machine-db/appengine/model/ips.go - infra/luci/luci-go - Git at Google

 // Copyright 2018 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package model

 import (
 	"context"

 	"go.chromium.org/luci/common/errors"
 	"go.chromium.org/luci/common/logging"

 	"go.chromium.org/luci/machine-db/api/config/v1"
 	"go.chromium.org/luci/machine-db/appengine/database"
 	"go.chromium.org/luci/machine-db/common"
 )

 // IP represents a row in the ips table.
 type IP struct {
 	Id     int64
 	IPv4   common.IPv4
 	VLANId int64
 }

 // IPsTable represents the table of IP addresses in the database.
 type IPsTable struct {
 	// current is the slice of IP addresses in the database.
 	current []*IP

 	// additions is a slice of IP addresses pending addition to the database.
 	additions []*IP
 	// removals is a slice of IP addresses pending removal from the database.
 	removals []*IP
 	// updates is a slice of IP addresses pending update in the database.
 	updates []*IP
 }

 // fetch fetches the IP addresses from the database.
 func (t *IPsTable) fetch(c context.Context) error {
 	db := database.Get(c)
 	rows, err := db.QueryContext(c, `
 		SELECT id, ipv4, vlan_id
 		FROM ips
 	`)
 	if err != nil {
 		return errors.Annotate(err, "failed to select IP addresses").Err()
 	}
 	defer rows.Close()
 	for rows.Next() {
 		ip := &IP{}
 		if err := rows.Scan(&ip.Id, &ip.IPv4, &ip.VLANId); err != nil {
 			return errors.Annotate(err, "failed to scan IP address").Err()
 		}
 		t.current = append(t.current, ip)
 	}
 	return nil
 }

 // needsUpdate returns true if the given row needs to be updated to match the given config.
 func (*IPsTable) needsUpdate(row, cfg *IP) bool {
 	return row.VLANId != cfg.VLANId
 }

 // computeChanges computes the changes that need to be made to the IP addresses in the database.
 func (t *IPsTable) computeChanges(c context.Context, vlans []*config.VLAN) error {
 	cfgs := make(map[common.IPv4]*IP, len(vlans))
 	for _, vlan := range vlans {
 		ipv4, length, err := common.IPv4Range(vlan.CidrBlock)
 		if err != nil {
 			return errors.Annotate(err, "failed to determine start address and range for CIDR block %q", vlan.CidrBlock).Err()
 		}
 		// TODO(smut): Mark the first address as the network address and the last address as the broadcast address.
 		for i := int64(0); i < length; i++ {
 			cfgs[ipv4] = &IP{
 				IPv4:   ipv4,
 				VLANId: vlan.Id,
 			}
 			ipv4++
 		}
 	}

 	for _, ip := range t.current {
 		if cfg, ok := cfgs[ip.IPv4]; ok {
 			// IP address found in the config.
 			if t.needsUpdate(ip, cfg) {
 				// IP address doesn't match the config.
 				cfg.Id = ip.Id
 				t.updates = append(t.updates, cfg)
 			}
 			// Record that the IP address config has been seen.
 			delete(cfgs, cfg.IPv4)
 		} else {
 			// IP address not found in the config.
 			t.removals = append(t.removals, ip)
 		}
 	}

 	// IP addresses remaining in the map are present in the config but not the database.
 	// Iterate deterministically over the slices to determine which IP addresses need to be added.
 	for _, vlan := range vlans {
 		ipv4, length, err := common.IPv4Range(vlan.CidrBlock)
 		if err != nil {
 			return errors.Annotate(err, "failed to determine start address and range for CIDR block %q", vlan.CidrBlock).Err()
 		}
 		for i := int64(0); i < length; i++ {
 			if ip, ok := cfgs[ipv4]; ok {
 				t.additions = append(t.additions, ip)
 			}
 			ipv4++
 		}
 	}
 	return nil
 }

 // add adds all IP addresses pending addition to the database, clearing pending additions.
 // No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
 func (t *IPsTable) add(c context.Context) error {
 	// Avoid using the database connection to prepare unnecessary statements.
 	if len(t.additions) == 0 {
 		return nil
 	}

 	db := database.Get(c)
 	stmt, err := db.PrepareContext(c, `
 		INSERT INTO ips (ipv4, vlan_id)
 		VALUES (?, ?)
 	`)
 	if err != nil {
 		return errors.Annotate(err, "failed to prepare statement").Err()
 	}
 	defer stmt.Close()

