[#1033] Fix database migrations

priv/repo/migrations/20170320193800_create_user.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreatePleroma.User do
   use Ecto.Migration
 
   def change do
-    create table(:users) do
+    create_if_not_exists table(:users) do
       add :email, :string
       add :password_hash, :string
       add :name, :string

priv/repo/migrations/20170321074828_create_activity.exs

@@ -2,13 +2,13 @@ defmodule Pleroma.Repo.Migrations.CreatePleroma.Activity do
   use Ecto.Migration
 
   def change do
-    create table(:activities) do
+    create_if_not_exists table(:activities) do
       add :data, :map
 
       timestamps()
     end
 
-    create index(:activities, [:data], using: :gin)
+    create_if_not_exists index(:activities, [:data], using: :gin)
 
   end
 end

priv/repo/migrations/20170321074832_create_object.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreatePleroma.Object do
   use Ecto.Migration
 
   def change do
-    create table(:objects) do
+    create_if_not_exists table(:objects) do
       add :data, :map
 
       timestamps()

priv/repo/migrations/20170330153447_add_index_to_objects.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddIndexToObjects do
   use Ecto.Migration
 
   def change do
-    create index(:objects, [:data], using: :gin)
+    create_if_not_exists index(:objects, [:data], using: :gin)
   end
 end

priv/repo/migrations/20170415141210_add_unique_index_to_email_and_nickname.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.AddUniqueIndexToEmailAndNickname do
   use Ecto.Migration
 
   def change do
-    create unique_index(:users, [:email])
-    create unique_index(:users, [:nickname])
+    create_if_not_exists unique_index(:users, [:email])
+    create_if_not_exists unique_index(:users, [:nickname])
   end
 end

priv/repo/migrations/20170418200143_create_webssub_server_subscription.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateWebsubServerSubscription do
   use Ecto.Migration
 
   def change do
-    create table(:websub_server_subscriptions) do
+    create_if_not_exists table(:websub_server_subscriptions) do
       add :topic, :string
       add :callback, :string
       add :secret, :string

priv/repo/migrations/20170426154155_create_websub_client_subscription.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateWebsubClientSubscription do
   use Ecto.Migration
 
   def change do
-    create table(:websub_client_subscriptions) do
+    create_if_not_exists table(:websub_client_subscriptions) do
       add :topic, :string
       add :secret, :string
       add :valid_until, :naive_datetime_usec

priv/repo/migrations/20170501133231_add_id_contraints_to_activities_and_objects_part_two.exs

@@ -1,10 +1,12 @@
 defmodule Pleroma.Repo.Migrations.AddIdContraintsToActivitiesAndObjectsPartTwo do
   use Ecto.Migration
 
-  def change do
+  def up do
     drop_if_exists index(:objects, ["(data->>\"id\")"], name: :objects_unique_apid_index)
     drop_if_exists index(:activities, ["(data->>\"id\")"], name: :activities_unique_apid_index)
-    create unique_index(:objects, ["(data->>'id')"], name: :objects_unique_apid_index)
-    create unique_index(:activities, ["(data->>'id')"], name: :activities_unique_apid_index)
+    create_if_not_exists unique_index(:objects, ["(data->>'id')"], name: :objects_unique_apid_index)
+    create_if_not_exists unique_index(:activities, ["(data->>'id')"], name: :activities_unique_apid_index)
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20170502083023_add_local_field_to_activities.exs

@@ -6,6 +6,6 @@ defmodule Pleroma.Repo.Migrations.AddLocalFieldToActivities do
       add :local, :boolean, default: true
     end
 
-    create index(:activities, [:local])
+    create_if_not_exists index(:activities, [:local])
   end
 end

priv/repo/migrations/20170506222027_add_unique_index_to_apid.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddUniqueIndexToAPID do
   use Ecto.Migration
 
   def change do
-    create unique_index(:users, [:ap_id])
+    create_if_not_exists unique_index(:users, [:ap_id])
   end
 end

priv/repo/migrations/20170529093232_longer_bios.exs

@@ -1,9 +1,16 @@
 defmodule Pleroma.Repo.Migrations.LongerBios do
   use Ecto.Migration
 
