Metadata insertion plugin

kong-0.9.7-0.rockspec

@@ -272,5 +272,9 @@ build = {
     ["kong.plugins.aws-lambda.handler"] = "kong/plugins/aws-lambda/handler.lua",
     ["kong.plugins.aws-lambda.schema"] = "kong/plugins/aws-lambda/schema.lua",
     ["kong.plugins.aws-lambda.v4"] = "kong/plugins/aws-lambda/v4.lua",
+
+    ["kong.plugins.metadata-insertion.handler"] = "kong/plugins/metadata-insertion/handler.lua",
+    ["kong.plugins.metadata-insertion.access"] = "kong/plugins/metadata-insertion/access.lua",
+    ["kong.plugins.metadata-insertion.schema"] = "kong/plugins/metadata-insertion/schema.lua",
   }
 }

kong/plugins/metadata-insertion/access.lua

@@ -0,0 +1,170 @@
+local _M = {}
+local request_querystring_factory = require "kong.plugins.metadata-insertion.factory.request_querystring_factory"
+local request_headers_factory = require "kong.plugins.metadata-insertion.factory.request_headers_factory"
+-- local debug = require "kong.plugins.metadata-insertion.tool.debug"
+local cache = require "kong.tools.database_cache"
+local singletons = require "kong.singletons"
+local responses = require "kong.tools.responses"
+local currentUserMetadata
+
+local function getPersistentMetadata()
+  -- retrieve metadata from cache or database for current user
+  currentUserMetadata = cache.get_or_set("metadata_keyvaluestore." .. ngx.ctx.authenticated_consumer.id, nil, function()
+    local metadata, err = singletons.dao.metadata_keyvaluestore:find_all({ consumer_id = ngx.ctx.authenticated_consumer.id })
+    if err then
+      return responses.send_HTTP_INTERNAL_SERVER_ERROR(err)
+    end
+    return metadata
+  end)
+
+  if currentUserMetadata then
+    return currentUserMetadata
+  end
+
+  return {}
+end
+
+local function resolveParameterValuePlaceholderWithMetadata(dataProvisioningName)
+  for _, elem in ipairs(currentUserMetadata) do
+    if elem.key == dataProvisioningName then
+      return elem.value
+    end
+  end
+  error("This API needs metadata that the current user does not provide.")
+end
+
+local function retrieveMetadataForConfigToken(querystringModifier)
+  local args = {}
+
+  for stringChunk in string.gmatch(querystringModifier, "%S+") do
+    table.insert(args, stringChunk)
+  end
+
+  assert(table.getn(args) == 2, "Invalid format")
+
+  -- Prepare arg name
+  local argName = args[1]
+  argName = argName:gsub(":", "")
+
+  -- Prepare arg value (replace placeholder name by metadata value)
+  local argValuePlaceholderName = args[2]
+  argValuePlaceholderName = argValuePlaceholderName:gsub("%%", "")
+  local parameterValue = resolveParameterValuePlaceholderWithMetadata(argValuePlaceholderName)
+  return argName, parameterValue
+end
+
+
+local function appendMetadataFromTransitoryStore(currentUserMetadata)
+
+  -- loop through transitory store and add the metadata in memory
+  -- transitory store take precedence over persitent metadata
+  if ngx.ctx.metadata_transitory_store and type(ngx.ctx.metadata_transitory_store) == "table" then
+
+    for _, transitoryStoreElem in ipairs(ngx.ctx.metadata_transitory_store) do
+
+      local persistentMetadataFound = false
+
+      -- replace persitent metadata with transitory store if it exist in both place
+      for index, persistentMetadataElem in ipairs(currentUserMetadata) do
+        if persistentMetadataElem.key == transitoryStoreElem.key then
+          currentUserMetadata[index] = transitoryStoreElem
+          persistentMetadataFound = true
+        end
+      end
+
+      -- if nothing found in persistent metadata, let's make sure we add the transitory store element as new
+      if persistentMetadataFound == false then
+        table.insert(currentUserMetadata, transitoryStoreElem)
+      end
+    end
+  end
+end
+
+local function updateQuerystring(confDataInsertion)
+
+  local RequestQuerystringFactory = request_querystring_factory:new()
+
+  RequestQuerystringFactory:mergeArgsWithRequestArgs()
+
+  -- Remove querystring(s)
+  if confDataInsertion.remove and confDataInsertion.remove.querystring then
+    for _, key in ipairs(confDataInsertion.remove.querystring) do
+      RequestQuerystringFactory:removeArgByKey(key)
+    end
+  end
+
+  -- Replace querystring(s)
+  if confDataInsertion.replace and confDataInsertion.replace.querystring then
+    for _, querystringModifier in pairs(confDataInsertion.replace.querystring) do
+      local parameterName, parameterValue = retrieveMetadataForConfigToken(querystringModifier)
+      RequestQuerystringFactory:replaceArgByKey(parameterName, parameterValue)
+    end
+  end
+
+  -- Add querystring(s)
+  if confDataInsertion.add and confDataInsertion.add.querystring then
+    for _, querystringModifier in pairs(confDataInsertion.add.querystring) do
+      local parameterName, parameterValue = retrieveMetadataForConfigToken(querystringModifier)
+      RequestQuerystringFactory:add(parameterName, parameterValue)
+    end
+  end
+
+  RequestQuerystringFactory:persist()
+end
+
+local function updateHeaders(confDataInsertion)
+
+  local RequestHeadersFactory = request_headers_factory:new()
+
+  RequestHeadersFactory:mergeArgsWithRequestArgs()
+
+  -- Remove querystring(s)
+  if confDataInsertion.remove and confDataInsertion.remove.headers then
+    for _, key in ipairs(confDataInsertion.remove.headers) do
+      RequestHeadersFactory:removeArgByKey(key)
+    end
+  end
+
+  -- Replace querystring(s)
+  if confDataInsertion.replace and confDataInsertion.replace.headers then
+    for _, headersModifier in pairs(confDataInsertion.replace.headers) do
+      local parameterName, parameterValue = retrieveMetadataForConfigToken(headersModifier)
+      RequestHeadersFactory:replaceArgByKey(parameterName, parameterValue)
+    end
+  end
+
+  -- Add querystring(s)
+  if confDataInsertion.add and confDataInsertion.add.headers then
+    for _, headersModifier in pairs(confDataInsertion.add.headers) do
+      local parameterName, parameterValue = retrieveMetadataForConfigToken(headersModifier)
+      RequestHeadersFactory:add(parameterName, parameterValue)
+    end
+  end
+
+  RequestHeadersFactory:persist()
+end
+
+function _M.execute(conf)
+
+  if ngx.ctx.authenticated_consumer == nil then
+    return responses.send_HTTP_UNAUTHORIZED("Metadata plugin can't be used without having an authenticated user.")
+  end
+
+  currentUserMetadata = getPersistentMetadata()
+  appendMetadataFromTransitoryStore(currentUserMetadata)
+
+  local _, err = pcall(function()
+
+    -----------------------------
+    -- Data Insertion Processing
+    -----------------------------
+    updateQuerystring(conf)
+    updateHeaders(conf)
+  end)
+
+  if err then
+    return responses.send_HTTP_BAD_REQUEST(err)
+  end
+end
+
+return _M

