Truncated output with `fig run`

[zwily]

Whenever I do a fig run command that returns many lines of output, the output is either truncated, or weirdly garbled. This typically happens when running fig run web rake routes. The output will typically come back missing 3-5 lines of output (randomly). docker run -it --rm $IMAGE rake routes works just fine.

Using fig 1.0.1.

[codekitchen]

I'm seeing this as well -- I can also repro in various containers just running fig run <box> ls -al

[zwily]

Here's a reduction of the issue...

Contents of fig.yml:

test:
  image: debian:wheezy

Using fig:

$ fig run --rm test seq 10
1Removing figptytest_test_run_7...

Using docker directly:

$ docker run -it --rm debian:wheezy seq 10
1
2
3
4
5
6
7
8
9
10

The fig results are inconsistent. Occasionally I've seen it return all the lines, but usually it exits after the first line. I suspect that there's a race condition with select somewhere in dockerpty, but haven't dug in yet.

(I'm kinda surprised more people haven't reported this.)

[aanand]

I've seen this myself, though very occasionally. I too suspect it's a dockerpty bug.

[nonsensery]

I've seen this happen (on Jenkins) when starting a background process inside the container. The fix seemed to be redirecting the I/O of the background process away from the TTY. Something along the lines of:

No Output:

bundle exec rails server &
cucumber

Output:

bundle exec rails server </dev/null &>/dev/null &
cucumber

[sylvinus]

Same issue for me. This pretty much makes fig run unusable in my case :(

I'm now prefixing all my commands with stdbuf -i0 -e0 -o0 which seems to make things better.

Thanks!

[dnephin]

The jenkins issue should be fixed as of the fig 1.0.1 release (with dockerpty v0.3.2) if you run:

fig run -T ...

For other people experiencing this issue, are you seeing it on jenkins, or are you using a virtual machine (boot2docker).

Does -T resolve the issue?

[nonsensery]

I am still seeing this with Fig 1.0.1 and the -T flag. IIRC, it is improved over Fig 1.0.0, but still happens. It seems to be a bit random, though—even with the output redirected, I sometimes don't seem to get all of the output in my Jenkins log.

[sylvinus]

Also still having the issue with 1.0.1

[Malet]

Also having this issue, running the equivalent docker command seems to return the correct and full output every time. Using the -T flag for run doesn't seem to change the random truncating behaviour.

[Malet]

This appears to be an issue with fig rather than dockerpty - I've made a test case here: https://github.com/Malet/fig-testcase

This fails when running with fig 1.0.1
7887410 appears to have upgraded docker-py, I haven't had time yet to try running the test with a fresh build of fig.

Edit: I've tried this with a freshly built fig from master and still have the same issues.

[nonsensery]

Awesome work, @Malet. I'm curious about the fix, could you elaborate on that?