-  def change do
+  def up do
     alter table(:users) do
       modify :bio, :text
     end
   end
+
+  def down do
+    alter table(:users) do
+      modify :bio, :string
+    end
+  end
+
 end

priv/repo/migrations/20170620095947_remove_activities_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.RemoveActivitiesIndex do
   use Ecto.Migration
 
   def change do
-    drop index(:activities, [:data])
+    drop_if_exists index(:activities, [:data])
   end
 end

priv/repo/migrations/20170620133028_add_object_activity_index.exs

@@ -3,6 +3,6 @@ defmodule Pleroma.Repo.Migrations.AddObjectActivityIndex do
 
   def change do
     # This was wrong, now a noop
-    # create index(:objects, ["(data->'object'->>'id')", "(data->>'type')"], name: :activities_create_objects_index)
+    # create_if_not_exists index(:objects, ["(data->'object'->>'id')", "(data->>'type')"], name: :activities_create_objects_index)
   end
 end

priv/repo/migrations/20170620142420_add_object_activity_index_part_two.exs

@@ -3,6 +3,6 @@ defmodule Pleroma.Repo.Migrations.AddObjectActivityIndexPartTwo do
 
   def change do
     drop_if_exists index(:objects, ["(data->'object'->>'id')", "(data->>'type')"], name: :activities_create_objects_index)
-    create index(:activities, ["(data->'object'->>'id')", "(data->>'type')"], name: :activities_create_objects_index)
+    create_if_not_exists index(:activities, ["(data->'object'->>'id')", "(data->>'type')"], name: :activities_create_objects_index)
   end
 end

priv/repo/migrations/20170701142005_add_actor_index_to_activity.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddActorIndexToActivity do
   use Ecto.Migration
 
   def change do
-    create index(:activities, ["(data->>'actor')", "inserted_at desc"], name: :activities_actor_index)
+    create_if_not_exists index(:activities, ["(data->>'actor')", "inserted_at desc"], name: :activities_actor_index)
   end
 end

priv/repo/migrations/20170906120646_add_mastodon_apps.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.AddMastodonApps do
   use Ecto.Migration
 
   def change do
-    create table(:apps) do
+    create_if_not_exists table(:apps) do
       add :client_name, :string
       add :redirect_uris, :string
       add :scopes, :string

priv/repo/migrations/20170906143140_create_o_auth_authorizations.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateOAuthAuthorizations do
   use Ecto.Migration
 
   def change do
-    create table(:oauth_authorizations) do
+    create_if_not_exists table(:oauth_authorizations) do
       add :app_id, references(:apps)
       add :user_id, references(:users)
       add :token, :string

priv/repo/migrations/20170906152508_create_o_auth_token.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateOAuthToken do
   use Ecto.Migration
 
   def change do
-    create table(:oauth_tokens) do
+    create_if_not_exists table(:oauth_tokens) do
       add :app_id, references(:apps)
       add :user_id, references(:users)
       add :token, :string

priv/repo/migrations/20170911123607_create_notifications.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateNotifications do
   use Ecto.Migration
 
   def change do
-    create table(:notifications) do
+    create_if_not_exists table(:notifications) do
       add :user_id, references(:users, on_delete: :delete_all)
       add :activity_id, references(:activities, on_delete: :delete_all)
       add :seen, :boolean, default: false
@@ -10,6 +10,6 @@ defmodule Pleroma.Repo.Migrations.CreateNotifications do
       timestamps()
     end
 
-    create index(:notifications, [:user_id])
+    create_if_not_exists index(:notifications, [:user_id])
   end
 end

priv/repo/migrations/20171019141706_create_password_reset_tokens.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreatePasswordResetTokens do
   use Ecto.Migration
 
   def change do
-    create table(:password_reset_tokens) do
+    create_if_not_exists table(:password_reset_tokens) do
       add :token, :string
       add :user_id, references(:users)
       add :used, :boolean, default: false

priv/repo/migrations/20171109091239_add_actor_to_activity.exs

@@ -12,7 +12,7 @@ defmodule Pleroma.Repo.Migrations.AddActorToActivity do
   end
 
   def down do
-    drop index(:activities, [:actor, "id DESC NULLS LAST"])
+    drop_if_exists index(:activities, [:actor, "id DESC NULLS LAST"])
     alter table(:activities) do
       remove :actor
     end

priv/repo/migrations/20171130135819_add_local_index_to_user.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddLocalIndexToUser do
   use Ecto.Migration
 
   def change do
-    create index(:users, [:local])
+    create_if_not_exists index(:users, [:local])
   end
 end

priv/repo/migrations/20171212163643_add_recipients_to_activities.exs

@@ -6,6 +6,6 @@ defmodule Pleroma.Repo.Migrations.AddRecipientsToActivities do
       add :recipients, {:array, :string}
     end
 
