change: check etcd cluster version when init_etcd

Signed-off-by: tokers <zchao1995@gmail.com>

bin/apisix

@@ -21,9 +21,9 @@ local function trim(s)
     return (s:gsub("^%s*(.-)%s*$", "%1"))
 end
 
--- Note: The `excute_cmd` return value will have a line break at the end,
+-- Note: The `execute_cmd` return value will have a line break at the end,
 -- it is recommended to use the `trim` function to handle the return value.
-local function excute_cmd(cmd)
+local function execute_cmd(cmd)
     local t, err = io.popen(cmd)
     if not t then
         return nil, "failed to execute command: " .. cmd .. ", error info:" .. err
@@ -33,7 +33,7 @@ local function excute_cmd(cmd)
     return data
 end
 
-excute_cmd("install -d -m 777 /tmp/apisix_cores/")
+execute_cmd("install -d -m 777 /tmp/apisix_cores/")
 
 local pkg_cpath_org = package.cpath
 local pkg_path_org = package.path
@@ -42,12 +42,14 @@ local apisix_home = "/usr/local/apisix"
 local pkg_cpath = apisix_home .. "/deps/lib64/lua/5.1/?.so;"
                   .. apisix_home .. "/deps/lib/lua/5.1/?.so;;"
 local pkg_path  = apisix_home ..    "/deps/share/lua/5.1/?.lua;;"
+local min_etcd_version = "3.4.0"
+
 
 -- only for developer, use current folder as working space
 local is_root_path = false
 local script_path = arg[0]
 if script_path:sub(1, 2) == './' then
-    apisix_home = trim(excute_cmd("pwd"))
+    apisix_home = trim(execute_cmd("pwd"))
     if not apisix_home then
         error("failed to fetch current path")
     end
@@ -640,16 +642,17 @@ local function read_yaml_conf()
     return default_conf
 end
 
+
 local function get_openresty_version()
     local str = "nginx version: openresty/"
-    local ret = excute_cmd("openresty -v 2>&1")
+    local ret = execute_cmd("openresty -v 2>&1")
     local pos = string.find(ret,str)
     if pos then
         return string.sub(ret, pos + string.len(str))
     end
 
     str = "nginx version: nginx/"
-    ret = excute_cmd("openresty -v 2>&1")
+    ret = execute_cmd("openresty -v 2>&1")
     pos = string.find(ret, str)
     if pos then
         return string.sub(ret, pos + string.len(str))
@@ -658,23 +661,82 @@ local function get_openresty_version()
     return nil
 end
 
+
 local function is_32bit_arch()
     local ok, ffi = pcall(require, "ffi")
     if ok then
         -- LuaJIT
         return ffi.abi("32bit")
     end
-    local ret = excute_cmd("getconf LONG_BIT")
+    local ret = execute_cmd("getconf LONG_BIT")
     local bits = tonumber(ret)
     return bits <= 32
 end
 
+
 local function split(self, sep)
     local sep, fields = sep or ":", {}
     local pattern = string.format("([^%s]+)", sep)
     self:gsub(pattern, function(c) fields[#fields + 1] = c end)
     return fields
- end
+end
+
+
+local function parse_semantic_version(ver)
+    local errmsg = "invalid semantic version: " .. ver
+
+    local parts = split(ver, "-")
+    if #parts > 2 then
+        return nil, errmsg
+    end
+
+    if #parts == 2 then
+        ver = parts[1]
+    end
+
+    local fields = split(ver, ".")
+    if #fields ~= 3 then
+        return nil, errmsg
+    end
+
+    local major = tonumber(fields[1])
+    local minor = tonumber(fields[2])
+    local patch = tonumber(fields[3])
+
+    if not (major and minor and patch) then
+        return nil, errmsg
+    end
+
+    return {
+        major = major,
+        minor = minor,
+        patch = patch,
+    }
+end
+
+
+local function compare_semantic_version(v1, v2)
+    local ver1, err = parse_semantic_version(v1)
+    if not ver1 then
+        return nil, err
+    end
+
+    local ver2, err = parse_semantic_version(v2)
+    if not ver2 then
+        return nil, err
+    end
+
+    if ver1.major ~= ver2.major then
+        return ver1.major < ver2.major
+    end
+
+    if ver1.minor ~= ver2.minor then
+        return ver1.minor < ver2.minor
+    end
+
+    return ver1.patch < ver2.patch
+end
+
 
 local function check_or_version(cur_ver_s, need_ver_s)
     local cur_vers = split(cur_ver_s, [[.]])
@@ -744,7 +806,7 @@ local function init()
     end
     -- print("etcd: ", yaml_conf.etcd.host)
 
-    local or_ver = excute_cmd("openresty -V 2>&1")
+    local or_ver = execute_cmd("openresty -V 2>&1")
     local with_module_status = true
     if or_ver and not or_ver:find("http_stub_status_module", 1, true) then
         io.stderr:write("'http_stub_status_module' module is missing in ",
@@ -766,7 +828,7 @@ local function init()
     local sys_conf = {
         lua_path = pkg_path_org,
         lua_cpath = pkg_cpath_org,
-        os_name = trim(excute_cmd("uname")),
+        os_name = trim(execute_cmd("uname")),
         apisix_lua_home = apisix_home,
         with_module_status = with_module_status,
         error_log = {level = "warn"},
@@ -871,13 +933,47 @@ local function init_etcd(show_output)
         yaml_conf.etcd.host = {yaml_conf.etcd.host}
     end
 
+    local cluster_version
     local host_count = #(yaml_conf.etcd.host)
+    -- check the etcd cluster version
+    for index, host in ipairs(yaml_conf.etcd.host) do
+        uri = host .. "/version"
+        local cmd = string.format("curl -s -m %d %s | sed -e 's/[{}]/''/g'", timeout * 2, uri)
+        local res = execute_cmd(cmd)
+        local m = split(res, [[%s*,%s*]])
+        local errmsg = string.format("got malformed version message: \"%s\" from etcd", res)
+
+        for i = 1, #m do
+            local mm = split(m[i], [[%s*:%s*]])
+            if #mm ~= 2 then
+                io.stderr:write(errmsg)
+                return
+            end
+
+            if mm[1] == "\"etcdcluster\"" then
+                cluster_version = string.sub(mm[2], 2, -2)
+                break
+            end
+        end
+
+        if not cluster_version then
+            io.stderr:write(errmsg)
+            return
+        end
+
+        if compare_semantic_version(cluster_version, min_etcd_version) then
+            io.stderr:write(string.format("etcd cluster version \"%s\" is less than the required version \"%s\", please upgrade your etcd cluster", cluster_version, min_etcd_version))
+            return
+        end
+
+        break
+    end
 
     -- check whether the user has enabled etcd v2 protocol
     for index, host in ipairs(yaml_conf.etcd.host) do
         uri = host .. "/v2/keys"
         local cmd = "curl -i -m ".. timeout * 2 .. " -o /dev/null -s -w %{http_code} " .. uri
-        local res = excute_cmd(cmd)
+        local res = execute_cmd(cmd)
         if res == "404" then
             io.stderr:write(string.format("failed: please make sure that you have enabled the v2 protocol of etcd on %s.\n", host))
             return
@@ -899,7 +995,7 @@ local function init_etcd(show_output)
                     .. "--connect-timeout " .. timeout
                     .. " --max-time " .. timeout * 2 .. " --retry 1 2>&1"
 
-            local res = excute_cmd(cmd)
+            local res = execute_cmd(cmd)
             if not res:find("index", 1, true)
                     and not res:find("createdIndex", 1, true) then
                 is_success = false