Documentation/upgrades: clean up 3.2, 3.3 guides

Make headers consistent.

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

Documentation/upgrades/upgrade_3_2.md

@@ -6,57 +6,38 @@ In the general case, upgrading from etcd 3.1 to 3.2 can be a zero-downtime, roll
 
 Before [starting an upgrade](#upgrade-procedure), read through the rest of this guide to prepare.
 
-### Server upgrade checklists (breaking change)
+### Upgrade checklists
 
-3.2 now rejects domains names for `--listen-peer-urls` and `--listen-client-urls` (3.1 only prints out warnings), since domain name is invalid for network interface binding. Make sure that those URLs are properly formated as `scheme://IP:port`.
+Highlighted breaking changes in 3.2.
 
-See [issue #6336](https://github.com/coreos/etcd/issues/6336) for more contexts.
+#### Change in gRPC dependency (>=3.2.10)
 
-### Client upgrade checklists (>=3.2.0)
+3.2.10 or later now requires [grpc/grpc-go](https://github.com/grpc/grpc-go/releases) `v1.7.5` (<=3.2.9 requires `v1.2.1`).
 
-3.2 introduces two breaking changes.
+##### Deprecate `grpclog.Logger`
 
-Previously, `clientv3.Lease.TimeToLive` API returned `lease.ErrLeaseNotFound` on non-existent lease ID. 3.2 instead returns TTL=-1 in its response and no error (see [#7305](https://github.com/coreos/etcd/pull/7305)).
+`grpclog.Logger` has been deprecated in favor of [`grpclog.LoggerV2`](https://github.com/grpc/grpc-go/blob/master/grpclog/loggerv2.go). `clientv3.Logger` is now `grpclog.LoggerV2`.
 
 Before
 
 ```go
-// when leaseID does not exist
-resp, err := TimeToLive(ctx, leaseID)
-resp == nil
-err == lease.ErrLeaseNotFound
+import "github.com/coreos/etcd/clientv3"
+clientv3.SetLogger(log.New(os.Stderr, "grpc: ", 0))
 ```
 
 After
 
-```go
-// when leaseID does not exist
-resp, err := TimeToLive(ctx, leaseID)
-resp.TTL == -1
-err == nil
-```
-
-`clientv3.NewFromConfigFile` is moved to `yaml.NewConfig`.
-
-Before
-
 ```go
 import "github.com/coreos/etcd/clientv3"
-clientv3.NewFromConfigFile
-```
-
-After
+import "google.golang.org/grpc/grpclog"
+clientv3.SetLogger(grpclog.NewLoggerV2(os.Stderr, os.Stderr, os.Stderr))
 
-```go
-import clientv3yaml "github.com/coreos/etcd/clientv3/yaml"
-clientv3yaml.NewConfig
+// log.New above cannot be used (not implement grpclog.LoggerV2 interface)
 ```
 
-### Client upgrade checklists (>=3.2.10)
-
-Note that >=3.2.10 requires `grpc/grpc-go` v1.7.4 (<=3.2.9 with v1.2.1), which introduces some breaking changes.
+##### Deprecate `grpc.ErrClientConnTimeout`
 
-Previously, `grpc.ErrClientConnTimeout` error is returned on client dial time-outs. >=3.2.10 instead returns `context.DeadlineExceeded` (see [#8504](https://github.com/coreos/etcd/issues/8504)).
+Previously, `grpc.ErrClientConnTimeout` error is returned on client dial time-outs. 3.2 instead returns `context.DeadlineExceeded` (see [#8504](https://github.com/coreos/etcd/issues/8504)).
 
