feat: agent metadata with custom collectors

internal/agent/agent.go

@@ -4,13 +4,21 @@ import (
 	"context"
 	"time"
 
+	"forge.cadoles.com/Cadoles/emissary/internal/agent/metadata"
+	"forge.cadoles.com/Cadoles/emissary/internal/client"
+	"forge.cadoles.com/Cadoles/emissary/internal/jwk"
 	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/api"
 	"gitlab.com/wpetit/goweb/logger"
 )
 
 type Agent struct {
+	thumbprint  string
+	privateKey  jwk.Key
+	client      *client.Client
 	controllers []Controller
 	interval    time.Duration
+	collectors  []metadata.Collector
 }
 
 func (a *Agent) Run(ctx context.Context) error {
@@ -21,10 +29,20 @@ func (a *Agent) Run(ctx context.Context) error {
 	ticker := time.NewTicker(a.interval)
 	defer ticker.Stop()
 
+	ctx = withClient(ctx, a.client)
+
 	for {
 		select {
 		case <-ticker.C:
 
+			logger.Debug(ctx, "registering agent")
+
+			if err := a.registerAgent(ctx, state); err != nil {
+				logger.Error(ctx, "could not register agent", logger.E(errors.WithStack(err)))
+
+				continue
+			}
+
 			logger.Debug(ctx, "state before reconciliation", logger.F("state", state))
 
 			if err := a.Reconcile(ctx, state); err != nil {
@@ -58,14 +76,67 @@ func (a *Agent) Reconcile(ctx context.Context, state *State) error {
 	return nil
 }
 
-func New(funcs ...OptionFunc) *Agent {
+func (a *Agent) registerAgent(ctx context.Context, state *State) error {
+	meta, err := a.collectMetadata(ctx)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	sorted := metadata.Sort(meta)
+
+	agent, err := a.client.RegisterAgent(ctx, a.privateKey, a.thumbprint, sorted)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	state.agentID = agent.ID
+
+	return nil
+}
+
+func (a *Agent) collectMetadata(ctx context.Context) (map[string]any, error) {
+	metadata := make(map[string]any)
+
+	for _, collector := range a.collectors {
+		name, value, err := collector.Collect(ctx)
+		if err != nil {
+			logger.Error(
+				ctx, "could not collect metadata",
+				logger.E(errors.WithStack(err)), logger.F("name", name),
+			)
+
+			continue
+		}
+
+		metadata[name] = value
+	}
+
+	return metadata, nil
+}
+
+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
+}
+
+func New(serverURL string, privateKey jwk.Key, thumbprint string, funcs ...OptionFunc) *Agent {
 	opt := defaultOption()
 	for _, fn := range funcs {
 		fn(opt)
 	}
 
+	client := client.New(serverURL)
+
 	return &Agent{
+		privateKey:  privateKey,
+		thumbprint:  thumbprint,
+		client:      client,
 		controllers: opt.Controllers,
 		interval:    opt.Interval,
+		collectors:  opt.Collectors,
 	}
 }

internal/agent/context.go

@@ -0,0 +1,27 @@
+package agent
+
+import (
+	"context"
+
+	"forge.cadoles.com/Cadoles/emissary/internal/client"
+	"github.com/pkg/errors"
+)
+
+type contextKey string
+
+const (
+	contextKeyClient contextKey = "client"
+)
+
+func withClient(ctx context.Context, client *client.Client) context.Context {
+	return context.WithValue(ctx, contextKeyClient, client)
+}
+
+func Client(ctx context.Context) *client.Client {
+	client, ok := ctx.Value(contextKeyClient).(*client.Client)
+	if !ok {
+		panic(errors.New("could not retrieve client from context"))
+	}
+
+	return client
+}

internal/agent/controller/spec/controller.go

@@ -4,18 +4,13 @@ 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
-}
+type Controller struct{}
 
 // Name implements node.Controller.
 func (c *Controller) Name() string {
@@ -24,56 +19,31 @@ func (c *Controller) Name() string {
 
