.

go/xcommon/xnet/lonet/lonet.py

-# Copyright (C) 2018  Nexedi SA and Contributors.
-#                     Kirill Smelkov <kirr@nexedi.com>
-#
-# This program is free software: you can Use, Study, Modify and Redistribute
-# it under the terms of the GNU General Public License version 3, or (at your
-# option) any later version, as published by the Free Software Foundation.
-#
-# You can also Link and Combine this program with other software covered by
-# the terms of any of the Free Software licenses or any of the Open Source
-# Initiative approved licenses and Convey the resulting work. Corresponding
-# source of such a combination shall include the source code for all other
-# software used.
-#
-# This program is distributed WITHOUT ANY WARRANTY; without even the implied
-# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-#
-# See COPYING file for full licensing terms.
-# See https://www.nexedi.com/licensing for rationale and options.
-
-# TODO doc, code
-# XXX see lonet.go for lonet organization and protocol.
-
-
-class SQLiteRegistry(object):
-
-    def __init__(self, dburi, network):
-        # XXX open
-        self.setup(network)
-
-
-# TODO

go/xcommon/xnet/lonet/lonet_test.go

-// Copyright (C) 2018  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-package lonet
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"net"
-	"reflect"
-	"testing"
-
-	"golang.org/x/sync/errgroup"
-
-	"lab.nexedi.com/kirr/go123/exc"
-)
-
-
-// FIXME dup from pipenet:
-// ---- 8< ----
-type mklistener interface {
-	Listen(string) (net.Listener, error)
-}
-
-func xlisten(n mklistener, laddr string) net.Listener {
-	l, err := n.Listen(laddr)
-	exc.Raiseif(err)
-	return l
-}
-
-func xaccept(l net.Listener) net.Conn {
-	c, err := l.Accept()
-	exc.Raiseif(err)
-	return c
-}
-
-type dialer interface {
-	Dial(context.Context, string) (net.Conn, error)
-}
-
-func xdial(n dialer, addr string) net.Conn {
-	c, err := n.Dial(context.Background(), addr)
-	exc.Raiseif(err)
-	return c
-}
-
-func xread(r io.Reader) string {
-	buf := make([]byte, 4096)
-	n, err := r.Read(buf)
-	exc.Raiseif(err)
-	return string(buf[:n])
-}
-
-func xwrite(w io.Writer, data string) {
-	_, err := w.Write([]byte(data))
-	exc.Raiseif(err)
-}
-
-func xwait(w interface { Wait() error }) {
-	err := w.Wait()
-	exc.Raiseif(err)
-}
-
-func assertEq(t *testing.T, a, b interface{}) {
-	t.Helper()
-	if !reflect.DeepEqual(a, b) {
-		fmt.Printf("not equal:\nhave: %v\nwant: %v\n", a, b)
-		t.Errorf("not equal:\nhave: %v\nwant: %v", a, b)
-		exc.Raise(0)
-	}
-}
-// ---- 8< ----
-
-// TODO test go-go
-// TODO test go-py
-
-// XXX handshake:
-// - ok,
-// - econnrefused (no such host, port not listening)
-// - network mismatch
-// - invalid request
-
-
-func TestLonet(t *testing.T) {
-	// FIXME ~100% dup from TestPipeNet
-
-	X := exc.Raiseif
-	ctx := context.Background()
-
-	subnet, err := Join(ctx, "")
-	X(err)
-	// XXX defer shutdown/rm this lonet fully?
-
-	xaddr := func(addr string) *Addr {
-		a, err := subnet.parseAddr(addr)
-		X(err)
-		return a
-	}
-
-	hα, err := subnet.NewHost(ctx, "α")
-	X(err)
-
-	hβ, err := subnet.NewHost(ctx, "β")
-	X(err)
-
-	assertEq(t, hα.Network(), subnet.Network())
-	assertEq(t, hβ.Network(), subnet.Network())
-	assertEq(t, hα.Name(), "α")
-	assertEq(t, hβ.Name(), "β")
-
-	l1, err := hα.Listen("")
-	X(err)
-	assertEq(t, l1.Addr(), xaddr("α:1"))
-
-	// zero port always stays unused even after autobind
-	_, err = hα.Dial(ctx, ":0")
-	assertEq(t, err, &net.OpError{Op: "dial", Net: subnet.Network(), Addr: xaddr("α:0"), Err: errConnRefused})
-
-
-	wg := &errgroup.Group{}
-	wg.Go(exc.Funcx(func() {
-		c1s := xaccept(l1)
-		assertEq(t, c1s.LocalAddr(), xaddr("α:2"))
-		assertEq(t, c1s.RemoteAddr(), xaddr("β:1"))
-
-		assertEq(t, xread(c1s), "ping")
-		xwrite(c1s, "pong")
-
-		c2s := xaccept(l1)
-		assertEq(t, c2s.LocalAddr(), xaddr("α:3"))
-		assertEq(t, c2s.RemoteAddr(), xaddr("β:2"))
-
-		assertEq(t, xread(c2s), "hello")
-		xwrite(c2s, "world")
-	}))
-
-	c1c := xdial(hβ, "α:1")
-	assertEq(t, c1c.LocalAddr(), xaddr("β:1"))
-	assertEq(t, c1c.RemoteAddr(), xaddr("α:2"))
-
-	xwrite(c1c, "ping")
-	assertEq(t, xread(c1c), "pong")
-
-	c2c := xdial(hβ, "α:1")
-	assertEq(t, c2c.LocalAddr(), xaddr("β:2"))
-	assertEq(t, c2c.RemoteAddr(), xaddr("α:3"))
-
-	xwrite(c2c, "hello")
-	assertEq(t, xread(c2c), "world")
-
-	xwait(wg)
-
-	l2 := xlisten(hα, ":0") // autobind again
-	assertEq(t, l2.Addr(), xaddr("α:4"))
-}

