History file being overidden if initially empty

[krystof-k]

Description

I'm running multiple containers via Docker Compose with all of them mapped to a single .irb-history file which is placed on Docker volume. When they are launched, the (last?) one overrides the history.

Consider following example:

• Dockerfile:

  FROM ruby:alpine
  RUN echo "IRB.conf[:HISTORY_FILE] = ENV['IRB_HISTORY_FILE'] if ENV['IRB_HISTORY_FILE']" >> ~/.irbrc

• docker-compose.yaml:

  services:
    first:
      build:
        context: .
      volumes:
        - history:/root/.history
      environment:
        HISTFILE: /root/.history/.bash_history
        IRB_HISTORY_FILE: /root/.history/.irb-history
      command: tail -f /dev/null
    second:
      extends:
        service: first
  volumes:
    history:

• run:

  docker compose up -d

  run in another terminal:

  docker compose exec first irb
  puts 'first'

  run in another terminal:

  docker compose exec second irb
  puts 'second'

  run in first terminal:

  docker compose down

  run in first terminal:

  docker compose run first cat /root/.history/.irb-history

  result:

  puts 'second'

Result of irb_info

irb(main):001:0> irb_info
=> 
Ruby version: 3.1.2                            
IRB version: irb 1.4.1 (2021-12-25)            
InputMethod: ReidlineInputMethod with Reline 0.3.0
.irbrc path: /root/.irbrc                      
RUBY_PLATFORM: aarch64-linux-musl              
LANG env: C.UTF-8                              
East Asian Ambiguous Width: 1 

Setting Files

~/.irbrc:

IRB.conf[:HISTORY_FILE] = ENV['IRB_HISTORY_FILE'] if ENV['IRB_HISTORY_FILE']

[krystof-k]

I understood that something that should probably handle this was done by @jeremyevans in #193, but it is definitely not working in this case.

I also tried "initializing" the file in the Dockerfile already (putting some content in it), but that didn't help.

[jeremyevans]

If you can provide steps to reproduce this issue without docker, I will look into it.

[krystof-k]

I have no idea how. However exactly the same approach for .bash_history is working with no issue.

[krystof-k]

OK, maybe I did.

First – ensure there is no history file existing.

Launch IRB in two windows, enter someting in the first, exit, enter something in the second, exit. You will have only the history from the second.

1st terminal:

• cd ~
• rm -f .irb_history
• irb
• puts 'first'
• exit

2nd terminal:

• irb
• puts 'second'
• exit

1st terminal:

• cat .irb_history:

  puts 'second'
  exit
  

[jeremyevans]

Thank you for that. I can reproduce the issue. I'll look into it, and hopefully have a fix today or next week.

[krystof-k]

Thanks. Unfortunately I'm afraid that this is not the same issue I'm actually facing in the Docker Compose setup with Rails :(

[jeremyevans]

Can you try this patch?:

diff --git a/lib/irb/ext/save-history.rb b/lib/irb/ext/save-history.rb
index 7acaebe..fd5db16 100644
--- a/lib/irb/ext/save-history.rb
+++ b/lib/irb/ext/save-history.rb
@@ -81,9 +81,9 @@ module IRB
             end
           }
         end
-        @loaded_history_lines = history.size
-        @loaded_history_mtime = File.mtime(history_file)
       end
+      @loaded_history_lines = history.size
+      nil
     end

     def save_history
@@ -107,21 +107,10 @@ module IRB
           raise
         end

-        if File.exist?(history_file) && @loaded_history_mtime &&
-           File.mtime(history_file) != @loaded_history_mtime
-          history = history[@loaded_history_lines..-1]
-          append_history = true
-        end
+        history = history[@loaded_history_lines..-1]

-        open(history_file, "#{append_history ? 'a' : 'w'}:#{IRB.conf[:LC_MESSAGES].encoding}", 0600) do |f|
+        open(history_file, "a:#{IRB.conf[:LC_MESSAGES].encoding}", 0600) do |f|
           hist = history.map{ |l| l.split("\n").join("\\\n") }
-          unless append_history
-            begin
-              hist = hist.last(num) if hist.size > num and num > 0
-            rescue RangeError # bignum too big to convert into `long'
-              # Do nothing because the bignum should be treated as inifinity
-            end
-          end
           f.puts(hist)
         end
       end

[krystof-k]

Is it enough if I just edit the file in /usr/local/bundle/gems/irb-1.4.1?

[jeremyevans]

That should work.

[krystof-k]

Yes! That seems to be working (my original issue in Docker Compose no longer occurs).

[jeremyevans]

OK. Let me update the tests and send a pull request for this.

[jeremyevans]

Looks like my previous diff fixed one issue, but broke others. Here's a much simpler diff that doesn't break any tests:

diff --git a/lib/irb/ext/save-history.rb b/lib/irb/ext/save-history.rb
index 7acaebe..83d0710 100644
--- a/lib/irb/ext/save-history.rb
+++ b/lib/irb/ext/save-history.rb
@@ -107,7 +107,7 @@ module IRB
           raise
         end

-        if File.exist?(history_file) && @loaded_history_mtime &&
+        if File.exist?(history_file) &&
            File.mtime(history_file) != @loaded_history_mtime
           history = history[@loaded_history_lines..-1]
           append_history = true

If there is no history file originally, @loaded_history_mtime is not set, but we should still append in that case, as it is obvious the file has changed.

[jeremyevans]

OK, I submitted #389 to fix this

[krystof-k]

That seems to be working as well. Awesome, many thanks!