Fabian Lee : Software Engineer

Ubuntu: resolving systemd error, “Start request repeated too quickly”

December 5, 2023
Categories: Linux

If your systemd service is failing with the following error message: XXX.service: Start request repeated too quickly The first thing to do is fix any underlying issues. Use ‘systemctl status <service>’, ‘journalctl -u <service>’, and search any log files produced by the service to understand why the service failed multiple times and exceeded its StartLimitBurst. … Ubuntu: resolving systemd error, “Start request repeated too quickly”

GitLab: least privilege for Kube-API calls from GitLab Agent for Kubernetes

October 22, 2023
Categories: DevOps

GitLab Agent for Kubernetes is an integration for the GitLab CI/CD pipeline that provides kubectl access from pipeline jobs, allowing Continuous Deployment into a live Kubernetes Cluster. However, the default role for this Agent is cluster-admin when doing a basic Helm install, which is far too permissive and needs to be scoped down to only … GitLab: least privilege for Kube-API calls from GitLab Agent for Kubernetes

GoLang: Running a Go binary as a systemd service on Ubuntu 22.04

October 29, 2022
Categories: Development, Linux

The Go language with its simplicity, concurrency support, rich package ecosystem, and ability to compile down to a single binary is an attractive solution for writing services on Ubuntu. However, the Go language does not natively provide a reliable way to daemonize itself. In this article I will describe how to take a couple of simple Go language programs … GoLang: Running a Go binary as a systemd service on Ubuntu 22.04

GCP: VM instances running as the Compute Engine default service account

March 31, 2022
Categories: Hyperscaler, Scripting

The Compute Engine default service account is automatically generated for your project with the Editor role, and by default is attached to all VM instances created in the project. You can pull the exact id using gcloud. gcloud iam service-accounts list –filter=”displayName:’Compute Engine default service account'” –format=’value(email)’ The syntax will be ${project_id}-compute@developer.gserviceaccount.com. If you want … GCP: VM instances running as the Compute Engine default service account

Kubernetes: using kubectl to wait for condition of pods, deployments, services

January 27, 2022
Categories: Containers

Instead of deploying a pod or service and periodically checking its status for readiness, or having your automation scripts wait for a certain number of seconds before moving to the next operation, it is much cleaner to use ‘kubectl wait’ to sense completion. Wait for pod Here is how you would wait for READY status … Kubernetes: using kubectl to wait for condition of pods, deployments, services

Ubuntu: Running a bash script periodically with a user-level Systemd timer

January 4, 2022
Categories: Linux

If you have a Bash script that needs to run periodically, you can run it using a crontab entry. But you can also have it invoked by Systemd using systemd.timer. Furthermore, you can run Systemd services as user-level services instead of the typical system-level service for even further isolation. Running via Systemd provides more powerful … Ubuntu: Running a bash script periodically with a user-level Systemd timer

Ubuntu: Running a bash script periodically with a system-level Systemd timer

January 4, 2022
Categories: Linux

If you have a Bash script that needs to run periodically, you can run it using a crontab entry or file. But you can also have it invoked from Systemd using systemd.timer. Running via Systemd provides more powerful constructs for invocation, configuration, monitoring, and logging. In this article, I will show how to periodically run … Ubuntu: Running a bash script periodically with a system-level Systemd timer

Ansible: creating a cron.d file for periodic system jobs

June 17, 2021
Categories: Automation

The legacy method of running crontab jobs from files located at /var/spool/cron (edited using ‘crontab -e’) is slowly giving way to files located in /etc/cron.d. This way of creating a file entry for each job is easily handled by Ansible using the cron module as shown below. – name: Creates a cron file under /etc/cron.d … Ansible: creating a cron.d file for periodic system jobs

GCP: Creating gcp service account with IAM roles using gcloud

March 17, 2021
Categories: Containers

Although the GCP console provides a manual interface for creating service accounts and assigning roles, it can also be done via the gcloud CLI. Using gcloud, even the json key file for the service account can be generated, which is essential for automation. The full Bash script, create_serviceaccount.sh can be found on github. But here … GCP: Creating gcp service account with IAM roles using gcloud