-    create index(:activities, [:recipients], using: :gin)
+    create_if_not_exists index(:activities, [:recipients], using: :gin)
   end
 end

priv/repo/migrations/20171212164525_fill_recipients_in_activities.exs

@@ -18,4 +18,6 @@ defmodule Pleroma.Repo.Migrations.FillRecipientsInActivities do
       end)
     end
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20180221210540_make_following_postgres_array.exs

@@ -1,7 +1,7 @@
 defmodule Pleroma.Repo.Migrations.MakeFollowingPostgresArray do
   use Ecto.Migration
 
-  def change do
+  def up do
     alter table(:users) do
       add :following_temp, {:array, :string}
     end
@@ -15,4 +15,6 @@ defmodule Pleroma.Repo.Migrations.MakeFollowingPostgresArray do
     end
     rename table(:users), :following_temp, to: :following
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20180327174350_drop_local_index_on_activities.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.DropLocalIndexOnActivities do
   use Ecto.Migration
 
   def change do
-    drop index(:users, [:local])
+    drop_if_exists index(:users, [:local])
   end
 end

priv/repo/migrations/20180327175831_actually_drop_local_index.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.ActuallyDropLocalIndex do
   use Ecto.Migration
 
   def change do
-    create index(:users, [:local])
+    create_if_not_exists index(:users, [:local])
     drop_if_exists index("activities", :local)
   end
 end

priv/repo/migrations/20180429094642_create_lists.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateLists do
   use Ecto.Migration
 
   def change do
-    create table(:lists) do
+    create_if_not_exists table(:lists) do
       add :user_id, references(:users, on_delete: :delete_all)
       add :title, :string
       add :following, {:array, :string}
@@ -10,6 +10,6 @@ defmodule Pleroma.Repo.Migrations.CreateLists do
       timestamps()
     end
 
-    create index(:lists, [:user_id])
+    create_if_not_exists index(:lists, [:user_id])
   end
 end

priv/repo/migrations/20180516154905_create_user_trigram_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.CreateUserTrigramIndex do
   use Ecto.Migration
 
   def change do
-    create index(:users, ["(nickname || name) gist_trgm_ops"], name: :users_trigram_index, using: :gist)
+    create_if_not_exists index(:users, ["(nickname || name) gist_trgm_ops"], name: :users_trigram_index, using: :gist)
   end
 end

priv/repo/migrations/20180530123448_add_list_follow_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddListFollowIndex do
   use Ecto.Migration
 
   def change do
-    create index(:lists, [:following])
+    create_if_not_exists index(:lists, [:following])
   end
 end

priv/repo/migrations/20180612110515_create_user_invite_tokens.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateUserInviteTokens do
   use Ecto.Migration
 
   def change do
-    create table(:user_invite_tokens) do
+    create_if_not_exists table(:user_invite_tokens) do
       add :token, :string
       add :used, :boolean, default: false
 

priv/repo/migrations/20180813003722_create_filters.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateFilters do
   use Ecto.Migration
 
   def change do
-    create table(:filters) do
+    create_if_not_exists table(:filters) do
       add :user_id, references(:users, on_delete: :delete_all)
       add :filter_id, :integer
       add :hide, :boolean
@@ -14,7 +14,7 @@ defmodule Pleroma.Repo.Migrations.CreateFilters do
       timestamps()
     end
 
-    create index(:filters, [:user_id])
-    create index(:filters, [:phrase], where: "hide = true", name: :hided_phrases_index)
+    create_if_not_exists index(:filters, [:user_id])
+    create_if_not_exists index(:filters, [:phrase], where: "hide = true", name: :hided_phrases_index)
   end
 end

priv/repo/migrations/20180829082446_add_recipients_to_and_cc_fields_to_activities.exs

@@ -7,7 +7,7 @@ defmodule Pleroma.Repo.Migrations.AddRecipientsToAndCcFieldsToActivities do
       add :recipients_cc, {:array, :string}
     end
 
