cmd_remote.v

1//! `koh remote` — the machine's remote, set up once and used by every repo.2//!3//! Setup is interactive by default, because it ends with a live connection4//! test: a remote is only saved once it has proved it can store an object and5//! refuse to overwrite it. `folder` and `s3` forms are available for a machine6//! being set up by a script, and an agent can read the current setting with7//! `--json` (which never prints the secret key).89module cli1011import json212import net.http13import net.urllib14import os15import src.fmt16import src.machine17import src.remote18import term.termios1920pub fn cmd_remote(raw []string) int {21	args := parse('remote', raw, Options{22		values: ['code']23		flags:  ['json', 'forget']24	}) or { return usage_error(err.msg()) }25	if args.value('code') != '' && args.positional.len == 0 {26		return usage_error('--code belongs to "koh remote <host>"')27	}28	if args.flag('forget') {29		if !machine.has_remote() {30			return refuse(args.json(), 'this machine has no remote to forget')31		}32		machine.forget_remote() or { return refuse(args.json(), err.msg()) }33		if args.json() {34			emit_json(json2.encode(RemoteJson{35				configured: false36			}))37			return 038		}39		ok("forgot this machine's remote")40		return 041	}42	if args.positional.len == 0 {43		if !machine.has_remote() {44			if args.json() {45				emit_json(json2.encode(RemoteJson{46					configured: false47				}))48				return 049			}50			return setup_wizard()51		}52		settings := machine.load_remote() or {53			// Otherwise the message to run "koh remote" again would loop.54			if !args.json() && interactive() {55				warn(err.msg())56				return setup_wizard()57			}58			return refuse(args.json(), err.msg())59		}60		if args.json() {61			emit_json(json2.encode(RemoteJson{62				configured: true63				kind:       settings.kind64				target:     describe(settings)65			}))66			return 067		}68		ok('remote: ${describe(settings)}')69		if !interactive() {70			note('run "koh remote folder <path>" or "koh remote s3 <endpoint> <bucket> <region>" to replace it')71			return 072		}73		print('  replace it? [y/N] ')74		if os.get_line().trim_right('\r') != 'y' {75			return 076		}77		// The old remote stays until the new one passes its test.78		return setup_wizard()79	}80	// A non-interactive form, still tested before it is saved.81	return set_remote(args)82}8384fn set_remote(args Args) int {85	if args.positional_at(0) !in [machine.kind_folder, machine.kind_s3] {86		return set_kepr_remote(args)87	}88	if args.value('code') != '' {89		return usage_error('--code belongs to "koh remote <host>", not to folder or s3')90	}91	kind := args.positional_at(0)92	match kind {93		machine.kind_folder {94			path := args.positional_at(1)95			if path == '' {96				return usage_error('remote folder needs a path: koh remote folder /Volumes/usb/koh')97			}98			settings := machine.RemoteSettings{99				kind: machine.kind_folder100				path: os.real_path(path)101			}102			return save_after_check(settings, args, '', '')103		}104		machine.kind_s3 {105			endpoint := args.positional_at(1)106			bucket := args.positional_at(2)107			region := args.positional_at(3)108			if endpoint == '' || bucket == '' || region == '' {109				return usage_error('remote s3 needs an endpoint, bucket and region: koh remote s3 https://s3.fr-par.scw.cloud my-bucket fr-par')110			}111			access_key, secret_key := s3_keys() or { return refuse(args.json(), err.msg()) }112			settings := machine.RemoteSettings{113				kind:     machine.kind_s3114				endpoint: endpoint115				bucket:   bucket116				region:   region117			}118			return save_after_check(settings, args, access_key, secret_key)119		}120		else {121			return usage_error('remote takes "folder", "s3", or a Kepr host')122		}123	}124}125126// kepr_host normalises a Kepr address: https unless the scheme says otherwise, and scheme, host127// and port only. A path, a query, a fragment or credentials would send the code somewhere else.128fn kepr_host(value string) !string {129	for letter in value {130		if letter <= ` ` {131			return error('"${value}" is not a Kepr address — try kepr.uk')132		}133	}134	text := if value.starts_with('http://') || value.starts_with('https://') {135		value136	} else {137		'https://${value}'138	}139	parsed := urllib.parse(text) or { return error('"${value}" is not a Kepr address — try kepr.uk') }140	if parsed.scheme !in ['http', 