feat(migrations) split plugins migrations

Proper architecture and CLI update for plugin-specific migrations. This
is the first step in separating the plugins out of the core repo as
planed for 0.5.0. It is related to #93.

This is implemented by using the same table as before
(`schema_migrations`) to keep track of the executed migrations, except
that each plugin and the core itself all have their own row.

For simplifications, migrations (plugins or core) now live in a single
file. The `database` folder disappeared for core and the migration lives
in the DAO. Plugins have migrations in a `migration` folder, named after
the type of the database (`cassandra.lua` currently).

For now, only the keyauth plugin has its own migrations.

The `kong migrations up|down` commands slightly changed. It takes a `-t`
parameter to specify which migrations to run (core or a plugin name) and
is running all migrations by default. `kong migrations list` lists all
executed migration for the core and all plugins.

- Needs tests (integration)
- Old unit tests were removed
- `database` was removed
- `kong migrations` slightly changed

kong-0.4.1-1.rockspec

@@ -78,6 +78,7 @@ build = {
     ["kong.reports.init_worker"] = "kong/reports/init_worker.lua",
     ["kong.reports.log"] = "kong/reports/log.lua",
 
+    ["kong.dao.cassandra.schema.migrations"] = "kong/dao/cassandra/schema/migrations.lua",
     ["kong.dao.error"] = "kong/dao/error.lua",
     ["kong.dao.schemas_validation"] = "kong/dao/schemas_validation.lua",
     ["kong.dao.schemas.apis"] = "kong/dao/schemas/apis.lua",
@@ -99,6 +100,7 @@ build = {
     ["kong.plugins.basicauth.api"] = "kong/plugins/basicauth/api.lua",
     ["kong.plugins.basicauth.daos"] = "kong/plugins/basicauth/daos.lua",
 
+    ["kong.plugins.keyauth.migrations.cassandra"] = "kong/plugins/keyauth/migrations/cassandra.lua",
     ["kong.plugins.keyauth.handler"] = "kong/plugins/keyauth/handler.lua",
     ["kong.plugins.keyauth.access"] = "kong/plugins/keyauth/access.lua",
     ["kong.plugins.keyauth.schema"] = "kong/plugins/keyauth/schema.lua",
@@ -181,5 +183,5 @@ build = {
     conf = { "kong.yml" },
     bin = { "bin/kong" }
   },
-  copy_directories = { "database/migrations/", "ssl" }
+  copy_directories = { "ssl" }
 }

kong/cli/migrations.lua

@@ -3,6 +3,7 @@
 local Migrations = require "kong.tools.migrations"
 local constants = require "kong.constants"
 local cutils = require "kong.cli.utils"
+local utils = require "kong.tools.utils"
 local input = require "kong.cli.utils.input"
 local IO = require "kong.tools.io"
 local lapp = require "lapp"
@@ -16,7 +17,9 @@ Commands:
                        list, up, down, reset
 
 Options:
-  -c,--config (default %s) path to configuration file
+  -c,--config (default %s) path to configuration file.
+  -t,--type (default all)  when 'up' or 'down', specify 'core' or 'plugin_name' to only run
+                           specific migrations.
 ]], constants.CLI.GLOBAL_KONG_CONF))
 
 -- $ kong migrations
@@ -25,8 +28,16 @@ if args.command == "migrations" then
 end
 
 local config_path = cutils.get_kong_config_path(args.config)
-local _, dao_factory = IO.load_configuration_and_dao(config_path)
-local migrations = Migrations(dao_factory, cutils.get_luarocks_install_dir())
+local configuration, dao_factory = IO.load_configuration_and_dao(config_path)
+local migrations = Migrations(dao_factory)
+
+local kind = args.type
+if kind ~= "all" and kind ~= "core" then
+  -- Assuming we are trying to run migrations for a plugin
+  if not utils.table_contains(configuration.plugins_available, kind) then
+    cutils.logger:error_exit("No \""..kind.."\" plugin enabled in the configuration.")
+  end
+end
 
