Steinar Bang @steinarb@mastodon.social

Rewriting applications to use pax-jdbc-config and liquibase http://steinar.bang.priv.no/?p=292 #apache_karaf #java_programming #declarative_services #derby #jdbc #karaf #liquibase #osgi #osgi_services #pax-jdbc #pax-jdbc-config #postgresql After creating the post Pluggable databases for apache karaf applications I posted a link to the blog post in the karaf user mailing list, and the immediate response was, “why didn’t I just pax-jdbc-config instead?“. The answer to that is that I didn’t know a

How I learned about linux’ “OOM Killer” http://steinar.bang.priv.no/?p=286 #debian #linux #javazone_2019 #liquibase #oom_killer #out_of_memory #virtual_memory #virtual_private_server #vps This blog post describes how I discovered a linux feature called “OOM Killer” that can have strange effects if it interrupts a program at a place where it really shouldn’t be interrupted. I have a low-end VPS (Virtual Private Server), or at least: it used to be low-end, now it’s at least one step above … Conti

Pluggable databases for apache karaf applications http://steinar.bang.priv.no/?p=265 #apache_karaf #java_programming #declarative_services #derby #jdbc #karaf #liquibase #osgi #osgi_services #pax-jdbc #postgresql Edit: I no longer use this approach. I use pax-jdbc-config instead.  See the article Rewriting applications to use pax-jdbc-config and liquibase for details When creating databases for my apache karaf based web applications, I want the following things: A database-independent schema cr

A Java programmer’s guide to delivering webapp frontends http://steinar.bang.priv.no/?p=269 #frontend #java_programming #bundlejs #frontend-maven-plugin #osgi_web_whiteboard #reactjs #servlet #servlet_30_annotations #servlet_container #war_file #web_descriptor #web_whiteboard #webxml #webpack When I started investigating (googling) web frontends, I found tutorials for various frameworks and I found tutorials using node.js to deliver frontends to web browsers on localhost. What I did not find, w

Use Jersey to provide REST APIs from karaf applications http://steinar.bang.priv.no/?p=261 #java_programming #maven #apache_karaf #declarative_services #dependency_injection #http_whiteboard #jersey #jsr330 #karaf #rest_api #web_whiteboard #whiteboard Edit: creating a REST API using jersey has been made simpler, see Simplified REST APIs from karaf using Jersey for details. The sample application https://github.com/steinarb/jersey-demo demonstrates how to use Jersey to provide a REST API from a

Deliver react.js from apache karaf http://steinar.bang.priv.no/?p=255 #apache_karaf #frontend #java_programming #maven #axios #bootstrap #declarative_services #frontend-maven-plugin #karaf #osgi_bundle #react-router #react.js #redux #redux-saga #web_whiteboard_extender #webpack Edit: delivering react.js has been made simpler, see Simplified delivery of react.js from apache karaf for details. A small barebones demo application/testbed, delivering a single-page web application from apache karaf,

Faking a debian repository for package development http://steinar.bang.priv.no/?p=250 #debian #apt #apt-get #aptly #debian_package #debian_package_development #debian_packaging #dpkg I use aptly to deliver my unofficial debian packages both to myself and others that might be interested. However I’ve found that using aptly to do package development is a bad idea, because you can’t (by design, probably) overwrite packages in an aptly archive.  You can only create new versions. For some installati

Develop OSGi applications using karaf http://steinar.bang.priv.no/?p=238 #Eclipse #java_programming #maven #apache_karaf #debugging #eclipse_ide #karaf #osgi #software_development Apache Karaf is a good platform for deploying OSGi based applications. Karaf is also a good platform for testing and debugging these applications. This article describes how to test and debug OSGi bundles and OSGi applications with karaf and eclipse. The basic flow of development, is: Build the application with maven

Installing apache karaf on debian http://steinar.bang.priv.no/?p=224 #debian #apache_karaf #apache_maven #application_server #apt #apt_archive #aptly #deban_9 #debian_package_archive #debian_stretch #java #karaf #maven #osgi #osgi_container #ssh_server #stretch Until the RFP (Request For Packaging) bug for karaf in the debian bug tracker is resolved, here is an APT archive with a karaf package for debian (architecture “all”).  The package is created using native debian packaging tools, and buil

