[Elastic Log Driver] Add new initialization functions and common fiel…

…ds (elastic#15786) (elastic#15827)

* add new initialization functions and other things for ECS and common fields

* clean up error handling

(cherry picked from commit 05c6121)

x-pack/dockerlogbeat/pipelinemanager/libbeattools.go

@@ -6,22 +6,27 @@ package pipelinemanager
 
 import (
 	"crypto/sha1"
+	"encoding/json"
 	"fmt"
+	"io"
 	"os"
 	"sort"
 	"time"
 
+	"github.com/gofrs/uuid"
 	"github.com/pkg/errors"
 	yaml "gopkg.in/yaml.v2"
 
 	"github.com/elastic/beats/libbeat/beat"
 	"github.com/elastic/beats/libbeat/cloudid"
 	"github.com/elastic/beats/libbeat/common"
+	"github.com/elastic/beats/libbeat/common/file"
 	"github.com/elastic/beats/libbeat/idxmgmt"
 	"github.com/elastic/beats/libbeat/logp"
 	"github.com/elastic/beats/libbeat/outputs"
 	"github.com/elastic/beats/libbeat/publisher/pipeline"
 	"github.com/elastic/beats/libbeat/publisher/processing"
+	"github.com/elastic/beats/libbeat/version"
 )
 
 // makeConfigHash is the helper function that turns a user config into a hash
@@ -47,18 +52,6 @@ func makeConfigHash(cfg map[string]string) string {
 // load pipeline starts up a new pipeline with the given config
 func loadNewPipeline(logOptsConfig map[string]string, name string, log *logp.Logger) (*Pipeline, error) {
 
-	hostname, err := os.Hostname()
-	if err != nil {
-		return nil, errors.Wrap(err, "error getting hostname")
-	}
-
-	info := beat.Info{
-		Beat:     "elastic-logging-plugin",
-		Version:  "0",
-		Name:     name,
-		Hostname: hostname,
-	}
-
 	newCfg, err := parseCfgKeys(logOptsConfig)
 	if err != nil {
 		return nil, errors.Wrap(err, "error parsing config keys")
@@ -81,7 +74,12 @@ func loadNewPipeline(logOptsConfig map[string]string, name string, log *logp.Log
 		return nil, fmt.Errorf("unpacking config failed: %v", err)
 	}
 
-	processing, err := processing.MakeDefaultSupport(false)(info, log, cfg)
+	info, err := getBeatInfo(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	processing, err := processing.MakeDefaultBeatSupport(true)(info, log, cfg)
 	if err != nil {
 		return nil, errors.Wrap(err, "error in MakeDefaultSupport")
 	}
@@ -128,7 +126,6 @@ func loadNewPipeline(logOptsConfig map[string]string, name string, log *logp.Log
 
 // parseCfgKeys helpfully parses the values in the map, so users can specify yml structures.
 func parseCfgKeys(cfg map[string]string) (map[string]interface{}, error) {
-
 	outMap := make(map[string]interface{})
 
 	for cfgKey, strVal := range cfg {
@@ -141,3 +138,129 @@ func parseCfgKeys(cfg map[string]string) (map[string]interface{}, error) {
 
 	return outMap, nil
 }
+
+// getBeatInfo returns the beat.Info type needed to start the pipeline
+func getBeatInfo(cfg *common.Config) (beat.Info, error) {
+	vers := version.GetDefaultVersion()
+	hostname, err := os.Hostname()
+	if err != nil {
+		return beat.Info{}, errors.Wrap(err, "error getting hostname")
+	}
+	eid, err := uuid.NewV4()
+	if err != nil {
+		return beat.Info{}, errors.Wrap(err, "error creating ephemeral ID")
+	}
+
+	type nameStr struct {
+		Name string `config:"name"`
+	}
+	name := nameStr{}
+	err = cfg.Unpack(&name)
+	if err != nil {
+		return beat.Info{}, fmt.Errorf("unpacking config failed: %v", err)
+	}
+
+	if name.Name == "" {
+		name.Name = "elastic-log-driver-" + hostname
+	}
+	id, err := loadMeta("/tmp/meta.json")
+	if err != nil {
+		return beat.Info{}, errors.Wrap(err, "error loading UUID")
+	}
+
+	info := beat.Info{
+		Beat:        "elastic-logging-plugin",
+		Name:        name.Name,
+		Hostname:    hostname,
+		Version:     vers,
+		EphemeralID: eid,
+		ID:          id,
+	}
+
+	return info, nil
+
+}
+
+// loadMeta loads the metadata file that contains the UUID
+func loadMeta(metaPath string) (uuid.UUID, error) {
+	type meta struct {
+		UUID uuid.UUID `json:"uuid"`
+	}
+	// check for an existing file
+	f, err := openRegular(metaPath)
+	if err != nil && !os.IsNotExist(err) {
+		return uuid.Nil, errors.Wrapf(err, "beat meta file %s failed to open", metaPath)
+	}
+
+	//return the UUID if it exists
+	if err == nil {
+		m := meta{}
+		if err := json.NewDecoder(f).Decode(&m); err != nil && err != io.EOF {
+			f.Close()
+			return uuid.Nil, errors.Wrapf(err, "Error reading %s", metaPath)
+		}
+
+		f.Close()
+		if m.UUID != uuid.Nil {
+			return m.UUID, nil
+		}
+	}
+
+	// file does not exist or ID is invalid, let's create a new one
+	newID, err := uuid.NewV4()
+	if err != nil {
+		return uuid.Nil, errors.Wrap(err, "error creating ID")
+	}
+	// write temporary file first
+	tempFile := metaPath + ".new"
+	f, err = os.OpenFile(tempFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return uuid.Nil, errors.Wrapf(err, "failed to create Beat meta file at %s", tempFile)
+	}
+
+	encodeErr := json.NewEncoder(f).Encode(meta{UUID: newID})
+	err = f.Sync()
+	if err != nil {
+		return uuid.Nil, errors.Wrapf(err, "beat meta file at %s failed to write", tempFile)
+	}
+
+	err = f.Close()
+	if err != nil {
+		return uuid.Nil, errors.Wrapf(err, "beat meta file at %s failed to close", tempFile)
+	}
+
+	if encodeErr != nil {
+		return uuid.Nil, errors.Wrapf(err, "beat meta file at %s failed to write", tempFile)
+	}
+
+	// move temporary file into final location
+	err = file.SafeFileRotate(metaPath, tempFile)
+	if err != nil {
+		return uuid.Nil, errors.Wrapf(err, "error rotating file to %s", metaPath)
+	}
+	return newID, nil
+}
+
+// openRegular is a wrapper to handle a file based on a path
+func openRegular(filename string) (*os.File, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return f, errors.Wrapf(err, "error opening file %s", filename)
+	}
+
+	info, err := f.Stat()
+	if err != nil {
+		f.Close()
+		return nil, errors.Wrapf(err, "error statting %s", filename)
+	}
+
+	if !info.Mode().IsRegular() {
+		f.Close()
+		if info.IsDir() {
+			return nil, fmt.Errorf("%s is a directory", filename)
+		}
+		return nil, fmt.Errorf("%s is not a regular file", filename)
+	}
+
+	return f, nil
+}