feat: Print config as indented JSON on startup (#73)

## Which problem is this PR solving? Print the config as indented JSON during startup if debug flag is enabled. ## Short description of the changes - When creating a new config, if the debug flag is set, marshal the config struct into json and print it ## How to verify that this has the expected result If the debug flag is set on startup, the config is printed out
honeycombio · Aug 16, 2023 · b091a33 · b091a33
1 parent 28443ac
commit b091a33
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Showing 2 changed files with 57 additions and 51 deletions.
diff --git a/assemblers/config.go b/assemblers/config.go
@@ -1,6 +1,7 @@
 package assemblers
 
 import (
+	"encoding/json"
 	"flag"
 	"time"
 )
@@ -28,49 +29,55 @@ var tstype = flag.String("timestamp_type", "", "Type of timestamps to use")
 var promisc = flag.Bool("promisc", true, "Set promiscuous mode")
 
 type config struct {
-	maxcount int
-	statsevery int
-	lazy bool
-	nodefrag bool
-	checksum bool
-	nooptcheck bool
-	ignorefsmerr bool
-	allowmissinginit bool
-	verbose bool
-	debug bool
-	quiet bool
-
-	iface string
-	fname string
-	snaplen int
-	tstype string
-	promisc bool
-
-	closeTimeout time.Duration
-	timeout time.Duration
+	Maxcount         int
+	Statsevery       int
+	Lazy             bool
+	Nodefrag         bool
+	Checksum         bool
+	Nooptcheck       bool
+	Ignorefsmerr     bool
+	Allowmissinginit bool
+	Verbose          bool
+	Debug            bool
+	Quiet            bool
+	Interface        string
+	FileName         string
+	Snaplen          int
+	TsType           string
+	Promiscuous      bool
+	CloseTimeout     time.Duration
+	Timeout          time.Duration
 }
 
 func NewConfig() *config {
-	return &config{
-		maxcount: *maxcount,
-		statsevery: *statsevery,
-		lazy: *lazy,
-		nodefrag: *nodefrag,
-		checksum: *checksum,
-		nooptcheck: *nooptcheck,
-		ignorefsmerr: *ignorefsmerr,
-		allowmissinginit: *allowmissinginit,
-		verbose: *verbose,
-		debug: *debug,
-		quiet: *quiet,
-
-		iface: *iface,
-		fname: *fname,
-		snaplen: *snaplen,
-		tstype: *tstype,
-		promisc: *promisc,
+	c := &config{
+		Maxcount:         *maxcount,
+		Statsevery:       *statsevery,
+		Lazy:             *lazy,
+		Nodefrag:         *nodefrag,
+		Checksum:         *checksum,
+		Nooptcheck:       *nooptcheck,
+		Ignorefsmerr:     *ignorefsmerr,
+		Allowmissinginit: *allowmissinginit,
+		Verbose:          *verbose,
+		Debug:            *debug,
+		Quiet:            *quiet,
+		Interface:        *iface,
+		FileName:         *fname,
+		Snaplen:          *snaplen,
+		TsType:           *tstype,
+		Promiscuous:      *promisc,
+		CloseTimeout:     closeTimeout,
+		Timeout:          timeout,
+	}
 
-		closeTimeout: closeTimeout,
-		timeout: timeout,
+	if c.Debug {
+		b, err := json.MarshalIndent(c, "", "  ")
+		if err != nil {
+			Debug("Failed to marshal agent config: %e", err)
+		} else {
+			Debug("Agent config: %s", string(b))
+		}
 	}
+	return c
 }
diff --git a/assemblers/tcp_assembler.go b/assemblers/tcp_assembler.go
@@ -4,7 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"log"
-	"os"
 	"strings"
 	"sync"
 	"time"
@@ -69,6 +68,7 @@ func NewTcpAssembler(config config, httpEvents chan HttpEvent) tcpAssembler {
 	} else if *quiet {
 		logLevel = -1
 	}
+
 	errorsMap = make(map[string]uint)
 	// Set up pcap packet capture
 	if *fname != "" {
@@ -122,7 +122,7 @@ func (h *tcpAssembler) Start() {
 		data := packet.Data()
 		bytes += int64(len(data))
 		// defrag the IPv4 packet if required
-		if !h.config.nodefrag {
+		if !h.config.Nodefrag {
 			ip4Layer := packet.Layer(layers.LayerTypeIPv4)
 			if ip4Layer == nil {
 				continue
@@ -153,7 +153,7 @@ func (h *tcpAssembler) Start() {
 		tcp := packet.Layer(layers.LayerTypeTCP)
 		if tcp != nil {
 			tcp := tcp.(*layers.TCP)
-			if h.config.checksum {
+			if h.config.Checksum {
 				err := tcp.SetNetworkLayerForChecksum(packet.NetworkLayer())
 				if err != nil {
 					log.Fatalf("Failed to set network layer for checksum: %s\n", err)
@@ -165,19 +165,18 @@ func (h *tcpAssembler) Start() {
 			stats.totalsz += len(tcp.Payload)
 			h.assembler.AssembleWithContext(packet.NetworkLayer().NetworkFlow(), tcp, &c)
 		}
-		if count%h.config.statsevery == 0 {
+		if count%h.config.Statsevery == 0 {
 			ref := packet.Metadata().CaptureInfo.Timestamp
-			flushed, closed := h.assembler.FlushWithOptions(reassembly.FlushOptions{T: ref.Add(-h.config.timeout), TC: ref.Add(-h.config.closeTimeout)})
-			// Debug("Forced flush: %d flushed, %d closed (%s)", flushed, closed, ref)
-			log.Printf("Forced flush: %d flushed, %d closed (%s)", flushed, closed, ref)
+			flushed, closed := h.assembler.FlushWithOptions(reassembly.FlushOptions{T: ref.Add(-h.config.Timeout), TC: ref.Add(-h.config.CloseTimeout)})
+			Debug("Forced flush: %d flushed, %d closed (%s)", flushed, closed, ref)
 		}
 
-		done := h.config.maxcount > 0 && count >= h.config.maxcount
-		if count%h.config.statsevery == 0 || done {
+		done := h.config.Maxcount > 0 && count >= h.config.Maxcount
+		if count%h.config.Statsevery == 0 || done {
 			errorsMapMutex.Lock()
 			errorMapLen := len(errorsMap)
 			errorsMapMutex.Unlock()
-			fmt.Fprintf(os.Stderr, "Processed %v packets (%v bytes) in %v (errors: %v, errTypes:%v)\n", count, bytes, time.Since(start), errors, errorMapLen)
+			Debug("Processed %v packets (%v bytes) in %v (errors: %v, errTypes:%v)\n", count, bytes, time.Since(start), errors, errorMapLen)
 		}
 	}
 }
@@ -193,7 +192,7 @@ func (h *tcpAssembler) Stop() {
 	h.streamFactory.WaitGoRoutines()
 	// Debug("%s\n", h.assembler.Dump())
 	log.Printf("%s\n", h.assembler.Dump())
-	if !h.config.nodefrag {
+	if !h.config.Nodefrag {
 		fmt.Printf("IPdefrag:\t\t%d\n", stats.ipdefrag)
 	}
 	fmt.Printf("TCP stats:\n")