Packaging karaf with native debian packaging tools http://steinar.bang.priv.no/?p=223 #debian #apache_karaf #apache_maven #application_server #java #karaf #maven #osgi #osgi_container #ssh_server Note! This is an improvement over the packaging in  Installing apache karaf on debian stretch, this package is packaged using native debian packaging tools instead of fpm, and is built from the karaf source tarball instead of the karaf binary tarball. Apache karaf is an OSGi container and application s

Setting up a debian package archive with aptly http://steinar.bang.priv.no/?p=214 #debian #apt #apt_archive #aptly #debian_9 #debian_package_archive #debian_stretch #stretch This article describes how to set up a debian archive with aptly on a debian 9 “stretch” computer, served by an nginx web server. Initial setup Add a DNS alias for your virtual nginx web site (outside of the scope of this blog post). The examples below assume that apt.mydomain.com is the DNS alias Install the … Continue rea

Installing apache karaf on debian stretch http://steinar.bang.priv.no/?p=209 #debian #java_programming #apache_karaf #apache_maven #application_server #java #karaf #maven #osgi #osgi_container #ssh_server Edit: It is now possible to install karaf on debian without building it yourself, the package installed is not the one described here, but the new and improved package built from source with native debian packaging tools, that can be found here  https://github.com/steinarb/karaf-debian Apache

Til minne om kaninen Daisy http://steinar.bang.priv.no/?p=196 #kanin #minnneord Jeg tar et avbrekk fra postinger om datateknikk til å minnes kaninen Daisy. En liten svart og hvit løvehodekanin. Hun ble født i november 2009 og døde 29. august 2017, litt over 7,5 år gammel. Ungene fikk først hilse på henne den 22. desember 2009. Fra rett over nyttår 2010 og fram til hun døde … Continue reading Til minne om kaninen Daisy →

Sign nginx website and dovecot imap server on debian with let’s encrypt http://steinar.bang.priv.no/?p=191 #debian #certbot #debian_8 #debian_jessie #dovecot #eff #electronic_frontier_foundation #jessie #lets_encrypt #nginx If you have a setup with a single server with multiple services (web, IMAP etc.), and one CNAME per service (www.somedomain.com, imap.somedomain.com), and you would like to get the services signed in a manner that doesn’t give warnings or errors in browsers  (especially brow

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Making a Java windows service in 10 minutes http://steinar.bang.priv.no/?p=171 #java_programming #maven #apache #daemon #apache #maven #izpack #java #javazone #javazone_2016 #m2e #maven3 #smtp_server #windows_service This blog post describes how to create a windows service from a Java application, it is a slightly more fleshed out version of the JavaZone 2016 lightning talk “A Java windows service in 10 minutes”. A problem sometimes encountered by a Java programmer, is to make your Java pro

Get update notifications in the MATE desktop on debian jessie http://steinar.bang.priv.no/?p=165 #debian #apt #notification #apt #notification #in #tooltray #debian8 #intel_skylake #jessie #mate #package #update #tooltray #notification #pending #updates #tooltray #notification #pk-update-icon #skylake One thing I have been missing since Gnome 2 was suceeded by the (IMO) horrible Gnome 3, is a tool tray notification icon for pending debian updates. When someone continued Gnome 2 as MATE and M

Logging to persistent tmpfs on Raspbian “jessie” http://steinar.bang.priv.no/?p=83 #raspberrypi #rpi #jessie #logging #persistent_ramdisk #raspbian #raspbian8 #raspbian_jessie #rsync #tmpfs The article describes how to set up logging to tmpfs with persistent storage to the sd card on a raspberry pi with raspbian 8 "jessie".

Sign nginx website and dovecot imap server on debian with let’s encrypt http://steinar.bang.priv.no/?p=191 #debian #certbot #debian #8 #debian #jessie #dovecot #eff #electronic #frontier #foundation #jessie #lets #encrypt #nginx If you have a setup with a single server with multiple services (web, IMAP etc.), and one CNAME per service (www.somedomain.com, imap.somedomain.com), and you would like to get the services signed in a manner that doesn’t give warnings or errors in browsers 

Using a Raspberry Pi 2 Model B as a router/firewall for the home LAN http://steinar.bang.priv.no/?p=66 #raspberry #pi #debian #dnsmasq #fail2ban #ferm #firewall #ip #masquerading #jessie #mosh #ntop #raspbian #raspbian #8 #raspbian #jessie #router #ssh Since 1999 I have been using a 1996 vintage DEC PII desktop as the router/firewall between the internet and my home network.  The DEC computer came to me with Win95 (or possibly Win98) in 1998, got SuSE linux and started its mission as router and