gregewing/apt-mirror repository overview

⁠apt-mirror

Reason for Being

I created this image because I was frustrated with the apt-mirror images I found in docker hub, they were all based on old baseimages.
So I created a new one and have set it to build automatically whenever there is a new ubuntu:latest basemiage published, so it should always be up to date.

High Level Information

This is built using ubuntu:latest, at the time of writing this is the Focal Fosa build (20.04). There have been rumours of problems with apt-mirror running on Ubuntu 20.04, but i've not had any issues with it during my testing.

The software installed in this image:

A note on Bandwidth Management:

I was also frustrated with the bandwidth limiting capability of apt-mirror as it seems pretty inaccurate. The mechanism in the apt-mirror app is to pass the responsibility on to wget by passing it a command line parameter to limit the bandwidth consumed, but in the wget man page the maintainers admit that the mechanism is not very good. Therefore I've added in tc command from iproute2 to limit the bandwidth to a rock-solid ceiling that you can control. The drawback from this approach is that we need to run a cron job on the docker host to read a file created by the running container in a docker volume that is mounted when the container starts. This provides the veth adapter in dockers network stack, which we need to know so that tc can apply the requested bandwidth limit, and not affect other containers bandwidth availability. It works like a charm, so long as you can configure cron on the docker host. I found that if I tried to use tc from inside the container then there was no effect, even if running it before the apt-mirror software starts as was suggested in a post I saw somewhere. Running it the way I have described us to alter the bandwidth consumption of the running apt-mirror without restarting it, which I prefer. There is however a dependency on iproute2 being installed on the docker host, and that it is available for you to run (perhaps via sudoers?).

Deploying:

I recommend creating a volume first, so that the scripts can go in the right places inside the container. This step is not necessary, but this will make sure that your bandwidth control script (limit_bw) is easy to get to whenever you re-create or upgrade the container:

Once this volume exists, we can use it when we create the container:

/var/spool/apt-mirror

docker run -d -it \<br>
--name=apt-mirror \<br>
-e TZ=Europe/London \<br>
-v apt-mirror-config:/var/spool/apt-mirror \<br>
--restart unless-stopped \<br>
 -p 9090:80 \<br>
gregewing/apt-mirror<br>

Configuring:

The list of repos that get mirrored is held in /etc/apt/mirror.list. This should provide persistence across re-creations of the container, and it does easily allow altering the list of mirrored repos without having the container running, simply by editing the config file in the volume directly on the host, even while the container is stopped. That's a fair bit more important than it might seem at first, as the container will automatically start a sync when it starts, and wont honour any changes to the config file until the next time the apt-mirror software starts, which could be a long time. So being able to edit the config file offline is a real plus.

Restart the container after making changes to /etc/apt/mirror.list

Managing Bandwidth:

To apply meaningful bandwidth controls I have created a few scripts. The anatomy is as follows:

* * * * * sudo /var/lib/docker/volumes/apt-mirror/_data/limit_bw

To change the allocated bandwidth, just alter the parameters in the limit_bw script, any changes will be applied next time the cron job executed. You can reach the limit_bw script for editing either my exec-ing into the container or my simply editing it in the mounted volume directly from the docker host. There are only two parameters to edit:

RATES  Bandwidths or rates.  These parameters accept a floating
              point number, possibly followed by either a unit (both SI
              and IEC units supported), or a float followed by a '%'
              character to specify the rate as a percentage of the
              device's speed (e.g. 5%, 99.5%). Warning: specifying the
              rate as a percentage means a fraction of the current
              speed; if the speed changes, the value will not be
              recalculated.

              bit or a bare number
                     Bits per second

              kbit   Kilobits per second

              mbit   Megabits per second

              gbit   Gigabits per second

              tbit   Terabits per second

              bps    Bytes per second

              kbps   Kilobytes per second

              mbps   Megabytes per second

              gbps   Gigabytes per second

              tbps   Terabytes per second

              To specify in IEC units, replace the SI prefix (k-, m-,
              g-, t-) with IEC prefix (ki-, mi-, gi- and ti-)
              respectively.

              TC store rates as a 32-bit unsigned integer in bps
              internally, so we can specify a max rate of 4294967295
              bps.

Enjoy :-)