 	// Add each IP address to the database, and update the slice of IP address with each addition.
 	// TODO(smut): Batch SQL operations if it becomes necessary.
 	logging.Infof(c, "Attempting to add %d IP addresses", len(t.additions))
 	for len(t.additions) > 0 {
 		ip := t.additions[0]
 		result, err := stmt.ExecContext(c, ip.IPv4, ip.VLANId)
 		if err != nil {
 			return errors.Annotate(err, "failed to add IP address %q", ip.IPv4).Err()
 		}
 		t.current = append(t.current, ip)
 		t.additions = t.additions[1:]
 		logging.Infof(c, "Added IP address %q", ip.IPv4)
 		ip.Id, err = result.LastInsertId()
 		if err != nil {
 			return errors.Annotate(err, "failed to get IP address ID %q", ip.IPv4).Err()
 		}
 	}
 	return nil
 }

 // remove removes all IP addresses pending removal from the database, clearing pending removals.
 // No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
 func (t *IPsTable) remove(c context.Context) error {
 	// Avoid using the database connection to prepare unnecessary statements.
 	if len(t.removals) == 0 {
 		return nil
 	}

 	db := database.Get(c)
 	stmt, err := db.PrepareContext(c, `
 		DELETE FROM ips
 		WHERE id = ?
 	`)
 	if err != nil {
 		return errors.Annotate(err, "failed to prepare statement").Err()
 	}
 	defer stmt.Close()

 	// Remove each IP address from the table. It's more efficient to update the slice of
 	// IP addresses once at the end rather than for each removal, so use a defer.
 	removed := make(map[int64]struct{}, len(t.removals))
 	defer func() {
 		var ips []*IP
 		for _, ip := range t.current {
 			if _, ok := removed[ip.Id]; !ok {
 				ips = append(ips, ip)
 			}
 		}
 		t.current = ips
 	}()
 	for len(t.removals) > 0 {
 		ip := t.removals[0]
 		if _, err := stmt.ExecContext(c, ip.Id); err != nil {
 			// Defer ensures the slice of IP addresses is updated even if we exit early.
 			return errors.Annotate(err, "failed to remove IP address %q", ip.IPv4).Err()
 		}
 		removed[ip.Id] = struct{}{}
 		t.removals = t.removals[1:]
 		logging.Infof(c, "Removed IP address %q", ip.IPv4)
 	}
 	return nil
 }

 // update updates all IP addresses pending update in the database, clearing pending updates.
 // No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
 func (t *IPsTable) update(c context.Context) error {
 	// Avoid using the database connection to prepare unnecessary statements.
 	if len(t.updates) == 0 {
 		return nil
 	}

 	db := database.Get(c)
 	stmt, err := db.PrepareContext(c, `
 		UPDATE ips
 		SET vlan_id = ?
 		WHERE id = ?
 	`)
 	if err != nil {
 		return errors.Annotate(err, "failed to prepare statement").Err()
 	}
 	defer stmt.Close()

 	// Update each IP address in the table. It's more efficient to update the slice of
 	// IP addresses once at the end rather than for each update, so use a defer.
 	updated := make(map[int64]*IP, len(t.updates))
 	defer func() {
 		for _, ip := range t.current {
 			if u, ok := updated[ip.Id]; ok {
 				ip.VLANId = u.VLANId
 			}
 		}
 	}()
 	for len(t.updates) > 0 {
 		ip := t.updates[0]
 		if _, err := stmt.ExecContext(c, ip.VLANId, ip.Id); err != nil {
 			return errors.Annotate(err, "failed to update IP address %q", ip.IPv4).Err()
 		}
 		updated[ip.Id] = ip
 		t.updates = t.updates[1:]
 		logging.Infof(c, "Updated IP address %q", ip.IPv4)
 	}
 	return nil
 }

 // ids returns a map of IP addresses to IDs.
 func (t *IPsTable) ids(c context.Context) map[common.IPv4]int64 {
 	ips := make(map[common.IPv4]int64, len(t.current))
 	for _, ip := range t.current {
 		ips[ip.IPv4] = ip.Id
 	}
 	return ips
 }

 // EnsureIPs ensures the database contains exactly the given IP addresses.
 func EnsureIPs(c context.Context, cfgs []*config.VLAN) error {
 	t := &IPsTable{}
 	if err := t.fetch(c); err != nil {
 		return errors.Annotate(err, "failed to fetch IP addresses").Err()
 	}
 	if err := t.computeChanges(c, cfgs); err != nil {
 		return errors.Annotate(err, "failed to compute changes").Err()
 	}
 	if err := t.add(c); err != nil {
 		return errors.Annotate(err, "failed to add IP addresses").Err()
 	}
 	if err := t.remove(c); err != nil {
 		return errors.Annotate(err, "failed to remove IP addresses").Err()
 	}
 	if err := t.update(c); err != nil {
 		return errors.Annotate(err, "failed to update IP addresses").Err()
 	}
 	return nil
 }
	// Copyright 2018 The LUCI Authors.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package model

	import (
	"context"

