main.go

package main

import (
	"log"

	"github.com/dmaes/nomad-logger/fluentbit"
	"github.com/dmaes/nomad-logger/nomad"
	"github.com/dmaes/nomad-logger/promtail"

	"github.com/alexflint/go-arg"
)

var args struct {
	NomadAddress        string `arg:"--nomad-addr,env:NOMAD_ADDR" default:"http://localhost:4646" help:"The address of the Nomad API"`
	NomadAllocsDir      string `arg:"--nomad-allocs-dir,env:NOMAD_ALLOCS_DIR" default:"/var/lib/nomad/alloc" help:"The location of the Nomad allocations data. Used to set the path to the logfiles"`
	NomadNodeID         string `arg:"--nomad-node-id,env:NOMAD_NODE_ID" default:"" help:"The ID of the Nomad node to collect logs for. If empty, we'll suppose this also runs in as a nomad job, and the available env vars will be used to determine the Node ID"`
	NomadMetaPrefix     string `arg:"--nomad-meta-prefix,env:NOMAD_META_PREFIX" default:"nomad-logger" help:"Consider meta keys that start with '$prefix.'. See log shippers for more info on meta usage."`
	ReloadCmd           string `arg:"--reload-cmd,env:RELOAD_CMD" default:"" help:"Optional command to execute after logshipper config has changed. Usefull to signal a service to reload it's config. Valid for fluentbit logshipper."`
	LogShipper          string `arg:"--log-shipper,env:LOG_SHIPPER" default:"promtail" help:"The logshipper to use. Options: fluentbit, promtail"`
	FluentbitConfFile   string `arg:"--fluentbit-conf-file,env:FLUENTBIT_CONF_FILE" default:"/etc/fluent-bit/nomad.conf" help:"The file in which we can write our input's and stuff. Will be completely overwritten, should be '@INCLUDE'ed from main config file."`
	FluentbitTagPrefix  string `arg:"--fluentbit-tag-prefix,env:FLUENTBIT_TAG_PREFIX" default:"nomad" help:"Prefix to use for fluentbit tags. Full tag will be '$prefix.$allocId"`
	FluentbitParser     string `arg:"--fluentbit-parser,env:FLUENTBIT_PARSER" default:"" help:"Parser to apply on every input. Empty string for none"`
	PromtailTargetsFile string `arg:"--promtail-targets-file,env:PROMTAIL_TARGETS_FILE" default:"/etc/promtail/nomad.yaml" help:"The promtail file_sd_config file where the generated config can be written. Will be completely overwritten, so don't put anything else there."`
}

func main() {
	arg.MustParse(&args)

	nomad := &nomad.Nomad{
		Address:    args.NomadAddress,
		AllocsDir:  args.NomadAllocsDir,
		MetaPrefix: args.NomadMetaPrefix,
	}

	if args.NomadNodeID != "" {
		nomad.NodeID = args.NomadNodeID
	} else {
		nomad.SetNodeIDFromEnvs()
	}

	switch args.LogShipper {
	case "fluentbit":
		fluentbit := &fluentbit.Fluentbit{
			Nomad:     nomad,
			ConfFile:  args.FluentbitConfFile,
			TagPrefix: args.FluentbitTagPrefix,
			Parser:    args.FluentbitParser,
			ReloadCmd: args.ReloadCmd,
		}
		fluentbit.Run()
	case "promtail":
		promtail := &promtail.Promtail{
			Nomad:       nomad,
			TargetsFile: args.PromtailTargetsFile,
		}
		promtail.Run()
	default:
		log.Fatalf("Invalid log shipper type '%s'", args.LogShipper)
	}

}