 // Reconcile implements node.Controller.
 func (c *Controller) Reconcile(ctx context.Context, state *agent.State) error {
-	machineID, err := machineid.Get()
+	cl := agent.Client(ctx)
+
+	agents, _, err := cl.QueryAgents(
+		ctx,
+		client.WithQueryAgentsLimit(1),
+		client.WithQueryAgentsID(state.AgentID()),
+	)
 	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)
-		}
+	if len(agents) == 0 {
+		logger.Error(ctx, "could not find remote matching agent")
 
 		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
+	if err := c.reconcileAgent(ctx, cl, state, agents[0]); err != nil {
+		return errors.WithStack(err)
 	}
 
 	return nil
 }
 
-func (c *Controller) reconcileAgent(ctx context.Context, state *agent.State, agent *datastore.Agent) error {
+func (c *Controller) reconcileAgent(ctx context.Context, client *client.Client, state *agent.State, agent *datastore.Agent) error {
 	ctx = logger.With(ctx, logger.F("agentID", agent.ID))
 
 	if agent.Status != datastore.AgentStatusAccepted {
@@ -82,7 +52,7 @@ func (c *Controller) reconcileAgent(ctx context.Context, state *agent.State, age
 		return nil
 	}
 
-	specs, err := c.client.GetAgentSpecs(ctx, agent.ID)
+	specs, err := client.GetAgentSpecs(ctx, agent.ID)
 	if err != nil {
 		logger.Error(ctx, "could not retrieve agent specs", logger.E(errors.WithStack(err)))
 
@@ -98,19 +68,8 @@ func (c *Controller) reconcileAgent(ctx context.Context, state *agent.State, age
 	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
+func NewController() *Controller {
+	return &Controller{}
 }
 
 var _ agent.Controller = &Controller{}

internal/agent/machineid/get.go

@@ -1,29 +0,0 @@
-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
-}

internal/agent/metadata/collector.go

@@ -0,0 +1,12 @@
+package metadata
+
+import (
+	"context"
+	"errors"
+)
+
+var ErrMetadataNotAvailable = errors.New("metadata not available")
+
+type Collector interface {
+	Collect(context.Context) (string, string, error)
+}

internal/agent/metadata/collector/buildinfo/collector.go

@@ -0,0 +1,31 @@
+package buildinfo
+
+import (
+	"context"
+	"runtime/debug"
+
+	"forge.cadoles.com/Cadoles/emissary/internal/agent/metadata"
+	"github.com/pkg/errors"
+)
+
+const (
+	MetadataBuildInfo = "buildinfo"
+)
+
+type Collector struct{}
+
+// Collect implements agent.MetadataCollector
+func (c *Collector) Collect(ctx context.Context) (string, string, error) {
+	buildInfo, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "", "", errors.WithStack(metadata.ErrMetadataNotAvailable)
+	}
+
+	return MetadataBuildInfo, buildInfo.String(), nil
+}
+
+func NewCollector() *Collector {
+	return &Collector{}
+}
+
+var _ metadata.Collector = &Collector{}

internal/agent/metadata/collector/shell/collector.go

@@ -0,0 +1,46 @@
+package shell
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"os/exec"
+	"strings"
+
+	"forge.cadoles.com/Cadoles/emissary/internal/agent/metadata"
+	"github.com/pkg/errors"
+)
+
+type Collector struct {
+	name    string
+	command string
+	args    []string
+}
+
+// Collect implements agent.MetadataCollector
+func (c *Collector) Collect(ctx context.Context) (string, string, error) {
+	cmd := exec.CommandContext(ctx, c.command, c.args...)
+
+	var buf bytes.Buffer
+
+	cmd.Stdout = &buf
+	cmd.Stderr = os.Stderr
+
+	if err := cmd.Run(); err != nil {
+		return "", "", errors.WithStack(err)
+	}
+
+	value := strings.TrimSpace(buf.String())
+
+	return c.name, value, nil
+}
+
+func NewCollector(name string, command string, args ...string) *Collector {
+	return &Collector{
+		name:    name,
+		command: command,
+		args:    args,
+	}
+}
+
+var _ metadata.Collector = &Collector{}