-    create index(:activities, [:recipients_to], using: :gin)
-    create index(:activities, [:recipients_cc], using: :gin)
+    create_if_not_exists index(:activities, [:recipients_to], using: :gin)
+    create_if_not_exists index(:activities, [:recipients_cc], using: :gin)
   end
 end

priv/repo/migrations/20180829182612_activities_add_to_cc_indices.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.ActivitiesAddToCcIndices do
   use Ecto.Migration
 
   def change do
-    create index(:activities, ["(data->'to')"], name: :activities_to_index, using: :gin)
-    create index(:activities, ["(data->'cc')"], name: :activities_cc_index, using: :gin)
+    create_if_not_exists index(:activities, ["(data->'to')"], name: :activities_to_index, using: :gin)
+    create_if_not_exists index(:activities, ["(data->'cc')"], name: :activities_cc_index, using: :gin)
   end
 end

priv/repo/migrations/20180829183529_remove_recipients_to_and_cc_fields_from_activities.exs

@@ -1,10 +1,17 @@
 defmodule Pleroma.Repo.Migrations.RemoveRecipientsToAndCcFieldsFromActivities do
   use Ecto.Migration
 
-  def change do
+  def up do
     alter table(:activities) do
       remove :recipients_to
       remove :recipients_cc
     end
   end
+
+  def down do
+    alter table(:activities) do
+      add :recipients_to, {:array, :string}
+      add :recipients_cc, {:array, :string}
+    end
+  end
 end

priv/repo/migrations/20180903114437_users_add_is_moderator_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.UsersAddIsModeratorIndex do
   use Ecto.Migration
 
   def change do
-    create index(:users, ["(info->'is_moderator')"], name: :users_is_moderator_index, using: :gin)
+    create_if_not_exists index(:users, ["(info->'is_moderator')"], name: :users_is_moderator_index, using: :gin)
   end
 end

priv/repo/migrations/20180918182427_create_push_subscriptions.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreatePushSubscriptions do
   use Ecto.Migration
 
   def change do
-    create table("push_subscriptions") do
+    create_if_not_exists table("push_subscriptions") do
       add :user_id, references("users", on_delete: :delete_all)
       add :token_id, references("oauth_tokens", on_delete: :delete_all)
       add :endpoint, :string
@@ -13,6 +13,6 @@ defmodule Pleroma.Repo.Migrations.CreatePushSubscriptions do
       timestamps()
     end
 
-    create index("push_subscriptions", [:user_id, :token_id], unique: true)
+    create_if_not_exists index("push_subscriptions", [:user_id, :token_id], unique: true)
   end
 end

priv/repo/migrations/20181201104428_add_uuid_extension.exs

@@ -1,7 +1,9 @@
 defmodule Pleroma.Repo.Migrations.AddUUIDExtension do
   use Ecto.Migration
 
-  def change do
+  def up do
     execute("create extension if not exists \"uuid-ossp\"")
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20181201105617_add_uui_ds_to_user_info.exs

@@ -1,7 +1,9 @@
 defmodule Pleroma.Repo.Migrations.AddUUIDsToUserInfo do
   use Ecto.Migration
 
-  def change do
+  def up do
     execute("update users set info = jsonb_set(info, '{\"id\"}', to_jsonb(uuid_generate_v4()))")
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20181206125616_add_tags_to_users.exs

@@ -6,6 +6,6 @@ defmodule Pleroma.Repo.Migrations.AddTagsToUsers do
       add :tags, {:array, :string}
     end
 
-    create index(:users, [:tags], using: :gin)
+    create_if_not_exists index(:users, [:tags], using: :gin)
   end
 end

priv/repo/migrations/20181218172826_users_and_activities_flake_id.exs

@@ -12,7 +12,7 @@ defmodule Pleroma.Repo.Migrations.UsersAndActivitiesFlakeId do
   #   4- update relation pkeys with the new ids
   #   5- rename the temporary column to id
   #   6- re-create the constraints
-  def change do
+  def up do
     # Old serial int ids are transformed to 128bits with extra padding.
     # The application (in `Pleroma.FlakeId`) handles theses IDs properly as integers; to keep compatibility
     # with previously issued ids.
@@ -75,6 +75,8 @@ defmodule Pleroma.Repo.Migrations.UsersAndActivitiesFlakeId do
     stop_clippy_heartbeats(clippy)
   end
 
