Tag Archives: Networks

dnsmasq: AWS – “Temporary failure in name resolution”, logs, debug and dnsmasq cache size

28 October 2019
 

 We are using AWS VPC DNS and sometimes facing with errors like “php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution“. The only advice from AWS tech. support was to configure a local dnsmasq service to act as a local DNS cache, but I did this already year ago and this issue happens once in 1-2-3… Read More »

OpenVPN: the No route to host and ERR_ADDRESS_UNREACHABLE errors – the cause and a solution

14 October 2019
 

 We have an OpenVPN Access Server running, see its setup in the OpenVPN: OpenVPN Access Server set up and AWS VPC peering configuration post. The VPN server is hosted in a first AWS VPC, while a Bitwarden service – in another one VPC. Between those VPCs we have a VPC peering configured, and the OpenVPN… Read More »

Redis: main configuration parameters and performance tuning overview

10 September 2019
 

 Currently configuring Redis server as our backend caching service and during that wrote this post with some things to pay attention at in Redis config file. Shortly enough but with links to other posts or documentation. Let’s begin with the redis-benchmark utility. Will be installed alongside with Redis service, so can be used right after… Read More »

Docker: Compose shared networks

20 August 2019
 

 We have a Docker Compose stack with Jenkins, SonarQube, and PostgresSQL, check the SonarQube: running tests from Jenkins Pipeline in Docker post. The problem is that they are described in the same Docker Compose file and are restarted by the same systemd file (check the Linux: systemd сервис для Docker Compose post, Rus) Thus, if… Read More »

Kubernetes: part 3 – AWS EKS overview and manual EKS cluster set up

15 August 2019
 

 Let’s proceed with our Kubernetes journey. Previous parts: Kubernetes: part 1 – architecture and main components overview Kubernetes: part 2 – a cluster set up on AWS with AWS cloud-provider and AWS LoadBalancer In this part we will start working with AWS Elastic Kuberneters Service (EKS) – its short overview, then will create Kubernetes Control… Read More »

Redis: Sentinel – bind 0.0.0.0, the localhost issue and the announce-ip option

10 April 2019
 

 Originally, in a Sentinel’s configs, I have used the bind 0.0.0.0 to make them accessible from external hosts. Because of this when I started rolling out this setup on a real environment faced with an issue when Sentinels could not determine a Master host and other Sentinel hosts. In this post – such an issue… Read More »

Prometheus: blackbox-exporter probe_http_status_code == 0 and its debug

6 March 2019
 

 Today I decided to upgrade Grafana to already released version 6.0 and all other Docker images as well. Upgrade was successful – Loki eventually started displaying previously missed log-file names and other tags, just – immediately I got a bunch of CRITICAL alerts in our Slack from the blackbox-exporter which is used to check every… Read More »

Arch Linux: OpenVPN – resolv.conf is not updated

2 March 2019
 

 On an Arch Linux setup – local resolv.conf not updated after connection to OpenVPN AS. As far as I know – the problem is specific to Arch Linux and its “child’s” like Manjaro Linux installations. Local openvpn installed via pacman – see the OpenVPN: OpenVPN Access Server set up and AWS VPC peering configuration post for… Read More »

OpenVPN: OpenVPN Access Server set up and AWS VPC peering configuration

21 February 2019
 

 OpenVPN Access Server is ready to use OpenVPN server which requires minimal configuration. The free version allows you to have two clients. If you need more – you can buy additional licenses. Infrastructure description Currently to access our resources such as Jenkins, Nexus etc we are using Allow Rules in AWS Security Groups where each user… Read More »