Merge dd0244f into dc8318c

bearmug · Feb 11, 2019 · b071790 · b071790
2 parents dc8318c + dd0244f
commit b071790
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diff --git a/.travis.yml b/.travis.yml
@@ -4,13 +4,26 @@ cache:
 
 services:
   - postgresql
+  - mysql
 
 addons:
   postgresql: "9.6"
+  apt:
+    sources:
+      - mysql-5.7-trusty
+    packages:
+      - mysql-server
+      - mysql-client
 
 before_script:
-  - psql -c "CREATE DATABASE migration;" -U postgres
-  - psql -c "CREATE USER migration WITH PASSWORD 'migration';" -U postgres
+  - psql -c "CREATE DATABASE puremigration;" -U postgres
+  - psql -c "CREATE USER puremigration WITH PASSWORD 'puremigration';" -U postgres
+
+before_install:
+  - sudo mysql_upgrade --force
+  - mysql -e "CREATE DATABASE puremigration;"
+  - mysql -e "CREATE USER 'puremigration'@'localhost' IDENTIFIED BY 'puremigration'";
+  - mysql -e "GRANT ALL PRIVILEGES ON puremigration.* TO 'puremigration'@'localhost';"
 
 language: erlang
 

diff --git a/Makefile b/Makefile
@@ -1,12 +1,13 @@
 REBAR = ./rebar3
 DOCKER = docker
-CONTAINER_NAME = postgres-migration-test-container
+CONTAINER_POSTGRES = postgres-migration-test-container
+CONTAINER_MYSQL = mysql-migration-test-container
 
 all: clean code-checks test cover
 
 travis: all coveralls
 
-local: format postgres-bounce all postgres-down
+local: format db-bounce all db-down
 
 clean:
 	$(REBAR) clean
@@ -33,14 +34,34 @@ format:
 	$(REBAR) fmt
 
 postgres-up:
-	$(DOCKER) run --name $(CONTAINER_NAME) \
+	$(DOCKER) run --name $(CONTAINER_POSTGRES) \
 	-p 5432:5432 \
-	-e POSTGRES_PASSWORD=migration \
-	-e POSTGRES_USER=migration \
-	-e POSTGRES_DB=migration \
+	-e POSTGRES_PASSWORD=puremigration \
+	-e POSTGRES_USER=puremigration \
+	-e POSTGRES_DB=puremigration \
 	-d postgres:9.6-alpine
 
 postgres-down:
-	-$(DOCKER) rm -f $(CONTAINER_NAME)
+	-$(DOCKER) rm -f $(CONTAINER_POSTGRES)
 
-postgres-bounce: postgres-down postgres-up
+mysql-up:
+	$(DOCKER) run --name $(CONTAINER_MYSQL) \
+	-p 3306:3306 \
+	-e MYSQL_ALLOW_EMPTY_PASSWORD=true \
+	-e MYSQL_USER=puremigration \
+	-e MYSQL_PASSWORD=puremigration \
+	-e MYSQL_DATABASE=puremigration \
+	-d mysql:5.7
+
+mysql-wait:
+	while ! docker exec -it mysql-migration-test-container mysqladmin ping --silent; do \
+        echo "mysql image starting, wait for 1 second..."; \
+        sleep 1; \
+    done; done
+
+mysql-down:
+	-$(DOCKER) rm -f $(CONTAINER_MYSQL)
+
+db-bounce: postgres-down mysql-down postgres-up mysql-up mysql-wait
+
+db-down: postgres-down mysql-down
diff --git a/README.md b/README.md
@@ -1,14 +1,14 @@
 # Erlang ❤ pure database migrations
-> Database version control engine. Effects-free.
+> PostgreSQL and MySQL version control engine. Effects-free.
 
 [![Build Status](https://travis-ci.org/bearmug/erlang-pure-migrations.svg?branch=master)](https://travis-ci.org/bearmug/erlang-pure-migrations)
 [![Coverage Status](https://coveralls.io/repos/github/bearmug/erlang-pure-migrations/badge.svg?branch=master)](https://coveralls.io/github/bearmug/erlang-pure-migrations?branch=master)
 [![Hex.pm](https://img.shields.io/hexpm/v/pure_migrations.svg)](https://hex.pm/packages/pure_migrations)
 
-Migrate your Erlang application PostgreSQL database with no effort.
+Migrate your PostgreSQL or MySQL database from Erlang code with no effort.
 This amazing toolkit has [one and only](https://en.wikipedia.org/wiki/Unix_philosophy)
 purpose - consistently upgrade database schema, using Erlang stack and
-plain SQL. Feel free to run it with any PostgreSQL Erlang driver (and see
+plain SQL. Feel free to run it with any PostgreSQL/MySQL Erlang library (and see
 several ready-to-use examples below). As an extra - do this in
 "no side-effects" mode.
 
