Category Archives: Troubleshooting

Various problems solutions

Linux: no sound after suspend/sleep – solution

30 April 2020
 

 I have a laptop with Arch Linux. It’s suspended with the systemctl suspend. The issue: after it’s wake up there is no sound. From the information found during the investigation (see links below) the issue happens because of the NVIDIA drivers and isn’t specific to the Arch Linux – can happen with any other Linux… Read More »

Steam: Civilization V, Arch Linux and ERROR:Invalid resolutions constraints: 0x0 must not be greater than 0x0

27 April 2020
 

 I’m using Steam on Arch Linux (see the Arch Linux: Steam installation). And I have Civilization V game here – my favorite game for last N-years. I have NVIDIA drivers installed and most of the games work fine, even World Of Tanks, but I wasn’t able to play Civilization from the moment I’ve installed Steam… Read More »

AWS: eksctl – “Put http://169.254.169.254/latest/api/token: net/http: request canceled”

26 April 2020
 

 We have a Docker image with the eksctl tool included. We also have an ЕС2 with Linux with the eksctl. There is an AWS IAM Instance Profile attached to this EC2 with the AdminAccess policy assigned. On this ЕС2 we have Jenkins running in a Docker container, and it spawns its jobs inside in additional… Read More »

AWS Elastic Kubernetes Service: a cluster creation automation, part 1 – CloudFormation

24 April 2020
 

 The task is: create automation to roll out an AWS Elastic Kubernetes Service cluster from scratch. Will use: Ansible: to automate CloudFormation stack creation and to execute eksctl with necessary parameters CloudFormation with NestedStacks: to create an infrastructure – VPC, subnets, SecurityGroups, IAM-roles, etc eksctl: to create a cluster itself using resources created by CloudFormation… Read More »

Linux: processes core dumps, systemd-coredump and Debian

14 March 2020
 

 Need to get a dump from fro ma PHP process on Debian 9. In this post will take a Linux kernel mechanism to create and manage processes dumps. Kernel’s dumps are created in another way, check Kdump на Arch Wiki. Linux Core Dump The kernel will create a process dump if it performed an invalid… Read More »

Redis: “psync scheduled to be closed ASAP for overcoming of output buffer limits” and the client-output-buffer-limit

26 February 2020
 

 We have a Redis-cluster with Master-slave replication and Sentinel, see the Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel, Redis: fork – Cannot allocate memory, Linux, virtual memory and vm.overcommit_memory, and Redis: main configuration parameters and performance tuning overview posts. The system worked great until we started using it much more actively. Redis… Read More »

Linux: PHP-FPM, Docker, STDOUT and STDERR – no an application’s error logs

24 February 2020
 

 We have a Docker image with NGINX, PHP-FPM, and Supervisor. In the same image, we have our PHP application included, which outputs its errors to the /dev/stderr as per its php.ini file: … [global] error_log=/dev/stderr … The problem is, that if run kubectl logs –  there will be no error output from the application. So,… Read More »

PHP: PHP-FPM ignores environment variables – solutions

19 February 2020
 

 We have a PHP-based application running in Kubernetes and uses settings from a /app/.env file plus environment variables. The problem is that application running in a Docker container can’t see an $TEST_VAR variable although it’s present in the Deployment: … containers: – name: application-dev-web image: bttrm-application:119 … – name: TEST_VAR valueFrom: secretKeyRef: name: bttrm-app-secret key:… Read More »

Kubernetes: running metrics-server in AWS EKS for a Kubernetes Pod AutoScaler

15 February 2020
 

 Assuming, we already have an AWS EKS cluster with worker nodes. In this post – we will connect to a newly created cluster, will create a test deployment with an HPA – Kubernetes Horizontal Pod AutoScaler and will try to get information about resources usage using kubectl top. Kubernetes cluster Create a test cluster using… Read More »

Debian: php7.3-curl : Depends: libcurl3 (>= 7.44.0) but it is not installable

23 January 2020
 

 We have a Jenkins job that runs a Docker container to build a PHP-application based on the Yii framework. Suddenly during the build, we got an error: … Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required… Read More »