Adding x509_cert input plugin

plugins/inputs/all/all.go

@@ -113,6 +113,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/webhooks"
 	_ "github.com/influxdata/telegraf/plugins/inputs/win_perf_counters"
 	_ "github.com/influxdata/telegraf/plugins/inputs/win_services"
+	_ "github.com/influxdata/telegraf/plugins/inputs/x509_cert"
 	_ "github.com/influxdata/telegraf/plugins/inputs/zfs"
 	_ "github.com/influxdata/telegraf/plugins/inputs/zipkin"
 	_ "github.com/influxdata/telegraf/plugins/inputs/zookeeper"

plugins/inputs/x509_cert/README.md

@@ -0,0 +1,45 @@
+# X509 Cert Input Plugin
+
+This plugin provides information about X509 certificate accessible via local
+file or network connection.
+
+
+### Configuration
+
+```toml
+# Reads metrics from a SSL certificate
+[[inputs.x509_cert]]
+  ## List of local SSL files
+  # files = ["/etc/ssl/certs/ssl-cert-snakeoil.pem"]
+  ## List of servers
+  # servers = ["tcp://example.org:443"]
+  ## Timeout for SSL connection
+  # timeout = 5
+  ## Optional TLS Config
+  # tls_ca = "/etc/telegraf/ca.pem"
+  # tls_cert = "/etc/telegraf/cert.pem"
+  # tls_key = "/etc/telegraf/key.pem"
+  ## Use TLS but skip chain & host verification
+  # insecure_skip_verify = false
+```
+
+
+### Metrics
+
+- `x509_cert`
+  - tags:
+    - `server` (only if `servers` parameter is defined)
+    - `file` (only if `files` parameter is defined)
+  - fields:
+    - `expiry` (int, seconds)
+    - `age` (int, seconds)
+    - `startdate` (int, seconds)
+    - `enddate` (int, seconds)
+
+
+### Example output
+
+```
+x509_cert,server=google.com:443,host=myhost age=1753627i,expiry=5503972i,startdate=1516092060i,enddate=1523349660i 1517845687000000000
+x509_cert,host=myhost,file=/path/to/the.crt age=7522207i,expiry=308002732i,startdate=1510323480i,enddate=1825848420i 1517845687000000000
+```

plugins/inputs/x509_cert/x509_cert.go

@@ -0,0 +1,188 @@
+package x509_cert
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
+	_tls "github.com/influxdata/telegraf/internal/tls"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+const sampleConfig = `
+  ## List of local SSL files
+  # files = ["/etc/ssl/certs/ssl-cert-snakeoil.pem"]
+  ## List of servers
+  # servers = ["tcp://example.org:443"]
+  ## Timeout for SSL connection
+  # timeout = 5
+  ## Optional TLS Config
+  # tls_ca = "/etc/telegraf/ca.pem"
+  # tls_cert = "/etc/telegraf/cert.pem"
+  # tls_key = "/etc/telegraf/key.pem"
+  ## Use TLS but skip chain & host verification
+  # insecure_skip_verify = false
+`
+const description = "Reads metrics from a SSL certificate"
+
+// X509Cert holds the configuration of the plugin.
+type X509Cert struct {
+	Servers []string          `toml:"servers"`
+	Files   []string          `toml:"files"`
+	Timeout internal.Duration `toml:"timeout"`
+	_tls.ClientConfig
+}
+
+// For tests
+var (
+	closeConn  bool
+	unsetCerts bool
+)
+
+// Description returns description of the plugin.
+func (c *X509Cert) Description() string {
+	return description
+}
+
+// SampleConfig returns configuration sample for the plugin.
+func (c *X509Cert) SampleConfig() string {
+	return sampleConfig
+}
+
+func (c *X509Cert) getRemoteCert(server string, timeout time.Duration) (*x509.Certificate, error) {
+	tlsCfg, err := c.ClientConfig.TLSConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	network := "tcp"
+	host_port := server
+	vals := strings.Split(server, "://")
+
+	if len(vals) > 1 {
+		network = vals[0]
+		host_port = vals[1]
+	}
+
+	ipConn, err := net.DialTimeout(network, host_port, timeout)
+	if err != nil {
+		return nil, err
+	}
+	defer ipConn.Close()
+
+	conn := tls.Client(ipConn, tlsCfg)
+	defer conn.Close()
+
+	if closeConn {
+		conn.Close()
+	}
+
+	hsErr := conn.Handshake()
+	if hsErr != nil {
+		return nil, hsErr
+	}
+
+	certs := conn.ConnectionState().PeerCertificates
+
+	if unsetCerts {
+		certs = nil
+	}
+
+	if certs == nil || len(certs) < 1 {
+		return nil, errors.New("couldn't get remote certificate")
+	}
+
+	return certs[0], nil
+}
+
+func getLocalCert(filename string) (*x509.Certificate, error) {
+	content, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	block, _ := pem.Decode(content)
+	if block == nil {
+		return nil, errors.New("failed to parse certificate PEM")
+	}
+
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return cert, nil
+}
+
+func getFields(cert *x509.Certificate, now time.Time) map[string]interface{} {
+	age := int(now.Sub(cert.NotBefore).Seconds())
+	expiry := int(cert.NotAfter.Sub(now).Seconds())
+	startdate := cert.NotBefore.Unix()
+	enddate := cert.NotAfter.Unix()
+	valid := expiry > 0
+
+	fields := map[string]interface{}{
+		"age":       age,
+		"expiry":    expiry,
+		"startdate": startdate,
+		"enddate":   enddate,
+		"valid":     valid,
+	}
+
+	return fields
+}
+
+// Gather adds metrics into the accumulator.
+func (c *X509Cert) Gather(acc telegraf.Accumulator) error {
+	now := time.Now()
+
+	for _, server := range c.Servers {
+		cert, err := c.getRemoteCert(server, c.Timeout.Duration*time.Second)
+		if err != nil {
+			return fmt.Errorf("cannot get remote SSL cert '%s': %s", server, err)
+		}
+
+		tags := map[string]string{
+			"server": server,
+		}
+
+		fields := getFields(cert, now)
+
+		acc.AddFields("x509_cert", fields, tags)
+	}
+
+	for _, file := range c.Files {
+		cert, err := getLocalCert(file)
+		if err != nil {
+			return fmt.Errorf("cannot get local SSL cert '%s': %s", file, err)
+		}
+
+		tags := map[string]string{
+			"file": file,
+		}
+
+		fields := getFields(cert, now)
+
+		acc.AddFields("x509_cert", fields, tags)
+	}
+
+	return nil
+}
+
+func init() {
+	inputs.Add("x509_cert", func() telegraf.Input {
+		return &X509Cert{
+			Files:   []string{},
+			Servers: []string{},
+			Timeout: internal.Duration{Duration: 5},
+		}
+	})
+}