Merge branch 'tc-geo-fdw-configurable' into 'master'

Make Geo FDW configurable

Closes #4558

See merge request gitlab-org/gitlab-ee!4020

changelogs/unreleased-ee/tc-geo-fdw-configurable.yml

+---
+title: Make it possible to enable/disable PostgreSQL FDW for Geo
+merge_request: 4020
+author:
+type: added

config/database_geo.yml.postgresql

@@ -9,6 +9,7 @@ production:
   username: git
   password: "secure password"
   host: localhost
+  fdw: true
 
 #
 # Development specific
@@ -21,6 +22,7 @@ development:
   username: postgres
   password: "secure password"
   host: localhost
+  fdw: true
 
 #
 # Staging specific
@@ -33,6 +35,7 @@ staging:
   username: git
   password: "secure password"
   host: localhost
+  fdw: true
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".
@@ -45,3 +48,4 @@ test: &test
   username: postgres
   password:
   host: localhost
+  fdw: true

doc/gitlab-geo/database.md

@@ -304,25 +304,25 @@ because we have not yet configured the secondary server. This is the next step.
     connections. The certificate can only be replicated by someone with access
     to the private key, which is **only** present on the primary node.
 
-1. Configure PostgreSQL to listen on network interfaces on secondary
+1. Configure PostreSQL to enable FDW support
 
     This step is similar to how we configured the primary instance.
-    We need to enable this, even if using a single node, to enable FDW support.
+    We need to enable this, to enable FDW support, even if using a single node.
 
     Edit `/etc/gitlab/gitlab.rb` and add the following, replacing the IP
     addresses with addresses appropriate to your network configuration:
 
     ```ruby
-    geo_primary_role['enable'] = true
-    
     # Secondary addresses
-    # - replace '5.6.7.8' with the secondary public address
+    # - replace '5.6.7.8' with the secondary private address
     postgresql['listen_address'] = '5.6.7.8'
     postgresql['trust_auth_cidr_addresses'] = ['127.0.0.1/32','5.6.7.8/32']
-    postgresql['md5_auth_cidr_addresses'] = ['5.6.7.8/32']
 
     # gitlab database user's password (defined previously)
     gitlab_rails['db_password'] = 'mypassword'
+
+    # enable fdw for the geo tracking database
+    geo_secondary['db_fdw'] = true
     ```
 
 1. Test that the `gitlab-psql` user can connect to the primary's database:
@@ -477,4 +477,5 @@ Read the [troubleshooting document](troubleshooting.md).
 [pgback]: http://www.postgresql.org/docs/9.2/static/app-pgbasebackup.html
 [external postgresql]: #external-postgresql-instances
 [tracking]: database_source.md#enable-tracking-database-on-the-secondary-server
+[FDW]: https://www.postgresql.org/docs/9.6/static/postgres-fdw.html
 [toc]: README.md#using-omnibus-gitlab

doc/gitlab-geo/database_source.md

@@ -33,8 +33,7 @@ recover. See below for more details.
 
 The following guide assumes that:
 
-- You are using PostgreSQL 9.6 or later
-  which includes the
+- You are using PostgreSQL 9.6 or later which includes the
   [`pg_basebackup` tool][pgback] and improved [Foreign Data Wrapper][FDW] support.
 - You have a primary node already set up (the GitLab server you are
   replicating from), running PostgreSQL 9.6 or later, and
@@ -291,6 +290,9 @@ node.
     sudo -u postgres psql -h $GEO_DB_HOST -d $GEO_DB_NAME -p $GEO_DB_PORT -c "GRANT USAGE ON FOREIGN SERVER gitlab_secondary TO $(GEO_DB_USER);"
     ```
 
+    And edit the content of `database_geo.yml` and to add `fdw: true` to
+    the  `production:` block.
+
 ### Step 4. Initiate the replication process
 
 Below we provide a script that connects the database on the secondary node to

ee/lib/gitlab/geo.rb

@@ -65,14 +65,22 @@ module Gitlab
       ::License.feature_available?(:geo)
     end
 