+  def down, do: :ok
+
   defp start_clippy_heartbeats() do
     count = from(a in "activities", select: count(a.id)) |> Repo.one!
 

priv/repo/migrations/20190109152453_add_visibility_function.exs

@@ -37,12 +37,12 @@ defmodule Pleroma.Repo.Migrations.AddVisibilityFunction do
   end
 
   def down do
-    drop(
+    drop_if_exists(
       index(:activities, ["activity_visibility(actor, recipients, data)"],
         name: :activities_visibility_index
       )
     )
 
-    execute("drop function activity_visibility(actor varchar, recipients varchar[], data jsonb)")
+    execute("drop function if exists activity_visibility(actor varchar, recipients varchar[], data jsonb)")
   end
 end

priv/repo/migrations/20190115085500_create_user_fts_index.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateUserFtsIndex do
   use Ecto.Migration
 
   def change do
-    create index(
+    create_if_not_exists index(
              :users,
              [
                """

priv/repo/migrations/20190118074940_fix_user_trigram_index.exs

@@ -4,7 +4,7 @@ defmodule Pleroma.Repo.Migrations.FixUserTrigramIndex do
   def up do
     drop_if_exists(index(:users, [], name: :users_trigram_index))
 
-    create(
+    create_if_not_exists(
       index(:users, ["(trim(nickname || ' ' || coalesce(name, ''))) gist_trgm_ops"],
         name: :users_trigram_index,
         using: :gist
@@ -15,7 +15,7 @@ defmodule Pleroma.Repo.Migrations.FixUserTrigramIndex do
   def down do
     drop_if_exists(index(:users, [], name: :users_trigram_index))
 
-    create(
+    create_if_not_exists(
       index(:users, ["(nickname || name) gist_trgm_ops"], name: :users_trigram_index, using: :gist)
     )
   end

priv/repo/migrations/20190123092341_users_add_is_admin_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.UsersAddIsAdminIndex do
   use Ecto.Migration
 
   def change do
-    create(index(:users, ["(info->'is_admin')"], name: :users_is_admin_index, using: :gin))
+    create_if_not_exists(index(:users, ["(info->'is_admin')"], name: :users_is_admin_index, using: :gin))
   end
 end

priv/repo/migrations/20190123125546_create_instances.exs

@@ -2,14 +2,14 @@ defmodule Pleroma.Repo.Migrations.CreateInstances do
   use Ecto.Migration
 
   def change do
-    create table(:instances) do
+    create_if_not_exists table(:instances) do
       add :host, :string
       add :unreachable_since, :naive_datetime_usec
 
       timestamps()
     end
 
-    create unique_index(:instances, [:host])
-    create index(:instances, [:unreachable_since])
+    create_if_not_exists unique_index(:instances, [:host])
+    create_if_not_exists index(:instances, [:unreachable_since])
   end
 end

priv/repo/migrations/20190123125839_fix_info_ids.exs

@@ -1,9 +1,11 @@
 defmodule Pleroma.Repo.Migrations.FixInfoIds do
   use Ecto.Migration
 
-  def change do
+  def up do
     execute(
       "update users set info = jsonb_set(info, '{id}', to_jsonb(uuid_generate_v4())) where info->'id' is null;"
     )
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20190126160540_change_push_subscriptions_varchar.exs

@@ -1,9 +1,15 @@
 defmodule Pleroma.Repo.Migrations.ChangePushSubscriptionsVarchar do
   use Ecto.Migration
 
-  def change do
+  def up do
     alter table(:push_subscriptions) do
       modify(:endpoint, :varchar)
     end
   end
+
+  def down do
+    alter table(:push_subscriptions) do
+      modify(:endpoint, :string)
+    end
+  end
 end

priv/repo/migrations/20190204200237_add_correct_dm_index.exs

@@ -19,7 +19,7 @@ defmodule Pleroma.Repo.Migrations.AddCorrectDMIndex do
   end
 
   def down do
-    drop(
+    drop_if_exists(
       index(:activities, ["activity_visibility(actor, recipients, data)", "id DESC"],
         name: :activities_visibility_index,
         concurrently: true,

priv/repo/migrations/20190205114625_create_thread_mutes.exs

@@ -2,11 +2,11 @@ defmodule Pleroma.Repo.Migrations.CreateThreadMutes do
   use Ecto.Migration
 
   def change do
-    create table(:thread_mutes) do
+    create_if_not_exists table(:thread_mutes) do
       add :user_id, references(:users, type: :uuid, on_delete: :delete_all)
       add :context, :string
     end
     
