feat: initial commit

This commit is contained in:
2023-02-02 10:55:24 +01:00
commit 088b6843a9
92 changed files with 7300 additions and 0 deletions

71
internal/agent/agent.go Normal file
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package agent
import (
"context"
"time"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
type Agent struct {
controllers []Controller
interval time.Duration
}
func (a *Agent) Run(ctx context.Context) error {
state := NewState()
logger.Info(ctx, "starting reconciliation ticker", logger.F("interval", a.interval))
ticker := time.NewTicker(a.interval)
defer ticker.Stop()
for {
select {
case <-ticker.C:
logger.Debug(ctx, "state before reconciliation", logger.F("state", state))
if err := a.Reconcile(ctx, state); err != nil {
logger.Error(ctx, "could not reconcile node with state", logger.E(errors.WithStack(err)))
continue
}
logger.Debug(ctx, "state after reconciliation", logger.F("state", state))
case <-ctx.Done():
return errors.WithStack(ctx.Err())
}
}
}
func (a *Agent) Reconcile(ctx context.Context, state *State) error {
for _, ctrl := range a.controllers {
ctrlCtx := logger.With(ctx, logger.F("controller", ctrl.Name()))
logger.Debug(
ctrlCtx, "executing controller",
logger.F("state", state),
)
if err := ctrl.Reconcile(ctrlCtx, state); err != nil {
return errors.WithStack(err)
}
}
return nil
}
func New(funcs ...OptionFunc) *Agent {
opt := defaultOption()
for _, fn := range funcs {
fn(opt)
}
return &Agent{
controllers: opt.Controllers,
interval: opt.Interval,
}
}

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package agent
import "context"
type Controller interface {
Name() string
Reconcile(ctx context.Context, state *State) error
}

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package gateway
import (
"context"
"forge.cadoles.com/Cadoles/emissary/internal/agent"
"forge.cadoles.com/Cadoles/emissary/internal/spec"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
type Controller struct {
proxies map[spec.GatewayID]*ReverseProxy
currentSpecRevision int
}
// Name implements node.Controller.
func (c *Controller) Name() string {
return "gateway-controller"
}
// Reconcile implements node.Controller.
func (c *Controller) Reconcile(ctx context.Context, state *agent.State) error {
gatewaySpec := spec.NewGatewaySpec()
if err := state.GetSpec(spec.NameGateway, gatewaySpec); err != nil {
if errors.Is(err, agent.ErrSpecNotFound) {
logger.Info(ctx, "could not find gateway spec, stopping all remaining proxies")
c.stopAllProxies(ctx)
return nil
}
return errors.WithStack(err)
}
logger.Info(ctx, "retrieved spec", logger.F("spec", gatewaySpec.SpecName()), logger.F("revision", gatewaySpec.SpecRevision()))
if c.currentSpecRevision == gatewaySpec.SpecRevision() {
logger.Info(ctx, "spec revision did not change, doing nothing")
return nil
}
c.updateProxies(ctx, gatewaySpec)
c.currentSpecRevision = gatewaySpec.SpecRevision()
logger.Info(ctx, "updating current spec revision", logger.F("revision", c.currentSpecRevision))
return nil
}
func (c *Controller) stopAllProxies(ctx context.Context) {
for gatewayID, proxy := range c.proxies {
logger.Info(ctx, "stopping proxy", logger.F("gatewayID", gatewayID))
if err := proxy.Stop(); err != nil {
logger.Error(
ctx, "error while stopping proxy",
logger.F("gatewayID", gatewayID),
logger.E(errors.WithStack(err)),
)
delete(c.proxies, gatewayID)
}
}
}
func (c *Controller) updateProxies(ctx context.Context, spec *spec.Gateway) {
// Stop and remove obsolete gateways
for gatewayID, proxy := range c.proxies {
if _, exists := spec.Gateways[gatewayID]; exists {
continue
}
logger.Info(ctx, "stopping proxy", logger.F("gatewayID", gatewayID))
if err := proxy.Stop(); err != nil {
logger.Error(
ctx, "error while stopping proxy",
logger.F("gatewayID", gatewayID),
logger.E(errors.WithStack(err)),
)
delete(c.proxies, gatewayID)
}
}
// (Re)start gateways
for gatewayID, gatewaySpec := range spec.Gateways {
proxy, exists := c.proxies[gatewayID]
if !exists {
proxy = NewReverseProxy()
c.proxies[gatewayID] = proxy
}
logger.Info(
ctx, "starting proxy",
logger.F("gatewayID", gatewayID),
logger.F("addr", gatewaySpec.Address),
logger.F("target", gatewaySpec.Target),
)
if err := proxy.Start(ctx, gatewaySpec.Address, gatewaySpec.Target); err != nil {
logger.Error(
ctx, "error while starting proxy",
logger.F("gatewayID", gatewayID),
logger.E(errors.WithStack(err)),
)
delete(c.proxies, gatewayID)
}
}
}
func NewController() *Controller {
return &Controller{
proxies: make(map[spec.GatewayID]*ReverseProxy),
currentSpecRevision: -1,
}
}
var _ agent.Controller = &Controller{}

