After a long ~5 years (from 2011) journey with approx I finally wanted to switch to something new like apt-cacher-ng. And after a bit of changes I finally managed to get apt-cacher-ng into my work flow.
Bit of History
I should first give you a brief on how I started using approx. It all started in MiniDebconf 2011 which I organized at my Alma-mater. I met Jonas Smedegaard here and from him I learned about approx. Jonas has a bunch of machines at his home and he was active user of approx and he showed it to me while explaining the Boxer project. I was quite impressed with approx. Back then I was using a 230kbps slow INTERNET connection and I was also maintaining a couple of packages in Debian. Updating the pbuilder chroots was time consuming task for me as I had to download multiple times over slow net. And approx largely solved this problem and I started using it.
5 years fast forward I now have quite fast INTERNET with good FUP. (About 50GB a month), but I still tend to use approx which makes building packages quite faster. I also use couple of containers on my laptop which all use my laptop as approx cache.
So why change to apt-cacher-ng?. Approx is a simple tool, it runs mainly with inetd and sits between apt and the repository on INTERNET. Where as apt-cacher-ng provides a lot of features. Below are some listed from the apt-cacher-ng manual.
- use of TLS/SSL repositories (may be possible with approx but I'm notsure how to do it)
- Access control of who can access caching server
- Integration with debdelta (I've not tried, approx also supports debdelta)
- Avoiding use of apt-cacher-ng for some hosts
- Avoiding caching of some file types
- Partial mirroring for offline usage.
- Selection of ipv4 or ipv6 for connections.
The biggest change I see is the speed difference between approx and apt-cacher-ng. I think this is mainly because apt-cacher-ng is threaded where as approx runs using inetd.
I do not want all features of apt-cacher-ng at the moment, but who knows in future I might need some features and hence I decided to switch to apt-cacher-ng over approx.
Transition from approx to apt-cacher-ng was smoother than I expected. There are 2 approaches you can use one is explicit routing another is transparent routing. I prefer transparent routing and I only had to change my /etc/apt/sources.list to use the actual repository URL.
deb http://deb.debian.org/debian unstable main contrib non-free deb-src http://deb.debian.org/debian unstable main deb http://deb.debian.org/debian experimental main contrib non-free deb-src http://deb.debian.org/debian experimental main
After above change I had to add a 01proxy configuration file to /etc/apt/apt.conf.d/ with following content.
I use explicit routing only when using apt-cacher-ng with pbuilder and debootstrap. Following snippet shows explicit routing through /etc/apt/sources.list.
deb http://localhost:3142/deb.debian.org/debian unstable main
Usage with pbuilder and friends
To use apt-cacher-ng with pbuilder you need to modify /etc/pbuilderrc to contain following line
Usage with debootstrap
To use apt-cacher-ng with debootstrap, pass MIRROR argument of debootstrap as http://localhost:3142/deb.debian.org/debian.
I've now completed full transition of my work flow to apt-cacher-ng and purged approx and its cache.
Jonas told me that its not 2 caches but 2 routing paths, one for transparent routing and another for explicit routing. So I guess there is nothing here to fix :-).