-    create unique_index(:thread_mutes, [:user_id, :context], name: :unique_index)
+    create_if_not_exists unique_index(:thread_mutes, [:user_id, :context], name: :unique_index)
   end
 end

priv/repo/migrations/20190315101315_create_registrations.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateRegistrations do
   use Ecto.Migration
 
   def change do
-    create table(:registrations, primary_key: false) do
+    create_if_not_exists table(:registrations, primary_key: false) do
       add :id, :uuid, primary_key: true
       add :user_id, references(:users, type: :uuid, on_delete: :delete_all)
       add :provider, :string
@@ -12,7 +12,7 @@ defmodule Pleroma.Repo.Migrations.CreateRegistrations do
       timestamps()
     end
 
-    create unique_index(:registrations, [:provider, :uid])
-    create unique_index(:registrations, [:user_id, :provider, :uid])
+    create_if_not_exists unique_index(:registrations, [:provider, :uid])
+    create_if_not_exists unique_index(:registrations, [:user_id, :provider, :uid])
   end
 end

priv/repo/migrations/20190325185009_create_notification_id_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.CreateNotificationIdIndex do
   use Ecto.Migration
 
   def change do
-  create index(:notifications, ["id desc nulls last"])
+    create_if_not_exists index(:notifications, ["id desc nulls last"])
   end
 end

priv/repo/migrations/20190328053912_create_scheduled_activities.exs

@@ -2,7 +2,7 @@ defmodule Pleroma.Repo.Migrations.CreateScheduledActivities do
   use Ecto.Migration
 
   def change do
-    create table(:scheduled_activities) do
+    create_if_not_exists table(:scheduled_activities) do
       add(:user_id, references(:users, type: :uuid, on_delete: :delete_all))
       add(:scheduled_at, :naive_datetime, null: false)
       add(:params, :map, null: false)
@@ -10,7 +10,7 @@ defmodule Pleroma.Repo.Migrations.CreateScheduledActivities do
       timestamps()
     end
 
-    create(index(:scheduled_activities, [:scheduled_at]))
-    create(index(:scheduled_activities, [:user_id]))
+    create_if_not_exists(index(:scheduled_activities, [:scheduled_at]))
+    create_if_not_exists(index(:scheduled_activities, [:user_id]))
   end
 end

priv/repo/migrations/20190403131720_add_oauth_token_indexes.exs

@@ -2,8 +2,8 @@ defmodule Pleroma.Repo.Migrations.AddOauthTokenIndexes do
   use Ecto.Migration
 
   def change do
-    create(unique_index(:oauth_tokens, [:token]))
-    create(index(:oauth_tokens, [:app_id]))
-    create(index(:oauth_tokens, [:user_id]))
+    create_if_not_exists(unique_index(:oauth_tokens, [:token]))
+    create_if_not_exists(index(:oauth_tokens, [:app_id]))
+    create_if_not_exists(index(:oauth_tokens, [:user_id]))
   end
 end

priv/repo/migrations/20190405160700_add_index_on_subscribers.exs

@@ -1,6 +1,6 @@
 defmodule Pleroma.Repo.Migrations.AddIndexOnSubscribers do
   use Ecto.Migration
-  
+
   @disable_ddl_transaction true
   def change do
     create index(:users, ["(info->'subscribers')"], name: :users_subscribers_index, using: :gin, concurrently: true)

priv/repo/migrations/20190408123347_create_conversations.exs

@@ -6,12 +6,12 @@ defmodule Pleroma.Repo.Migrations.CreateConversations do
   use Ecto.Migration
 
   def change do
-    create table(:conversations) do
+    create_if_not_exists table(:conversations) do
       add(:ap_id, :string, null: false)
       timestamps()
     end
 
-    create table(:conversation_participations) do
+    create_if_not_exists table(:conversation_participations) do
       add(:user_id, references(:users, type: :uuid, on_delete: :delete_all))
       add(:conversation_id, references(:conversations, on_delete: :delete_all))
       add(:read, :boolean, default: false)
@@ -19,8 +19,8 @@ defmodule Pleroma.Repo.Migrations.CreateConversations do
       timestamps()
     end
 