-    def self.fdw?
-      self.cache_value(:geo_fdw?) do
-        ::Geo::BaseRegistry.connection.execute(
+    def self.fdw_capable?
+      self.cache_value(:geo_fdw_capable?) do
+        ::Geo::TrackingBase.connection.execute(
           "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = '#{FDW_SCHEMA}' AND table_type = 'FOREIGN TABLE'"
         ).first.fetch('count').to_i.positive?
       end
     end
 
+    def self.fdw?
+      return false unless self.fdw_capable?
+
+      # FDW is enabled by default, disable it by setting `fdw: false` in config/database_geo.yml
+      value = Rails.configuration.geo_database['fdw']
+      value.nil? ? true : value
+    end
+
     def self.fdw_table(table_name)
       FDW_SCHEMA + ".#{table_name}"
     end

scripts/prepare_postgres_fdw.sh

@@ -8,3 +8,8 @@ CREATE SCHEMA gitlab_secondary;
 IMPORT FOREIGN SCHEMA public FROM SERVER gitlab_secondary INTO gitlab_secondary;
 GRANT USAGE ON FOREIGN SERVER gitlab_secondary TO current_user;
 EOF
+
+# Ensure the FDW setting is enabled
+sed -i '/fdw:/d' config/database_geo.yml
+sed -i '/gitlabhq_geo_test/a\
+\ \ fdw: true' config/database_geo.yml

spec/ee/spec/lib/gitlab/geo_spec.rb

@@ -18,24 +18,57 @@ describe Gitlab::Geo, :geo do
     end
   end
 
-  describe 'fdw?' do
+  describe 'fdw_capable?' do
     let(:fdw_check) { "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'gitlab_secondary' AND table_type = 'FOREIGN TABLE'" }
 
     before do
-      allow(::Geo::BaseRegistry.connection).to receive(:execute).with(anything).and_call_original
+      allow(::Geo::TrackingBase.connection).to receive(:execute).with(anything).and_call_original
     end
 
     it 'returns true when PostgreSQL FDW is enabled' do
-      expect(::Geo::BaseRegistry.connection).to receive(:execute).with(fdw_check).and_return([{ 'count' => 1 }])
+      expect(::Geo::TrackingBase.connection).to receive(:execute).with(fdw_check).and_return([{ 'count' => 1 }])
 
-      expect(described_class.fdw?).to be_truthy
+      expect(described_class.fdw_capable?).to be_truthy
+    end
+
+    it 'returns false when PostgreSQL FDW is not enabled' do
+      expect(::Geo::TrackingBase.connection).to receive(:execute).with(fdw_check).and_return([{ 'count' => 0 }])
+
+      expect(described_class.fdw_capable?).to be_falsey
+    end
   end
 
+  describe 'fdw?' do
     it 'returns false when PostgreSQL FDW is not enabled' do
-      expect(::Geo::BaseRegistry.connection).to receive(:execute).with(fdw_check).and_return([{ 'count' => 0 }])
+      allow(::Geo::TrackingBase.connection).to receive(:execute).and_return([{ 'count' => 0 }])
+      allow(Rails.configuration).to receive(:geo_database).and_return('fdw' => true)
+
+      expect(described_class.fdw?).to be_falsey
+    end
+
+    context 'with fdw capable' do
+      before do
+        allow(described_class).to receive(:fdw_capable?).and_return(true)
+      end
+
+      it 'returns true by default' do
+        allow(Rails.configuration).to receive(:geo_database).and_return('fdw' => nil)
+
+        expect(described_class.fdw?).to be_truthy
+      end
+
+      it 'returns false if configured in `config/database_geo.yml`' do
+        allow(Rails.configuration).to receive(:geo_database).and_return('fdw' => false)
 
         expect(described_class.fdw?).to be_falsey
       end
+
+      it 'returns true if configured in `config/database_geo.yml`' do
+        allow(Rails.configuration).to receive(:geo_database).and_return('fdw' => true)
+
+        expect(described_class.fdw?).to be_truthy
+      end
+    end
   end
 
   describe 'primary?' do