InstanceApiStatus.Healthy) {
throw new Error(
`Attempt to access instance URL when instance is not in a healthy state.`,
)
}
return internalUrl
},
startRequest: () => {
if (status !== InstanceApiStatus.Healthy) {
throw new Error(
`Attempt to start an instance request when instance is not in a healthy state.`,
)
}
return startRequest()
},
shutdown: async (reason) => {
if (reason) {
_shutdownReason = reason
error(`Panic shutdown for ${reason}`)
} else {
dbg(`Graceful shutdown`)
}
if (status === InstanceApiStatus.ShuttingDown) {
warn(`Already shutting down`)
return
}
return shutdownManager.shutdown()
},
}
const _safeShutdown = async (reason?: Error) => {
if (status === InstanceApiStatus.ShuttingDown) {
warn(`Already shutting down, ${reason} will not be reported.`)
return
}
return api.shutdown(reason)
}
instanceApis[id] = api
const healthyGuard = () => {
if (status !== InstanceApiStatus.ShuttingDown) return
throw new Error(
`HealthyGuard detected instance is shutting down. Aborting further initialization.`,
)
}
/*
Create serialized client communication functions to prevent race conditions
*/
const clientLimiter = new Bottleneck({ maxConcurrent: 1 })
const updateInstanceStatus = clientLimiter.wrap(
client.updateInstanceStatus,
)
const updateInstance = clientLimiter.wrap(client.updateInstance)
const createInvocation = clientLimiter.wrap(client.createInvocation)
const pingInvocation = clientLimiter.wrap(client.pingInvocation)
const finalizeInvocation = clientLimiter.wrap(client.finalizeInvocation)
/*
Handle async setup
*/
;(async () => {
const { version } = instance
/*
Obtain empty port
*/
dbg(`Obtaining port`)
const [newPort, releasePort] = await port.alloc()
shutdownManager.add(() => {
dbg(`Releasing port`)
releasePort()
}, CLEANUP_PRIORITY_LAST)
systemInstanceLogger.breadcrumb(`port:${newPort}`)
dbg(`Found port`)
/*
Create the user instance logger
*/
healthyGuard()
const userInstanceLogger = InstanceLogger(instance.id, `exec`)
/*
Start the instance
*/
dbg(`Starting instance`)
dbg(`Set instance status: starting`)
healthyGuard()
await updateInstanceStatus(instance.id, InstanceStatus.Starting)
shutdownManager.add(async () => {
dbg(`Set instance status: idle`)
await updateInstanceStatus(id, InstanceStatus.Idle).catch(error)
})
healthyGuard()
/*
Spawn the child process
*/
const childProcess = await (async () => {
try {
const cp = await pbService.spawn({
command: 'serve',
name: instance.subdomain,
slug: instance.id,
port: newPort,
env: instance.secrets || {},
version,
onUnexpectedStop: (code) => {
warn(
`PocketBase processes exited unexpectedly with ${code}. Putting in maintenance mode.`,
)
shutdownManager.add(async () => {
await updateInstance(instance.id, {
maintenance: true,
})
userInstanceLogger.error(
`Putting instance in maintenance mode because it shut down with return code ${code}. `,
)
})
setImmediate(() => {
_safeShutdown(
new Error(
`PocketBase processes exited unexpectedly with ${code}. Putting in maintenance mode.`,
),
).catch(error)
})
},
})
return cp
} catch (e) {
warn(`Error spawning: ${e}`)
userInstanceLogger.error(
`Could not launch PocketBase ${instance.version}. It may be time to upgrade.`,
)
throw new Error(
`Could not launch PocketBase ${instance.version}. It may be time to upgrade.`,
)
}
})()
const { pid: _pid } = childProcess
const pid = _pid()
assertTruthy(pid, `Expected PID here but got ${pid}`)
dbg(`PocketBase instance PID: ${pid}`)
systemInstanceLogger.breadcrumb(`pid:${pid}`)
shutdownManager.add(async () => {
dbg(`killing ${id}`)
await childProcess.kill().catch(error)
dbg(`killed ${id}`)
})
/*
Create the invocation record
*/
healthyGuard()