-    create index(:conversation_participations, [:conversation_id])
-    create unique_index(:conversation_participations, [:user_id, :conversation_id])
-    create unique_index(:conversations, [:ap_id])
+    create_if_not_exists index(:conversation_participations, [:conversation_id])
+    create_if_not_exists unique_index(:conversation_participations, [:user_id, :conversation_id])
+    create_if_not_exists unique_index(:conversations, [:ap_id])
   end
 end

priv/repo/migrations/20190410152859_add_participation_updated_at_index.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddParticipationUpdatedAtIndex do
   use Ecto.Migration
 
   def change do
-    create index(:conversation_participations, ["updated_at desc"])
+    create_if_not_exists index(:conversation_participations, ["updated_at desc"])
   end
 end

priv/repo/migrations/20190411094120_add_index_on_user_info_deactivated.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddIndexOnUserInfoDeactivated do
   use Ecto.Migration
 
   def change do
-    create(index(:users, ["(info->'deactivated')"], name: :users_deactivated_index, using: :gin))
+    create_if_not_exists(index(:users, ["(info->'deactivated')"], name: :users_deactivated_index, using: :gin))
   end
 end

priv/repo/migrations/20190413082658_create_bookmarks.exs

@@ -2,13 +2,13 @@ defmodule Pleroma.Repo.Migrations.CreateBookmarks do
   use Ecto.Migration
 
   def change do
-    create table(:bookmarks) do
+    create_if_not_exists table(:bookmarks) do
       add(:user_id, references(:users, type: :uuid, on_delete: :delete_all))
       add(:activity_id, references(:activities, type: :uuid, on_delete: :delete_all))
 
       timestamps()
     end
 
-    create(unique_index(:bookmarks, [:user_id, :activity_id]))
+    create_if_not_exists(unique_index(:bookmarks, [:user_id, :activity_id]))
   end
 end

priv/repo/migrations/20190414125034_migrate_old_bookmarks.exs

@@ -6,7 +6,7 @@ defmodule Pleroma.Repo.Migrations.MigrateOldBookmarks do
   alias Pleroma.User
   alias Pleroma.Repo
 
-  def change do
+  def up do
     query =
       from(u in User,
         where: u.local == true,
@@ -18,7 +18,7 @@ defmodule Pleroma.Repo.Migrations.MigrateOldBookmarks do
     |> Enum.each(fn %{id: user_id, bookmarks: bookmarks} ->
       Enum.each(bookmarks, fn ap_id ->
         activity = Activity.get_create_by_object_ap_id(ap_id)
-	unless is_nil(activity), do: {:ok, _} = Bookmark.create(user_id, activity.id)
+	      unless is_nil(activity), do: {:ok, _} = Bookmark.create(user_id, activity.id)
       end)
     end)
 
@@ -26,4 +26,10 @@ defmodule Pleroma.Repo.Migrations.MigrateOldBookmarks do
       remove(:bookmarks)
     end
   end
+
+  def down do
+    alter table(:users) do
+      add :bookmarks, {:array, :string}, null: false, default: []
+    end
+  end
 end

priv/repo/migrations/20190501125843_add_fts_index_to_objects.exs

@@ -3,6 +3,6 @@ defmodule Pleroma.Repo.Migrations.AddFTSIndexToObjects do
 
   def change do
     drop_if_exists index(:activities, ["(to_tsvector('english', data->'object'->>'content'))"], using: :gin, name: :activities_fts)
-    create index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
+    create_if_not_exists index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
   end
 end

priv/repo/migrations/20190501133552_add_refresh_token_index_to_token.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddRefreshTokenIndexToToken do
   use Ecto.Migration
 
   def change do
-    create(unique_index(:oauth_tokens, [:refresh_token]))
+    create_if_not_exists(unique_index(:oauth_tokens, [:refresh_token]))
   end
 end

priv/repo/migrations/20190513175809_change_hide_column_in_filter_table.exs

@@ -1,9 +1,15 @@
 defmodule Pleroma.Repo.Migrations.ChangeHideColumnInFilterTable do
   use Ecto.Migration
 