 if args.command == "list" then
 
@@ -35,11 +46,17 @@ if args.command == "list" then
     cutils.logger:error_exit(err)
   elseif migrations then
     cutils.logger:info(string.format(
-      "Executed migrations for %s on keyspace %s:\n%s",
-      cutils.colors.yellow(dao_factory.type),
+      "Executed migrations for keyspace %s (%s):",
       cutils.colors.yellow(dao_factory._properties.keyspace),
-      table.concat(migrations, ", ")
+      dao_factory.type
     ))
+
+    for _, row in ipairs(migrations) do
+      cutils.logger:info(string.format("%s: %s",
+        cutils.colors.yellow(row.id),
+        table.concat(row.migrations, ", ")
+      ))
+    end
   else
     cutils.logger:info(string.format(
       "No migrations have been run yet for %s on keyspace: %s",
@@ -50,48 +67,72 @@ if args.command == "list" then
 
 elseif args.command == "up" then
 
-  cutils.logger:info(string.format(
-    "Migrating %s keyspace \"%s\"",
-    cutils.colors.yellow(dao_factory.type),
-    cutils.colors.yellow(dao_factory._properties.keyspace))
-  )
+  local function migrate(identifier)
+    cutils.logger:info(string.format(
+      "Migrating %s on keyspace \"%s\" (%s)",
+      cutils.colors.yellow(identifier),
+      cutils.colors.yellow(dao_factory._properties.keyspace),
+      dao_factory.type
+    ))
 
-  migrations:migrate(function(migration, err)
+    local err = migrations:migrate(identifier, function(identifier, migration)
+      if migration then
+        cutils.logger:info(string.format(
+          "%s migrated up to: %s",
+          identifier,
+          cutils.colors.yellow(migration.name)
+        ))
+      end
+    end)
     if err then
       cutils.logger:error_exit(err)
-    elseif migration then
-      cutils.logger:success("Migrated up to: "..cutils.colors.yellow(migration.name))
-    else
-      cutils.logger:success("Schema already up to date")
     end
-  end)
+  end
+
+  if kind == "all" then
+    migrate("core")
+    for _, plugin_name in ipairs(configuration.plugins_available) do
+      local has_migrations = utils.load_module_if_exists("kong.plugins."..plugin_name..".migrations."..dao_factory.type)
+      if has_migrations then
+        migrate(plugin_name)
+      end
+    end
+  else
+    migrate(kind)
+  end
+
+  cutils.logger:success("Schema up to date")
 
 elseif args.command == "down" then
 
+  if kind == "all" then
+    cutils.logger:error_exit("You must specify 'core' or a plugin name for this command.")
+  end
+
   cutils.logger:info(string.format(
-    "Rollbacking %s keyspace \"%s\"",
-    cutils.colors.yellow(dao_factory.type),
-    cutils.colors.yellow(dao_factory._properties.keyspace)
+    "Rollbacking %s in keyspace \"%s\" (%s)",
+    cutils.colors.yellow(kind),
+    cutils.colors.yellow(dao_factory._properties.keyspace),
+    dao_factory.type
   ))
 
-  migrations:rollback(function(migration, err)
-    if err then
-      cutils.logger:error_exit(err)
-    elseif migration then
-      cutils.logger:success("Rollbacked: "..cutils.colors.yellow(migration.name))
-    else
-      cutils.logger:success("No migration to rollback")
-    end
-  end)
+  local rollbacked, err = migrations:rollback(kind)
+  if err then
+    cutils.logger:error_exit(err)
+  elseif rollbacked then
+    cutils.logger:success("\""..kind.."\" rollbacked: "..cutils.colors.yellow(rollbacked.name))
+  else
+    cutils.logger:success("No migration to rollback")
+  end
 
 elseif args.command == "reset" then
 
   local keyspace = dao_factory._properties.keyspace
 
   cutils.logger:info(string.format(
-    "Resetting %s keyspace \"%s\"",
-    cutils.colors.yellow(dao_factory.type),
-    cutils.colors.yellow(keyspace)
+    "Resetting \"%s\" keyspace (%s)",
+    cutils.colors.yellow(keyspace),
+    dao_factory.type
   ))
 
   if input.confirm("Are you sure? You will lose all of your data, this operation is irreversible.") then