coreos – Tarik Billa

How do I check if my local docker image is outdated, without pushing from somewhere else?

April 7, 2024 by Tarik

You can query the registry API for the image digest and compare it to that of what you’ve pulled. $ cat digest-v2.sh #!/bin/sh ref=”${1:-library/ubuntu:latest}” repo=”${ref%:*}” tag=”${ref##*:}” acceptM=”application/vnd.docker.distribution.manifest.v2+json” acceptML=”application/vnd.docker.distribution.manifest.list.v2+json” token=$(curl -s “https://auth.docker.io/token?service=registry.docker.io&scope=repository:${repo}:pull” \ | jq -r ‘.token’) curl -H “Accept: ${acceptM}” \ -H “Accept: ${acceptML}” \ -H “Authorization: Bearer $token” \ -I -s “https://registry-1.docker.io/v2/${repo}/manifests/${tag}” $ ./digest-v2.sh … Read more

How can I find which version of CoreOS is running on a given machine

September 20, 2023 by Tarik

The version is stored in cat /etc/os-release

systemd: “Environment” directive to set PATH

August 9, 2023 by Tarik

You can’t use EnvVars in Environment directives. The whole Environment= will be ignored. If you use EnvironmentFile=, then the specified file will be loaded without substitution. So PATH=/local/bin:$PATH would be exactly that, and this is probably not what you want. Under CentOS7 the following works. # /etc/systemd/system/nagios.service.d/env.conf [Service] Environment=”PATH=/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin” > sudo systemctl daemon-reload > sudo … Read more

x509 certificate signed by unknown authority- Kubernetes

August 5, 2023 by Tarik

mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config

Docker Compose to CoreOS

August 3, 2023 by Tarik

taken from https://docs.docker.com/compose/install/ the only thing is that /usr is read only, but /opt/bin is writable and in the path, so: sd-xx~ # mkdir /opt/ sd-xx~ # mkdir /opt/bin sd-xx~ # curl -L https://github.com/docker/compose/releases/download/1.3.3/docker-compose-`uname -s`-`uname -m` > /opt/bin/docker-compose % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left … Read more

How to auto restart a Docker container after a reboot in CoreOS?

August 1, 2023 by Tarik

if you start the daemon with docker -d -r, it will restart all containers that were running prior the daemon stopped. This will become the default behavior in the next release.

Allow scheduling of pods on Kubernetes master?

July 22, 2023 by Tarik

If you are using Kubernetes 1.7 and above: kubectl taint node mymasternode node-role.kubernetes.io/master:NoSchedule-

Postgres – testing database connection in bash

July 10, 2023 by Tarik

pg_isready is a utility for checking the connection status of a PostgreSQL database server. The exit status specifies the result of the connection check. It can easily be used in bash. PostgresSQL Docs – pg_isready Example Usage: pg_isready -d <db_name> -h <host_name> -p <port_number> -U <db_user> Installation sudo apt install -y postgresql-client Exit Status pg_isready … Read more

Pulling images from private registry in Kubernetes

May 14, 2023 by Tarik

To add to what @rob said, as of docker 1.7, the use of .dockercfg has been deprecated and they now use a ~/.docker/config.json file. There is support for this type of secret in kube 1.1, but you must create it using different keys/type configuration in the yaml: First, base64 encode your ~/.docker/config.json: cat ~/.docker/config.json | … Read more

Should I use forever/pm2 within a (Docker) container?

May 12, 2023 by Tarik

My take is do not use an in-container process supervisor (forever, pm2) and instead use docker restart policy via the –restart=always (or one of the other flavors of that option). This is more inline with the overall docker philosophy, and should operate very similarly to in-container process supervision since docker containers start running very quickly. … Read more