set chrome-option --no-sandbox to allow execution as root (for docker)

config/config.exs

@@ -1,9 +1,12 @@
 use Mix.Config
 
-# config :pdf_generator,
-#   wkhtml_path: "/usr/bin/wkhtmltopdf",
-#   pdftk_path:  "/usr/bin/pdftk",
-#   command_prefix:   "/usr/bin/xvfb-run"
+config :pdf_generator,
+  #   wkhtml_path: "/usr/bin/wkhtmltopdf",
+  #   pdftk_path:  "/usr/bin/pdftk",
+  #   command_prefix:   "/usr/bin/xvfb-run",
+
+  # allow chrome to run as root
+  disable_chrome_sandbox: true
 
 import_config "#{Mix.env}.exs"
 

lib/pdf_generator.ex

@@ -83,10 +83,12 @@ defmodule PdfGenerator do
 
   ## Options
 
+   * `:generator` – either `chrome` or `wkhtmltopdf` (default)
+   * `:no_sandbox` – disable sandbox for chrome, required to run as root (read: _docker_)
    * `:page_size` - output page size, defaults to "A4"
    * `:open_password` - password required to open PDF. Will apply encryption to PDF
    * `:edit_password` - password required to edit PDF
-   * `:shell_params` - list of command-line arguments to wkhtmltopdf
+   * `:shell_params` - list of command-line arguments to wkhtmltopdf or chrome
      see http://wkhtmltopdf.org/usage/wkhtmltopdf.txt for all options
    * `:delete_temporary` - true to remove the temporary html generated in
      the system tmp dir
@@ -171,6 +173,7 @@ defmodule PdfGenerator do
   def make_command(:chrome, options, content, {html_path, pdf_path}) do
     executable_on_path = System.find_executable("chrome-headless-render-pdf")
     nodejs_on_path     = System.find_executable("nodejs")
+    disable_sandbox    = Application.get_env(:pdf_generator, :disable_chrome_sandbox) || options[:no_sandbox]
     js_file = Application.app_dir(:pdf_generator) <> "/../../../../node_modules/chrome-headless-render-pdf/dist/cli/chrome-headless-render-pdf.js"
 
     {executable, executable_args} =
@@ -187,12 +190,17 @@ defmodule PdfGenerator do
         {:url,  url} -> url
         _html        -> "file://" <> html_path
       end
-    arguments = executable_args ++ [
-      "--url", source,
-      "--pdf", pdf_path,
-      "--paper-width",   width,
-      "--paper-height", height,
-    ] ++ more_params
+    arguments = List.flatten([
+      executable_args,
+      [
+        "--url", source,
+        "--pdf", pdf_path,
+        "--paper-width",   width,
+        "--paper-height", height,
+      ],
+      more_params,
+      if(disable_sandbox, do: ["--chrome-option", "--no-sandbox"], else: [])
+    ])
     {executable, arguments} # |> IO.inspect()
   end
 

mix.exs

@@ -46,7 +46,7 @@ defmodule PdfGenerator.Mixfile do
   defp deps do
     [
         # communication with external programs
-        {:ex_doc, "~> 0.16", only: :dev, runtime: false}
+        {:ex_doc, "~> 0.19", only: :dev, runtime: false}
     ]
   end
 end

mix.lock

@@ -1,5 +1,8 @@
 %{
-  "earmark": {:hex, :earmark, "1.2.3", "206eb2e2ac1a794aa5256f3982de7a76bf4579ff91cb28d0e17ea2c9491e46a4", [:mix], []},
-  "ex_doc": {:hex, :ex_doc, "0.16.2", "3b3e210ebcd85a7c76b4e73f85c5640c011d2a0b2f06dcdf5acdb2ae904e5084", [:mix], [{:earmark, "~> 1.1", [hex: :earmark, optional: false]}]},
+  "earmark": {:hex, :earmark, "1.3.2", "b840562ea3d67795ffbb5bd88940b1bed0ed9fa32834915125ea7d02e35888a5", [:mix], [], "hexpm"},
+  "ex_doc": {:hex, :ex_doc, "0.20.2", "1bd0dfb0304bade58beb77f20f21ee3558cc3c753743ae0ddbb0fd7ba2912331", [:mix], [{:earmark, "~> 1.3", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.10", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm"},
+  "makeup": {:hex, :makeup, "0.8.0", "9cf32aea71c7fe0a4b2e9246c2c4978f9070257e5c9ce6d4a28ec450a839b55f", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.13.0", "be7a477997dcac2e48a9d695ec730b2d22418292675c75aa2d34ba0909dcdeda", [:mix], [{:makeup, "~> 0.8", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm"},
+  "nimble_parsec": {:hex, :nimble_parsec, "0.5.0", "90e2eca3d0266e5c53f8fbe0079694740b9c91b6747f2b7e3c5d21966bba8300", [:mix], [], "hexpm"},
   "porcelain": {:hex, :porcelain, "2.0.3", "2d77b17d1f21fed875b8c5ecba72a01533db2013bd2e5e62c6d286c029150fdc", [:mix], []},
 }

test/pdf_generator_test.exs

@@ -31,7 +31,7 @@ defmodule PdfGeneratorTest do
     assert {:ok, "%PDF-1" <> _pdf} = @html |> PdfGenerator.generate_binary
   end
 
-  test "chrome-headless" do
+  test "chrome-headless from file" do
     {:ok, temp_filename } = PdfGenerator.generate(@html, generator: :chrome, page_size: "A5")
 
     # File should exist and has some size
@@ -43,6 +43,12 @@ defmodule PdfGeneratorTest do
     assert String.slice( pdf, 0, 6) == "%PDF-1"
   end
 
+  test "chrome-headless from URL (assuming google.com is up and running)" do
+    {status, result} = PdfGenerator.generate({:url, "http://google.com"}, generator: :chrome)
+    assert status == :ok
+    assert result |> File.read! |> String.slice(0, 6) == "%PDF-1"
+  end
+
   test "generate! returns a filename" do
     @html
     |> PdfGenerator.generate!