kong/plugins/metadata-insertion/api.lua

@@ -0,0 +1,19 @@
+local crud = require "kong.api.crud_helpers"
+
+return {
+  ["/consumers/:username_or_id/metadata/"] = {
+    before = function(self, dao_factory, helpers)
+      crud.find_consumer_by_username_or_id(self, dao_factory, helpers)
+      self.params.consumer_id = self.consumer.id
+    end,
+    GET = function(self, dao_factory)
+      crud.paginated_set(self, dao_factory.metadata_keyvaluestore)
+    end,
+    PUT = function(self, dao_factory)
+      crud.put(self.params, dao_factory.metadata_keyvaluestore)
+    end,
+    POST = function(self, dao_factory)
+      crud.post(self.params, dao_factory.metadata_keyvaluestore)
+    end
+  }
+}

kong/plugins/metadata-insertion/daos.lua

@@ -0,0 +1,16 @@
+local SCHEMA = {
+  primary_key = { "id" },
+  table = "metadata_keyvaluestore",
+  fields = {
+    id = { type = "id", dao_insert_value = true },
+    created_at = { type = "timestamp", immutable = true, dao_insert_value = true },
+    consumer_id = { type = "id", required = true, foreign = "consumers:id" },
+    key = { type = "string", required = true },
+    value = { type = "string", required = true }
+  },
+  marshall_event = function(self, t)
+    return { id = t.id, consumer_id = t.consumer_id, key = t.key }
+  end
+}
+
+return { metadata_keyvaluestore = SCHEMA }

kong/plugins/metadata-insertion/factory/request_headers_factory.lua

@@ -0,0 +1,50 @@
+local req_set_header = ngx.req.set_header
+local req_get_headers = ngx.req.get_headers
+local HOST = "host"
+local RequestHeadersFactory = {}
+local args = {}
+
+function RequestHeadersFactory:new()
+  return RequestHeadersFactory
+end
+
+function RequestHeadersFactory:getArgs()
+  return args
+end
+
+function RequestHeadersFactory:mergeArgsWithRequestArgs()
+  local requestArgs = req_get_headers()
+  for k, v in pairs(requestArgs) do
+    args[k] = v
+  end
+end
+
+function RequestHeadersFactory:persist()
+  for key, value in pairs(args) do
+    if key:lower() ~= HOST then
+      if value == "metadata_asked_for_removal" then
+        req_set_header(key, nil)
+      else
+        req_set_header(key, value)
+      end
+    end
+  end
+end
+
+function RequestHeadersFactory:removeArgByKey(key)
+  if args[key] then
+    args[key] = "metadata_asked_for_removal"
+  end
+end
+
+function RequestHeadersFactory:replaceArgByKey(key, value)
+  if args[key] then
+    args[key] = value
+  end
+end
+
+function RequestHeadersFactory:add(key, value)
+  args[key] = value
+end
+
+return RequestHeadersFactory

