config.go

// Copyright 2018 ETH Zurich
// Copyright 2020 ETH Zurich, Anapaya Systems
//
// 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 config contains the configuration of the SCION dispatcher.
package config

import (
	"context"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"regexp"

	"github.com/scionproto/scion/pkg/addr"
	"github.com/scionproto/scion/pkg/log"
	"github.com/scionproto/scion/pkg/private/serrors"
	"github.com/scionproto/scion/private/app"
	"github.com/scionproto/scion/private/config"
	"github.com/scionproto/scion/private/env"
	api "github.com/scionproto/scion/private/mgmtapi"
	"github.com/scionproto/scion/private/topology"
)

var _ config.Config = (*Config)(nil)

var pattern = "^AS([0-9a-fA-F]{1,4})[_]([0-9a-fA-F]{1,4})[_]([0-9a-fA-F]{1,4})$"

type Config struct {
	Features   env.Features `toml:"features,omitempty"`
	Logging    log.Config   `toml:"log,omitempty"`
	Metrics    env.Metrics  `toml:"metrics,omitempty"`
	API        api.Config   `toml:"api,omitempty"`
	Dispatcher Dispatcher   `toml:"dispatcher,omitempty"`
}

// Dispatcher contains the dispatcher specific config.
type Dispatcher struct {
	config.NoDefaulter
	// ID is the SCION element ID. This is used to choose the relevant
	// portion of the topology file for some services.
	ID string `toml:"id,omitempty"`
	// ConfigDir for loading extra files (currently, only topology.json and staticInfoConfig.json)
	ConfigDir string `toml:"config_dir,omitempty"`
	// UnderlayPort is the native port opened by the dispatcher (default 30041)
	UnderlayPort int `toml:"underlay_port,omitempty"`
}

func (cfg *Dispatcher) Validate() error {
	if cfg.UnderlayPort == 0 {
		cfg.UnderlayPort = topology.EndhostPort
	}
	if cfg.ID == "" {
		return serrors.New("id must be set")
	}
	return nil
}

func (cfg *Dispatcher) Sample(dst io.Writer, path config.Path, ctx config.CtxMap) {
	config.WriteString(dst, fmt.Sprintf(dispSample, idSample))
}

func (cfg *Dispatcher) ConfigName() string {
	return "dispatcher"
}

func (cfg *Config) InitDefaults() {
	config.InitAll(
		&cfg.Features,
		&cfg.Logging,
		&cfg.Metrics,
		&cfg.API,
		&cfg.Dispatcher,
	)
}

func (cfg *Config) Validate() error {
	return config.ValidateAll(
		&cfg.Features,
		&cfg.Logging,
		&cfg.Metrics,
		&cfg.API,
		&cfg.Dispatcher,
	)
}

func (cfg *Config) Sample(dst io.Writer, path config.Path, _ config.CtxMap) {
	config.WriteSample(dst, path, config.CtxMap{config.ID: idSample},
		&cfg.Features,
		&cfg.Logging,
		&cfg.Metrics,
		&cfg.API,
		&cfg.Dispatcher,
	)
}

func (cfg *Config) ConfigName() string {
	return "dispatcher_config"
}

func (cfg *Config) Topolgies(ctx context.Context) (map[addr.AS]*topology.Loader, error) {
	entries, err := os.ReadDir(cfg.Dispatcher.ConfigDir)
	if err != nil {
		return nil, err
	}
	topologies := make(map[addr.AS]*topology.Loader)
	for _, e := range entries {
		var path string
		if e.Type().IsDir() && regexp.MustCompile(pattern).FindSubmatch([]byte(e.Name())) != nil {
			path = filepath.Join(cfg.Dispatcher.ConfigDir, e.Name(), env.TopologyFile)
		}
		if e.Type().IsRegular() && e.Name() == env.TopologyFile {
			path = filepath.Join(cfg.Dispatcher.ConfigDir, env.TopologyFile)
		}
		if path != "" {
			topo, err := topology.NewLoader(topology.LoaderCfg{
				File:   path,
				Reload: app.SIGHUPChannel(ctx),
			})
			if err != nil {
				log.Error("loading topologies", "err", err)
				continue
			}
			topologies[topo.IA().AS()] = topo
		}
	}
	if len(topologies) == 0 {
		return nil, serrors.New("No topologies load!")
	}
	return topologies, nil
}