'https'] || parsed.host == '' || parsed.path.trim_right('/') != ''141		|| parsed.raw_query != '' || parsed.fragment != '' {142		return error('"${value}" is not a Kepr address — try kepr.uk')143	}144	// Credentials in the address have nowhere to go: `urllib` would quietly drop them, and Kepr145	// would see a different address than the one typed.146	if text.all_after('//').contains('@') {147		return error('"${value}" is not a Kepr address — try kepr.uk')148	}149	return '${parsed.scheme}://${parsed.host}'150}151152fn set_kepr_remote(args Args) int {153	if args.positional.len != 1 {154		return usage_error('koh remote <host> accepts one Kepr host')155	}156	host := kepr_host(args.positional_at(0)) or { return refuse(args.json(), err.msg()) }157	connect_url := '${host}/connect?machine=${urllib.query_escape(machine.name())}'158	println('Open ${connect_url} and sign in')159	mut code := args.value('code')160	if code == '' {161		if !interactive() {162			return fail('setting up a Kepr remote needs a terminal, or use --code <code>')163		}164		// Only a person about to type the code gets a browser opened for them: with `--code` the165		// page has been read already, and a script must never take over the desktop. `open` or166		// `xdg-open` is launched with an argument vector rather than a shell — neither the host nor167		// this machine's name is ours to quote for one — and a browser that will not open is not168		// an error.169		mut browser := os.new_process(if os.user_os() == 'macos' { 'open' } else { 'xdg-open' })170		browser.set_args([connect_url])171		browser.run()172		print('paste the code: ')173		code = os.get_line().trim_space()174	}175	// Redirects are refused: a 3xx would hand the one-time code to whatever it points at.176	response := http.fetch(177		url:            '${host}/api/connect'178		method:         .post179		header:         http.new_header(180			key:   .content_type181			value: 'application/x-www-form-urlencoded'182		)183		data:           'code=${urllib.query_escape(code)}'184		enable_http2:   false185		allow_redirect: false186	) or { return refuse(args.json(), 'could not reach Kepr: ${err.msg()}') }187	if response.status_code == 404 {188		// One 404 covers a wrong code, an expired one, and a Kepr that hands out nothing. The two189		// are told apart by asking for the connect page: 302 means the endpoint is there.190		probe := http.fetch(191			url:            connect_url192			method:         .get193			enable_http2:   false194			allow_redirect: false195		) or {196			return refuse(args.json(), 'that code is wrong or has expired — nothing was changed')197		}198		if probe.status_code == 404 {199			return refuse(args.json(), 'this Kepr doesn\'t hand out bucket access; use "koh remote s3"')200		}201		if probe.status_code != 302 {202			return refuse(args.json(), 'this Kepr answered ${probe.status_code} for its connect page — nothing was changed')203		}204		return refuse(args.json(), 'that code is wrong or has expired — nothing was changed')205	}206	if response.status_code != 200 {207		return refuse(args.json(), 'Kepr refused the code (${response.status_code}) — nothing was changed')208	}209	reply := json2.decode[KeprReply](response.body) or {210		return refuse(args.json(), 'Kepr returned an invalid response — nothing was changed')211	}212	if reply.endpoint == '' || reply.bucket == '' || reply.region == ''213		|| reply.access_key_id == '' || reply.secret_access_key == '' {214		return refuse(args.json(), 'Kepr returned incomplete settings — nothing was changed')215	}216	settings := machine.RemoteSettings{217		kind:     machine.kind_s3218		endpoint: reply.endpoint219		bucket:   reply.bucket220		region:   reply.region221		kepr:     host222	}223	return save_after_check(settings, args, reply.access_key_id, reply.secret_access_key)224}225226// save_after_check is the whole point: nothing is written to ~/.config/koh227// until the remote has passed the test.228fn save_after_check(settings machine.RemoteSettings, args Args, access_key string, secret_key string) int {229	mut backend := build_backend(settings, access_key, secret_key) or {230		return refuse(args.json(), err.msg())231	}232	remote.check(mut backend) or {233		return refuse(args.json(), 'the remote did not pass its test: ${err.msg()}')234	}235	machine.save_remote(settings) or { return refuse(args.json(), err.msg()) }236	if settings.kind == machine.kind_s3 {237		