Support a reporting via Syslog (#604)

* Support a reporting via syslog

* Update dependencies

report/syslog.go

@@ -0,0 +1,97 @@
+/* Vuls - Vulnerability Scanner
+Copyright (C) 2018  Future Architect, Inc. Japan.
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package report
+
+import (
+	"fmt"
+	"log/syslog"
+	"strings"
+
+	"github.com/pkg/errors"
+
+	"github.com/future-architect/vuls/config"
+	"github.com/future-architect/vuls/models"
+)
+
+// SyslogWriter send report to syslog
+type SyslogWriter struct{}
+
+func (w SyslogWriter) Write(rs ...models.ScanResult) (err error) {
+	conf := config.Conf.Syslog
+	facility, _ := conf.GetFacility()
+	severity, _ := conf.GetSeverity()
+	raddr := fmt.Sprintf("%s:%s", conf.Host, conf.Port)
+
+	sysLog, err := syslog.Dial(conf.Protocol, raddr, severity|facility, conf.Tag)
+	if err != nil {
+		return errors.Wrap(err, "Failed to initialize syslog client")
+	}
+
+	for _, r := range rs {
+		messages := w.encodeSyslog(r)
+		for _, m := range messages {
+			if _, err = fmt.Fprintf(sysLog, m); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (w SyslogWriter) encodeSyslog(result models.ScanResult) (messages []string) {
+	ipv4Addrs := strings.Join(result.IPv4Addrs, ",")
+	ipv6Addrs := strings.Join(result.IPv6Addrs, ",")
+
+	for cveID, vinfo := range result.ScannedCves {
+		var kvPairs []string
+		kvPairs = append(kvPairs, fmt.Sprintf(`server_name="%s"`, result.ServerName))
+		kvPairs = append(kvPairs, fmt.Sprintf(`os_family="%s"`, result.Family))
+		kvPairs = append(kvPairs, fmt.Sprintf(`os_release="%s"`, result.Release))
+		kvPairs = append(kvPairs, fmt.Sprintf(`ipv4_addr="%s"`, ipv4Addrs))
+		kvPairs = append(kvPairs, fmt.Sprintf(`ipv6_addr="%s"`, ipv6Addrs))
+
+		var pkgNames []string
+		for _, pkg := range vinfo.AffectedPackages {
+			pkgNames = append(pkgNames, pkg.Name)
+		}
+		pkgs := strings.Join(pkgNames, ",")
+		kvPairs = append(kvPairs, fmt.Sprintf(`packages="%s"`, pkgs))
+
+		kvPairs = append(kvPairs, fmt.Sprintf(`cve_id="%s"`, cveID))
+		for _, cvss := range vinfo.Cvss2Scores() {
+			if cvss.Type != models.NVD {
+				continue
+			}
+			kvPairs = append(kvPairs, fmt.Sprintf(`severity="%s"`, cvss.Value.Severity))
+			kvPairs = append(kvPairs, fmt.Sprintf(`cvss_score_v2="%.2f"`, cvss.Value.Score))
+			kvPairs = append(kvPairs, fmt.Sprintf(`cvss_vector_v2="%s"`, cvss.Value.Vector))
+		}
+
+		if content, ok := vinfo.CveContents[models.NVD]; ok {
+			kvPairs = append(kvPairs, fmt.Sprintf(`cwe_id="%s"`, content.CweID))
+			if config.Conf.Syslog.Verbose {
+				kvPairs = append(kvPairs, fmt.Sprintf(`source_link="%s"`, content.SourceLink))
+				kvPairs = append(kvPairs, fmt.Sprintf(`summary="%s"`, content.Summary))
+			}
+		}
+
+		// message: key1="value1" key2="value2"...
+		messages = append(messages, strings.Join(kvPairs, " "))
+	}
+	return messages
+}