Coerce string object storage options to booleans

Admins that accidentally configure `use_iam_profile` or `path_style`
with string values (e.g. `"true"`) instead of boolean values would see
obscure unmarshaling errors in Workhorse. To avoid this trouble, coerce
these string values o boolean values.

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5588

changelogs/unreleased/sh-coerce-object-storage-params.yml

+---
+title: Coerce string object storage options to booleans
+merge_request: 39901
+author:
+type: fixed

lib/object_storage/config.rb

@@ -34,11 +34,11 @@ module ObjectStorage
     end
 
     def use_iam_profile?
-      credentials.fetch(:use_iam_profile, false)
+      Gitlab::Utils.to_boolean(credentials[:use_iam_profile], default: false)
     end
 
     def use_path_style?
-      credentials.fetch(:path_style, false)
+      Gitlab::Utils.to_boolean(credentials[:path_style], default: false)
     end
 
     def server_side_encryption

spec/lib/object_storage/config_spec.rb

 # frozen_string_literal: true
 
 require 'fast_spec_helper'
+require 'rspec-parameterized'
 
 RSpec.describe ObjectStorage::Config do
+  using RSpec::Parameterized::TableSyntax
+
   let(:region) { 'us-east-1' }
   let(:bucket_name) { 'test-bucket' }
-  let(:path_style) { false }
-  let(:use_iam_profile) { false }
   let(:credentials) do
     {
       provider: 'AWS',
       aws_access_key_id: 'AWS_ACCESS_KEY_ID',
       aws_secret_access_key: 'AWS_SECRET_ACCESS_KEY',
-      region: region,
-      path_style: path_style,
-      use_iam_profile: use_iam_profile
+      region: region
     }
   end
 
@@ -52,6 +51,14 @@ RSpec.describe ObjectStorage::Config do
     it { expect(subject.bucket).to eq(bucket_name) }
   end
 
+  describe '#use_iam_profile' do
+    it { expect(subject.use_iam_profile?).to be false }
+  end
+
+  describe '#use_path_style' do
+    it { expect(subject.use_path_style?).to be false }
+  end
+
   context 'with unconsolidated settings' do
     describe 'consolidated_settings? returns false' do
       it { expect(subject.consolidated_settings?).to be false }
@@ -68,25 +75,47 @@ RSpec.describe ObjectStorage::Config do
     end
   end
 
-  context 'with IAM profile in use' do
-    let(:use_iam_profile) { true }
+  context 'with IAM profile configured' do
+    where(:value, :expected) do
+      true    | true
+      "true"  | true
+      "yes"   | true
+      false   | false
+      "false" | false
+      "no"    | false
+      nil     | false
+    end
+
+    with_them do
+      before do
+        credentials[:use_iam_profile] = value
+      end
 
-    it '#use_iam_profile? returns true' do
-      expect(subject.use_iam_profile?).to be true
+      it 'coerces the value to a boolean' do
+        expect(subject.use_iam_profile?).to be expected
+      end
     end
   end
 
-  context 'with IAM profile not in use' do
-    it '#use_iam_profile? returns false' do
-      expect(subject.use_iam_profile?).to be false
+  context 'with path style configured' do
+    where(:value, :expected) do
+      true    | true
+      "true"  | true
+      "yes"   | true
+      false   | false
+      "false" | false
+      "no"    | false
+      nil     | false
     end
-  end
 
-  context 'with path style' do
-    let(:path_style) { true }
+    with_them do
+      before do
+        credentials[:path_style] = value
+      end
 
-    it '#use_path_style? returns true' do
-      expect(subject.use_path_style?).to be true
+      it 'coerces the value to a boolean' do
+        expect(subject.use_path_style?).to be expected
+      end
     end
   end