feat(pdk): kong.node.is[_not]_data_plane|control_plane|traditional|et…

…c. helpers

### Summary

Adds following PDK functions:

- `kong.node.is_data_plane()`
- `kong.node.is_control_plane()`
- `kong.node.is_traditional()`
- `kong.node.is_dbless()`
- `kong.node.is_hybrid()`
- `kong.node.is_serving_http_traffic()`
- `kong.node.is_serving_stream_traffic()`
- `kong.node.is_serving_proxy_traffic()`
- `kong.node.is_serving_admin_apis()`
- `kong.node.is_serving_admin_gui()`
- `kong.node.is_serving_status_apis()`
- `kong.node.is_not_data_plane()`
- `kong.node.is_not_control_plane()`
- `kong.node.is_not_traditional()`
- `kong.node.is_not_hybrid()`
- `kong.node.is_not_serving_http_traffic()`
- `kong.node.is_not_serving_stream_traffic()`
- `kong.node.is_not_serving_proxy_traffic()`
- `kong.node.is_not_serving_admin_apis()`
- `kong.node.is_not_serving_admin_gui()`
- `kong.node.is_not_serving_status_apis()`

Signed-off-by: Aapo Talvensaari <[email protected]>

kong/api/routes/clustering.lua

@@ -12,7 +12,7 @@ return {
     schema = kong.db.clustering_data_planes.schema,
     methods = {
       GET = function(self, dao, helpers)
-        if kong.configuration.role ~= "control_plane" then
+        if kong.node.is_not_control_plane() then
           return kong.response.exit(400, {
             message = "this endpoint is only available when Kong is " ..
                       "configured to run as Control Plane for the cluster"
@@ -28,7 +28,7 @@ return {
     schema = kong.db.clustering_data_planes.schema,
     methods = {
       GET = function(self, db, helpers)
-        if kong.configuration.role ~= "control_plane" then
+        if kong.node.is_not_control_plane() then
           return kong.response.exit(400, {
             message = "this endpoint is only available when Kong is " ..
                       "configured to run as Control Plane for the cluster"

kong/api/routes/config.lua

@@ -86,7 +86,7 @@ end
 return {
   ["/config"] = {
     GET = function(self, db)
-      if kong.db.strategy ~= "off" then
+      if kong.node.is_not_dbless() then
         return kong.response.exit(400, {
           message = "this endpoint is only available when Kong is " ..
                     "configured to not use a database"
@@ -109,7 +109,7 @@ return {
       return kong.response.exit(200, { config = file.buf:get() })
     end,
     POST = function(self, db)
-      if kong.db.strategy ~= "off" then
+      if kong.node.is_not_dbless() then
         return kong.response.exit(400, {
           message = "this endpoint is only available when Kong is " ..
                     "configured to not use a database"

kong/api/routes/debug.lua

@@ -20,7 +20,7 @@ local DEFAULT_LOG_LEVEL_TIMEOUT    = 60 -- 60s
 
 
 local function handle_put_log_level(self, broadcast)
-  if kong.configuration.database == "off" then
+  if kong.node.is_dbless() then
     local message = "cannot change log level when not using a database"
     return kong.response.exit(405, { message = message })
   end
@@ -113,18 +113,16 @@ local routes = {
 }
 
 
-local cluster_name
+local cluster_name = kong.node.is_control_plane()
+        and "/debug/cluster/control-planes-nodes/log-level/:log_level"
+         or "/debug/cluster/log-level/:log_level"
 
-if kong.configuration.role == "control_plane" then
-  cluster_name = "/debug/cluster/control-planes-nodes/log-level/:log_level"
-else
-  cluster_name = "/debug/cluster/log-level/:log_level"
-end
 
 routes[cluster_name] = {
   PUT = function(self)
     return handle_put_log_level(self, CLUSTER_LEVEL_BROADCAST)
   end
 }
 
+
 return routes

kong/api/routes/health.lua

@@ -7,10 +7,6 @@ local knode  = (kong and kong.node) and kong.node or
                require "kong.pdk.node".new()
 
 
-local dbless = kong.configuration.database == "off"
-local data_plane_role = kong.configuration.role == "data_plane"
-
-
 return {
   ["/status"] = {
     GET = function(self, dao, helpers)
@@ -49,7 +45,7 @@ return {
       -- to make decisions when something changes in the data-plane (e.g.
       -- if the gateway gets unexpectedly restarted and its configuration
       -- has been reset to empty).
-      if dbless or data_plane_role then
+      if kong.node.is_dbless() then
         status_response.configuration_hash = declarative.get_current_hash()
         -- remove the meanless database entry when in dbless mode or data plane
         status_response.database = nil

kong/api/routes/upstreams.lua

@@ -223,7 +223,7 @@ local api_routes = {
 }
 
 -- upstream targets' healthcheck management is not available in the hybrid mode
-if kong.configuration.role ~= "control_plane" then
+if kong.node.is_not_control_plane() then
   api_routes["/upstreams/:upstreams/targets/:targets/healthy"] = {
     PUT = function(self, db)
       return set_target_health(self, db, true)