-  def change do
+  def up do
     alter table(:filters) do
       modify :hide, :boolean, default: false
     end
   end
+
+  def down do
+    alter table(:filters) do
+      modify :hide, :boolean
+    end
+  end
 end

priv/repo/migrations/20190515222404_add_thread_visibility_function.exs

@@ -68,6 +68,6 @@ defmodule Pleroma.Repo.Migrations.AddThreadVisibilityFunction do
   end
 
   def down do
-    execute("drop function thread_visibility(actor varchar, activity_id varchar)")
+    execute("drop function if exists thread_visibility(actor varchar, activity_id varchar)")
   end
 end

priv/repo/migrations/20190518032627_create_config.exs

@@ -2,12 +2,12 @@ defmodule Pleroma.Repo.Migrations.CreateConfig do
   use Ecto.Migration
 
   def change do
-    create table(:config) do
+    create_if_not_exists table(:config) do
       add(:key, :string)
       add(:value, :binary)
       timestamps()
     end
 
-    create(unique_index(:config, :key))
+    create_if_not_exists(unique_index(:config, :key))
   end
 end

priv/repo/migrations/20190525071417_add_non_follows_and_non_followers_fields_to_notification_settings.exs

@@ -1,10 +1,12 @@
 defmodule Pleroma.Repo.Migrations.AddNonFollowsAndNonFollowersFieldsToNotificationSettings do
   use Ecto.Migration
 
-  def change do
+  def up do
     execute("""
     update users set info = jsonb_set(info, '{notification_settings}', '{"local": true, "remote": true, "follows": true, "followers": true, "non_follows": true, "non_followers": true}')
     where local=true
     """)
   end
+
+  def down, do: :ok
 end

priv/repo/migrations/20190603115238_add_index_on_activities_local.exs

@@ -2,6 +2,6 @@ defmodule Pleroma.Repo.Migrations.AddIndexOnActivitiesLocal do
   use Ecto.Migration
 
   def change do
-    create(index("activities", [:local]))
+    create_if_not_exists(index("activities", [:local]))
   end
 end

priv/repo/migrations/20190603173419_add_tag_index_to_objects.exs

@@ -3,6 +3,6 @@ defmodule Pleroma.Repo.Migrations.AddTagIndexToObjects do
 
   def change do
     drop_if_exists index(:activities, ["(data #> '{\"object\",\"tag\"}')"], using: :gin, name: :activities_tags)
-    create index(:objects, ["(data->'tag')"], using: :gin, name: :objects_tags)
+    create_if_not_exists index(:objects, ["(data->'tag')"], using: :gin, name: :objects_tags)
   end
 end

priv/repo/migrations/20190622151019_add_group_key_to_config.exs

@@ -6,7 +6,7 @@ defmodule Pleroma.Repo.Migrations.AddGroupKeyToConfig do
       add(:group, :string)
     end
 
-    drop(unique_index("config", :key))
-    create(unique_index("config", [:group, :key]))
+    drop_if_exists(unique_index("config", :key))
+    create_if_not_exists(unique_index("config", [:group, :key]))
   end
 end

priv/repo/optional_migrations/rum_indexing/20190510135645_add_fts_index_to_objects_two.exs

@@ -14,7 +14,7 @@ defmodule Pleroma.Repo.Migrations.AddFtsIndexToObjectsTwo do
       return new;
     end
     $$ LANGUAGE plpgsql")
-    execute("create index objects_fts on objects using RUM (fts_content rum_tsvector_addon_ops, inserted_at) with (attach = 'inserted_at', to = 'fts_content');")
+    execute("create index if not exists objects_fts on objects using RUM (fts_content rum_tsvector_addon_ops, inserted_at) with (attach = 'inserted_at', to = 'fts_content');")
 
     execute("CREATE TRIGGER tsvectorupdate BEFORE INSERT OR UPDATE ON objects
     FOR EACH ROW EXECUTE PROCEDURE objects_fts_update()")
@@ -23,12 +23,12 @@ defmodule Pleroma.Repo.Migrations.AddFtsIndexToObjectsTwo do
   end
 
   def down do
-    execute "drop index objects_fts"
-    execute "drop trigger tsvectorupdate on objects"
-    execute "drop function objects_fts_update()"
+    execute "drop index if exists objects_fts"
+    execute "drop trigger if exists tsvectorupdate on objects"
+    execute "drop function if exists objects_fts_update()"
     alter table(:objects) do
       remove(:fts_content, :tsvector)
     end
-    create index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
+    create_if_not_exists index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
   end
 end