	"go.chromium.org/luci/common/errors"
	"go.chromium.org/luci/common/logging"

	"go.chromium.org/luci/machine-db/api/config/v1"
	"go.chromium.org/luci/machine-db/appengine/database"
	"go.chromium.org/luci/machine-db/common"
	)

	// IP represents a row in the ips table.
	type IP struct {
	Id int64
	IPv4 common.IPv4
	VLANId int64
	}

	// IPsTable represents the table of IP addresses in the database.
	type IPsTable struct {
	// current is the slice of IP addresses in the database.
	current []*IP

	// additions is a slice of IP addresses pending addition to the database.
	additions []*IP
	// removals is a slice of IP addresses pending removal from the database.
	removals []*IP
	// updates is a slice of IP addresses pending update in the database.
	updates []*IP
	}

	// fetch fetches the IP addresses from the database.
	func (t *IPsTable) fetch(c context.Context) error {
	db := database.Get(c)
	rows, err := db.QueryContext(c, `
	SELECT id, ipv4, vlan_id
	FROM ips
	`)
	if err != nil {
	return errors.Annotate(err, "failed to select IP addresses").Err()
	}
	defer rows.Close()
	for rows.Next() {
	ip := &IP{}
	if err := rows.Scan(&ip.Id, &ip.IPv4, &ip.VLANId); err != nil {
	return errors.Annotate(err, "failed to scan IP address").Err()
	}
	t.current = append(t.current, ip)
	}
	return nil
	}

	// needsUpdate returns true if the given row needs to be updated to match the given config.
	func (IPsTable) needsUpdate(row, cfg IP) bool {
	return row.VLANId != cfg.VLANId
	}

	// computeChanges computes the changes that need to be made to the IP addresses in the database.
	func (t IPsTable) computeChanges(c context.Context, vlans []config.VLAN) error {
	cfgs := make(map[common.IPv4]*IP, len(vlans))
	for _, vlan := range vlans {
	ipv4, length, err := common.IPv4Range(vlan.CidrBlock)
	if err != nil {
	return errors.Annotate(err, "failed to determine start address and range for CIDR block %q", vlan.CidrBlock).Err()
	}
	// TODO(smut): Mark the first address as the network address and the last address as the broadcast address.
	for i := int64(0); i < length; i++ {
	cfgs[ipv4] = &IP{
	IPv4: ipv4,
	VLANId: vlan.Id,
	}
	ipv4++
	}
	}

	for _, ip := range t.current {
	if cfg, ok := cfgs[ip.IPv4]; ok {
	// IP address found in the config.
	if t.needsUpdate(ip, cfg) {
	// IP address doesn't match the config.
	cfg.Id = ip.Id
	t.updates = append(t.updates, cfg)
	}
	// Record that the IP address config has been seen.
	delete(cfgs, cfg.IPv4)
	} else {
	// IP address not found in the config.
	t.removals = append(t.removals, ip)
	}
	}

	// IP addresses remaining in the map are present in the config but not the database.
	// Iterate deterministically over the slices to determine which IP addresses need to be added.
	for _, vlan := range vlans {
	ipv4, length, err := common.IPv4Range(vlan.CidrBlock)
	if err != nil {
	return errors.Annotate(err, "failed to determine start address and range for CIDR block %q", vlan.CidrBlock).Err()
	}
	for i := int64(0); i < length; i++ {
	if ip, ok := cfgs[ipv4]; ok {
	t.additions = append(t.additions, ip)
	}
	ipv4++
	}
	}
	return nil
	}

	// add adds all IP addresses pending addition to the database, clearing pending additions.
	// No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
	func (t *IPsTable) add(c context.Context) error {
	// Avoid using the database connection to prepare unnecessary statements.
	if len(t.additions) == 0 {
	return nil
	}

	db := database.Get(c)
	stmt, err := db.PrepareContext(c, `
	INSERT INTO ips (ipv4, vlan_id)
	VALUES (?, ?)
	`)
	if err != nil {
	return errors.Annotate(err, "failed to prepare statement").Err()
	}
	defer stmt.Close()

