Problem
You have a remote server (Debian) running some Docker containers and you want to make sure that they all restart in the event of a kernel panick.
solution
sysctl kernel.panic=20
echo c > /proc/sysrq-trigger
Problem
You want to install some default locales in a Docker image, and the suggestion is to use locale-gen to do so, but it does not work as expected.
Solution
In order to be able to use the locale-gen and install the locales you need you will have to uncomment the ones needed from /etc/locale.gen first and then use the locale-gen. Example below:
## Set up locales ## Uncomment the ones we need as locale-gen does not work without that RUN sed -i '/en_US.UTF-8/s/^#//' /etc/locale.gen RUN sed -i '/de_DE.UTF-8/s/^#//' /etc/locale.gen ## Now install them and set the default one RUN locale-gen ENV LANG en_US.UTF-8 ENV LANGUAGE en_US:en ENV LC_ALL en_US.UTF-8
Problem
When trying to use the dockercloud-agent with docker you have the following error in the /var/log/dockercloud/agent.log
level=fatal msg="Error starting daemon: Error initializing network controller: Error creating default \"bridge\" network: cannot create network xxx... (docker0): conflicts with network yyy.... (docker0): networks have same bridge name"
Solution
If you remove the file var/lib/docker/network/files/local-kv.db as suggested here, then if you look again at the log files, it should be a message that the docker daemon has been started:
016/11/17 10:30:28 Respawning docker daemon 2016/11/17 10:30:28 Starting docker daemon: [/usr/bin/docker daemon -H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375 --userland-proxy=false --tlscert /etc/dockercloud/agent/cert.pem --tlskey /etc/dockercloud/agent/key.pem --tlscacert /etc/dockercloud/agent/ca.pem --tlsverify] 2016/11/17 10:30:28 Docker daemon (PID:4036) has been started
Problem
You would like to clear Docker containers that have been exited and not cleared properly.
Solution
Run the following to find out the containers that have exited and remove them.
sudo docker ps -a | grep 'Exited' | tail -n +1 | awk '{ print $1 }' | xargs sudo docker rm
Problem
You would like to know the IP for a running Docker container.
Solution
Run the following two commands (taken from here
docker ps docker inspect container_name | grep IPAddress
Problem
Trying to remove some unused docker images that you no longer use with docker rmi image_id you get the following error message:
Error response from daemon: conflict: unable to delete 75d009de0479 (must be forced) - image is referenced in one or more repositories
Solution
Use the following to delete multiple images (ie ubuntu):
docker images ubuntu | tail -n +2 | awk '{ print $1 ":" $2 }' | xargs sudo docker rmi
Mentioned here
Problem
After playing around with docker containers for some time the terminated/unused ones are still hanging around your system, and prevent you from using a new container with the same name as any of the previous ones with the error:
Error response from daemon: Conflict. The name "container_name" is already in use by container 61f023f06a98. You have to remove (or rename) that container to be able to reuse that name.
Solution
You can remove all the containers by using the following:
docker rm $(docker ps -aq)
Trying to deploy a rails application in a cloud provider ie dreamhost, that uses OpenStack these are the steps needed:
sudo docker pull rails:latest
rails new docker_test
FROM rails:onbuild
sudo docker build -t rails_docker_test .
sudo docker images
sudo docker run --name rails_test -p 0.0.0.0:3000:3000 -d rails_docker_test
sudo docker login --username=yourhubusername --email=youremail@company.com
, and then when you get ‘Login Succeeded’, push your image to your account:
sudo docker push yourhubusername/rails_docker_test
Problem
You want to install rvm as a single user in a new linux but when trying to install it with the normal installation instruction:
curl -sSL https://get.rvm.io | bash -s stable --ruby
it fails with the following error:
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
Solution
You are behind a proxy server and you need to setup your environment variables for the server in your .profile file like the following (and make sure you source the file afterwards with . ~/.profile):
export http_proxy=http://xxx.xxx.xxx.xxx:port_no/ export https_proxy=https://xxx.xxx.xxx.xxx:port_no/
In order to be able to use Elixir with the help of Docker, so that you can run different containers with different versions, and to have a shared code folder, you could follow the steps below:
sudo docker pull trenpixster/elixir
sudo ps docker images
sudo docker run -t -i trenpixster/elixir:1.0.3 /bin/bash
sudo docker run -v /home/user/Prog:/Prog -t -i trenpixster/elixir:1.0.3 /bin/bash
where the folders after the -v option are /home/user/Prog (host) and /Prog (docker)
sudo docker run -p 8000 -v /home/user/Prog:/Prog -t -i trenpixster/elixir:1.0.3 /bin/bash