go/xcommon/xnet/lonet/registry.go

-// Copyright (C) 2018  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-package lonet
-// registry of network hosts.
-
-import (
-	"context"
-	"errors"
-	"fmt"
-)
-
-// registry represents access to lonet network registry.
-//
-// The registry holds information about hosts available on the network, and
-// for each host its OS listening address. Whenever host α needs to establish	XXX dup with lonet.go
-// connection to address on host β, it queries the registry for β and further
-// talks to β on that address. Correspondingly when a host joins the network,
-// it announces itself to the registry so that other hosts could see it.
-//
-// The registry could be implemented in several ways, for example:
-//
-//	- dedicated network server,
-//	- hosts broadcasting information to each other similar to ARP,
-//	- shared memory or file,
-//	- ...
-type registry interface {
-	// XXX + network name?
-
-	// Announce announces host to registry.
-	//
-	// The host is named as hostname on lonet network and is listening for
-	// incoming lonet protocol connections on OS-level osladdr address.
-	//
-	// Returned error, if !nil, is *registryError with .Err describing the
-	// error cause:
-	//
-	//	- errRegistryDown  if registry cannot be accessed,	XXX (and its underlying cause?)
-	//	- errHostDup       if hostname was already announced,
-	//	- some other error indicating e.g. IO problem.
-	Announce(ctx context.Context, hostname, osladdr string) error
-
-	// Query queries registry for host.
-	//
-	// If successful - it returns OS-level network address to connect to
-	// the host via lonet protocol handshake.
-	//
-	// Returned error, if !nil, is *registryError with .Err describing the
-	// error cause:
-	//
-	//	- errRegistryDown  if registry cannot be accessed,	XXX ^^^
-	//	- errNoHost        if hostname was not announced to registry,
-	//	- some other error indicating e.g. IO problem.
-	Query(ctx context.Context, hostname string) (osladdr string, _ error)
-
-	// Close closes access to registry.
-	//
-	// Close interrupts all in-flight Announce and Query requests started
-	// via closing registry connection. Those interrupted requests will
-	// return with errRegistryDown error cause.
-	Close() error
-}
-
-var errRegistryDown = errors.New("registry is down")
-var errNoHost       = errors.New("no such host")
-var errHostDup      = errors.New("host already registered")
-
-// registryError represents an error of a registry operation.
-type registryError struct {
-	// XXX name of the network? - XXX yes
-	Registry string		// name of the registry
-	Op       string		// operation that failed
-	Args     interface{}	// operation arguments, if any
-	Err	 error		// actual error that occurred during the operation
-}
-
-func (e *registryError) Error() string {
-	s := e.Registry + ": " + e.Op
-	if e.Args != nil {
-		s += fmt.Sprintf(" %s", e.Args)
-	}
-	s += ": " + e.Err.Error()
-	return s
-}
-
-func (e *registryError) Cause() error {
-	return e.Err
-}

