Introduce ineffassign tooling, fixes

`ineffassign` detects ineffectual assignments in Go code. This change
introduces a `bin/ineffassign` into ci, and fixes 4 ineffectual
assignments caught by ineffassign.

Also perform a one-time gofmt cleanup:
- `gofmt -s -w controller/`
- `gofmt -s -w pkg/`

Part of #217

Signed-off-by: Andrew Seigner <siggy@buoyant.io>

.travis.yml

@@ -37,6 +37,7 @@ jobs:
         - ./bin/protoc-go.sh
         - go test -race -v ./...
         - go vet ./...
+        - ./bin/ineffassign
         - ./bin/lint
 
     - language: node_js

Gopkg.lock

@@ -330,6 +330,14 @@
   pruneopts = ""
   revision = "104e2578924bb3b211150c19414d0144b82165bb"
 
+[[projects]]
+  branch = "master"
+  digest = "1:0856bb71810be4fa4293ee4ecb6382f602003c928e02ac42dc9b28e4f11fff4c"
+  name = "github.com/gordonklaus/ineffassign"
+  packages = ["."]
+  pruneopts = ""
+  revision = "1003c8bd00dc2869cb5ca5282e6ce33834fed514"
+
 [[projects]]
   digest = "1:64d212c703a2b94054be0ce470303286b177ad260b2f89a307e3d1bb6c073ef6"
   name = "github.com/gorilla/websocket"
@@ -1252,6 +1260,7 @@
     "github.com/golang/protobuf/protoc-gen-go",
     "github.com/golang/protobuf/ptypes",
     "github.com/golang/protobuf/ptypes/duration",
+    "github.com/gordonklaus/ineffassign",
     "github.com/gorilla/websocket",
     "github.com/grpc-ecosystem/go-grpc-prometheus",
     "github.com/julienschmidt/httprouter",

Gopkg.toml

@@ -1,5 +1,6 @@
 required = [
   "github.com/golang/protobuf/protoc-gen-go",
+  "github.com/gordonklaus/ineffassign",
   "golang.org/x/lint/golint",
   "k8s.io/code-generator/cmd/client-gen",
   "k8s.io/code-generator/cmd/deepcopy-gen",

TEST.md

@@ -37,6 +37,12 @@ To analyze the Go code without running tests, run:
 go vet ./...
 ```
 
+To detect ineffectual assignments using ineffassign, run:
+
+```bash
+bin/ineffassign
+```
+
 To lint the Go code using golint, run:
 
 ```bash

bin/ineffassign

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -eu
+
+cd "$(pwd -P)"
+
+bindir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+rootdir="$( cd $bindir/.. && pwd )"
+
+cd "$rootdir"
+
+# install ineffassign from vendor
+go install ./vendor/github.com/gordonklaus/ineffassign
+
+ineffassign ./

cli/Dockerfile-bin

@@ -1,5 +1,5 @@
 ## compile binaries
-FROM gcr.io/linkerd-io/go-deps:fb05ef23 as golang
+FROM gcr.io/linkerd-io/go-deps:ef1a4319 as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY cli cli
 COPY chart chart

cli/cmd/endpoints.go

@@ -83,7 +83,7 @@ requests.`,
 			output := renderEndpoints(endpoints, options)
 			_, err = fmt.Print(output)
 
-			return nil
+			return err
 		},
 	}
 

cni-plugin/Dockerfile

@@ -1,5 +1,5 @@
 ## compile cni-plugin utility
-FROM gcr.io/linkerd-io/go-deps:fb05ef23 as golang
+FROM gcr.io/linkerd-io/go-deps:ef1a4319 as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY proxy-init proxy-init
 COPY pkg pkg

controller/Dockerfile

@@ -1,5 +1,5 @@
 ## compile controller services
-FROM gcr.io/linkerd-io/go-deps:fb05ef23 as golang
+FROM gcr.io/linkerd-io/go-deps:ef1a4319 as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY controller/gen controller/gen
 COPY pkg pkg

controller/api/proxy/endpoint_listener_test.go

@@ -51,12 +51,12 @@ var (
 	}
 
 	add = []*updateAddress{
-		&updateAddress{address: addedAddress1, pod: pod1},
-		&updateAddress{address: addedAddress2, pod: pod2},
+		{address: addedAddress1, pod: pod1},
+		{address: addedAddress2, pod: pod2},
 	}
 
 	remove = []*updateAddress{
-		&updateAddress{address: removedAddress1},
+		{address: removedAddress1},
 	}
 )
 
