feature: support etcd v3, by mocking v2 API

.travis.yml

@@ -23,7 +23,6 @@ addons:
       - libreadline-dev
       - libssl-dev
       - perl
-      - etcd
   homebrew:
     update: true
 

.travis/linux_apisix_current_luarocks_runner.sh

@@ -39,6 +39,8 @@ do_install() {
     sudo make install > build.log 2>&1 || (cat build.log && exit 1)
     cd ..
     rm -rf luarocks-2.4.4
+
+    ./utils/install-etcd.sh
 }
 
 script() {
@@ -48,8 +50,8 @@ script() {
     sudo service etcd start
     sudo service etcd stop
     mkdir -p ~/etcd-data
-    /usr/bin/etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
-    etcd --version
+    etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
+    etcdctl version
     sleep 5
 
     sudo rm -rf /usr/local/apisix

.travis/linux_openresty_mtls_runner.sh

@@ -59,6 +59,7 @@ do_install() {
 
     sudo luarocks install luacheck > build.log 2>&1 || (cat build.log && exit 1)
 
+    ./utils/install-etcd.sh
 
     if [ ! -f "build-cache/apisix-master-0.rockspec" ]; then
         create_lua_deps
@@ -92,8 +93,8 @@ script() {
     openresty -V
     sudo service etcd stop
     mkdir -p ~/etcd-data
-    /usr/bin/etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
-    etcd --version
+    etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
+    etcdctl version
     sleep 5
 
 

.travis/linux_openresty_runner.sh

@@ -74,6 +74,8 @@ do_install() {
 
     sudo luarocks install luacheck > build.log 2>&1 || (cat build.log && exit 1)
 
+    ./utils/install-etcd.sh
+
     if [ ! -f "build-cache/apisix-master-0.rockspec" ]; then
         create_lua_deps
 
@@ -127,8 +129,8 @@ script() {
     openresty -V
     sudo service etcd stop
     mkdir -p ~/etcd-data
-    /usr/bin/etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
-    etcd --version
+    etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
+    etcdctl version
     sleep 5
 
     ./build-cache/grpc_server_example &

.travis/linux_tengine_runner.sh

@@ -259,6 +259,8 @@ do_install() {
 
     sudo luarocks install luacheck > build.log 2>&1 || (cat build.log && exit 1)
 
+    ./utils/install-etcd.sh
+
     git clone https://github.com/iresty/test-nginx.git test-nginx
     make utils
 
@@ -280,8 +282,8 @@ script() {
     openresty -V
     sudo service etcd stop
     mkdir -p ~/etcd-data
-    /usr/bin/etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
-    etcd --version
+    etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls='http://0.0.0.0:2379' --data-dir ~/etcd-data > /dev/null 2>&1 &
+    etcdctl version
     sleep 5
 
     ./build-cache/grpc_server_example &

.travis/osx_openresty_runner.sh

@@ -65,7 +65,7 @@ script() {
     export_or_prefix
     export PATH=$OPENRESTY_PREFIX/nginx/sbin:$OPENRESTY_PREFIX/luajit/bin:$OPENRESTY_PREFIX/bin:$PATH
 
-    etcd --enable-v2=true &
+    etcd &
     sleep 1
 
     ./grpc_server_example &

README.md

@@ -166,10 +166,9 @@ There are several ways to install the Apache Release version of APISIX:
         apisix start
         ```
 
-**Note**: Apache APISIX does not yet support the v3 protocol of etcd, so you need to enable v2 protocol when starting etcd.
-We are doing support for etcd v3 protocol.
+**Note**: Apache APISIX would not support the v2 protocol of etcd anymore since APISIX v2.0, so you need to enable v3 protocol when starting etcd, if etcd version is below v3.4.
 ```shell
-etcd --enable-v2=true &
+export ETCDCTL_API=3
 ```
 
 ## For Developer

README_CN.md

@@ -165,10 +165,9 @@ CentOS 7, Ubuntu 16.04, Ubuntu 18.04, Debian 9, Debian 10, macOS, **ARM64** Ubun
         apisix start
         ```
 
-**注意**：Apache APISIX 现在还不支持 etcd 的 v3 协议，所以启动 etcd 时需要开启 v2 协议的支持。
-我们正在做 etcd v3 协议的支持。
+**注意**：Apache APISIX 从 v2.0 开始不再支持 etcd v2 协议，如果 etcd 版本低于 v3.4，启动 etcd 时需要开启 v3 协议的支持。
 ```shell
-etcd --enable-v2=true &
+export ETCDCTL_API=3
 ```
 
 ## 针对开发者