kong/plugins/metadata-insertion/factory/request_querystring_factory.lua

@@ -0,0 +1,42 @@
+local req_get_uri_args = ngx.req.get_uri_args
+local req_set_uri_args = ngx.req.set_uri_args
+
+local RequestQuerystringFactory = {}
+local args = {}
+
+function RequestQuerystringFactory:new()
+  return RequestQuerystringFactory
+end
+
+function RequestQuerystringFactory:getArgs()
+  return args
+end
+
+function RequestQuerystringFactory:mergeArgsWithRequestArgs()
+  local requestArgs = req_get_uri_args()
+  for k, v in pairs(requestArgs) do
+    args[k] = v
+  end
+end
+
+function RequestQuerystringFactory:persist()
+  req_set_uri_args(args)
+end
+
+function RequestQuerystringFactory:removeArgByKey(key)
+  if args[key] then
+    args[key] = nil
+  end
+end
+
+function RequestQuerystringFactory:replaceArgByKey(key, value)
+  if args[key] then
+    args[key] = value
+  end
+end
+
+function RequestQuerystringFactory:add(key, value)
+  args[key] = value
+end
+
+return RequestQuerystringFactory

kong/plugins/metadata-insertion/handler.lua

@@ -0,0 +1,15 @@
+local BasePlugin = require "kong.plugins.base_plugin"
+local access = require "kong.plugins.metadata-insertion.access"
+
+local MetadataInsertionHandler = BasePlugin:extend()
+
+function MetadataInsertionHandler:new()
+  MetadataInsertionHandler.super.new(self, "metadata-insertion")
+end
+
+function MetadataInsertionHandler:access(conf)
+  MetadataInsertionHandler.super.access(self)
+  access.execute(conf)
+end
+
+return MetadataInsertionHandler

kong/plugins/metadata-insertion/hooks.lua

@@ -0,0 +1,17 @@
+local events = require "kong.core.events"
+local cache = require "kong.tools.database_cache"
+
+local function invalidate(message_t)
+  if message_t.collection == "metadata_keyvaluestore" then
+    cache.delete(cache.metadata_keyvaluestore(message_t.old_entity and message_t.old_entity.key or message_t.entity.key))
+  end
+end
+
+return {
+  [events.TYPES.ENTITY_UPDATED] = function(message_t)
+    invalidate(message_t)
+  end,
+  [events.TYPES.ENTITY_DELETED] = function(message_t)
+    invalidate(message_t)
+  end
+}

kong/plugins/metadata-insertion/migrations/cassandra.lua

@@ -0,0 +1,21 @@
+return {
+  {
+    name = "2017-01-05-000000_init_metadata",
+    up =  [[
+      CREATE TABLE IF NOT EXISTS metadata_keyvaluestore(
+        id uuid,
+        consumer_id uuid,
+        key text,
+        value text,
+        created_at timestamp,
+        PRIMARY KEY (id)
+      );
+
+      CREATE INDEX IF NOT EXISTS ON metadata_keyvaluestore(key);
+      CREATE INDEX IF NOT EXISTS metadata_keyvaluestore_consumer_id ON metadata_keyvaluestore(consumer_id);
+    ]],
+    down = [[
+      DROP TABLE metadata_keyvaluestore;
+    ]]
+  }
+}

kong/plugins/metadata-insertion/migrations/postgres.lua

@@ -0,0 +1,28 @@
+return {
+  {
+    name = "2017-01-05-000000_init_metadata",
+    up = [[
+      CREATE TABLE IF NOT EXISTS metadata_keyvaluestore(
+        id uuid,
+        consumer_id uuid REFERENCES consumers (id) ON DELETE CASCADE,
+        key text,
+        value text,
+        created_at timestamp without time zone default (CURRENT_TIMESTAMP(0) at time zone 'utc'),
+        PRIMARY KEY (id)
+      );
+
+      DO $$
+      BEGIN
+        IF (SELECT to_regclass('metadata_keyvaluestore_key_idx')) IS NULL THEN
+          CREATE INDEX metadata_keyvaluestore_key_idx ON metadata_keyvaluestore(key);
+        END IF;
+        IF (SELECT to_regclass('metadata_keyvaluestore_consumer_idx')) IS NULL THEN
+          CREATE INDEX metadata_keyvaluestore_consumer_idx ON metadata_keyvaluestore(consumer_id);
+        END IF;
+      END$$;
+    ]],
+    down = [[
+      DROP TABLE metadata_keyvaluestore;
+    ]]
+  }
+}