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package gateway
import (
"context"
"net/http"
"net/http/httputil"
"net/url"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
type ReverseProxy struct {
addr string
target string
server *http.Server
}
func (p *ReverseProxy) Start(ctx context.Context, addr, target string) error {
alreadyRunning := p.server != nil && target == p.target && addr == p.target
if alreadyRunning {
return nil
}
if p.server != nil {
if err := p.Stop(); err != nil {
return errors.WithStack(err)
}
}
server := &http.Server{
Addr: addr,
}
url, err := url.Parse(target)
if err != nil {
return errors.WithStack(err)
}
proxy := httputil.NewSingleHostReverseProxy(url)
server.Handler = proxy
p.server = server
p.addr = addr
p.target = target
go func() {
if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
logger.Error(ctx, "error while listening", logger.E(errors.WithStack(err)))
}
if err := p.Stop(); err != nil {
logger.Error(ctx, "error while stopping gateway", logger.E(errors.WithStack(err)))
}
}()
return nil
}
func (p *ReverseProxy) Stop() error {
if p.server == nil {
return nil
}
if err := p.server.Close(); err != nil && !errors.Is(err, http.ErrServerClosed) {
return errors.WithStack(err)
}
p.server = nil
return nil
}
func NewReverseProxy() *ReverseProxy {
return &ReverseProxy{}
}

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package openwrt
import (
"bytes"
"context"
"os"
"os/exec"
"forge.cadoles.com/Cadoles/emissary/internal/agent"
"forge.cadoles.com/Cadoles/emissary/internal/openwrt/uci"
"forge.cadoles.com/Cadoles/emissary/internal/spec"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
type UCIController struct {
binPath string
currentSpecRevision int
}
// Name implements node.Controller.
func (*UCIController) Name() string {
return "uci-controller"
}
// Reconcile implements node.Controller.
func (c *UCIController) Reconcile(ctx context.Context, state *agent.State) error {
uciSpec := spec.NewUCISpec()
if err := state.GetSpec(spec.NameUCI, uciSpec); err != nil {
if errors.Is(err, agent.ErrSpecNotFound) {
logger.Info(ctx, "could not find uci spec, doing nothing")
return nil
}
return errors.WithStack(err)
}
logger.Info(ctx, "retrieved spec", logger.F("spec", uciSpec.SpecName()), logger.F("revision", uciSpec.SpecRevision()))
if c.currentSpecRevision == uciSpec.SpecRevision() {
logger.Info(ctx, "spec revision did not change, doing nothing")
return nil
}
if err := c.updateConfiguration(ctx, uciSpec); err != nil {
logger.Error(ctx, "could not update configuration", logger.E(errors.WithStack(err)))
return nil
}
c.currentSpecRevision = uciSpec.SpecRevision()
logger.Info(ctx, "updating current spec revision", logger.F("revision", c.currentSpecRevision))
return nil
}
func (c *UCIController) updateConfiguration(ctx context.Context, spec *spec.UCI) error {
logger.Info(ctx, "importing uci config")
if err := c.importConfig(ctx, spec.Config); err != nil {
return errors.WithStack(err)
}
if err := c.execPostImportCommands(ctx, spec.PostImportCommands); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *UCIController) importConfig(ctx context.Context, uci *uci.UCI) error {
cmd := exec.CommandContext(ctx, c.binPath, "import")
var buf bytes.Buffer
if _, err := buf.WriteString(uci.Export()); err != nil {
return errors.WithStack(err)
}
cmd.Stdin = &buf
cmd.Stderr = os.Stderr
cmd.Stdout = os.Stdout
if err := cmd.Run(); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *UCIController) execPostImportCommands(ctx context.Context, commands []*spec.UCIPostImportCommand) error {
for _, postImportCmd := range commands {
cmd := exec.CommandContext(ctx, postImportCmd.Command, postImportCmd.Args...)
cmd.Stderr = os.Stderr
cmd.Stdout = os.Stdout
if err := cmd.Run(); err != nil {
return errors.WithStack(err)
}
}
return nil
}
func NewUCIController(binPath string) *UCIController {
return &UCIController{
binPath: binPath,
currentSpecRevision: -1,
}
}
var _ agent.Controller = &UCIController{}