go/xcommon/xnet/lonet/registry_sqlite.go

-// Copyright (C) 2018  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-package lonet
-// registry implemented as shared SQLite file.
-
-import (
-	"context"
-	"errors"
-	"fmt"
-
-	"crawshaw.io/sqlite"
-	"crawshaw.io/sqlite/sqliteutil"
-
-	"lab.nexedi.com/kirr/go123/xerr"
-)
-
-// registry schema	(keep in sync wrt .setup())
-//
-// hosts:
-//	hostname	text !null PK
-//	osladdr		text !null
-//
-// meta:
-//	name		text !null PK
-//	value		text !null
-//
-// "schemaver"  text	- version of db schema.
-// "network"    text	- name of lonet network this registry serves.
-
-const schemaVer = "lonet.1"
-
-type sqliteRegistry struct {
-	dbpool *sqlite.Pool
-
-	uri    string	// URI db was originally opened with
-}
-
-// openRegistrySQLite opens SQLite registry located at dburi.
-//
-// the registry is setup/verified to be serving specified lonet network.
-func openRegistrySQLite(ctx context.Context, dburi, network string) (_ *sqliteRegistry, err error) {
-	r := &sqliteRegistry{uri: dburi}
-	defer r.regerr(&err, "open")
-
-	dbpool, err := sqlite.Open(dburi, 0, /* poolSize= */16)	// XXX pool size ok?
-	if err != nil {
-		return nil, err
-	}
-
-	r.dbpool = dbpool
-
-	// initialize/check db
-	err = r.setup(ctx, network)
-	if err != nil {
-		r.Close()
-		return nil, err
-	}
-
-	return r, nil
-}
-
-// Close implements registry.
-func (r *sqliteRegistry) Close() (err error) {
-	defer r.regerr(&err, "close")
-	return r.dbpool.Close()
-}
-
-// withConn runs f on a dbpool connection.
-//
-// connection is first allocated from dbpool and put back after call to f.
-func (r *sqliteRegistry) withConn(ctx context.Context, f func(*sqlite.Conn) error) error {
-	conn := r.dbpool.Get(ctx.Done())
-	if conn == nil {
-		// either ctx cancel or dbpool close
-		if ctx.Err() != nil {
-			return ctx.Err()
-		}
-		return errRegistryDown // db closed
-	}
-	defer r.dbpool.Put(conn)
-	return f(conn)
-}
-
-var errNoRows   = errors.New("query: empty result")
-var errManyRows = errors.New("query: multiple results")
-
-// query1 is like sqliteutil.Exec but checks that exactly 1 row is returned.
-//
-// if query results in no rows - errNoRows is returned.
-// if query results in more than 1 row - errManyRows is returned.
-func query1(conn *sqlite.Conn, query string, resultf func(stmt *sqlite.Stmt), argv ...interface{}) error {
-	nrow := 0
-	err := sqliteutil.Exec(conn, query, func(stmt *sqlite.Stmt) error {
-		if nrow == 1 {
-			return errManyRows
-		}
-		nrow++
-		resultf(stmt)
-		return nil
-	}, argv...)
-	if err != nil {
-		return err
-	}
-	if nrow == 0 {
-		return errNoRows
-	}
-	return nil
-}
-
-// setup initializes/checks registry database to be of expected schema and configuration.
-func (r *sqliteRegistry) setup(ctx context.Context, network string) (err error) {
-	defer xerr.Contextf(&err, "setup %q", network)
-
-	return r.withConn(ctx, func(conn *sqlite.Conn) (err error) {
-		// NOTE: keep in sync wrt top-level text.
-		err = sqliteutil.ExecScript(conn, `
-			CREATE TABLE IF NOT EXISTS hosts (
-				hostname	TEXT NON NULL PRIMARY KEY,
-				osladdr		TEXT NON NULL
-			);
-
-			CREATE TABLE IF NOT EXISTS meta (
-				name		TEXT NON NULL PRIMARY KEY,
-				value		TEXT NON NULL
-			);
-		`)
-		if err != nil {
-			return err
-		}
-
-		// do whole checks/init under transaction, so that there is
