Archive for the ‘Docker’ Category

Since a couple of days, I was plagued by some DNS problems when using Docker 1.10+. Seems that the dnsmasq process is writing the address 127.0.1.1 into the resolv.conf. The purpose of the dnsmasq is to cache DNS queries. Unfortunately, it was no longer available in my Docker containers. The only solution for now (maybe it is a workaround) is to throw dnsmasq out. You can do this by editing the file:

/etc/NetworkManager/NetworkManager.conf

Open the file with an editor and comment out the line

dns=dnsmasq   ---> #dns=dnsmasq

After that, kill dnsmasq and restart the network-manager. You should see the changes in the resolv.conf after that:

sudo killall dnsmasq
sudo service network-manager
restart cat /etc/resolv.conf

When you’re running Ubuntu 15.04 with Docker, you must use systemctl to enable/disable your Docker service. Unfortunately, the old /etc/default/docker configuration file is not read. You must change the docker.service file and add these lines:

....

[Service]
EnvironmentFile=-/etc/default/docker
ExecStart=/usr/bin/docker -d -H fd:// $DOCKER_OPTS
MountFlags=slave
LimitNOFILE=1048576
LimitNPROC=1048576
LimitCORE=infinity

....

(On my Ubuntu 15.04 system, the file resides at /etc/systemd/system/multi-user.target.wants/)

Restart Docker with:

$ sudo systemctl restart docker 

Ubuntu 15.04 and Docker 1.6.0

Posted: April 27, 2015 in Docker, Ubuntu
Tags: , , ,

When you upgrade to Ubuntu 15.04 and install docker using the get.docker.io script, you’ll probably run into an error like “Are you trying to connect to a TLS-enabled daemon without TLS?”.

Ubuntu 15.04 changed to systemd and you should enable docker with this command:

$ systemctl enable docker

Restart your computer, and it should be working.