feat: bypass unix socket proxy if the socket file is deleted (#172)

Author: spacewander

.github/workflows/ci.yml

@@ -43,8 +43,10 @@ jobs:
       - name: get dependencies
         run: sudo apt install -y cpanminus build-essential libncurses5-dev libreadline-dev libssl-dev perl
 
-      - name: Install Lua
-        uses: leafo/gh-actions-lua@v8
+      - name: Setup Lua
+        uses: leafo/gh-actions-lua@v8.0.0
+        with:
+          luaVersion: "5.1.5"
 
       - name: Install Luarocks
         uses: leafo/gh-actions-luarocks@v4

lib/resty/etcd/v3.lua

@@ -26,6 +26,7 @@ local encode_base64 = ngx.encode_base64
 local decode_base64 = ngx.decode_base64
 local semaphore     = require("ngx.semaphore")
 local health_check  = require("resty.etcd.health_check")
+local pl_path       = require("pl.path")
 
 math.randomseed(now() * 1000 + ngx.worker.pid())
 
@@ -83,7 +84,14 @@ local function request_uri_via_unix_socket(self, uri, params)
 
     local path, query
     params.scheme, params.host, params.port, path, query = unpack(parsed_uri)
+
+    local use_unix_socket = false
     if params.unix_socket_proxy then
+        local sock_path = params.unix_socket_proxy:sub(#"unix:" + 1)
+        use_unix_socket = pl_path.exists(sock_path)
+    end
+
+    if use_unix_socket then
         if not params.headers then
             params.headers = {}
         end
@@ -342,6 +350,7 @@ function _M.new(opts)
         tab_insert(endpoints, {
             full_prefix = host .. utils.normalize(api_prefix),
             http_host   = host,
+            parsed_uri  = m,
             scheme      = m[1],
             host        = m[2] or "127.0.0.1",
             address     = addr,
@@ -634,6 +643,14 @@ local function http_request_chunk(self, http_cli)
         return nil, err
     end
 
+    if not endpoint.port then
+        local sock_path = endpoint.address:sub(#"unix:" + 1)
+        if not pl_path.exists(sock_path) then
+            endpoint.address = endpoint.parsed_uri[2]
+            endpoint.port = endpoint.parsed_uri[3]
+        end
+    end
+
     local ok
     ok, err = http_cli:connect({
         scheme = endpoint.scheme,

rockspec/lua-resty-etcd-master-0.1-0.rockspec

@@ -14,6 +14,8 @@ description = {
 
 dependencies = {
    "api7-lua-resty-http = 0.1.0",
+   "luafilesystem = 1.7.0-2",
+   "penlight = 1.9.2-1",
    "lua-typeof = 0.1"
 }
 

t/v3/unix_socket.t

@@ -126,3 +126,66 @@ value: bcd3
 closed
 ok
 --- timeout: 5
+
+
+
+=== TEST 2: request over unix socket, unix socket doesn't exist
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            local etcd, err = require("resty.etcd").new({protocol = "v3", http_host = "http://127.0.0.1:2379",
+                unix_socket_proxy = "unix:$TEST_NGINX_HTML_DIR/bad.sock"})
+            check_res(etcd, err)
+
+            local res, err = etcd:set("/test", "abc")
+            check_res(res, err)
+
+            ngx.timer.at(0.1, function ()
+                etcd:set("/test", "bcd3")
+            end)
+
+            ngx.timer.at(0.2, function ()
+                etcd:set("/test", "bcd4")
+            end)
+
+            local cur_time = ngx.now()
+            local body_chunk_fun, err, http_cli = etcd:watch("/test", {timeout = 0.5, need_cancel = true})
+
+            if type(http_cli) ~= "table" then
+                ngx.say("need_cancel failed")
+            end
+
+            if not body_chunk_fun then
+                ngx.say("failed to watch: ", err)
+            end
+
+            local chunk, err = body_chunk_fun()
+            ngx.say("created: ", chunk.result.created)
+            local chunk, err = body_chunk_fun()
+            ngx.say("value: ", chunk.result.events[1].kv.value)
+
+            local res, err = etcd:watchcancel(http_cli)
+            if not res then
+                ngx.say("failed to cancel: ", err)
+            end
+
+            local chunk, err = body_chunk_fun()
+            ngx.say(err)
+
+            ngx.say("ok")
+        }
+    }
+--- request
+GET /t
+--- no_error_log
+[error]
+--- grep_error_log eval
+qr/hit with host 127.0.0.1/
+--- grep_error_log_out
+--- response_body
+created: true
+value: bcd3
+closed
+ok
+--- timeout: 5