kong/cluster_events/init.lua

@@ -85,18 +85,9 @@ function _M.new(opts)
   local poll_delay    = max(opts.poll_delay    or 0, 0)
 
   do
-    local db_strategy
-
-    if opts.db.strategy == "postgres" then
-      db_strategy = require "kong.cluster_events.strategies.postgres"
-
-    elseif opts.db.strategy == "off" then
-      db_strategy = require "kong.cluster_events.strategies.off"
-
-    else
-      return error("no cluster_events strategy for " ..
-                   opts.db.strategy)
-    end
+    local db_strategy = kong.node.is_dbless()
+                    and require("kong.cluster_events.strategies.off")
+                     or require("kong.cluster_events.strategies.postgres")
 
     local event_ttl_in_db = max(poll_offset * 10, MIN_EVENT_TTL_IN_DB)
 

kong/clustering/init.lua

@@ -114,14 +114,12 @@ function _M:init_worker()
     filters = filters,
   }
 
-  local role = self.conf.role
-
-  if role == "control_plane" then
+  if kong.node.is_control_plane() then
     self:init_cp_worker(basic_info)
     return
   end
 
-  if role == "data_plane" then
+  if kong.node.is_data_plane() then
     self:init_dp_worker(basic_info)
   end
 end

kong/db/dao/workspaces.lua

@@ -3,7 +3,7 @@ local Workspaces = {}
 
 function Workspaces:truncate()
   self.super.truncate(self)
-  if kong.configuration.database == "off" then
+  if kong.node.is_dbless() then
     return true
   end
 

kong/db/declarative/export.lua

@@ -69,7 +69,7 @@ end
 
 
 local function begin_transaction(db)
-  if db.strategy == "postgres" then
+  if kong.node.is_not_dbless() then
     local ok, err = db.connector:connect("read")
     if not ok then
       return nil, err
@@ -86,7 +86,7 @@ end
 
 
 local function end_transaction(db)
-  if db.strategy == "postgres" then
+  if kong.node.is_not_dbless() then
     -- just finish up the read-only transaction,
     -- either COMMIT or ROLLBACK is fine.
     db.connector:query("ROLLBACK;", "read")

kong/db/schema/init.lua

@@ -1692,7 +1692,7 @@ function Schema:process_auto_fields(data, context, nulls, opts)
   local resolve_references
   if is_select and not nulls then
     if kong and kong.configuration then
-      resolve_references = kong.configuration.role ~= "control_plane"
+      resolve_references = kong.node.is_not_control_plane()
     else
       resolve_references = true
     end

kong/db/strategies/postgres/connector.lua

@@ -313,7 +313,7 @@ end
 
 
 function _mt:init_worker(strategies)
-  if ngx.worker.id() == 0 and #kong.configuration.admin_listeners > 0 then
+  if ngx.worker.id() == 0 and kong.node.is_serving_admin_apis() then
     local table_names = get_names_of_tables_with_ttl(strategies)
     local ttl_escaped = self:escape_identifier("ttl")
     local expire_at_escaped = self:escape_identifier("expire_at")

kong/global.lua

@@ -226,11 +226,10 @@ function _GLOBAL.init_cluster_events(kong_config, db)
 end
 
 
-local function get_lru_size(kong_config)
-  if (process.type() == "privileged agent")
-  or (kong_config.role == "control_plane")
-  or (kong_config.role == "traditional" and #kong_config.proxy_listeners  == 0
-                                        and #kong_config.stream_listeners == 0)
+local function get_lru_size()
+  if process.type() == "privileged agent"
+  or kong.node.is_control_plane()
+  or (kong.node.is_traditional() and kong.node.is_not_serving_proxy_traffic())
   then
     return 1000
   end
@@ -243,7 +242,7 @@ function _GLOBAL.init_cache(kong_config, cluster_events, worker_events)
   local page = 1
   local cache_pages = 1
 
-  if kong_config.database == "off" then
+  if kong.node.is_dbless() then
     db_cache_ttl = 0
     db_cache_neg_ttl = 0
    end
@@ -258,7 +257,7 @@ function _GLOBAL.init_cache(kong_config, cluster_events, worker_events)
     page            = page,
     cache_pages     = cache_pages,
     resty_lock_opts = LOCK_OPTS,
-    lru_size        = get_lru_size(kong_config),
+    lru_size        = get_lru_size(),
   })
 end
 
@@ -269,7 +268,7 @@ function _GLOBAL.init_core_cache(kong_config, cluster_events, worker_events)
   local page = 1
   local cache_pages = 1
 
-  if kong_config.database == "off" then
+  if kong.node.is_dbless() then
     db_cache_ttl = 0
     db_cache_neg_ttl = 0
   end
@@ -284,7 +283,7 @@ function _GLOBAL.init_core_cache(kong_config, cluster_events, worker_events)
     page            = page,
     cache_pages     = cache_pages,
     resty_lock_opts = LOCK_OPTS,
-    lru_size        = get_lru_size(kong_config),
+    lru_size        = get_lru_size(),
   })
 end