http-boot-config/config/remote/remote.go

package remote

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"time"

	"git.faercol.me/faercol/http-boot-config/config/logger"
	"github.com/google/uuid"
)

var ErrNotEnrolled = errors.New("client not enrolled")

const getBootRoute = "/config"
const reqTimeout = 5 * time.Second

type clientConfig struct {
	EFIConfig struct {
		ID      string `json:"ID"`
		Name    string `json:"name"`
		Options map[string]struct {
			Name   string `json:"name"`
			Path   string `json:"path"`
			DiskID string `json:"disk_id"`
		} `json:"options"`
		SelectedOption string `json:"selected_option"`
	} `json:"efi_config"`
	NetConfig struct {
		MulticastGroup string `json:"multicast_group"`
		Port           int    `json:"port"`
	} `json:"net_config"`
}

func getRemoteConfig(ctx context.Context, host string, id uuid.UUID, l *logger.SimpleLogger) ([]byte, error) {
	subCtx, cancel := context.WithTimeout(ctx, reqTimeout)
	defer cancel()
	req, err := http.NewRequestWithContext(subCtx, http.MethodGet, host+getBootRoute, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}
	q := req.URL.Query()
	q.Add("id", id.String())
	req.URL.RawQuery = q.Encode()

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to query server: %w", err)
	}

	switch resp.StatusCode {
	case http.StatusBadRequest:
		return nil, fmt.Errorf("invalid UUID")
	case http.StatusNotFound:
		return nil, ErrNotEnrolled
	case http.StatusOK:
		dat, err := io.ReadAll(resp.Body)
		if err != nil {
			return nil, fmt.Errorf("failed to read response: %w", err)
		}
		return dat, nil
	default:
		return nil, fmt.Errorf("unexpected server error (%d)", resp.StatusCode)
	}
}

func DisplayRemoteConfigJSON(ctx context.Context, host string, id uuid.UUID, l *logger.SimpleLogger) error {
	dat, err := getRemoteConfig(ctx, host, id, l)
	if err != nil {
		return err
	}

	// We want to prettify the output for the user
	buf := bytes.NewBuffer(nil)
	if err := json.Indent(buf, dat, "", "  "); err != nil {
		return fmt.Errorf("failed to format result: %w", err)
	}

	l.Info(buf.String())
	return nil
}

func DisplayRemoteConfigPretty(ctx context.Context, host string, id uuid.UUID, l *logger.SimpleLogger) error {
	dat, err := getRemoteConfig(ctx, host, id, l)
	if err != nil {
		return err
	}

	var parsedConf clientConfig
	if err := json.Unmarshal(dat, &parsedConf); err != nil {
		return fmt.Errorf("invalid JSON format for result: %w", err)
	}

	l.Infof("Got the following config for client %s:", parsedConf.EFIConfig.Name)
	selectedOption, ok := parsedConf.EFIConfig.Options[parsedConf.EFIConfig.SelectedOption]
	if !ok {
		l.Info(" * No selected boot option for client")
	} else {
		l.Infof(" * Client is set to boot to %s", selectedOption.Name)
	}
	l.Info(" * Available options are:")
	for _, option := range parsedConf.EFIConfig.Options {
		l.Infof("\t - %s: %s (disk id %s)", option.Name, option.Path, option.DiskID)
	}
	l.Infof(" * Remote boot server is listening on %s:%d", parsedConf.NetConfig.MulticastGroup, parsedConf.NetConfig.Port)

	return nil
}