-		// e.g. no race wrt another process setting config.
-		defer sqliteutil.Save(conn)(&err)
-
-		// check/init schema version
-		ver, err := r.config(conn, "schemaver")
-		if err != nil {
-			return err
-		}
-		if ver == "" {
-			ver = schemaVer
-			err = r.setConfig(conn, "schemaver", ver)
-			if err != nil {
-				return err
-			}
-		}
-		if ver != schemaVer {
-			return fmt.Errorf("schema version mismatch: want %q; have %q", schemaVer, ver)
-		}
-
-		// check/init network name
-		dbnetwork, err := r.config(conn, "network")
-		if err != nil {
-			return err
-		}
-		if dbnetwork == "" {
-			dbnetwork = network
-			err = r.setConfig(conn, "network", dbnetwork)
-			if err != nil {
-				return err
-			}
-		}
-		if dbnetwork != network {
-			return fmt.Errorf("network name mismatch: want %q; have %q", network, dbnetwork)
-		}
-
-
-		return nil
-	})
-}
-
-// config gets one registry configuration value by name.
-//
-// if there is no record corresponding to name - ("", nil) is returned.
-// XXX add ok ret to indicate presence of value?
-func (r *sqliteRegistry) config(conn *sqlite.Conn, name string) (value string, err error) {
-	defer xerr.Contextf(&err, "config: get %q", name)
-
-	err = query1(conn, "SELECT value FROM meta WHERE name = ?", func(stmt *sqlite.Stmt) {
-		value = stmt.ColumnText(0)
-	}, name)
-
-	switch err {
-	case errNoRows:
-		return "", nil
-	case errManyRows:
-		value = ""
-	}
-
-	return value, err
-}
-
-// setConfig sets one registry configuration value by name.
-func (r *sqliteRegistry) setConfig(conn *sqlite.Conn, name, value string) (err error) {
-	defer xerr.Contextf(&err, "config: set %q = %q", name, value)
-
-	err = sqliteutil.Exec(conn,
-		"INSERT OR REPLACE INTO meta (name, value) VALUES (?, ?)", nil,
-		name, value)
-	return err
-}
-
-// Announce implements registry.
-func (r *sqliteRegistry) Announce(ctx context.Context, hostname, osladdr string) (err error) {
-	defer r.regerr(&err, "announce", hostname, osladdr)
-
-	return r.withConn(ctx, func(conn *sqlite.Conn) error {
-		err := sqliteutil.Exec(conn,
-			"INSERT INTO hosts (hostname, osladdr) VALUES (?, ?)", nil,
-			hostname, osladdr)
-
-		switch sqlite.ErrCode(err) {
-		case sqlite.SQLITE_CONSTRAINT_UNIQUE:
-			err = errHostDup
-		}
-
-		return err
-	})
-}
-
-var errRegDup = errors.New("registry broken: duplicate host entries")
-
-// Query implements registry.
-func (r *sqliteRegistry) Query(ctx context.Context, hostname string) (osladdr string, err error) {
-	defer r.regerr(&err, "query", hostname)
-
-	err = r.withConn(ctx, func(conn *sqlite.Conn) error {
-		err := query1(conn, "SELECT osladdr FROM hosts WHERE hostname = ?",
-			func (stmt *sqlite.Stmt) {
-				osladdr = stmt.ColumnText(0)
-			}, hostname)
-
-		switch err {
-		case errNoRows:
-			return errNoHost
-
-		case errManyRows:
-			// hostname is PK - we should not get several results
-			osladdr = ""
-			return errRegDup
-		}
-
-		return err
-	})
-
-	return osladdr, err
-}
-
-// regerr is syntactic sugar to wrap !nil *errp into registryError.
-//
-// intended too be used like
-//
-//	defer r.regerr(&err, "operation", arg1, arg2, ...)
-func (r *sqliteRegistry) regerr(errp *error, op string, args ...interface{}) {
-	if *errp == nil {
-		return
-	}
-
-	// XXX name of the network
-	*errp = &registryError{
-		Registry: r.uri,
-		Op:       op,
-		Args:     args,
-		Err:      *errp,
-	}
-}