@@ -181,7 +181,7 @@ func TestEndpointListener(t *testing.T) {
 		}
 
 		add := []*updateAddress{
-			&updateAddress{address: addedAddress1, pod: podForAddedAddress1},
+			{address: addedAddress1, pod: podForAddedAddress1},
 		}
 		listener.Update(add, nil)
 
@@ -238,7 +238,7 @@ func TestEndpointListener(t *testing.T) {
 		)
 
 		add := []*updateAddress{
-			&updateAddress{address: addedAddress1, pod: podForAddedAddress1},
+			{address: addedAddress1, pod: podForAddedAddress1},
 		}
 		listener.Update(add, nil)
 
@@ -286,7 +286,7 @@ func TestEndpointListener(t *testing.T) {
 		)
 
 		add := []*updateAddress{
-			&updateAddress{address: addedAddress1, pod: podForAddedAddress1},
+			{address: addedAddress1, pod: podForAddedAddress1},
 		}
 		listener.Update(add, nil)
 

controller/api/proxy/endpoints_watcher_test.go

@@ -99,7 +99,7 @@ status:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name1"}: map[uint32]*servicePort{
-					8989: &servicePort{
+					8989: {
 						addresses: []*updateAddress{
 							makeUpdateAddress("172.17.0.12", 8989, "ns", "name1-1"),
 							makeUpdateAddress("172.17.0.19", 8989, "ns", "name1-2"),
@@ -112,22 +112,22 @@ status:
 								Namespace: "ns",
 							},
 							Subsets: []v1.EndpointSubset{
-								v1.EndpointSubset{
+								{
 									Addresses: []v1.EndpointAddress{
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.12",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-1"},
 										},
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.19",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-2"},
 										},
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.20",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-3"},
 										},
 									},
-									Ports: []v1.EndpointPort{v1.EndpointPort{Port: 8989}},
+									Ports: []v1.EndpointPort{{Port: 8989}},
 								},
 							},
 						},
@@ -199,7 +199,7 @@ status:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name1"}: map[uint32]*servicePort{
-					8989: &servicePort{
+					8989: {
 						addresses: []*updateAddress{
 							makeUpdateAddress("10.233.66.239", 8990, "ns", "name1-f748fb6b4-hpwpw"),
 							makeUpdateAddress("10.233.88.244", 8990, "ns", "name1-f748fb6b4-6vcmw"),
@@ -211,18 +211,18 @@ status:
 								Namespace: "ns",
 							},
 							Subsets: []v1.EndpointSubset{
-								v1.EndpointSubset{
+								{
 									Addresses: []v1.EndpointAddress{
-										v1.EndpointAddress{
+										{
 											IP:        "10.233.66.239",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-f748fb6b4-hpwpw"},
 										},
-										v1.EndpointAddress{
+										{
 											IP:        "10.233.88.244",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-f748fb6b4-6vcmw"},
 										},
 									},
-									Ports: []v1.EndpointPort{v1.EndpointPort{Port: 8990, Protocol: "TCP"}},
+									Ports: []v1.EndpointPort{{Port: 8990, Protocol: "TCP"}},
 								},
 							},
 						},
@@ -281,7 +281,7 @@ status:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "world"}: map[uint32]*servicePort{
-					7778: &servicePort{
+					7778: {
 						addresses: []*updateAddress{
 							makeUpdateAddress("10.1.30.135", 7779, "ns", "world-575bf846b4-tp4hw"),
 						},
@@ -292,14 +292,14 @@ status:
 								Namespace: "ns",
 							},
 							Subsets: []v1.EndpointSubset{
-								v1.EndpointSubset{
+								{
 									Addresses: []v1.EndpointAddress{
-										v1.EndpointAddress{
+										{
 											IP:        "10.1.30.135",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "world-575bf846b4-tp4hw"},
 										},
 									},
-									Ports: []v1.EndpointPort{v1.EndpointPort{Name: "app", Port: 7779, Protocol: "TCP"}},
+									Ports: []v1.EndpointPort{{Name: "app", Port: 7779, Protocol: "TCP"}},
 								},
 							},
 						},
@@ -363,7 +363,7 @@ status:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name1"}: map[uint32]*servicePort{
-					8989: &servicePort{
+					8989: {
 						addresses: []*updateAddress{
 							makeUpdateAddress("172.17.0.25", 8989, "ns", "name1-3"),
 						},
@@ -374,22 +374,22 @@ status:
 								Namespace: "ns",
 							},
 							Subsets: []v1.EndpointSubset{
-								v1.EndpointSubset{
+								{
 									Addresses: []v1.EndpointAddress{
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.23",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-1"},
 										},
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.24",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-2"},
 										},
-										v1.EndpointAddress{
+										{
 											IP:        "172.17.0.25",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "name1-3"},
 										},
 									},
-									Ports: []v1.EndpointPort{v1.EndpointPort{Port: 8989}},
+									Ports: []v1.EndpointPort{{Port: 8989}},
 								},
 							},
 						},
@@ -417,7 +417,7 @@ spec:
 			expectedNoEndpointsServiceExists: true,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name2"}: map[uint32]*servicePort{
-					7979: &servicePort{
+					7979: {
 						targetPort: intstr.IntOrString{Type: intstr.Int, IntVal: 7979},
 						endpoints:  &v1.Endpoints{},
 					},
@@ -443,7 +443,7 @@ spec:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name3"}: map[uint32]*servicePort{
-					6969: &servicePort{
+					6969: {
 						targetPort: intstr.IntOrString{Type: intstr.Int, IntVal: 6969},
 						endpoints:  &v1.Endpoints{},
 					},
@@ -460,7 +460,7 @@ spec:
 			expectedNoEndpointsServiceExists: false,
 			expectedState: servicePorts{
 				serviceID{namespace: "ns", name: "name4"}: map[uint32]*servicePort{
-					5959: &servicePort{
+					5959: {
 						targetPort: intstr.IntOrString{Type: intstr.Int, IntVal: 5959},
 						endpoints:  &v1.Endpoints{},
 					},

