fix(storage): replace retired azure-storage-blob with maintained azure-blob

The azure-storage-blob / azure-storage-common gems were retired by Microsoft
on 13 Sep 2024 and are unmaintained. They also forced a manual `cgi ~> 0.5.1`
pin under Ruby 4.0 (azure-storage-common needs CGI.parse, which Ruby 4.0's
stripped stdlib omits and Rails 8 no longer pulls in transitively).

Swap to testdouble/azure-blob, a maintained drop-in Active Storage adapter:

- Gemfile: azure-storage-blob -> azure-blob; drop the now-redundant cgi pin
  (azure-blob declares cgi as a dependency, so the full library resolves again).
- config/storage.yml: microsoft service AzureStorage -> AzureBlob.
- Rewrite the signing regression guard to exercise the AzureBlob Active Storage
  service (offline URL signing for download + direct upload), replacing the old
  azure-storage-common internal-class assertions.

Same Azure account / container / keys, so no data migration or infra change.

Closes #7094

Author: tacoda

Gemfile

@@ -8,16 +8,11 @@ gem "rails", "~> 8.0"
 gem "after_party" # Post-deployment tasks
 gem "amazing_print" # Easier console reading
 gem "authtrail" # Track Devise login activity
-gem "azure-storage-blob", require: false
+gem "azure-blob", require: false # Active Storage adapter for Azure (maintained replacement for retired azure-storage-blob)
 gem "blueprinter" # JSON serialization
 gem "bugsnag" # Error tracking in production
 gem "caxlsx", "~> 4.5" # Excel spreadsheets - TODO can we remove this version restriction?
 gem "caxlsx_rails", "~> 0.7.1" # Excel spreadsheets - TODO can we remove this version restriction?
-# Ruby 4.0 ships a cgi stdlib with only escape/unescape; azure-storage-common needs the
-# full library's CGI.parse to sign blob URLs. Rails 8 no longer pulls cgi in transitively,
-# so without this the stripped stdlib wins and every Active Storage read/write 500s.
-# Guarded by spec/lib/azure_storage_signing_spec.rb. Remove when azure-storage-blob is dropped.
-gem "cgi", "~> 0.5.1"
 gem "cssbundling-rails", "~> 1.4" # CSS compilation
 gem "delayed_job_active_record" # Background job processing
 gem "devise" # Authentication

Gemfile.lock

@@ -92,14 +92,9 @@ GEM
       dumb_delegator
     axe-core-rspec (4.12.0)
       axe-core-api (= 4.12.0)
-    azure-storage-blob (2.0.3)
-      azure-storage-common (~> 2.0)
-      nokogiri (~> 1, >= 1.10.8)
-    azure-storage-common (2.0.4)
-      faraday (~> 1.0)
-      faraday_middleware (~> 1.0, >= 1.0.0.rc1)
-      net-http-persistent (~> 4.0)
-      nokogiri (~> 1, >= 1.10.8)
+    azure-blob (0.8.0)
+      cgi
+      rexml
     base64 (0.3.0)
     bcrypt (3.1.22)
     benchmark (0.5.0)
@@ -237,8 +232,6 @@ GEM
     faraday-patron (1.0.0)
     faraday-rack (1.0.0)
     faraday-retry (1.0.4)
-    faraday_middleware (1.2.1)
-      faraday (~> 1.0)
     ffi (1.17.4)
     ffi (1.17.4-arm64-darwin)
     ffi (1.17.4-x86_64-darwin)
@@ -342,15 +335,12 @@ GEM
       benchmark
       logger
     mini_mime (1.1.5)
-    mini_portile2 (2.8.9)
     minitest (6.0.6)
       drb (~> 2.0)
       prism (~> 1.5)
     multi_xml (0.8.1)
       bigdecimal (>= 3.1, < 5)
     multipart-post (2.4.1)
-    net-http-persistent (4.0.8)
-      connection_pool (>= 2.2.4, < 4)
     net-imap (0.6.4.1)
       date
       net-protocol
@@ -361,9 +351,6 @@ GEM
     net-smtp (0.5.1)
       net-protocol
     nio4r (2.7.5)
-    nokogiri (1.19.4)
-      mini_portile2 (~> 2.8.2)
-      racc (~> 1.4)
     nokogiri (1.19.4-arm64-darwin)
       racc (~> 1.4)
     nokogiri (1.19.4-x86_64-darwin)
@@ -709,7 +696,6 @@ GEM
 
 PLATFORMS
   arm64-darwin
-  ruby
   x86_64-darwin
   x86_64-linux
 
@@ -719,7 +705,7 @@ DEPENDENCIES
   annotaterb
   authtrail
   axe-core-rspec
-  azure-storage-blob
+  azure-blob
   blueprinter
   brakeman
   bugsnag
@@ -729,7 +715,6 @@ DEPENDENCIES
   capybara-screenshot
   caxlsx (~> 4.5)
   caxlsx_rails (~> 0.7.1)
-  cgi (~> 0.5.1)
   cssbundling-rails (~> 1.4)
   database_cleaner-active_record
   delayed_job_active_record

config/storage.yml

@@ -23,7 +23,7 @@ local:
 
