refactor codebase:

- trailing whitespace in docs
- reduce panic and return err
- use log instead of fmt

design/reconciliation.md

@@ -14,7 +14,7 @@ For each reconciling cycle, we get P from k8s API. Comparing M and P, we have th
 2. P’ consist of remaining pods of P
 3. If P’ = M, the current state matches the membership state. GOTO Resize.
 4. If len(P’) < len(M)/2 + 1, quorum lost. Go to recovery process (TODO).
-5. Remove one member that in M but does not in P's. GOTO Resize. 
+5. Remove one member that in M but does not in P's. GOTO Resize.
 
 ### Resize
 

pkg/cluster/cluster.go

@@ -121,7 +121,7 @@ func (c *Cluster) create(spec *Spec) {
 		panic(fmt.Sprintf("(TODO: we need to clean up already created ones.)\nError: %v", err))
 	}
 	c.idCounter++
-	fmt.Println("created cluster:", members)
+	log.Println("created cluster:", members)
 }
 
 func (c *Cluster) Update(spec *Spec) {

pkg/cluster/reconcile.go

@@ -44,15 +44,15 @@ func (c *Cluster) reconcile(running etcdutil.MemberSet) error {
 		c.updateMembers(etcdcli)
 	}
 
-	log.Println("Running pods:", running)
+	log.Println("Running pods:\t", running)
-	log.Println("Expected membership:", c.members)
+	log.Println("Expected membership:\t", c.members)
 
 	unknownMembers := running.Diff(c.members)
 	if unknownMembers.Size() > 0 {
 		log.Println("Removing unexpected pods:", unknownMembers)
 		for _, m := range unknownMembers {
 			if err := c.removePodAndService(m.Name); err != nil {
-				panic(err)
+				return err
 			}
 		}
 	}
@@ -63,11 +63,11 @@ func (c *Cluster) reconcile(running etcdutil.MemberSet) error {
 	}
 
 	if L.Size() < c.members.Size()/2+1 {
-		fmt.Println("Disaster recovery")
+		log.Println("Disaster recovery")
 		return c.disasterRecovery()
 	}
 
-	fmt.Println("Recovering one member")
+	log.Println("Recovering one member")
 	toRecover := c.members.Diff(L).PickOne()
 
 	if err := c.removeMember(toRecover); err != nil {
@@ -101,7 +101,7 @@ func (c *Cluster) addOneMember() error {
 	newMember := &etcdutil.Member{Name: newMemberName}
 	resp, err := etcdcli.MemberAdd(context.TODO(), []string{newMember.PeerAddr()})
 	if err != nil {
-		panic(err)
+		return err
 	}
 	newMember.ID = resp.Member.ID
 	c.members.Add(newMember)