fix: Configure ChromicPDF for all environments

README.md

@@ -13,6 +13,7 @@ To start your Phoenix server:
 
 - Run `mix setup` to install and setup dependencies
 - Run `mix build_code_vectors` to download the ICD-9 codelist, precompute vectors, and store the results in the database.
+- PDF generation is managed with [ChromicPDF](https://github.com/bitcrowd/chromic_pdf/tree/2c13cd2690204e6a30d817e72a3d1ef13e8a2441) which assumes an executable is available at [these locations](https://github.com/bitcrowd/chromic_pdf/blob/2c13cd2690204e6a30d817e72a3d1ef13e8a2441/lib/chromic_pdf/pdf/chrome_runner.ex#L64). If you are having trouble getting Chrome to launch, this [StackExchange](https://apple.stackexchange.com/a/467415) was useful.
 - Start Phoenix endpoint with `mix phx.server` or inside IEx with `iex -S mix phx.server`
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.

config/prod.exs

@@ -16,5 +16,8 @@ config :swoosh, local: false
 # Do not print debug messages in production
 config :logger, level: :info
 
+# NOTE: This path is the default from `apt-get install google-chrome-stable_current_amd64.deb` as found in Dockerfile
+config :medicode, chrome_executable: "/usr/bin/google-chrome"
+
 # Runtime production configuration, including reading
 # of environment variables, is done on config/runtime.exs.

config/test.exs

@@ -39,3 +39,5 @@ config :logger, level: :warning
 
 # Initialize plugs at runtime for faster test compilation
 config :phoenix, :plug_init_mode, :runtime
+
+config :medicode, skip_chromic_pdf: true

lib/medicode/application.ex

@@ -10,31 +10,32 @@ defmodule Medicode.Application do
 
   @impl true
   def start(_type, _args) do
-    children = [
-      MedicodeWeb.Telemetry,
-      Medicode.Repo,
-      {DNSCluster, query: Application.get_env(:medicode, :dns_cluster_query) || :ignore},
-      {Phoenix.PubSub, name: :medicode_pubsub},
-      # Start the Finch HTTP client for sending emails
-      {Finch, name: Medicode.Finch},
-      transcription_spec(),
-      token_classification_spec(),
-      text_embedding_spec(),
-      {Registry, keys: :unique, name: :transcription_registry},
-      {
-        Medicode.TranscriptionSupervisor,
-        strategy: :one_for_one, max_restarts: 1
-      },
-      {
-        Medicode.ClassificationSupervisor,
-        strategy: :one_for_one, max_restarts: 1
-      },
-      {ChromicPDF, chromic_pdf_opts()},
-      # Start a worker by calling: Medicode.Worker.start_link(arg)
-      # {Medicode.Worker, arg},
-      # Start to serve requests, typically the last entry
-      MedicodeWeb.Endpoint
-    ]
+    children =
+      [
+        MedicodeWeb.Telemetry,
+        Medicode.Repo,
+        {DNSCluster, query: Application.get_env(:medicode, :dns_cluster_query) || :ignore},
+        {Phoenix.PubSub, name: :medicode_pubsub},
+        # Start the Finch HTTP client for sending emails
+        {Finch, name: Medicode.Finch},
+        transcription_spec(),
+        token_classification_spec(),
+        text_embedding_spec(),
+        {Registry, keys: :unique, name: :transcription_registry},
+        {
+          Medicode.TranscriptionSupervisor,
+          strategy: :one_for_one, max_restarts: 1
+        },
+        {
+          Medicode.ClassificationSupervisor,
+          strategy: :one_for_one, max_restarts: 1
+        }
+      ] ++ chromic_pdf_spec()
+
+    # Start a worker by calling: Medicode.Worker.start_link(arg)
+    # {Medicode.Worker, arg},
+    # Start to serve requests, typically the last entry
+    children = children ++ [MedicodeWeb.Endpoint]
 
     # See https://hexdocs.pm/elixir/Supervisor.html
     # for other strategies and supported options
@@ -62,17 +63,25 @@ defmodule Medicode.Application do
     Vectors.child_spec(Medicode.TextEmbeddingServing)
   end
 
-  defp chromic_pdf_opts do
-    # NOTE: Security implications of using Chrome:
-    # https://github.com/bitcrowd/chromic_pdf/blob/2c13cd2690204e6a30d817e72a3d1ef13e8a2441/lib/chromic_pdf.ex#L71
-    #
-    # `chrome_executable` recommendation found here:
-    # https://community.fly.io/t/cant-install-chrome-chromium-via-dockerfile-or-ssh/5303/6
-    [
-      disable_scripts: true,
-      offline: true,
-      no_sandbox: true,
-      chrome_executable: "/usr/bin/google-chrome"
-    ]
+  defp chromic_pdf_spec do
+    if Application.get_env(:medicode, :skip_chromic_pdf, false) do
+      []
+    else
+      # NOTE: Security implications of using Chrome:
+      # https://github.com/bitcrowd/chromic_pdf/blob/2c13cd2690204e6a30d817e72a3d1ef13e8a2441/lib/chromic_pdf.ex#L71
+      #
+      # `chrome_executable` recommendation found here:
+      # https://community.fly.io/t/cant-install-chrome-chromium-via-dockerfile-or-ssh/5303/6
+      [
+        {ChromicPDF,
+         [
+           disable_scripts: true,
+           offline: true,
+           no_sandbox: true,
+           chrome_executable: Application.get_env(:medicode, :chrome_executable) || nil,
+           discard_stderr: false
+         ]}
+      ]
+    end
   end
 end