feat: allow disabling health check (#163)

Signed-off-by: spacewander <[email protected]>

Author: spacewander

health_check.md

@@ -33,10 +33,15 @@ Get the current status of the target.
 
 `syntax: mode = health_check.get_check_mode()`
 
-Get the current health check running mode. When `mode` is `round-robin`, it means running in [Round robin](#round-robin-based-health-check) mode, and `shared-dict` means running in [Policy](#policy-based-health-check) mode operation.
+Get the current health check running mode. When `mode` is `round-robin`, it means running in [Round robin](#round-robin-based-health-check) mode, and `shared-dict` means running in [Policy](#policy-based-health-check) mode operation, `disabled` means the health check is disabled.
 
-When using this method to get the health check running mode, you can use `health_check.ROUND_ROBIN_MODE` and `health_check.SHARED_DICT_MODE` to judge and compare.
+When using this method to get the health check running mode, you can use `health_check.ROUND_ROBIN_MODE` and `health_check.SHARED_DICT_MODE`, `health_check.DISABLED_MODE` to judge and compare.
 
+### disable
+
+`syntax: mode = health_check.disable()`
+
+Disable health check.
 
 ## Config
 

lib/resty/etcd/health_check.lua

@@ -6,10 +6,12 @@ local conf
 
 local HEALTH_CHECK_MODE_ROUND_ROBIN = "round-robin"
 local HEALTH_CHECK_MODE_SHARED_DICT = "shared-dict"
+local HEALTH_CHECK_MODE_DISABLED = "disabled"
 
 local _M = {}
 _M.ROUND_ROBIN_MODE = HEALTH_CHECK_MODE_ROUND_ROBIN
 _M.SHARED_DICT_MODE = HEALTH_CHECK_MODE_SHARED_DICT
+_M.DISABLED_MODE = HEALTH_CHECK_MODE_DISABLED
 
 local round_robin_unhealthy_target_hosts
 
@@ -23,6 +25,10 @@ local function get_target_status(etcd_host)
         return nil, "etcd health check uninitialized"
     end
 
+    if conf.disabled then
+        return true
+    end
+
     if type(etcd_host) ~= "string" then
         return false, "etcd host invalid"
     end
@@ -75,6 +81,10 @@ local function report_failure(etcd_host)
         return nil, "etcd health check uninitialized"
     end
 
+    if conf.disabled then
+        return
+    end
+
     if type(etcd_host) ~= "string" then
         return nil, "etcd host invalid"
     end
@@ -110,15 +120,29 @@ _M.report_failure = report_failure
 local function get_check_mode()
     -- round-robin: nginx worker memory round-robin based health check
     -- shared-dict: nginx shared memory policy based health check
-    if conf and conf.shm_name then
-        return HEALTH_CHECK_MODE_SHARED_DICT
-    else
-        return HEALTH_CHECK_MODE_ROUND_ROBIN
+    if conf then
+        if conf.disabled then
+            return HEALTH_CHECK_MODE_DISABLED
+        elseif conf.shm_name then
+            return HEALTH_CHECK_MODE_SHARED_DICT
+        end
     end
+
+    return HEALTH_CHECK_MODE_ROUND_ROBIN
 end
 _M.get_check_mode = get_check_mode
 
 
+function _M.disable()
+    if not conf then
+        conf = {}
+    end
+
+    conf.disabled = true
+    _M.conf = conf
+end
+
+
 function _M.init(opts)
     opts = opts or {}
     if not conf or opts.shm_name ~= conf.shm_name then

t/v3/health_check.t

@@ -810,3 +810,82 @@ qr/healthy check use \S+ \w+/
 --- grep_error_log_out
 healthy check use round robin
 healthy check use ngx.shared dict
+
+
+
+=== TEST 20: disable health check
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            local health_check = require("resty.etcd.health_check")
+            health_check.disable()
+            local etcd, err = require "resty.etcd" .new({
+                protocol = "v3",
+                http_host = {
+                    "http://127.0.0.1:42379",
+                    "http://127.0.0.1:22379",
+                    "http://127.0.0.1:32379",
+                },
+            })
+
+            local res
+            res, err = etcd:set("/test/etcd/unhealthy", "hello")
+            ngx.say(err)
+            res, err = etcd:set("/test/etcd/healthy", "hello")
+            if err == nil then
+                ngx.say("http://127.0.0.1:22379: OK")
+            else
+                ngx.say(err)
+            end
+        }
+    }
+--- request
+GET /t
+--- response_body
+http://127.0.0.1:42379: connection refused
+http://127.0.0.1:42379: connection refused
+--- no_error_log eval
+qr/update endpoint: http:\/\/127.0.0.1:42379 to unhealthy/
+
+
+
+=== TEST 21: health check disabled mode
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            local etcd, err = require "resty.etcd" .new({
+                protocol = "v3",
+                http_host = {
+                    "http://127.0.0.1:12379",
+                    "http://127.0.0.1:22379",
+                    "http://127.0.0.1:32379",
+                },
+            })
+
+            local health_check = require("resty.etcd.health_check")
+            local mode = health_check.get_check_mode()
+
+            health_check.init({
+                shm_name = "etcd_cluster_health_check",
+            })
+
+            mode = health_check.get_check_mode()
+            if mode == health_check.SHARED_DICT_MODE then
+                ngx.say("passed")
+            end
+
+            health_check.disable()
+
+            mode = health_check.get_check_mode()
+            if mode == health_check.DISABLED_MODE then
+                ngx.say("passed")
+            end
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+passed