machine.save_credentials(machine.Credentials{238			access_key: access_key239			secret_key: secret_key240		}) or { return refuse(args.json(), err.msg()) }241	}242	if args.json() {243		emit_json(json2.encode(RemoteJson{244			configured: true245			kind:       settings.kind246			target:     describe(settings)247		}))248		return 0249	}250	ok('remote set to ${describe(settings)}')251	note('every repo on this machine now offers to it')252	return 0253}254255fn build_backend(settings machine.RemoteSettings, access_key string, secret_key string) !remote.Backend {256	if settings.kind == machine.kind_folder {257		return remote.new_folder(settings.path)!258	}259	return remote.new_s3(settings.endpoint, settings.bucket, settings.region, access_key,260		secret_key)!261}262263fn setup_wizard() int {264	if !interactive() {265		return fail('setting up a remote needs a terminal, or use: koh remote folder <path>, koh remote s3 <endpoint> <bucket> <region>')266	}267	println('  choose a remote:')268	println('    ${fmt.amber('1')} folder   a directory, on a disk or a NAS')269	println('    ${fmt.amber('2')} s3       an S3-compatible bucket')270	print('  which? [1] ')271	if os.get_line().trim_space() == '2' {272		return wizard_s3()273	}274	print('  folder path: ')275	path := os.get_line().trim_space()276	if path == '' {277		return fail('no path given — nothing was saved')278	}279	settings := machine.RemoteSettings{280		kind: machine.kind_folder281		path: os.real_path(path)282	}283	return save_after_check(settings, Args{}, '', '')284}285286fn wizard_s3() int {287	print('  endpoint [https://s3.fr-par.scw.cloud]: ')288	endpoint := or_default(os.get_line().trim_space(), 'https://s3.fr-par.scw.cloud')289	print('  bucket: ')290	bucket := os.get_line().trim_space()291	print('  region [fr-par]: ')292	region := or_default(os.get_line().trim_space(), 'fr-par')293	if bucket == '' {294		return fail('no bucket given — nothing was saved')295	}296	access_key, secret_key := s3_keys() or { return fail(err.msg()) }297	settings := machine.RemoteSettings{298		kind:     machine.kind_s3299		endpoint: endpoint300		bucket:   bucket301		region:   region302	}303	return save_after_check(settings, Args{}, access_key, secret_key)304}305306// s3_keys takes the keys from the environment when a script supplies them, and307// otherwise asks, so they never have to be typed into a shell history.308fn s3_keys() !(string, string) {309	access_key := os.getenv('KOH_ACCESS_KEY')310	secret_key := os.getenv('KOH_SECRET_KEY')311	if access_key != '' && secret_key != '' {312		return access_key, secret_key313	}314	if !interactive() {315		return error('S3 keys are missing — set KOH_ACCESS_KEY and KOH_SECRET_KEY, or run koh remote on a terminal')316	}317	print('  access key: ')318	access_key_typed := os.get_line().trim_space()319	// Hidden input needs a terminal on both ends; with output redirected, the320	// key is read like any other line.321	mut secret_key_typed := ''322	mut saved := termios.Termios{}323	if os.is_atty(1) != 0 && os.getenv('TERM') != 'dumb' && termios.tcgetattr(0, mut saved) == 0 {324		// V's hidden read returns on end of input without turning echo back325		// on, so the terminal's state is kept here and put back. A failed326		// read is an empty key, which is refused below.327		secret_key_typed = os.input_password('  secret key: ') or {328			println('')329			if termios.set_state(0, saved) != 0 {330				warn('the terminal may no longer echo — run "stty sane"')331			}332			''333		}334	} else {335		print('  secret key: ')336		secret_key_typed = os.get_line()337	}338	secret_key_typed = secret_key_typed.trim_space()339	if access_key_typed == '' || secret_key_typed == '' {340		return error('both keys are needed — nothing was saved')341	}342	return access_key_typed, secret_key_typed343}344345fn describe(settings machine.RemoteSettings) string {346	if settings.kind == machine.kind_folder {347		return 'folder ${settings.path}'348	}349	return 's3 ${settings.endpoint}/${settings.bucket} (${settings.region})'350}351352fn or_default(value string, fallback string) string {353	return if value == '' { fallback } else { value }354}355356struct RemoteJson {357	configured bool358	kind       string359	target     string360}361362struct KeprReply {363	endpoint          string364	bucket            string365	region            string366	access_key_id     string367	secret_access_key string368}