 Before
 
@@ -83,6 +64,52 @@ if err == context.DeadlineExceeded {
 }
 ```
 
+#### Change in `--listen-peer-urls` and `--listen-client-urls`
+
+3.2 now rejects domains names for `--listen-peer-urls` and `--listen-client-urls` (3.1 only prints out warnings), since domain name is invalid for network interface binding. Make sure that those URLs are properly formated as `scheme://IP:port`.
+
+See [issue #6336](https://github.com/coreos/etcd/issues/6336) for more contexts.
+
+#### Change in `clientv3.Lease.TimeToLive` API
+
+Previously, `clientv3.Lease.TimeToLive` API returned `lease.ErrLeaseNotFound` on non-existent lease ID. 3.2 instead returns TTL=-1 in its response and no error (see [#7305](https://github.com/coreos/etcd/pull/7305)).
+
+Before
+
+```go
+// when leaseID does not exist
+resp, err := TimeToLive(ctx, leaseID)
+resp == nil
+err == lease.ErrLeaseNotFound
+```
+
+After
+
+```go
+// when leaseID does not exist
+resp, err := TimeToLive(ctx, leaseID)
+resp.TTL == -1
+err == nil
+```
+
+#### Change in `clientv3.NewFromConfigFile`
+
+`clientv3.NewFromConfigFile` is moved to `yaml.NewConfig`.
+
+Before
+
+```go
+import "github.com/coreos/etcd/clientv3"
+clientv3.NewFromConfigFile
+```
+
+After
+
+```go
+import clientv3yaml "github.com/coreos/etcd/clientv3/yaml"
+clientv3yaml.NewConfig
+```
+
 ### Server upgrade checklists
 
 #### Upgrade requirements

Documentation/upgrades/upgrade_3_3.md

@@ -111,23 +111,7 @@ curl -L http://localhost:2379/v3beta/kv/put \
 
 Requests to `/v3alpha` endpoints will redirect to `/v3beta`, and `/v3alpha` will be removed in 3.4 release.
 
-#### `gcr.io/etcd-development/etcd` as primary container registry
-
-etcd uses [`gcr.io/etcd-development/etcd`](https://gcr.io/etcd-development/etcd) as a primary container registry, and [`quay.io/coreos/etcd`](https://quay.io/coreos/etcd) as secondary.
-
-Before
-
-```bash
-docker pull quay.io/coreos/etcd:v3.2.5
-```
-
-After
-
-```bash
-docker pull gcr.io/etcd-development/etcd:v3.3.0
-```
-
-#### Change in `Snapshot` API error type
+#### Change in clientv3 `Snapshot` API error type
 
 Previously, clientv3 `Snapshot` API returned raw [`grpc/*status.statusError`] type error. v3.3 now translates those errors to corresponding public error types, to be consistent with other APIs.
 
@@ -173,7 +157,7 @@ _, err = io.Copy(f, rc)
 err == context.DeadlineExceeded
 ```
 
-#### Deprecate `golang.org/x/net/context` imports
+#### Change in `golang.org/x/net/context` imports
 
 `clientv3` has deprecated `golang.org/x/net/context`. If a project vendors `golang.org/x/net/context` in other code (e.g. etcd generated protocol buffer code) and imports `github.com/coreos/etcd/clientv3`, it requires Go 1.9+ to compile.
 
@@ -191,9 +175,9 @@ import "context"
 cli.Put(context.Background(), "f", "v")
 ```
 
-#### Upgrade grpc/grpc-go to `v1.7.4`
+#### Change in gRPC dependency
 
-3.3 now requires [grpc/grpc-go](https://github.com/grpc/grpc-go/releases) `v1.7.4`.
+3.3 now requires [grpc/grpc-go](https://github.com/grpc/grpc-go/releases) `v1.7.5`.
 
 ##### Deprecate `grpclog.Logger`
 
@@ -245,6 +229,22 @@ if err == context.DeadlineExceeded {
 }
 ```
 
+#### Change in official container registry
+
+etcd now uses [`gcr.io/etcd-development/etcd`](https://gcr.io/etcd-development/etcd) as a primary container registry, and [`quay.io/coreos/etcd`](https://quay.io/coreos/etcd) as secondary.
+
+Before
+
+```bash
+docker pull quay.io/coreos/etcd:v3.2.5
+```
+
+After
+
+```bash
+docker pull gcr.io/etcd-development/etcd:v3.3.0
+```
+
 ### Server upgrade checklists
 
 #### Upgrade requirements