const invocation = await createInvocation(instance, pid)
shutdownManager.add(async () => {
await finalizeInvocation(invocation).catch(error)
})
/*
API state, timers, etc
*/
const tm = createTimerManager({})
shutdownManager.add(() => tm.shutdown())
let openRequestCount = 0
let lastRequest = now()
internalUrl = mkInternalUrl(newPort)
const RECHECK_TTL = 1000 // 1 second
startRequest = () => {
lastRequest = now()
openRequestCount++
const id = openRequestCount
dbg(`started new request`)
return () => {
openRequestCount--
dbg(`ended request (${openRequestCount} still open)`)
}
}
{
tm.repeat(
safeCatch(`idleCheck`, systemInstanceLogger, async () => {
raw(`idle check: ${openRequestCount} open requests`)
if (
openRequestCount === 0 &&
lastRequest + DAEMON_PB_IDLE_TTL < now()
) {
dbg(`idle for ${DAEMON_PB_IDLE_TTL}, shutting down`)
healthyGuard()
await _safeShutdown().catch(error)
return false
} else {
raw(`${openRequestCount} requests remain open`)
}
return true
}),
RECHECK_TTL,
)
}
{
tm.repeat(
() =>
pingInvocation(invocation)
.then(() => true)
.catch((e) => {
warn(`_pingInvocation failed with ${e}`)
return true
}),
1000,
)
}
dbg(`${internalUrl} is running`)
status = InstanceApiStatus.Healthy
healthyGuard()
await updateInstanceStatus(instance.id, InstanceStatus.Running)
})().catch((e) => {
warn(`Instance failed to start with ${e}`)
_safeShutdown(e).catch(error)
})
return api
}
const getInstanceByIdOrSubdomain = async (idOrSubdomain: InstanceId) => {
{
dbg(`Trying to get instance by ID: ${idOrSubdomain}`)
const [instance, owner] = await client
.getInstanceById(idOrSubdomain)
.catch((e: ClientResponseError) => {
if (e.status !== 404) {
throw new Error(
`Unexpected response ${JSON.stringify(e)} from mothership`,
)
}
return []
})
if (instance && owner) {
dbg(`${idOrSubdomain} is an instance ID`)
return { instance, owner }
}
}
{
dbg(`Trying to get instance by subdomain: ${idOrSubdomain}`)
const [instance, owner] =
await client.getInstanceBySubdomain(idOrSubdomain)
if (instance && owner) {
dbg(`${idOrSubdomain} is a subdomain`)
return { instance, owner }
}
}
dbg(`${idOrSubdomain} is neither an instance nor a subdomain`)
return {}
}
;(await proxyService()).use(
(subdomain) => subdomain !== PUBLIC_MOTHERSHIP_NAME,
['/api(/*)', '/_(/*)', '(/*)'],
async (req, res, meta, logger) => {
const { dbg } = logger
const { subdomain: instanceIdOrSubdomain, host, proxy } = meta
const { instance, owner } = await getInstanceByIdOrSubdomain(
instanceIdOrSubdomain,
)
if (!owner) {
throw new Error(`Instance owner is invalid`)
}
if (!instance) {
throw new Error(
`Subdomain ${instanceIdOrSubdomain} does not resolve to an instance`,
)
}
/*
Maintenance check
*/
dbg(`Checking for maintenance mode`)
if (instance.maintenance) {
throw new Error(
`This instance is in Maintenance Mode. See ${mkDocUrl(
`usage/maintenance`,
)} for more information.`,
)
}
/*
Owner check
*/
dbg(`Checking for verified account`)
if (!owner?.verified) {
throw new Error(`Log in at ${mkAppUrl()}} to verify your account.`)
}
const api = await getInstanceApi(instance)
const endRequest = api.startRequest()
res.on('close', endRequest)
if (req.closed) {
throw new Error(`Request already closed.`)
}
dbg(
`Forwarding proxy request for ${
req.url
} to instance ${api.internalUrl()}`,
)
proxy.web(req, res, { target: api.internalUrl() })
return true
},
`InstanceService`,
)
const shutdown = async () => {
dbg(`Shutting down instance manager`)
const p = Promise.all(map(instanceApis, (api) => api.shutdown()))
await p
}
const getInstanceApiIfExistsById = (id: InstanceId) => instanceApis[id]
return { shutdown, getInstanceApiIfExistsById }
},
)