Make the secrets commands inline aware

Rather than redirecting the global $stdout, which is not never clever in
a threaded program, we'll make the secrets commands aware they are
being inlined, so they return the value instead of printing it.

Additionally we no longer need to interrupt the parent process on error
as we've inlined the command - exit 1 is enough.

lib/kamal/cli/secrets.rb

@@ -3,26 +3,26 @@ class Kamal::Cli::Secrets < Kamal::Cli::Base
   option :adapter, type: :string, aliases: "-a", required: true, desc: "Which vault adapter to use"
   option :account, type: :string, required: true, desc: "The account identifier or username"
   option :from, type: :string, required: false, desc: "A vault or folder to fetch the secrets from"
+  option :inline, type: :boolean, required: false, hidden: true
   def fetch(*secrets)
-    results = adapter(options[:adapter]).fetch(secrets, **options.slice(:account, :from).symbolize_keys)
-    puts JSON.dump(results).shellescape
-  rescue => e
-    handle_error(e)
+    handle_output(inline: options[:inline]) do
+      results = adapter(options[:adapter]).fetch(secrets, **options.slice(:account, :from).symbolize_keys)
+      JSON.dump(results).shellescape
+    end
   end
 
   desc "extract", "Extract a single secret from the results of a fetch call"
+  option :inline, type: :boolean, required: false, hidden: true
   def extract(name, secrets)
-    parsed_secrets = JSON.parse(secrets)
+    handle_output(inline: options[:inline]) do
+      parsed_secrets = JSON.parse(secrets)
 
-    if (value = parsed_secrets[name]).nil?
-      value = parsed_secrets.find { |k, v| k.end_with?("/#{name}") }&.last
+      value = parsed_secrets[name] || parsed_secrets.find { |k, v| k.end_with?("/#{name}") }&.last
+
+      raise "Could not find secret #{name}" if value.nil?
+
+      value
     end
-
-    raise "Could not find secret #{name}" if value.nil?
-
-    puts value
-  rescue => e
-    handle_error(e)
   end
 
   private
@@ -30,11 +30,18 @@ class Kamal::Cli::Secrets < Kamal::Cli::Base
       Kamal::Secrets::Adapters.lookup(adapter)
     end
 
+    def handle_output(inline: nil)
+      yield.tap do |output|
+        puts output unless inline
+      end
+    rescue => e
+      handle_error(e)
+    end
+
     def handle_error(e)
       $stderr.puts "  \e[31mERROR (#{e.class}): #{e.message}\e[0m"
       $stderr.puts e.backtrace if ENV["VERBOSE"]
 
-      Process.kill("INT", Process.ppid) if ENV["KAMAL_SECRETS_INT_PARENT"]
       exit 1
     end
 end