diff --git a/.travis.yml b/.travis.yml
index 0d81c09d20a8..456b606a5be7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,16 +8,8 @@ go:
 go_import_path: google.golang.org/grpc
 
 before_install:
-  - if [[ $TRAVIS_GO_VERSION = 1.8* ]]; then go get -u github.com/golang/lint/golint honnef.co/go/tools/cmd/staticcheck; fi
-  - go get -u golang.org/x/tools/cmd/goimports github.com/axw/gocov/gocov github.com/mattn/goveralls golang.org/x/tools/cmd/cover
-  - if [[ "$TRAVIS_EVENT_TYPE" = "cron" && $TRAVIS_GO_VERSION = 1.8* ]]; then PROTOBUF_VERSION=3.3.0 ./install-protobuf.sh; fi
+  - if [[ "$TRAVIS_GO_VERSION" = 1.8* ]]; then ./vet.sh -install || exit 1; fi
 
 script:
-  - 'if [[ "$TRAVIS_EVENT_TYPE" = "cron" && $TRAVIS_GO_VERSION = 1.8* ]]; then PATH=/home/travis/bin:$PATH make proto && ! git status --porcelain | tee /dev/stderr | read || (git status; git diff; exit 1); fi'
-  - 'set -o pipefail && git ls-files "*.go" | xargs grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" 2>&1 | tee /dev/stderr | (! read)'
-  - 'set -o pipefail && gofmt -s -d -l . 2>&1 | tee /dev/stderr | (! read)'
-  - 'set -o pipefail && goimports -l . 2>&1 | tee /dev/stderr | (! read)'
-  - 'if [[ $TRAVIS_GO_VERSION = 1.8* ]]; then ! golint ./... | grep -vE "(_mock|_string|\.pb)\.go:"; fi'
-  - 'if [[ $TRAVIS_GO_VERSION = 1.8* ]]; then ! go tool vet -all . 2>&1 | grep -vF .pb.go:; fi' # https://github.com/golang/protobuf/issues/214
+  - if [[ "$TRAVIS_GO_VERSION" = 1.8* ]]; then ./vet.sh || exit 1; fi
   - make test testrace
-  - 'if [[ $TRAVIS_GO_VERSION = 1.8* ]]; then staticcheck -ignore google.golang.org/grpc/transport/transport_test.go:SA2002 ./...; fi' # TODO(menghanl): fix these
diff --git a/Makefile b/Makefile
index 7b6033623b63..eb284c238f3a 100644
--- a/Makefile
+++ b/Makefile
@@ -20,7 +20,6 @@ proto:
 		echo "error: protoc not installed" >&2; \
 		exit 1; \
 	fi
-	go get -u -v github.com/golang/protobuf/protoc-gen-go golang.org/x/tools/cmd/stringer
 	go generate google.golang.org/grpc/...
 
 test: testdeps
@@ -32,9 +31,6 @@ testrace: testdeps
 clean:
 	go clean -i google.golang.org/grpc/...
 
