Bump the minimum Go version to 1.9.

This is tracked here: vitessio#3219

Note that this also triggers a Debian version upgrade to their latest
stable version "stretch" which was released this summer.

This required several additional changes and cleanups:

- Remove outdated GO15VENDOREXPERIMENT.
- Docker: Upgrade Java to 8 (from 7).
- Docker: Upgrade PHP to 7 (from 5).
- Docker: Use "pip" from distribution and do not install it ourselves.
- Docker: PHP: Use "pecl install grpc" and no longer compile it ourselves. Relevant parts in travis/install_grpc.sh have been removed.
- Docker: Do no longer install etcd and consule in the common image because we call bootstrap.sh when building the flavored image and that installs these two as well.
- travis/install_grpc.sh changes:
  - Do no longer compile gRPC because for PHP and Python we can use other ways to install the shared library.
  - Do no longer compile protobuf. Instead, download pre-compiled "protoc" binary in bootstrap.sh.
  - Updated Python and PHP versions to 1.6 as we did earlier for Go.

.travis.yml

@@ -7,7 +7,7 @@ dist: precise
 sudo: false
 language: go
 go:
-  - 1.8
+  - 1.9
 go_import_path: github.com/youtube/vitess
 addons:
   apt:

bootstrap.sh

@@ -48,6 +48,24 @@ mkdir -p $VTROOT/vthook
 echo "Updating git submodules..."
 git submodule update --init
 
+# Install "protoc" protobuf compiler binary.
+protoc_version=3.4.0
+protoc_dist=$VTROOT/dist/protoc
+protoc_version_file=$protoc_dist/version
+if [[ -f $protoc_version_file && "$(cat $protoc_version_file)" == "$protoc_version" ]]; then
+  echo "skipping protoc install. remove $protoc_version_file to force re-install."
+else
+  rm -rf $protoc_dist
+  mkdir -p $protoc_dist
+  download_url=https://github.com/google/protobuf/releases/download/v${protoc_version}/protoc-${protoc_version}-linux-x86_64.zip
+  (cd $protoc_dist && \
+    wget $download_url && \
+    unzip protoc-${protoc_version}-linux-x86_64.zip)
+  [ $? -eq 0 ] || fail "protoc download failed"
+  echo "$protoc_version" > $protoc_version_file
+fi
+ln -snf $protoc_dist/bin/protoc $VTROOT/bin/protoc
+
 # install zookeeper
 zk_ver=3.4.6
 zk_dist=$VTROOT/dist/vt-zookeeper-$zk_ver

composer.json

@@ -9,7 +9,7 @@
     "php": ">=5.5.0",
     "stanley-cheung/protobuf-php": "v0.6",
     "google/auth": "v0.10",
-    "grpc/grpc": "v1.0.0"
+    "grpc/grpc": "v1.6.0"
   },
   "autoload": {
     "psr-4": {

dev.env

@@ -34,8 +34,6 @@ mkdir -p $VTDATAROOT
 
 export VTPORTSTART=15000
 
-export GO15VENDOREXPERIMENT=1
-
 for pypath in $(find $VTROOT/dist -name site-packages -or -name dist-packages | grep -v src/python/grpcio/.tox/py27/lib/python2.7/site-packages)
 do
   export PYTHONPATH=$(prepend_path $PYTHONPATH $pypath)

doc/GettingStarted.md

@@ -73,7 +73,7 @@ OS X 10.11 (El Capitan) should work as well, the installation instructions are b
 
 In addition, Vitess requires the software and libraries listed below.
 
-1.  [Install Go 1.8+](http://golang.org/doc/install).
+1.  [Install Go 1.9+](http://golang.org/doc/install).
 
 2.  Install [MariaDB 10.0](https://downloads.mariadb.org/) or
     [MySQL 5.6](http://dev.mysql.com/downloads/mysql). You can use any

doc/GettingStartedKubernetes.md

@@ -9,13 +9,13 @@ The `kubectl` steps will apply to any Kubernetes cluster.
 
 ## Prerequisites
 
-To complete the exercise in this guide, you must locally install Go 1.8+,
+To complete the exercise in this guide, you must locally install Go 1.9+,
 Vitess' `vtctlclient` tool, and Google Cloud SDK. The
 following sections explain how to set these up in your environment.
 
-### Install Go 1.8+
+### Install Go 1.9+
 
-You need to install [Go 1.8+](http://golang.org/doc/install) to build the
+You need to install [Go 1.9+](http://golang.org/doc/install) to build the
 `vtctlclient` tool, which issues commands to Vitess.
 
 After installing Go, make sure your `GOPATH` environment