fix(migrations) handle missing schema_migrations

Handle occasional error where the schema_migrations columnfamily would
be missing thus preventing the migrations to work properly.

We now print a better error for the unaware user and suggest that the
"kong migrations reset" command should be run to fix this.

Fix Kong#250


Former-commit-id: 4e62f5f36fd20dc029a92f2f54e88a372879ad06

kong-0.4.0-1.rockspec

@@ -44,6 +44,7 @@ build = {
 
     ["kong.cli.utils"] = "kong/cli/utils/utils.lua",
     ["kong.cli.utils.signal"] = "kong/cli/utils/signal.lua",
+    ["kong.cli.utils.input"] = "kong/cli/utils/input.lua",
     ["kong.cli.db"] = "kong/cli/db.lua",
     ["kong.cli.config"] = "kong/cli/config.lua",
     ["kong.cli.quit"] = "kong/cli/quit.lua",

kong/cli/migrations.lua

@@ -3,8 +3,9 @@
 local Migrations = require "kong.tools.migrations"
 local constants = require "kong.constants"
 local cutils = require "kong.cli.utils"
+local input = require "kong.cli.utils.input"
 local IO = require "kong.tools.io"
-local lapp = require("lapp")
+local lapp = require "lapp"
 local args = lapp(string.format([[
 Kong datastore migrations.
 
@@ -50,7 +51,7 @@ if args.command == "list" then
 elseif args.command == "up" then
 
   cutils.logger:info(string.format(
-    "Migrating %s keyspace: %s",
+    "Migrating %s keyspace \"%s\"",
     cutils.colors.yellow(dao_factory.type),
     cutils.colors.yellow(dao_factory._properties.keyspace))
   )
@@ -68,7 +69,7 @@ elseif args.command == "up" then
 elseif args.command == "down" then
 
   cutils.logger:info(string.format(
-    "Rolling back %s keyspace: %s",
+    "Rollbacking %s keyspace \"%s\"",
     cutils.colors.yellow(dao_factory.type),
     cutils.colors.yellow(dao_factory._properties.keyspace)
   ))
@@ -85,22 +86,22 @@ elseif args.command == "down" then
 
 elseif args.command == "reset" then
 
+  local keyspace = dao_factory._properties.keyspace
+
   cutils.logger:info(string.format(
-    "Reseting %s keyspace: %s",
+    "Resetting %s keyspace \"%s\"",
     cutils.colors.yellow(dao_factory.type),
-    cutils.colors.yellow(dao_factory._properties.keyspace))
-  )
+    cutils.colors.yellow(keyspace)
+  ))
 
-  migrations:reset(function(migration, err)
+  if input.confirm("Are you sure? You will lose all of your data, this operation is irreversible.") then
+    local res, err = dao_factory.migrations:drop_keyspace(keyspace)
     if err then
       cutils.logger:error_exit(err)
-    elseif migration then
-      cutils.logger:success("Rollbacked: "..cutils.colors.yellow(migration.name))
     else
-      cutils.logger:success("Schema reseted")
+      cutils.logger:success("Keyspace successfully reset")
     end
-  end)
-
+  end
 else
   lapp.quit("Invalid command: "..args.command)
 end

kong/cli/utils/input.lua

@@ -0,0 +1,24 @@
+local _M = {}
+
+local ANSWERS = {
+  y = true,
+  Y = true,
+  yes = true,
+  YES = true,
+  n = false,
+  N = false,
+  no = false,
+  NO = false
+}
+
+function _M.confirm(question)
+  local answer
+  repeat
+    io.write(question.." [Y/n] ")
+    answer = ANSWERS[io.read("*l")]
+  until answer ~= nil
+
+  return answer
+end
+
+return _M

kong/dao/cassandra/migrations.lua

@@ -1,4 +1,5 @@
 local cassandra = require "cassandra"
+local stringy = require "stringy"
 local BaseDao = require "kong.dao.cassandra.base_dao"
 
 local Migrations = BaseDao:extend()
@@ -48,7 +49,9 @@ function Migrations:get_migrations()
   end
 
   rows, err = Migrations.super._execute(self, self.queries.get_migrations)
-  if err then
+  if err and stringy.find(err.message, "unconfigured columnfamily schema_migrations") ~= nil then
+    return nil, "Missing mandatory column family \"schema_migrations\" in configured keyspace. Please consider running \"kong migrations reset\" to fix this."
+  elseif err then
     return nil, err
   elseif rows and #rows > 0 then
     return rows[1].migrations
@@ -63,6 +66,13 @@ function Migrations:delete_migration(migration_name)
     { cassandra.list({ migration_name }) })
 end
 
+-- Drop the entire keyspace
+-- @param `keyspace` Name of the keyspace to drop
+-- @return query result
+function Migrations:drop_keyspace(keyspace)
+  return Migrations.super._execute(self, string.format("DROP keyspace \"%s\"", keyspace))
+end
+
 function Migrations:drop()
   -- never drop this
 end

kong/tools/migrations.lua

@@ -153,18 +153,4 @@ function Migrations:rollback(callback)
   callback(migration_to_rollback)
 end
 
--- Execute all migrations DOWN
--- @param {function} callback A function to execute on each migration (ie: for logging)
-function Migrations:reset(callback)
-  local done = false
-  while not done do
-    self:rollback(function(migration, err)
-      if not migration and not err then
-        done = true
-      end
-      callback(migration, err)
-    end)
-  end
-end
-
 return Migrations