feat(db-labels): add labels

kong-3.2.1-0.rockspec

@@ -80,6 +80,7 @@ build = {
     ["kong.clustering.compat.removed_fields"] = "kong/clustering/compat/removed_fields.lua",
     ["kong.clustering.config_helper"] = "kong/clustering/config_helper.lua",
     ["kong.clustering.tls"] = "kong/clustering/tls.lua",
+    ["kong.clustering.labels"] = "kong/clustering/labels.lua",
 
     ["kong.cluster_events"] = "kong/cluster_events/init.lua",
     ["kong.cluster_events.strategies.cassandra"] = "kong/cluster_events/strategies/cassandra.lua",
@@ -247,6 +248,7 @@ build = {
     ["kong.db.migrations.core.016_280_to_300"] = "kong/db/migrations/core/016_280_to_300.lua",
     ["kong.db.migrations.core.017_300_to_310"] = "kong/db/migrations/core/017_300_to_310.lua",
     ["kong.db.migrations.core.018_310_to_320"] = "kong/db/migrations/core/018_310_to_320.lua",
+    ["kong.db.migrations.core.019_320_to_330"] = "kong/db/migrations/core/019_320_to_330.lua",
     ["kong.db.migrations.operations.200_to_210"] = "kong/db/migrations/operations/200_to_210.lua",
     ["kong.db.migrations.operations.210_to_211"] = "kong/db/migrations/operations/210_to_211.lua",
     ["kong.db.migrations.operations.212_to_213"] = "kong/db/migrations/operations/212_to_213.lua",

kong.conf.default

@@ -385,6 +385,13 @@
                                  # to be sent across from CP to DP in Hybrid mode
                                  # Default is 4Mb - 4 * 1024 * 1024 due to historical reasons
 
+#cluster_dp_labels =             # Labels for the data plane. These key-value entries are
+                                 # exposed via the clustering/data_planes endpoint.
+                                 # The value must be configured as a string in JSON format.
+                                 #
+                                 # Example:
+                                 # `{ "deployment" : "aws", "region" : "us-east-1" }`
+
 #------------------------------------------------------------------------------
 # HYBRID MODE CONTROL PLANE
 #------------------------------------------------------------------------------

kong/clustering/control_plane.lua

@@ -235,6 +235,7 @@ function _M:handle_cp_websocket()
       ip = dp_ip,
       version = dp_version,
       sync_status = sync_status, -- TODO: import may have been failed though
+      labels = data.labels or {}
     }, { ttl = purge_delay })
     if not ok then
       ngx_log(ngx_ERR, _log_prefix, "unable to update clustering data plane status: ", err, log_suffix)

kong/clustering/data_plane.lua

@@ -10,6 +10,7 @@ local declarative = require("kong.db.declarative")
 local constants = require("kong.constants")
 local utils = require("kong.tools.utils")
 local pl_stringx = require("pl.stringx")
+local dp_labels = require("kong.clustering.labels")
 
 
 local assert = assert
@@ -124,12 +125,21 @@ function _M:communicate(premature)
     return
   end
 
+  -- load dp labels
+  local labels, load_err = dp_labels.load_labels()
+  ngx.log(ngx.ERR, "LABELS LOADED AS "..require('inspect')(labels))
+  if load_err then
+    ngx_log(ngx_ERR, _log_prefix, load_err)
+  end
+
   -- connection established
-  -- first, send out the plugin list to CP so it can make decision on whether
-  -- sync will be allowed later
+  -- first, send out the plugin list and DP labels to CP
+  -- The CP will make the decision on whether sync will be allowed
+  -- based no the received information
   local _
   _, err = c:send_binary(cjson_encode({ type = "basic_info",
-                                        plugins = self.plugins_list, }))
+                                        plugins = self.plugins_list,
+                                        labels = labels }))
   if err then
     ngx_log(ngx_ERR, _log_prefix, "unable to send basic information to control plane: ", uri,
                      " err: ", err, " (retrying after ", reconnection_delay, " seconds)", log_suffix)

