Merge pull request #57 from moorereason/iss43

Add a merge_key configuration option

README.md

@@ -94,6 +94,10 @@ Copy config/config.dist.yaml to config.yaml and change parameters:
 
 * **merge_reports** (bool): merge multiple similar reports to one?
 
+* **merge_key** (string): Go template string used to generate a key to merge
+  reports.  Only used when `merge_reports` is enabled.
+  Default is `{{ .ReportMetadata.OrgName }}!{{ .ReportMetadata.Email }}!{{ .PolicyPublished.Domain }}`.
+
 * **log_debug** (bool): print debug log messages?
 
 * **log_datetime** (bool): add datetime to log messages?

cmd/dmarc-report-converter/config.go

@@ -15,6 +15,7 @@ type config struct {
 	LookupAddr   bool   `yaml:"lookup_addr"`
 	LookupLimit  int    `yaml:"lookup_limit"`
 	MergeReports bool   `yaml:"merge_reports"`
+	MergeKey     string `yaml:"merge_key"`
 	LogDebug     bool   `yaml:"log_debug"`
 	LogDatetime  bool   `yaml:"log_datetime"`
 }
@@ -51,6 +52,7 @@ type Output struct {
 	template         *template.Template
 	AssetsPath       string `yaml:"assets_path"`
 	ExternalTemplate string `yaml:"external_template"`
+	mergeKeyTemplate *template.Template
 }
 
 func (o *Output) isStdout() bool {
@@ -90,6 +92,10 @@ func loadConfig(path string) (*config, error) {
 		return nil, fmt.Errorf("'input.imap.security' must be one of: tls, starttls, plaintext")
 	}
 
+	if c.MergeKey == "" {
+		c.MergeKey = `{{ .ReportMetadata.OrgName }}!{{ .ReportMetadata.Email }}!{{ .PolicyPublished.Domain }}`
+	}
+
 	// Determine which template is used based upon Output.Format.
 	t := txtTmpl
 	switch c.Output.Format {
@@ -125,5 +131,7 @@ func loadConfig(path string) (*config, error) {
 		c.Output.fileTemplate = ft
 	}
 
+	c.Output.mergeKeyTemplate = template.Must(template.New("merge_key").Funcs(tmplFuncs).Parse(c.MergeKey))
+
 	return &c, nil
 }

cmd/dmarc-report-converter/files.go

@@ -141,7 +141,7 @@ func (c *filesConverter) convert() {
 }
 
 func (c *filesConverter) merge() error {
-	reports, err := groupMergeReports(c.reports)
+	reports, err := groupMergeReports(c.reports, c.cfg.Output.mergeKeyTemplate)
 	if err != nil {
 		return err
 	}

cmd/dmarc-report-converter/merge.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
+	"html/template"
 	"log"
 
 	"github.com/tierpod/dmarc-report-converter/pkg/dmarc"
@@ -19,11 +21,18 @@ func mergeReports(reports []dmarc.Report) dmarc.Report {
 	return first
 }
 
-func groupReportsKey(r dmarc.Report) string {
-	return fmt.Sprintf("%v!%v!%v", r.ReportMetadata.OrgName, r.ReportMetadata.Email, r.PolicyPublished.Domain)
+func groupReportsKey(r dmarc.Report, t *template.Template) (string, error) {
+	var buf bytes.Buffer
+
+	err := t.Execute(&buf, r)
+	if err != nil {
+		return "", err
+	}
+
+	return buf.String(), nil
 }
 
-func groupMergeReports(reports []dmarc.Report) ([]dmarc.Report, error) {
+func groupMergeReports(reports []dmarc.Report, t *template.Template) ([]dmarc.Report, error) {
 	if len(reports) == 0 {
 		return nil, fmt.Errorf("reports list is empty")
 	}
@@ -36,7 +45,11 @@ func groupMergeReports(reports []dmarc.Report) ([]dmarc.Report, error) {
 
 	// group reports by key
 	for _, r := range reports {
-		key := groupReportsKey(r)
+		key, err := groupReportsKey(r, t)
+		if err != nil {
+			return reports, fmt.Errorf("error generating merge key: %s", err)
+		}
+
 		//lint:ignore S1036 we dont want to add nil value
 		if _, found := grouped[key]; found {
 			grouped[key] = append(grouped[key], r)

config/config.dist.yaml

@@ -38,5 +38,8 @@ lookup_addr: no
 # merge multiple similar reports to one?
 merge_reports: yes
 
+# Go template string used to generate a key to merge reports.
+#merge_reports: "{{ .ReportMetadata.OrgName }}!{{ .ReportMetadata.Email }}!{{ .PolicyPublished.Domain }}"
+
 log_debug: no
 log_datetime: no