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package persistence
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"forge.cadoles.com/Cadoles/emissary/internal/agent"
"forge.cadoles.com/Cadoles/emissary/internal/spec"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
type Controller struct {
trackedSpecRevisions map[spec.Name]int
filename string
loaded bool
}
// Name implements node.Controller.
func (c *Controller) Name() string {
return "persistence-controller"
}
// Reconcile implements node.Controller.
func (c *Controller) Reconcile(ctx context.Context, state *agent.State) error {
specs := state.Specs()
changed := c.specChanged(state.Specs())
switch {
// If first cycle, load state from file system
case !c.loaded:
logger.Info(ctx, "first cycle, loading state", logger.F("stateFile", c.filename))
if err := c.loadState(ctx, state); err != nil {
if errors.Is(err, os.ErrNotExist) {
logger.Info(ctx, "state file not found", logger.F("stateFile", c.filename))
c.loaded = true
return nil
}
return errors.WithStack(err)
}
c.trackSpecsRevisions(specs)
c.loaded = true
return nil
// If specs did not change, return
case !changed:
logger.Info(ctx, "no changes detected, doing nothing")
return nil
// If specs has changed, save it
case changed:
logger.Info(ctx, "saving state", logger.F("stateFile", c.filename))
if err := c.writeState(ctx, state); err != nil {
return errors.WithStack(err)
}
c.trackSpecsRevisions(specs)
}
return nil
}
func (c *Controller) specChanged(specs agent.Specs) bool {
if len(specs) != len(c.trackedSpecRevisions) {
return true
}
for name, spec := range specs {
trackedRevision, exists := c.trackedSpecRevisions[name]
if !exists {
return true
}
if trackedRevision != spec.SpecRevision() {
return true
}
}
for trackedSpecName, trackedRevision := range c.trackedSpecRevisions {
spec, exists := specs[trackedSpecName]
if !exists {
return true
}
if trackedRevision != spec.SpecRevision() {
return true
}
}
return false
}
func (c *Controller) trackSpecsRevisions(specs agent.Specs) {
c.trackedSpecRevisions = make(map[spec.Name]int)
for name, spec := range specs {
c.trackedSpecRevisions[name] = spec.SpecRevision()
}
}
func (c *Controller) loadState(ctx context.Context, state *agent.State) error {
data, err := ioutil.ReadFile(c.filename)
if err != nil {
return errors.WithStack(err)
}
if err := json.Unmarshal(data, state); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *Controller) writeState(ctx context.Context, state *agent.State) error {
dir, file := filepath.Split(c.filename)
if dir == "" {
dir = "."
}
f, err := ioutil.TempFile(dir, file)
if err != nil {
return errors.Errorf("cannot create temp file: %v", err)
}
defer func() {
if err == nil {
return
}
if err := os.Remove(f.Name()); err != nil {
if errors.Is(err, os.ErrNotExist) {
return
}
logger.Error(ctx, "could not remove temporary file", logger.E(errors.WithStack(err)))
}
}()
defer func() {
if err := f.Close(); err != nil {
if errors.Is(err, os.ErrClosed) {
return
}
logger.Error(ctx, "could not close temporary file", logger.E(errors.WithStack(err)))
}
}()
data, err := json.Marshal(state)
if err != nil {
return errors.WithStack(err)
}
name := f.Name()
if err := ioutil.WriteFile(name, data, os.ModePerm); err != nil {
return errors.Errorf("cannot write data to temporary file %q: %v", name, err)
}
if err := f.Sync(); err != nil {
return errors.Errorf("can't flush temporary file %q: %v", name, err)
}
if err := f.Close(); err != nil {
return errors.Errorf("can't close temporary file %q: %v", name, err)
}
// get the file mode from the original file and use that for the replacement
// file, too.
destInfo, err := os.Stat(c.filename)
switch {
case os.IsNotExist(err):
// Do nothing
case err != nil:
return errors.WithStack(err)
default:
sourceInfo, err := os.Stat(name)
if err != nil {
return errors.WithStack(err)
}
if sourceInfo.Mode() != destInfo.Mode() {
if err := os.Chmod(name, destInfo.Mode()); err != nil {
return fmt.Errorf("can't set filemode on temporary file %q: %v", name, err)
}
}
}
if err := os.Rename(name, c.filename); err != nil {
return fmt.Errorf("cannot replace %q with temporary file %q: %v", c.filename, name, err)
}
return nil
}
func NewController(filename string) *Controller {
return &Controller{
filename: filename,
trackedSpecRevisions: make(map[spec.Name]int),
}
}
var _ agent.Controller = &Controller{}

