Internet connection not working from within docker container
Hello everyone,
we have problems building docker images on Fiware instance. The problem is, that from within a docker container, we can't download any data from internet. Commands like wget, composer, apt-get don't work. Strangely ping to any live address works fine from within containers.
My Dockerfile starts like this:
FROM php:7.0.4-apache
RUN apt-get update && apt-get install -y zlib1g-dev libicu-dev g++
...
ADD entrypoint.sh /
RUN chmod +x /entrypoint.sh
ENTRYPOINT ["/entrypoint.sh"]
but the build fails...
Building web
Step 1 : FROM php:7.0.4-apache
---> ce68d55b8d56
Step 2 : RUN apt-get update && apt-get install -y zlib1g-dev libicu-dev g++
---> Running in 9108f4c9afcc
Ign http://httpredir.debian.org jessie InRelease
Ign http://security.debian.org jessie/updates InRelease
Ign http://httpredir.debian.org jessie-updates InRelease
Get:1 http://httpredir.debian.org jessie-updates Release.gpg [1554 B]
Get:2 http://httpredir.debian.org jessie-updates Release.gpg [1554 B]
Err http://security.debian.org jessie/updates Release.gpg
Connection failed [IP: 195.20.242.89 80]
Err http://httpredir.debian.org jessie Release.gpg
Connection failed
Get:3 http://httpredir.debian.org jessie-updates Release.gpg [1554 B]
Same problems occurred when we uploaded existing container that works on different machines (Linode) to Fiware instance.
Internet connection from Instance itself works, just not from within a docker container.
Has anyone had the same issues with connectivity?
Thank you
Have you tried checking the DNS configuration of the container? http://odino.org/cannot-connect-to-the-internet-from-your-docker-containers/
Thanks. We have tried changing DNS provider before and now again following your tip. Didn't help, pinging works but nothing else. When we deploy the same docker container to Linode, it works. So we think it's something Fiware related. Thanks.
I tried to reproduce on a FIWARE instance with a docker engine, but it had no problem with the apt-get install. What happens when you do the same apt-get on the docker host? --Ken
This fixed it for us: https://rahulait.wordpress.com/2016/02/28/modifying-default-mtu-for-docker-containers/ That's for debian 8 image, we had to switch from ubuntu.