@@ -26,7 +26,10 @@ several ready-to-use examples below). As an extra - do this in
     + [PostgreSQL and processone/p1_pgsql](#postgresql-and--processone-p1-pgsql--https---githubcom-processone-p1-pgsql-)
       - [Onboarding comments](#onboarding-comments-2)
       - [Code sample](#code-sample-2)
-- [No-effects approach and tools used to achieve it](#no-effects-approach-and-tools-used-to-achieve-it)
+    + [MySQL and mysql-otp/mysql-otp](#mysql-and--mysql-otp-mysql-otp--https---githubcom-mysql-otp-mysql-otp-)
+      - [Onboarding comments](#onboarding-comments-3)
+      - [Code sample](#code-sample-3)
+- ["No-effects" approach and tools used to achieve it](#-no-effects--approach-and-tools-used-to-achieve-it)
   * [Tool #1: effects externalization](#tool--1--effects-externalization)
   * [Tool #2: make effects explicit](#tool--2--make-effects-explicit)
 - [Functional programming abstractions used](#functional-programming-abstractions-used)
@@ -36,11 +39,17 @@ several ready-to-use examples below). As an extra - do this in
 
 # Current limitations
  * **up** transactional migration available only. No **downgrade**
- or **rollback** possible. Either whole **up** migration completes OK
- or failed and rolled back to the state before migration.
+    calls available. Either whole **up** migration completes OK
+    or failed and rolled back to the state before migration.
+ * Validated MySQL implementation obviously featured with 
+    [**implicit commit**](https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html)
+    behavior, which means that truly transactional MySQL upgrades limited 
+    in scope. At the same time you free to use another MySQL library or
+    have your own transaction callback, as it is proposed by [API](#quick-start).
  * migrations engine **deliberately isolated from any specific
- database library**. This way engine user is free to choose from variety
- of frameworks (see tested combinations [here](#compatibility-table)) and so on.
+    database library**. This way engine user is free to choose from variety
+    of frameworks (see tested combinations [here](#compatibility-table)) 
+    and so on.
 
 # Quick start
 Just call `pure_migrations:migrate/3` (see specification [here](src/engine.erl#L9)), providing:
@@ -51,8 +60,8 @@ Just call `pure_migrations:migrate/3` (see specification [here](src/engine.erl#L
 Migration logic is idempotent and could be executed multiple times
 against the same database with the same migration scripts set. Moreover,
 it is safe to migrate your database concurrently (as a part of nodes
-startup in scalable environments, for example). Please see verified
-integrations and live code snippets below.
+startup in scalable environments and if you providing proper transaction
+handler). Please see verified integrations and live code snippets below.
 
 ## Compatibility table
 All integrations validated against PostgreSQL 9.4/9.6
@@ -62,6 +71,7 @@ All integrations validated against PostgreSQL 9.4/9.6
 | postgres  | [epgsql/epgsql:4.2.1](https://github.com/epgsql/epgsql/releases/tag/4.2.1) | [epgsql test](test/epgsql_migrations_SUITE.erl)
 | postgres  | [semiocast/pgsql:v26.0.2](https://github.com/semiocast/pgsql/releases/tag/v26.0.2) | [spgsql test](test/spgsql_migrations_SUITE.erl)
 | postgres  | [processone/p1_pgsql:1.1.6](https://github.com/processone/p1_pgsql/releases/tag/1.1.6) | [p1pgsql test](test/p1pgsql_migrations_SUITE.erl)
+| mysql     | [mysql-otp/mysql-otp:1.4.0](https://github.com/mysql-otp/mysql-otp/releases/tag/1.4.0) | [otp_mysql test](test/otp_mysql_migrations_SUITE.erl)
 | postgres  | any library with basic sql functional | [generic test](test/pure_migrations_SUITE.erl)
 
 ## Live integrations
@@ -211,7 +221,56 @@ Also see examples from live epgsql integration tests
 [here](test/p1pgsql_migrations_SUITE.erl)
 </details>
 
-# No-effects approach and tools used to achieve it
+### MySQL and [mysql-otp/mysql-otp](https://github.com/mysql-otp/mysql-otp)
+#### Onboarding comments
++ almost no result-set parsing required
+- [implicit commit](https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html)
+  specifics a kind an obstacle for simple and safe migration
+- mysql docker tooling should be operated carefully and ensured for 
+  proper startup before any use
+#### Code sample
+<details>
+  <summary>Click to expand</summary>
+
+  ```erlang
+  Conn = ?config(conn, Opts),
+  MigrationCall =
+    pure_migrations:migrate(
+      "scripts/folder/path",
+      fun(F) ->
+        %% no full-scope tx API available here
+        %% or use mysql:transaction/2, but please be aware about
+        %% mysql implicit transactions commit behavior
+        try F() of
+          Res -> Res
+        catch
+          _:Problem -> {rollback_unavailable, Problem}
+        end
+      end,
+      fun(Q) ->
+        case mysql:query(Conn, Q) of
+          {error, Details} -> {error, Details};
+          {ok,[<<"version">>,<<"filename">>],[]} -> [];
+          {ok,[<<"version">>,<<"filename">>], Data} ->
+              [{V, binary_to_list(F)} || [V, F] <- Data];
+          {ok,[<<"max(version)">>],[[null]]} -> -1;
+          {ok,[<<"max(version)">>],[[V]]} -> V;
+          {ok, _} -> ok;
+          ok -> ok
+        end
+      end),
+  ...
+  %% more preparation steps if needed
+  ...
+  %% migration call
+  ok = MigrationCall(),
+
+  ```
+Also see examples from live epgsql integration tests
+[here](test/otp_mysql_migrations_SUITE.erl)
+</details>
+
+# "No-effects" approach and tools used to achieve it
 Oh, **there is more!** Library implemented in the [way](https://en.wikipedia.org/wiki/Pure_function),
 that all side-effects either externalized or deferred explicitly. Reasons
 are quite common:

diff --git a/rebar.config b/rebar.config
@@ -4,6 +4,7 @@
                             {epgsql,    {git, "https://github.com/epgsql/epgsql", {tag, "4.2.1"}}},
                             {spgsql,    {git, "https://github.com/semiocast/pgsql", {tag, "v26.0.2"}}},
                             {p1pgsql,    {git, "https://github.com/processone/p1_pgsql", {tag, "1.1.6"}}},
+                            {mysqlotp,    {git, "https://github.com/mysql-otp/mysql-otp", {tag, "1.4.0"}}},
                             {coveralls, {git, "https://github.com/markusn/coveralls-erl", {tag, "v2.0.1"}}}
                            ]},
                     {eunit_opts             , [verbose]},

diff --git a/src/dialect_postgres.erl → src/db_dialect.erl b/src/dialect_postgres.erl → src/db_dialect.erl
@@ -1,6 +1,10 @@
--module(dialect_postgres).
+-module(db_dialect).
 
--export([init/0, migrations_done/0, save_migration/2, latest_existing_version/0]).
+-export([ init/0
+        , migrations_done/0
+        , save_migration/2
+        , latest_existing_version/0
+        ]).
 
 init() ->
     "CREATE TABLE IF NOT EXISTS database_migrations_history (

diff --git a/src/pure_migrations.erl b/src/pure_migrations.erl
@@ -14,7 +14,7 @@
       F :: fun(() -> ok | error()),
       R :: fun(() -> ok | error()).
 migrate(Path, FTx, FQuery) ->
-    ok = FQuery(dialect_postgres:init()),
+    ok = FQuery(db_dialect:init()),
     fun() ->
             FTx(flatten(map(
                           find_migrations(Path, FQuery),
@@ -26,11 +26,11 @@ do_migration(Path, FQuery, {V, F}) ->
     compose(
       fun() -> file:read_file(ScriptPath) end,
       fun({ok, ScriptBody}) ->
-              ExpectedVersion = FQuery(dialect_postgres:latest_existing_version()) + 1,
+              ExpectedVersion = FQuery(db_dialect:latest_existing_version()) + 1,
               case V of
                   ExpectedVersion ->
                       ok = FQuery(ScriptBody),
-                      ok = FQuery(dialect_postgres:save_migration(V, F));
+                      ok = FQuery(db_dialect:save_migration(V, F));
                   _ -> {
                         error,
                         unexpected_version,
@@ -45,7 +45,7 @@ find_migrations(ScriptsLocation, FQuery) ->
       fun(Files) -> filter_script_files(Files, ScriptsLocation, FQuery) end).
 
 filter_script_files({ok, Files}, _Folder, FQuery) ->
-    MigrationsDone = sets:from_list(FQuery(dialect_postgres:migrations_done())),
+    MigrationsDone = sets:from_list(FQuery(db_dialect:migrations_done())),
     lists:filter(
       fun(N) -> not sets:is_element(N, MigrationsDone) end,
       lists:keysort(1, [version_and_filename(F) || F <- Files]));

diff --git a/test/config/test.config b/test/config/test.config
@@ -1,11 +1,20 @@
-[{postgres, [{
-              config, [
-                       {host, "localhost"},
-                       {port, 5432},
-                       {database, "migration"},
-                       {username, "migration"},
-                       {secret, "migration"},
-                       {timeout, 10000}
-                      ]
-             }]
- }].
+[ {postgres, [{
+               config, [
+                        {host, "localhost"},
+                        {port, 5432},
+                        {database, "puremigration"},
+                        {username, "puremigration"},
+                        {secret, "puremigration"},
+                        {timeout, 10000}
+                       ]
+              }]}
+, {mysql, [{
+            config, [
+                     {host, "localhost"},
+                     {port, 3306},
+                     {database, "puremigration"},
+                     {username, "puremigration"},
+                     {secret, "puremigration"},
+                     {timeout, 10000}
+                    ]
+           }]}].