kong/clustering/labels.lua

@@ -0,0 +1,62 @@
+local cjson     = require "cjson.safe"
+local pl_tablex = require "pl.tablex"
+
+local fmt      = string.format
+local re_match = ngx.re.match
+
+local MAX_KEY_SIZE   = 63
+local MAX_VALUE_SIZE = MAX_KEY_SIZE
+local MAX_KEYS       = 10
+
+local BASE_PTRN = "[a-z0-9]([\\w\\.:-]*[a-z0-9]|)$"
+local KEY_PTRN  = "(?!kong)(?!konnect)(?!insomnia)(?!mesh)(?!kic)" .. BASE_PTRN
+local VAL_PTRN  = BASE_PTRN
+
+
+local function validate_table(labels_t)
+  return pl_tablex.size(labels_t) <= MAX_KEYS
+end
+
+
+local function validate_pattern(str, max_size, pattern)
+  if str == "" or #str > max_size then
+    return false, fmt(
+      "%s must have between 1 and %d characters", str, max_size)
+  end
+  if not re_match(str, pattern, "ajoi") then
+    return false, fmt("%s not conforming with pattern %s", str, pattern)
+  end
+  return true
+end
+
+
+local function load_labels()
+  local labels, err = cjson.decode(kong.configuration.cluster_dp_labels or "{}")
+  if not labels then
+    return nil, err
+  end
+
+  local ok
+  ok, err = validate_table(labels)
+  if not ok then
+    return nil, "labels validation failed: " .. err
+  end
+
+  for k, v in pairs(labels) do
+    ok, err = validate_pattern(k, MAX_KEY_SIZE, KEY_PTRN)
+    if not ok then
+      return nil, "label name validation failed: " .. err
+    end
+    ok, err = validate_pattern(v, MAX_VALUE_SIZE, VAL_PTRN)
+    if not ok then
+      return nil, "label value validation failed: " .. err
+    end
+  end
+
+  return labels
+end
+
+
+return {
+  load_labels = load_labels
+}

kong/conf_loader/init.lua

@@ -534,6 +534,7 @@ local CONF_PARSERS = {
   cluster_ocsp = { enum = { "on", "off", "optional" } },
   cluster_max_payload = { typ = "number" },
   cluster_use_proxy = { typ = "boolean" },
+  cluster_dp_labels = { typ = "string" },
 
   kic = { typ = "boolean" },
   pluginserver_names = { typ = "array" },

kong/db/migrations/core/019_320_to_330.lua

@@ -0,0 +1,19 @@
+return {
+    postgres = {
+      up = [[
+        DO $$
+            BEGIN
+            ALTER TABLE IF EXISTS ONLY "clustering_data_planes" ADD "labels" JSONB;
+            EXCEPTION WHEN DUPLICATE_COLUMN THEN
+              -- Do nothing, accept existing state
+            END;
+        $$;
+      ]]
+    },
+
+    cassandra = {
+      up = [[
+        ALTER TABLE clustering_data_planes ADD labels map<text,text>;
+      ]]
+    },
+  }

kong/db/migrations/core/init.lua

@@ -16,4 +16,5 @@ return {
   "016_280_to_300",
   "017_300_to_310",
   "018_310_to_320",
+  "019_320_to_330",
 }

kong/db/schema/entities/clustering_data_planes.lua

@@ -30,5 +30,6 @@ return {
                       default = "unknown",
                     }
     },
+    { labels = typedefs.labels },
   },
 }

kong/db/schema/typedefs.lua

@@ -828,4 +828,24 @@ typedefs.ttl = Schema.define {
   between = { 0, DAO_MAX_TTL },
 }
 
+
+local function validate_labels(field)
+  local pattern = (field == "k" and "(?!kong)(?!konnect)(?!insomnia)(?!mesh)(?!kic)" or "") ..
+                  "[a-z0-9]([\\w\\.:-]*[a-z0-9]|)$"
+
+  return function(expr)
+    if not ngx.re.match(expr, pattern, "ajoi") then
+      return false, string.format("field %s does not match allowed pattern %s", expr, pattern)
+    end
+    return true
+  end
+end
+
+typedefs.labels = Schema.define {
+  type = "map",
+  keys = { type = "string", len_min = 1, len_max = 63, custom_validator = validate_labels("k") },
+  values = { type = "string", len_min = 1, len_max = 63, custom_validator = validate_labels("v") },
+  len_max = 10,
+}
+
 return typedefs

kong/templates/kong_defaults.lua

@@ -36,6 +36,7 @@ cluster_data_plane_purge_delay = 1209600
 cluster_ocsp = off
 cluster_max_payload = 4194304
 cluster_use_proxy = off
+cluster_dp_labels = NONE
 
 lmdb_environment_path = dbless.lmdb
 lmdb_map_size = 128m

spec/05-migration/db/migrations/core/019_320_to_330_spec.lua

@@ -0,0 +1,7 @@
+local uh = require "spec/upgrade_helpers"
+
+describe("database migration", function()
+    uh.old_after_up("has created the expected new columns", function()
+        assert.table_has_column("clustering_data_planes", "labels", "jsonb", "map<text,text>")
+    end)
+end)