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package spec
import (
"context"
"forge.cadoles.com/Cadoles/emissary/internal/agent"
"forge.cadoles.com/Cadoles/emissary/internal/agent/machineid"
"forge.cadoles.com/Cadoles/emissary/internal/client"
"forge.cadoles.com/Cadoles/emissary/internal/datastore"
"forge.cadoles.com/Cadoles/emissary/internal/server"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/api"
"gitlab.com/wpetit/goweb/logger"
)
type Controller struct {
client *client.Client
}
// Name implements node.Controller.
func (c *Controller) Name() string {
return "spec-controller"
}
// Reconcile implements node.Controller.
func (c *Controller) Reconcile(ctx context.Context, state *agent.State) error {
machineID, err := machineid.Get()
if err != nil {
return errors.WithStack(err)
}
ctx = logger.With(ctx, logger.F("machineID", machineID))
agent, err := c.client.RegisterAgent(ctx, machineID)
isAlreadyRegisteredErr, _ := isAPIError(err, server.ErrCodeAlreadyRegistered)
switch {
case isAlreadyRegisteredErr:
agents, _, err := c.client.QueryAgents(
ctx,
client.WithQueryAgentsLimit(1),
client.WithQueryAgentsRemoteID(machineID),
)
if err != nil {
return errors.WithStack(err)
}
if len(agents) == 0 {
logger.Error(ctx, "could not find remote matching agent")
return nil
}
if err := c.reconcileAgent(ctx, state, agents[0]); err != nil {
return errors.WithStack(err)
}
return nil
case agent != nil:
if err := c.reconcileAgent(ctx, state, agent); err != nil {
return errors.WithStack(err)
}
return nil
case err != nil:
logger.Error(ctx, "could not contact server", logger.E(errors.WithStack(err)))
return nil
}
return nil
}
func (c *Controller) reconcileAgent(ctx context.Context, state *agent.State, agent *datastore.Agent) error {
ctx = logger.With(ctx, logger.F("agentID", agent.ID))
if agent.Status != datastore.AgentStatusAccepted {
logger.Error(ctx, "unexpected agent status", logger.F("status", agent.Status))
return nil
}
specs, err := c.client.GetAgentSpecs(ctx, agent.ID)
if err != nil {
logger.Error(ctx, "could not retrieve agent specs", logger.E(errors.WithStack(err)))
return nil
}
state.ClearSpecs()
for _, spec := range specs {
state.SetSpec(spec)
}
return nil
}
func NewController(serverURL string) *Controller {
client := client.New(serverURL)
return &Controller{client}
}
func isAPIError(err error, code api.ErrorCode) (bool, any) {
apiError := &api.Error{}
if errors.As(err, &apiError) && apiError.Code == code {
return true, apiError.Data
}
return false, nil
}
var _ agent.Controller = &Controller{}

