isle/go/cmd/entrypoint/hosts.go

package main

import (
	"isle/bootstrap"
	"errors"
	"fmt"
	"os"
	"regexp"
	"sort"

	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
	"gopkg.in/yaml.v3"
)

var hostNameRegexp = regexp.MustCompile(`^[a-z][a-z0-9\-]*$`)

func validateHostName(name string) error {

	if !hostNameRegexp.MatchString(name) {
		return errors.New("a host's name must start with a letter and only contain letters, numbers, and dashes")
	}

	return nil
}

var subCmdHostsList = subCmd{
	name:      "list",
	descr:     "Lists all hosts in the network, and their IPs",
	checkLock: true,
	do: func(subCmdCtx subCmdCtx) error {

		flags := subCmdCtx.flagSet(false)

		logLevelStr := flags.StringP(
			"log-level", "l", "info",
			`Maximum log level which should be output. Values can be "debug", "info", "warn", "error", "fatal". Does not apply to sub-processes`,
		)

		if err := flags.Parse(subCmdCtx.args); err != nil {
			return fmt.Errorf("parsing flags: %w", err)
		}

		ctx := subCmdCtx.ctx

		logLevel := mlog.LevelFromString(*logLevelStr)
		if logLevel == nil {
			return fmt.Errorf("couldn't parse log level %q", *logLevelStr)
		}

		logger := subCmdCtx.logger.WithMaxLevel(logLevel.Int())

		hostBootstrap, err := loadHostBootstrap()
		if err != nil {
			return fmt.Errorf("loading host bootstrap: %w", err)
		}

		hostsMap, err := hostBootstrap.GetGarageBootstrapHosts(ctx, logger)
		if err != nil {
			return fmt.Errorf("retrieving hosts from garage: %w", err)
		}

		type host struct {
			Name   string `yaml:"name"`
			Nebula struct {
				IP string `yaml:"ip"`
			} `yaml:"nebula"`
			Garage bootstrap.GarageHost `yaml:"garage,omitempty"`
		}

		hosts := make([]host, 0, len(hostsMap))
		for _, h := range hostsMap {

			host := host{
				Name:   h.Name,
				Garage: h.Garage,
			}

			host.Nebula.IP = h.IP().String()

			hosts = append(hosts, host)
		}

		sort.Slice(hosts, func(i, j int) bool { return hosts[i].Name < hosts[j].Name })

		return yaml.NewEncoder(os.Stdout).Encode(hosts)
	},
}

var subCmdHostsDelete = subCmd{
	name:      "delete",
	descr:     "Deletes a host from the network",
	checkLock: true,
	do: func(subCmdCtx subCmdCtx) error {

		flags := subCmdCtx.flagSet(false)

		hostName := flags.StringP(
			"hostname", "h", "",
			"Name of the host to delete",
		)

		if err := flags.Parse(subCmdCtx.args); err != nil {
			return fmt.Errorf("parsing flags: %w", err)
		}

		if *hostName == "" {
			return errors.New("--hostname is required")
		}

		hostBootstrap, err := loadHostBootstrap()
		if err != nil {
			return fmt.Errorf("loading host bootstrap: %w", err)
		}

		client := hostBootstrap.GlobalBucketS3APIClient()

		return bootstrap.RemoveGarageBootstrapHost(subCmdCtx.ctx, client, *hostName)
	},
}

var subCmdHosts = subCmd{
	name:  "hosts",
	descr: "Sub-commands having to do with configuration of hosts in the network",
	do: func(subCmdCtx subCmdCtx) error {
		return subCmdCtx.doSubCmd(
			subCmdHostsDelete,
			subCmdHostsList,
		)
	},
}