internal/agent/metadata/metadata.go

@@ -0,0 +1,3 @@
+package metadata
+
+type Metadata map[string]any

internal/agent/metadata/sort.go

@@ -0,0 +1,37 @@
+package metadata
+
+import (
+	"sort"
+)
+
+type Tuple struct {
+	Key   string `json:"key"`
+	Value any    `json:"value"`
+}
+
+func Sort(metadata map[string]any) []Tuple {
+	keys := make([]string, 0, len(metadata))
+	for k := range metadata {
+		keys = append(keys, k)
+	}
+
+	sort.Strings(keys)
+
+	tuples := make([]Tuple, len(keys))
+
+	for i, k := range keys {
+		tuples[i] = Tuple{k, metadata[k]}
+	}
+
+	return tuples
+}
+
+func FromSorted(tuples []Tuple) map[string]any {
+	metadata := make(map[string]any)
+
+	for _, t := range tuples {
+		metadata[t.Key] = t.Value
+	}
+
+	return metadata
+}

internal/agent/option.go

@@ -1,31 +0,0 @@
-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
-	}
-}

internal/agent/options.go

@@ -0,0 +1,43 @@
+package agent
+
+import (
+	"time"
+
+	"forge.cadoles.com/Cadoles/emissary/internal/agent/metadata"
+	"forge.cadoles.com/Cadoles/emissary/internal/client"
+)
+
+type Options struct {
+	Client      *client.Client
+	Interval    time.Duration
+	Controllers []Controller
+	Collectors  []metadata.Collector
+}
+
+type OptionFunc func(*Options)
+
+func defaultOption() *Options {
+	return &Options{
+		Controllers: make([]Controller, 0),
+		Interval:    10 * time.Second,
+		Collectors:  make([]metadata.Collector, 0),
+	}
+}
+
+func WithControllers(controllers ...Controller) OptionFunc {
+	return func(opt *Options) {
+		opt.Controllers = controllers
+	}
+}
+
+func WithInterval(interval time.Duration) OptionFunc {
+	return func(opt *Options) {
+		opt.Interval = interval
+	}
+}
+
+func WithCollectors(collectors ...metadata.Collector) OptionFunc {
+	return func(opts *Options) {
+		opts.Collectors = collectors
+	}
+}

internal/agent/state.go

@@ -3,6 +3,7 @@ package agent
 import (
 	"encoding/json"
 
+	"forge.cadoles.com/Cadoles/emissary/internal/datastore"
 	"forge.cadoles.com/Cadoles/emissary/internal/spec"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
@@ -13,7 +14,8 @@ var ErrSpecNotFound = errors.New("spec not found")
 type Specs map[spec.Name]spec.Spec
 
 type State struct {
-	specs Specs `json:"specs"`
+	agentID datastore.AgentID
+	specs   Specs
 }
 
 func NewState() *State {
@@ -24,8 +26,10 @@ func NewState() *State {
 
 func (s *State) MarshalJSON() ([]byte, error) {
 	state := struct {
+		ID    datastore.AgentID           `json:"agentId"`
 		Specs map[spec.Name]*spec.RawSpec `json:"specs"`
 	}{
+		ID: s.agentID,
 		Specs: func(specs map[spec.Name]spec.Spec) map[spec.Name]*spec.RawSpec {
 			rawSpecs := make(map[spec.Name]*spec.RawSpec)
 
@@ -51,7 +55,8 @@ func (s *State) MarshalJSON() ([]byte, error) {
 
 func (s *State) UnmarshalJSON(data []byte) error {
 	state := struct {
-		Specs map[spec.Name]*spec.RawSpec `json:"specs"`
+		AgentID datastore.AgentID           `json:"agentId"`
+		Specs   map[spec.Name]*spec.RawSpec `json:"specs"`
 	}{}
 
 	if err := json.Unmarshal(data, &state); err != nil {
@@ -71,6 +76,10 @@ func (s *State) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+func (s *State) AgentID() datastore.AgentID {
+	return s.agentID
+}
+
 func (s *State) Specs() Specs {
 	return s.specs
 }