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package machineid
import (
"github.com/btcsuite/btcd/btcutil/base58"
"github.com/denisbrodbeck/machineid"
"github.com/pkg/errors"
)
const salt = "emissary.cadoles.com"
func Get() (string, error) {
machineID, err := getProtectedMachineID()
if err != nil {
return "", errors.WithStack(err)
}
return machineID, nil
}
func getProtectedMachineID() (string, error) {
id, err := machineid.ProtectedID(salt)
if err != nil {
return "", errors.WithStack(err)
}
encoded := base58.Encode([]byte(id))
return encoded, nil
}

31
internal/agent/option.go Normal file
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package agent
import (
"time"
)
type Option struct {
Interval time.Duration
Controllers []Controller
}
type OptionFunc func(*Option)
func defaultOption() *Option {
return &Option{
Controllers: make([]Controller, 0),
Interval: 10 * time.Second,
}
}
func WithControllers(controllers ...Controller) OptionFunc {
return func(opt *Option) {
opt.Controllers = controllers
}
}
func WithInterval(interval time.Duration) OptionFunc {
return func(opt *Option) {
opt.Interval = interval
}
}

109
internal/agent/state.go Normal file
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package agent
import (
"encoding/json"
"forge.cadoles.com/Cadoles/emissary/internal/spec"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
)
var ErrSpecNotFound = errors.New("spec not found")
type Specs map[spec.Name]spec.Spec
type State struct {
specs Specs `json:"specs"`
}
func NewState() *State {
return &State{
specs: make(map[spec.Name]spec.Spec),
}
}
func (s *State) MarshalJSON() ([]byte, error) {
state := struct {
Specs map[spec.Name]*spec.RawSpec `json:"specs"`
}{
Specs: func(specs map[spec.Name]spec.Spec) map[spec.Name]*spec.RawSpec {
rawSpecs := make(map[spec.Name]*spec.RawSpec)
for name, sp := range specs {
rawSpecs[name] = &spec.RawSpec{
Name: sp.SpecName(),
Revision: sp.SpecRevision(),
Data: sp.SpecData(),
}
}
return rawSpecs
}(s.specs),
}
data, err := json.Marshal(state)
if err != nil {
return nil, errors.WithStack(err)
}
return data, nil
}
func (s *State) UnmarshalJSON(data []byte) error {
state := struct {
Specs map[spec.Name]*spec.RawSpec `json:"specs"`
}{}
if err := json.Unmarshal(data, &state); err != nil {
return errors.WithStack(err)
}
s.specs = func(rawSpecs map[spec.Name]*spec.RawSpec) Specs {
specs := make(Specs)
for name, raw := range rawSpecs {
specs[name] = spec.Spec(raw)
}
return specs
}(state.Specs)
return nil
}
func (s *State) Specs() Specs {
return s.specs
}
func (s *State) ClearSpecs() *State {
s.specs = make(map[spec.Name]spec.Spec)
return s
}
func (s *State) SetSpec(sp spec.Spec) *State {
if s.specs == nil {
s.specs = make(map[spec.Name]spec.Spec)
}
s.specs[sp.SpecName()] = sp
return s
}
func (s *State) GetSpec(name spec.Name, dest any) error {
spec, exists := s.specs[name]
if !exists {
return errors.WithStack(ErrSpecNotFound)
}
if err := mapstructure.Decode(spec, dest); err != nil {
return errors.WithStack(err)
}
if err := mapstructure.Decode(spec.SpecData(), dest); err != nil {
return errors.WithStack(err)
}
return nil
}