 # Use rails credentials:edit to set the Azure Storage secret (as azure_storage:storage_access_key)
 microsoft:
-  service: AzureStorage
+  service: AzureBlob
   storage_account_name: <%= ENV['STORAGE_ACCOUNT_NAME'] %>
   storage_access_key: <%= ENV['STORAGE_ACCESS_KEY'] %>
   container: <%= ENV['STORAGE_CONTAINER'] %>

spec/lib/azure_storage_signing_spec.rb

@@ -1,39 +1,54 @@
-require "rails_helper"
-require "azure/storage/blob"
+# frozen_string_literal: true
 
-# Production stores every attachment on Azure (config.active_storage.service = :microsoft),
-# and azure-storage-common signs both uploads and download URLs with CGI.parse. Ruby 4.0's
-# stdlib cgi ships only escape/unescape, so the Gemfile has to pin the real cgi gem back in
-# — Rails 8 stopped pulling it in transitively. When that pin goes missing, every Active
-# Storage read and write 500s in production while CI stays green, because the test
-# environment uses Disk storage and never touches this code.
+require "rails_helper"
+require "active_storage/service/azure_blob_service"
+
+# Production stores every attachment on Azure (config.active_storage.service = :microsoft,
+# service: AzureBlob). The azure-blob gem signs both uploads and download URLs with CGI.parse.
+# Ruby 4.0's stdlib cgi ships only escape/unescape, so a full cgi gem must resolve — azure-blob
+# declares it as a dependency, which pulls it back in (Rails 8 stopped doing so transitively).
+# When that goes missing, every Active Storage read and write 500s in production while CI stays
+# green, because the test environment uses Disk storage and never touches this code.
 #
-# See https://github.com/rubyforgood/casa/issues/7093
+# This is the regression guard for the retired azure-storage-blob → azure-blob migration.
+# See https://github.com/rubyforgood/casa/issues/7094 (and the earlier #7093).
 RSpec.describe "Azure Storage request signing" do
-  let(:account_name) { "casaaccount" }
-  let(:access_key) { Base64.strict_encode64("not-a-real-key") }
+  let(:service) do
+    ActiveStorage::Service::AzureBlobService.new(
+      storage_account_name: "casaaccount",
+      storage_access_key: Base64.strict_encode64("not-a-real-key"),
+      container: "casa"
+    )
+  end
 
   it "has the full CGI library, not Ruby 4.0's escape-only stdlib" do
     expect(CGI).to respond_to(:parse)
   end
 
-  # Exercised by CaseCourtReportsController#save_report when it attaches the .docx.
-  it "signs an upload request" do
-    signer = Azure::Storage::Common::Core::Auth::SharedKey.new(account_name, access_key)
-    uri = URI("https://#{account_name}.blob.core.windows.net/casa/report.docx?comp=block&blockid=abc")
-
-    signature = signer.sign(:put, uri, {"Content-Type" => "application/vnd.openxmlformats-officedocument.wordprocessingml.document"})
-
-    expect(signature).to start_with("#{account_name}:")
+  # Exercised by active_storage/blobs/redirect#show when a user downloads a court report.
+  it "signs a private download URL locally, without hitting Azure" do
+    url = service.url(
+      "report.docx",
+      expires_in: 5.minutes,
+      filename: ActiveStorage::Filename.new("report.docx"),
+      disposition: :attachment,
+      content_type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+    )
+
+    expect(url).to start_with("https://casaaccount.blob.core.windows.net/casa/report.docx")
+    expect(url).to include("sig=")
   end
 
-  # Exercised by active_storage/blobs/redirect#show when a user downloads the report.
-  it "signs a download URL" do
-    generator = Azure::Storage::Common::Core::Auth::SharedAccessSignature.new(account_name, access_key)
-    uri = URI("https://#{account_name}.blob.core.windows.net/casa/report.docx")
-
-    signed_uri = generator.signed_uri(uri, false, service: "b", permissions: "r", expiry: "2050-01-01T00:00:00Z")
-
-    expect(signed_uri.query).to include("sig=")
+  # Exercised whenever an attachment is uploaded (e.g. CaseCourtReportsController#save_report).
+  it "signs a direct-upload URL locally, without hitting Azure" do
+    url = service.url_for_direct_upload(
+      "report.docx",
+      expires_in: 5.minutes,
+      content_type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+      content_length: 1024,
+      checksum: "md5-checksum"
+    )
+
+    expect(url).to include("sig=")
   end
 end