go/xcommon/xnet/lonet/registry_sqlite_test.go

-// Copyright (C) 2018  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-package lonet
-
-import (
-	"context"
-	"fmt"
-	"io/ioutil"
-	"os"
-	"testing"
-
-	"lab.nexedi.com/kirr/go123/exc"
-)
-
-func TestRegistrySQLite(t *testing.T) {
-	X := exc.Raiseif
-
-	work, err := ioutil.TempDir("", "t-registry-sqlite")
-	X(err)
-	defer os.RemoveAll(work)
-
-	dbpath := work + "/1.db"
-
-	ctx := context.Background()
-
-	r, err := openRegistrySQLite(ctx, dbpath, "aaa")
-	X(err)
-
-	// query checks that result of Query(hostname) is as expected.
-	//
-	// if expect is error - it checks that Query returns error with cause == expect.
-	// otherwise expect must be string and it will check that Query
-	// succeeds and returns osladdr == expect.
-	query := func(r *sqliteRegistry, hostname string, expect interface{}) {
-		// XXX ^^^ -> `r registry` (needs .Network() to get network name) ?
-		t.Helper()
-
-		osladdr, err := r.Query(ctx, hostname)
-		if ewant, iserr := expect.(error); iserr {
-			// error expected
-			// XXX construct full registry error around ewant + reflect.DeepCompare?
-			e, ok := err.(*registryError)
-			if !(ok && e.Err == ewant && osladdr == "") {
-				t.Fatalf("%s: query %q:\nwant: \"\", %v\nhave: %q, %v",
-					r.uri, hostname, ewant, osladdr, err)
-			}
-		} else {
-			// !error expected
-			laddr := expect.(string)
-			if !(osladdr == laddr && err == nil) {
-				t.Fatalf("%s: query %q:\nwant: %q, nil\nhave: %q, %v",
-					r.uri, hostname, laddr, osladdr, err)
-			}
-		}
-	}
-
-	// announce checks that result of Announce(hostname, osladdr) is as expected.
-	//
-	// if len(errv) == 1 - it checks that Announce returns error with cause == errv[0].
-	// otherwise it will check that Announce succeeds and returns nil error.
-	announce := func(r *sqliteRegistry, hostname, osladdr string, errv ...error) {
-		t.Helper()
-		err := r.Announce(ctx, hostname, osladdr)
-		var ewant error
-		if len(errv) > 0 {
-			ewant = errv[0]
-			if len(errv) > 1 {
-				panic("only 1 error allowed in announce check")
-			}
-		}
-		if ewant != nil {
-			// error expected
-			// XXX construct full registry error around ewant + reflect.DeepCompare?
-			e, ok := err.(*registryError)
-			if (!ok && e.Err == ewant) {
-				t.Fatalf("%s: announce %q %q:\nwant %v\nhave: %v",
-					r.uri, hostname, osladdr, ewant, err)
-			}
-		} else {
-			// !error expected
-			if err != nil {
-				t.Fatalf("%s: announce %q %q: %s", r.uri, hostname, osladdr, err)
-			}
-		}
-	}
-
-
-
-	ø := errNoHost
-
-	// r.Network() == ...
-	query(r, "α", ø)
-	announce(r, "α", "alpha:1234")
-	announce(r, "α", "alpha:1234", errHostDup)
-	announce(r, "α", "alpha:1235", errHostDup)
-	query(r, "α", "alpha:1234")
-	query(r, "β", ø)
-
-	r2, err := openRegistrySQLite(ctx, dbpath, "aaa")
-	// r2.Network() == ...
-	query(r2, "α", "alpha:1234")
-	query(r2, "β", ø)
-	announce(r2, "β", "beta:zzz")
-	query(r2, "β", "beta:zzz")
-
-	query(r, "β", "beta:zzz")
-
-	X(r.Close())
-
-	query(r, "α", errRegistryDown)
-	query(r, "β", errRegistryDown)
-	announce(r, "γ", "gamma:qqq", errRegistryDown)
-	query(r, "γ", errRegistryDown)
-
-	query(r2, "α", "alpha:1234")
-
-	X(r2.Close())
-
-	query(r2, "α", errRegistryDown)
-
-
-	// verify network mismatch detection works
-	r3, err := openRegistrySQLite(ctx, dbpath, "bbb")
-	if !(r3 == nil && err != nil) {
-		t.Fatalf("network mismatch: not detected")
-	}
-	errWant := fmt.Sprintf(`%s: open []: setup "bbb": network name mismatch: want "bbb"; have "aaa"`, dbpath)
-	if err.Error() != errWant {
-		t.Fatalf("network mismatch: error:\nhave: %q\nwant: %q", err.Error(), errWant)
-	}
-}