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alpine-user

Re: [alpine-user] APK hangs on some packages

From: Natanael Copa <ncopa_at_alpinelinux.org>
Date: Wed, 3 Apr 2019 15:53:40 +0100

On Wed, 3 Apr 2019 16:14:52 +0200
Tristan Kohl <tristan_at_iceity.de> wrote:

> Hey guys,
>
> I build most of my images on top of Alpine. However for the last couple
> of days I come accross some weird problem which causes apk add to hang
> for some packages. I tried following Dockerfile on an Alpine 3.9 host
> with Docker 18.09.1-ce and my Void Linux desktop with docker 18.09.4.
>
>
> FROM alpine:latest
>
> RUN apk add --no-cache build-base cmake git linux-headers perl
>
> <snip>
>
>
>
> #> docker build -t test .
> Sending build context to Docker daemon 2.56kB
> Step 1/18 : FROM alpine:latest
> ---> 5cb3aa00f899
> Step 2/18 : RUN apk add --no-cache build-base cmake git linux-headers perl
> ---> Running in 9736754a88cc
> fetch http://dl-cdn.alpinelinux.org/alpine/v3.9/main/x86_64/APKINDEX.tar.gz
> fetch
> http://dl-cdn.alpinelinux.org/alpine/v3.9/community/x86_64/APKINDEX.tar.gz
> (1/41) Upgrading musl (1.1.20-r3 -> 1.1.20-r4)
> (2/41) Installing binutils (2.31.1-r2)
> (3/41) Installing libmagic (5.35-r0)
> (4/41) Installing file (5.35-r0)
> (5/41) Installing gmp (6.1.2-r1)
> (6/41) Installing isl (0.18-r0)
> (7/41) Installing libgomp (8.2.0-r2)
> (8/41) Installing libatomic (8.2.0-r2)
> (9/41) Installing libgcc (8.2.0-r2)
> (10/41) Installing mpfr3 (3.1.5-r1)
> (11/41) Installing mpc1 (1.0.3-r1)
> (12/41) Installing libstdc++ (8.2.0-r2)
> (13/41) Installing gcc (8.2.0-r2)
>
>
> Process hangs here (I let it alone for >1h and then killed it), but
> running an Alpine instance via
>
> docker run -it --rm alpine
>
> and trying to install those packages manually one by one has worked both
> times I tried this (today and on Sunday). However, installing gcc or
> build-base did not work (aka. hang) two or three times and only
> succedded on consecutive tries. Weirdly enough, calling
>
> apk add g++
>
> pulled in gcc and finished within seconds as I was used to...
>
> So I "think" there is no problem with docker's network setup but I have
> no idea of the inner workings so please tell me where to look if you
> think this is a docker issue.

This sounds like an MTU blackhole issue. I know that Fastly
(dl-cdn.a.o) does not have a working PMTU, because they filter
out need-to-frag ICMP packets. I guess its their DDoS feature that
does.

Check the MTU size in your container, on the host and in your LAN.

If you host and container have differnet MTU size, then you can
probably resolve it with clamp-mss on your host.

There is also a tool called 'mtu' that can help you find where a
blackhole is, in case it is a problem with your ISP or somewhere else
on the internet.

  apk add mtu

-nc


>
> Cheers,
> Tristan
>
> P.S.: Previous builds ~2 weeks ago worked and there was no docker update
> as far as I can remember.
>
>
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Received on Wed Apr 03 2019 - 15:53:40 UTC