controller/api/proxy/k8s_resolver.go

@@ -171,7 +171,7 @@ func (k *k8sResolver) localKubernetesServiceIDFromDNSName(host string) (*service
 	// doesn't require Kubernetes to do this, but some hosting providers like
 	// GKE do it, and so we need to support it for transparency.
 	if !matched {
-		hostLabels, matched = maybeStripSuffixLabels(hostLabels, []string{"cluster", "local"})
+		hostLabels, _ = maybeStripSuffixLabels(hostLabels, []string{"cluster", "local"})
 	}
 	// TODO:
 	// ```

controller/api/proxy/k8s_resolver_test.go

@@ -70,7 +70,7 @@ func TestGetState(t *testing.T) {
 		{
 			servicePorts: servicePorts{
 				serviceID{namespace: "ns", name: "name"}: map[uint32]*servicePort{
-					8888: &servicePort{
+					8888: {
 						addresses: []*updateAddress{
 							makeUpdateAddress("10.1.30.135", 7779, "ns", "world-575bf846b4-tp4hw"),
 						},
@@ -80,14 +80,14 @@ func TestGetState(t *testing.T) {
 								Namespace: "ns",
 							},
 							Subsets: []v1.EndpointSubset{
-								v1.EndpointSubset{
+								{
 									Addresses: []v1.EndpointAddress{
-										v1.EndpointAddress{
+										{
 											IP:        "10.1.30.135",
 											TargetRef: &v1.ObjectReference{Kind: "Pod", Namespace: "ns", Name: "world-575bf846b4-tp4hw"},
 										},
 									},
-									Ports: []v1.EndpointPort{v1.EndpointPort{Name: "app", Port: 7779, Protocol: "TCP"}},
+									Ports: []v1.EndpointPort{{Name: "app", Port: 7779, Protocol: "TCP"}},
 								},
 							},
 						},