-coverage: testdeps
-	./coverage.sh --coveralls
-
 .PHONY: \
 	all \
 	deps \
diff --git a/benchmark/benchmain/main.go b/benchmark/benchmain/main.go
index be3856e1560c..0d8a6961a99c 100644
--- a/benchmark/benchmain/main.go
+++ b/benchmark/benchmain/main.go
@@ -259,7 +259,7 @@ func init() {
 		runMode[0] = true
 		runMode[1] = true
 	default:
-		log.Fatalf("Unknown workloads setting: %v (want %v, %v, or %v)",
+		log.Fatalf("Unknown workloads setting: %v (want one of: %v)",
 			workloads, strings.Join(allWorkloads, ", "))
 	}
 	switch compressorMode {
diff --git a/coverage.sh b/coverage.sh
deleted file mode 100755
index b85f9181dee9..000000000000
--- a/coverage.sh
+++ /dev/null
@@ -1,48 +0,0 @@
-#!/usr/bin/env bash
-
-
-set -e
-
-workdir=.cover
-profile="$workdir/cover.out"
-mode=set
-end2endtest="google.golang.org/grpc/test"
-
-generate_cover_data() {
-    rm -rf "$workdir"
-    mkdir "$workdir"
-
-    for pkg in "$@"; do
-        if [ $pkg == "google.golang.org/grpc" -o $pkg == "google.golang.org/grpc/transport" -o $pkg == "google.golang.org/grpc/metadata" -o $pkg == "google.golang.org/grpc/credentials" ]
-            then
-                f="$workdir/$(echo $pkg | tr / -)"
-                go test -covermode="$mode" -coverprofile="$f.cover" "$pkg"
-                go test -covermode="$mode" -coverpkg "$pkg" -coverprofile="$f.e2e.cover" "$end2endtest"
-        fi
-    done
-
-    echo "mode: $mode" >"$profile"
-    grep -h -v "^mode:" "$workdir"/*.cover >>"$profile"
-}
-
-show_cover_report() {
-    go tool cover -${1}="$profile"
-}
-
-push_to_coveralls() {
-    goveralls -coverprofile="$profile"
-}
-
-generate_cover_data $(go list ./...)
-show_cover_report func
-case "$1" in
-"")
-    ;;
---html)
-    show_cover_report html ;;
---coveralls)
-    push_to_coveralls ;;
-*)
-    echo >&2 "error: invalid option: $1" ;;
-esac
-rm -rf "$workdir"
diff --git a/install-protobuf.sh b/install-protobuf.sh
deleted file mode 100755
index e962f7f613a0..000000000000
--- a/install-protobuf.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-
-set -ex
-
-die() {
-    echo "$@" >&2
-    exit 1
-}
-
-case "$PROTOBUF_VERSION" in
-3*)
-    basename=protoc-$PROTOBUF_VERSION
-    ;;
-*)
-    die "unknown protobuf version: $PROTOBUF_VERSION"
-    ;;
-esac
-
-cd /home/travis
-
-wget https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/$basename-linux-x86_64.zip
-unzip $basename-linux-x86_64.zip
-bin/protoc --version
diff --git a/vet.sh b/vet.sh
new file mode 100755
index 000000000000..e18fb29085d2
--- /dev/null
+++ b/vet.sh
@@ -0,0 +1,74 @@
+#!/bin/bash
+
+set -ex  # Exit on error; debugging enabled.
+set -o pipefail  # Fail a pipe if any sub-command fails.
+
+die() {
+  echo "$@" >&2
+  exit 1
+}
+
+# TODO: Remove this check and the mangling below once "context" is imported
+# directly.
+if git status --porcelain | read; then
+  die "Uncommitted or untracked files found; commit changes first"
+fi
+# Undo any edits made by this script.
+cleanup() {
+  git reset --hard HEAD
+}
+trap cleanup EXIT
+
+# Check proto in manual runs or cron runs.
+if [[ "$TRAVIS" != "true" || "$TRAVIS_EVENT_TYPE" = "cron" ]]; then
+  check_proto="true"
+fi
+
+if [ "$1" = "-install" ]; then
+  go get -d \
+    google.golang.org/grpc/...
+  go get -u \
+    github.com/golang/lint/golint \
+    golang.org/x/tools/cmd/goimports \
+    honnef.co/go/tools/cmd/staticcheck \
+    github.com/golang/protobuf/protoc-gen-go \
+    golang.org/x/tools/cmd/stringer
+  if [[ "$check_proto" = "true" ]]; then
+    if [[ "$TRAVIS" = "true" ]]; then
+      PROTOBUF_VERSION=3.3.0
+      cd /home/travis
+      wget https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/$basename-linux-x86_64.zip
+      unzip $basename-linux-x86_64.zip
+      bin/protoc --version
+    elif ! which protoc > /dev/null; then
+      die "Please install protoc into your path"
+    fi
+  fi
+  exit 0
+elif [[ "$#" -ne 0 ]]; then
+  die "Unknown argument(s): $*"
+fi
+
+git ls-files "*.go" | xargs grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" 2>&1 | tee /dev/stderr | (! read)
+gofmt -s -d -l . 2>&1 | tee /dev/stderr | (! read)
+goimports -l . 2>&1 | tee /dev/stderr | (! read)
+golint ./... 2>&1 | (grep -vE "(_mock|_string|\.pb)\.go:" || true) | tee /dev/stderr | (! read)
+
+# Rewrite golang.org/x/net/context -> context imports (see grpc/grpc-go#1484).
+# TODO: Remove this mangling once "context" is imported directly (grpc/grpc-go#711).
+git ls-files "*.go" | xargs sed -i 's:"golang.org/x/net/context":"context":'
+set +o pipefail
+# TODO: Stop filtering pb.go files once golang/protobuf#214 is fixed.
+# TODO: Remove clientconn exception once go1.6 support is removed.
+go tool vet -all . 2>&1 | grep -vE 'clientconn.go:.*cancel' | grep -vF '.pb.go:' | tee /dev/stderr | (! read)
+set -o pipefail
+git reset --hard HEAD
+
+if [[ "$check_proto" = "true" ]]; then
+  PATH=/home/travis/bin:$PATH make proto && \
+    git status --porcelain 2>&1 | (! read) || \
+    (git status; git --no-pager diff; exit 1)
+fi
+
+# TODO(menghanl): fix errors in transport_test.
+staticcheck -ignore google.golang.org/grpc/transport/transport_test.go:SA2002 ./...