GCP: Using gcloud to create and configure a service account

January 30, 2021
Categories: Virtualization

If you need to bootstrap a GCP project’s infrastructure, one of the first things you will want is a service account. The creation of the service account, creating its key, and then assigning binding roles can all be done from the GCP console but for scripting purposes can also be done using the gcloud utility. … GCP: Using gcloud to create and configure a service account

Java: Spring Boot application as a service using SysV on Ubuntu 14.04

April 17, 2018
Categories: Java, Linux

Although in modern architectures you typically see Spring Boot executable jars running as the primary process of a container, there are still many deployment scenarios where running the jar as a service at boot time is required. With Ubuntu 14.04, we can use SysV to run a Spring Boot application at boot time. This will … Java: Spring Boot application as a service using SysV on Ubuntu 14.04

Java: Spring Boot application as a service using systemd on Ubuntu 16.04

April 15, 2018
Categories: Java, Linux

Although in modern architectures you typically see Spring Boot executable jars running as the primary process of a container, there are still many deployment scenarios where running the jar as a service at boot time is required. With Ubuntu 16.04, we can use the built-in systemd supervisor to run a Spring Boot application at boot … Java: Spring Boot application as a service using systemd on Ubuntu 16.04

CloudFoundry: Persisting spring-music data using Postgres service, Part 2

November 16, 2017
Categories: Containers, Java

Cloud Foundry is an opinionated Platform-as-a-Service that allows you to manage applications at scale. This article is part of a series that explores different facets of a Cloud Foundry deployment using the spring-music project as an example. This article is Part 2 of a series on Cloud Foundry concepts: Deploying the spring-music webapp, Part 1 Persisting … CloudFoundry: Persisting spring-music data using Postgres service, Part 2

Ubuntu: Enabling syslog on Ubuntu and custom templates

May 24, 2017
Categories: Linux, Logging

Syslog is a message logging standard has been around for decades, but has renewed popularity as a method of log capture with the advent of containerization and centralized logging solutions. Enabling an Ubutu 14.04 or 16.04 host to act as a syslog server only takes a few simple steps.

GoLang: Running a Go binary as a systemd service on Ubuntu 16.04

May 21, 2017
Categories: Linux, Scripting

Update Oct 2022: This article has now been written for GoLang 1.19 on Ubuntu 22.04. Go has changed the way it handles SIGURG signals, and Systemd services no longer directly forward to syslog. Read my newer article here. The Go language with its simplicity, concurrency support, rich package ecosystem, and ability to compile down to a single … GoLang: Running a Go binary as a systemd service on Ubuntu 16.04

GoLang: Running a Go binary as a SysV service on Ubuntu 14.04

May 20, 2017
Categories: Linux, Scripting

The Go language with its simplicity, concurrency support, rich package ecosystem, and ability to compile down to a single binary is an attractive solution for writing services on Ubuntu. However, the Go language does not natively provide a reliable way to daemonize itself. In this article I will describe how to take a couple of simple Go language programs, … GoLang: Running a Go binary as a SysV service on Ubuntu 14.04

ELK: Running ElastAlert as a service on Ubuntu 14.04

April 17, 2017
Categories: Linux, Monitoring

ElastAlert from the Yelp Engineering group provides a very flexible platform for alerting on conditions coming from ElasticSearch. In a previous article I fully describe running interactively on an Ubuntu server, and now I’ll expand on that by running it at system startup using a System-V init script. One of the challenges of getting ElastAlert to run as a … ELK: Running ElastAlert as a service on Ubuntu 14.04

EMC OnDemand: OnDemand versus Amazon EC2

November 23, 2012
Categories: Documentum

As you can imagine, potential customers have a lot of very legitimate questions when considering the move to EMC OnDemand. For both new customers as well as those who are migrating their existing content into the EMC secure private cloud one of the questions we hear a lot is, “Why would I choose EMC OnDemand … EMC OnDemand: OnDemand versus Amazon EC2