api: add hardcoded versioning support

Added the _VERSION variable to the exported table.
Is part of the task [1].

1. github.com/tarantool/roadmap-internal/issues/204

Author: GRISHNOV

.github/workflows/publish.yaml

@@ -6,6 +6,16 @@ on:
     tags: ['*']
 
 jobs:
+  version-check:
+    # We need this job to run only on push with tag.
+    if: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags/') }}
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Check module version
+        uses: tarantool/actions/check-module-version@master
+        with:
+          module-name: 'migrator'
+
   publish-scm-1:
     if: github.ref == 'refs/heads/master'
     runs-on: ubuntu-20.04
@@ -18,6 +28,7 @@ jobs:
 
   publish-tag:
     if: startsWith(github.ref, 'refs/tags/')
+    needs: version-check
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added:
+- Versioning support
 
 ## [0.4.2]
 ### Fixed:

migrations-scm-1.rockspec

@@ -17,6 +17,7 @@ build = {
     install = {
         lua = {
             ['migrator'] = 'migrator/init.lua',
+            ['migrator.version'] = 'migrator/version.lua',
             ['migrator.utils'] = 'migrator/utils.lua',
             ['migrator.directory-loader'] = 'migrator/directory-loader.lua',
             ['migrator.config-loader'] = 'migrator/config-loader.lua',

migrator/init.lua

@@ -176,5 +176,7 @@ return {
     set_loader = set_loader,
     set_use_cartridge_ddl = set_use_cartridge_ddl,
 
-    get_schema = get_schema
+    get_schema = get_schema,
+
+    _VERSION = require('migrator.version'),
 }

migrator/version.lua

@@ -0,0 +1,4 @@
+-- Сontains the module version.
+-- Requires manual update in case of release commit.
+
+return '0.4.2'