From 883b2a518a60121434b3895604e97e0c67fd8095 Mon Sep 17 00:00:00 2001
From: Kyle Havlovitz <kylehav@gmail.com>
Date: Fri, 6 Jul 2018 16:05:25 -0700
Subject: [PATCH] Store the time CARoot is rotated out instead of when to prune

---
 agent/consul/connect_ca_endpoint.go |  2 +-
 agent/consul/leader.go              | 16 ++++++----------
 agent/structs/connect_ca.go         |  6 +++---
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/agent/consul/connect_ca_endpoint.go b/agent/consul/connect_ca_endpoint.go
index 1e04f6733..4cdb72ff7 100644
--- a/agent/consul/connect_ca_endpoint.go
+++ b/agent/consul/connect_ca_endpoint.go
@@ -178,7 +178,7 @@ func (s *ConnectCA) ConfigurationSet(
 		newRoot := *r
 		if newRoot.Active {
 			newRoot.Active = false
-			newRoot.RotateOutAt = time.Now().Add(caRootExpireDuration)
+			newRoot.RotatedOutAt = time.Now()
 		}
 		newRoots = append(newRoots, &newRoot)
 	}
diff --git a/agent/consul/leader.go b/agent/consul/leader.go
index 2b0497dc3..8b32226dc 100644
--- a/agent/consul/leader.go
+++ b/agent/consul/leader.go
@@ -33,7 +33,7 @@ var (
 	caRootPruneInterval = time.Hour
 
 	// caRootExpireDuration is the duration after which an inactive root is considered
-	// "expired".
+	// "expired". Currently this is based on the default leaf cert TTL of 3 days.
 	caRootExpireDuration = 7 * 24 * time.Hour
 
 	// minAutopilotVersion is the minimum Consul version in which Autopilot features
@@ -568,10 +568,6 @@ func (s *Server) setCAProvider(newProvider ca.Provider, root *structs.CARoot) {
 // startCARootPruning starts a goroutine that looks for stale CARoots
 // and removes them from the state store.
 func (s *Server) startCARootPruning() {
-	if !s.config.ConnectEnabled {
-		return
-	}
-
 	s.caPruningLock.Lock()
 	defer s.caPruningLock.Unlock()
 
@@ -602,6 +598,10 @@ func (s *Server) startCARootPruning() {
 
 // pruneCARoots looks for any CARoots that have been rotated out and expired.
 func (s *Server) pruneCARoots() error {
+	if !s.config.ConnectEnabled {
+		return nil
+	}
+
 	idx, roots, err := s.fsm.State().CARoots(nil)
 	if err != nil {
 		return err
@@ -609,7 +609,7 @@ func (s *Server) pruneCARoots() error {
 
 	var newRoots structs.CARoots
 	for _, r := range roots {
-		if !r.Active && !r.RotateOutAt.IsZero() && r.RotateOutAt.Before(time.Now()) {
+		if !r.Active && !r.RotatedOutAt.IsZero() && time.Now().Sub(r.RotatedOutAt) > caRootExpireDuration {
 			s.logger.Printf("[INFO] connect: pruning old unused root CA (ID: %s)", r.ID)
 			continue
 		}
@@ -640,10 +640,6 @@ func (s *Server) pruneCARoots() error {
 
 // stopCARootPruning stops the CARoot pruning process.
 func (s *Server) stopCARootPruning() {
-	if !s.config.ConnectEnabled {
-		return
-	}
-
 	s.caPruningLock.Lock()
 	defer s.caPruningLock.Unlock()
 
diff --git a/agent/structs/connect_ca.go b/agent/structs/connect_ca.go
index 52b9c16f1..375a7df32 100644
--- a/agent/structs/connect_ca.go
+++ b/agent/structs/connect_ca.go
@@ -73,10 +73,10 @@ type CARoot struct {
 	// cannot be active.
 	Active bool
 
-	// RotateOutAt is the time at which this CA can be removed from the state.
+	// RotatedOutAt is the time at which this CA was removed from the state.
 	// This will only be set on roots that have been rotated out from being the
-	// active one.
-	RotateOutAt time.Time `json:"-"`
+	// active root.
+	RotatedOutAt time.Time `json:"-"`
 
 	RaftIndex
 }