FEATURE: start tracking information about migrations that run

This commit adds a new tracking table that lets us know

- When a migration ran
- What version Discourse was at
- How long it took
- What version Rails was at

The built in tracking in Rails is very limited, does not track this info

db/migrate/20000225050318_add_schema_migration_details.rb

@@ -0,0 +1,30 @@
+class AddSchemaMigrationDetails < ActiveRecord::Migration
+  def up
+    # schema_migrations table is way too thin, does not give info about
+    # duration of migration or the date it happened, this migration together with the
+    # monkey patch adds a lot of information to the migration table
+
+    create_table :schema_migration_details do |t|
+      t.string :version, null: false
+      t.string :name
+      t.string :hostname
+      t.string :git_version
+      t.string :rails_version
+      t.integer :duration
+      t.string :direction # this really should be a pg enum type but annoying to wire up for little gain
+      t.datetime :created_at, null: false
+    end
+
+    add_index :schema_migration_details, [:version]
+
+    execute("INSERT INTO schema_migration_details(version, created_at)
+             SELECT version, current_timestamp
+             FROM schema_migrations
+             ORDER BY version
+            ")
+  end
+
+  def down
+    drop_table :schema_migration_details
+  end
+end

lib/freedom_patches/schema_migration_details.rb

@@ -0,0 +1,54 @@
+module FreedomPatches
+  module SchemaMigrationDetails
+    def exec_migration(conn, direction)
+      rval = nil
+
+      time = Benchmark.measure do
+        rval=super
+      end
+
+      sql = <<SQL
+      INSERT INTO schema_migration_details(
+        version,
+        hostname,
+        name,
+        git_version,
+        duration,
+        direction,
+        rails_version,
+        created_at
+      ) values (
+        :version,
+        :hostname,
+        :name,
+        :git_version,
+        :duration,
+        :direction,
+        :rails_version,
+        :created_at
+      )
+SQL
+
+      hostname = `hostname` rescue ""
+      sql = ActiveRecord::Base.send(:sanitize_sql_array, [sql, {
+        version: version || "",
+        duration: (time.real * 1000).to_i,
+        hostname: hostname,
+        name: name,
+        git_version: Discourse.git_version,
+        created_at: Time.zone.now,
+        direction: direction.to_s,
+        rails_version: Rails.version
+      }])
+
+      conn.execute(sql)
+
+      rval
+    end
+
+  end
+end
+
+class ActiveRecord::Migration
+  prepend FreedomPatches::SchemaMigrationDetails
+end

spec/components/freedom_patches/schema_migration_details_spec.rb

@@ -0,0 +1,32 @@
+require 'rails_helper'
+require_dependency "freedom_patches/schema_migration_details"
+
+describe FreedomPatches::SchemaMigrationDetails do
+
+  # we usually don't really need this model so lets not clutter up with it
+  class SchemaMigrationDetail < ActiveRecord::Base
+  end
+
+  class TestMigration < ActiveRecord::Migration
+    def up
+      sleep 0.001
+    end
+  end
+
+  it "logs information on migration" do
+    migration = TestMigration.new("awesome_migration","20160225050318")
+
+    ActiveRecord::Base.connection_pool.with_connection do |conn|
+      migration.exec_migration(conn, :up)
+    end
+
+    info = SchemaMigrationDetail.find_by(version: "20160225050318")
+
+    expect(info.duration).to be > 0
+    expect(info.git_version).to eq Discourse.git_version
+    expect(info.direction).to eq "up"
+    expect(info.rails_version).to eq Rails.version
+    expect(info.filename).to eq migration.filename
+    expect(info.name).to eq "awesome_migration"
+  end
+end