Adds support for run once mode

context.go

@@ -12,18 +12,21 @@ import (
 )
 
 const (
-	CERT_DESCRIPTION  = "Created by Let's Encrypt Certificate Manager"
-	ISSUER_PRODUCTION = "Let's Encrypt"
-	ISSUER_STAGING    = "fake CA"
+	CERT_DESCRIPTION    = "Created by Let's Encrypt Certificate Manager"
+	ISSUER_PRODUCTION   = "Let's Encrypt"
+	ISSUER_STAGING      = "fake CA"
+	RENEWAL_PERIOD_DAYS = 20
 )
 
 type Context struct {
 	Acme    *letsencrypt.Client
 	Rancher *rancher.Client
 
-	CertificateName string
-	Domains         []string
-	RenewalTime     int
+	CertificateName   string
+	Domains           []string
+	RenewalDayTime    int
+	RenewalPeriodDays int
+	RunOnce           bool
 
 	ExpiryDate    time.Time
 	RancherCertId string
@@ -46,9 +49,23 @@ func (c *Context) InitContext() {
 	domainParam := getEnvOption("DOMAINS", true)
 	keyTypeParam := getEnvOption("PUBLIC_KEY_TYPE", true)
 	certNameParam := getEnvOption("CERT_NAME", true)
-	timeParam := getEnvOption("RENEWAL_TIME", true)
+	dayTimeParam := getEnvOption("RENEWAL_TIME", true)
 	providerParam := getEnvOption("PROVIDER", true)
 	resolversParam := getEnvOption("DNS_RESOLVERS", false)
+	renewalDays := getEnvOption("RENEWAL_PERIOD_DAYS", false)
+	runOnce := getEnvOption("RUN_ONCE", false)
+
+	if b, err := strconv.ParseBool(runOnce); err == nil {
+		c.RunOnce = b
+	} else {
+		c.RunOnce = false
+	}
+
+	if i, err := strconv.Atoi(renewalDays); err == nil {
+		c.RenewalPeriodDays = i
+	} else {
+		c.RenewalPeriodDays = RENEWAL_PERIOD_DAYS
+	}
 
 	if eulaParam != "Yes" {
 		logrus.Fatalf("Terms of service were not accepted")
@@ -70,9 +87,9 @@ func (c *Context) InitContext() {
 	}
 
 	c.CertificateName = certNameParam
-	c.RenewalTime, err = strconv.Atoi(timeParam)
-	if err != nil || c.RenewalTime < 0 || c.RenewalTime > 23 {
-		logrus.Fatalf("Invalid value for RENEWAL_TIME: %s", timeParam)
+	c.RenewalDayTime, err = strconv.Atoi(dayTimeParam)
+	if err != nil || c.RenewalDayTime < 0 || c.RenewalDayTime > 23 {
+		logrus.Fatalf("Invalid value for RENEWAL_TIME: %s", dayTimeParam)
 	}
 
 	apiVersion := letsencrypt.ApiVersion(apiVerParam)

manager.go

@@ -8,12 +8,19 @@ import (
 	"github.com/Sirupsen/logrus"
 )
 
-const (
-	RENEW_BEFORE_DAYS = 20
-)
-
 func (c *Context) Run() {
 	c.startup()
+	if c.RunOnce {
+		// Renew certificate if it's about to expire
+		if time.Now().UTC().After(c.getRenewalDate()) {
+			c.renew()
+		} else {
+			logrus.Infof("Certificate %s expires on %s", c.CertificateName,
+				c.ExpiryDate.UTC().Format(time.UnixDate))
+		}
+		return
+	}
+
 	for {
 		<-c.timer()
 		c.renew()
@@ -142,7 +149,10 @@ func (c *Context) timer() <-chan time.Time {
 }
 
 func (c *Context) getRenewalDate() time.Time {
-	date := c.ExpiryDate.AddDate(0, 0, -RENEW_BEFORE_DAYS)
+	if c.ExpiryDate.IsZero() {
+		logrus.Fatalf("Could not determine expiry date for certificate: %s", c.CertificateName)
+	}
+	date := c.ExpiryDate.AddDate(0, 0, -c.RenewalPeriodDays)
 	dYear, dMonth, dDay := date.Date()
-	return time.Date(dYear, dMonth, dDay, c.RenewalTime, 0, 0, 0, time.UTC)
+	return time.Date(dYear, dMonth, dDay, c.RenewalDayTime, 0, 0, 0, time.UTC)
 }