	// Add each IP address to the database, and update the slice of IP address with each addition.
	// TODO(smut): Batch SQL operations if it becomes necessary.
	logging.Infof(c, "Attempting to add %d IP addresses", len(t.additions))
	for len(t.additions) > 0 {
	ip := t.additions[0]
	result, err := stmt.ExecContext(c, ip.IPv4, ip.VLANId)
	if err != nil {
	return errors.Annotate(err, "failed to add IP address %q", ip.IPv4).Err()
	}
	t.current = append(t.current, ip)
	t.additions = t.additions[1:]
	logging.Infof(c, "Added IP address %q", ip.IPv4)
	ip.Id, err = result.LastInsertId()
	if err != nil {
	return errors.Annotate(err, "failed to get IP address ID %q", ip.IPv4).Err()
	}
	}
	return nil
	}

	// remove removes all IP addresses pending removal from the database, clearing pending removals.
	// No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
	func (t *IPsTable) remove(c context.Context) error {
	// Avoid using the database connection to prepare unnecessary statements.
	if len(t.removals) == 0 {
	return nil
	}

	db := database.Get(c)
	stmt, err := db.PrepareContext(c, `
	DELETE FROM ips
	WHERE id = ?
	`)
	if err != nil {
	return errors.Annotate(err, "failed to prepare statement").Err()
	}
	defer stmt.Close()

	// Remove each IP address from the table. It's more efficient to update the slice of
	// IP addresses once at the end rather than for each removal, so use a defer.
	removed := make(map[int64]struct{}, len(t.removals))
	defer func() {
	var ips []*IP
	for _, ip := range t.current {
	if _, ok := removed[ip.Id]; !ok {
	ips = append(ips, ip)
	}
	}
	t.current = ips
	}()
	for len(t.removals) > 0 {
	ip := t.removals[0]
	if _, err := stmt.ExecContext(c, ip.Id); err != nil {
	// Defer ensures the slice of IP addresses is updated even if we exit early.
	return errors.Annotate(err, "failed to remove IP address %q", ip.IPv4).Err()
	}
	removed[ip.Id] = struct{}{}
	t.removals = t.removals[1:]
	logging.Infof(c, "Removed IP address %q", ip.IPv4)
	}
	return nil
	}

	// update updates all IP addresses pending update in the database, clearing pending updates.
	// No-op unless computeChanges was called first. Idempotent until computeChanges is called again.
	func (t *IPsTable) update(c context.Context) error {
	// Avoid using the database connection to prepare unnecessary statements.
	if len(t.updates) == 0 {
	return nil
	}

	db := database.Get(c)
	stmt, err := db.PrepareContext(c, `
	UPDATE ips
	SET vlan_id = ?
	WHERE id = ?
	`)
	if err != nil {
	return errors.Annotate(err, "failed to prepare statement").Err()
	}
	defer stmt.Close()

	// Update each IP address in the table. It's more efficient to update the slice of
	// IP addresses once at the end rather than for each update, so use a defer.
	updated := make(map[int64]*IP, len(t.updates))
	defer func() {
	for _, ip := range t.current {
	if u, ok := updated[ip.Id]; ok {
	ip.VLANId = u.VLANId
	}
	}
	}()
	for len(t.updates) > 0 {
	ip := t.updates[0]
	if _, err := stmt.ExecContext(c, ip.VLANId, ip.Id); err != nil {
	return errors.Annotate(err, "failed to update IP address %q", ip.IPv4).Err()
	}
	updated[ip.Id] = ip
	t.updates = t.updates[1:]
	logging.Infof(c, "Updated IP address %q", ip.IPv4)
	}
	return nil
	}

	// ids returns a map of IP addresses to IDs.
	func (t *IPsTable) ids(c context.Context) map[common.IPv4]int64 {
	ips := make(map[common.IPv4]int64, len(t.current))
	for _, ip := range t.current {
	ips[ip.IPv4] = ip.Id
	}
	return ips
	}

	// EnsureIPs ensures the database contains exactly the given IP addresses.
	func EnsureIPs(c context.Context, cfgs []*config.VLAN) error {
	t := &IPsTable{}
	if err := t.fetch(c); err != nil {
	return errors.Annotate(err, "failed to fetch IP addresses").Err()
	}
	if err := t.computeChanges(c, cfgs); err != nil {
	return errors.Annotate(err, "failed to compute changes").Err()
	}
	if err := t.add(c); err != nil {
	return errors.Annotate(err, "failed to add IP addresses").Err()
	}
	if err := t.remove(c); err != nil {
	return errors.Annotate(err, "failed to remove IP addresses").Err()
	}
	if err := t.update(c); err != nil {
	return errors.Annotate(err, "failed to update IP addresses").Err()
	}
	return nil
	}