# Push mirroring As explained in [Debian’s documentation](https://www.debian.org/mirror/push_mirroring) on this subject: > Push mirroring is a form of mirroring that minimizes the time it takes > for changes to the main archive to reach mirrors. The server mirror uses > a triggering mechanism to immediately inform the client mirror that it > needs to be updated. > Push mirroring takes a little more effort to set up since the maintainers > of the upstream and downstream mirror must exchange information. The > benefit is that the upstream mirror initiates the mirror process immediately > after its archive has been updated. This allows changes to the archive to > propagate extremely quickly. So instead of relying on cron jobs to keep things in sync, mirrors can be asked to sync when it is necessary. SSH is usually used, however we can offer HTTP triggers if preferred. ## Setup Your mirror should have previously been set up to use cron jobs and [mirroring scripts](https://documentation.ubuntu.com/project/release-team/mirror-scripts.md#mirror-scripts). We recommend that you create an `ubuntu` user and grant it permissions to the directory where your mirror is stored. Then place the keys below (or from whichever mirror you are syncing from) into that user’s `authorized_keys` file. When the upstream mirror connects as the `ubuntu` user to your mirror, it will run the script and background the process. Meanwhile, the `rsync` command called by the script will connect to the upstream mirror and sync any changes as needed. When this setup has been completed, [let us know](https://documentation.ubuntu.com/project/release-team/mirrors.md#mirrors-communication) and we’ll set up the necessary trigger commands on our end. If the command is not run in the background, you can try redirecting `stdin`, `stdout` and `stderr` to `/dev/null` using the following command : ```none command="~/archive-sync /dev/null 2>/dev/null &" ``` ## Keys These are the SSH keys used for triggering Archive and Releases mirrors respectively. Be sure to change the `command=` option to the location of your mirroring script and do **not** remove the backgrounding character (`&`) after it. The keys below are for mirrors pushed by **Canonical-only**. These mirrors should be syncing from **`rsync.archive.ubuntu.com`** (for packages) and **`rsync.releases.ubuntu.com`** (for CD release images). Connections from Canonical will be originating from the IP address: `91.189.88.154` and `185.125.188.80` for Archive, and `91.189.88.156` and `185.125.188.81` for Releases – so ensure that your firewalls allow this. If you are not being pushed by Canonical, contact the mirror administrator of the mirror you’re being pushed from for their keys and be sure to have your sync source set to their mirror. ### Archive trigger key ```none -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA384 Ubuntu Archive trigger SSH key for Canonical. SSH key fingerprint: c8:ea:0f:db:86:da:64:86:de:76:64:b8:84:33:4b:23 no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,command="~/archive-sync &",from="91.189.88.154,185.125.188.80" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAt8xHRbCVFT3Uw/B+TavIlDYRoLMxOKlN3HnBeniFUJTto5Im52FbT3ODfMszz5/BIAnXBf1baWDljHErx4huohh9MxyovZ0h8GYCmMy7dZzsrV5eYhLXd2idCOKIl6gr0BTgTlJOKOgVEoZ2YtiU9MnNzRk3gkBeCMDJrnQOCC8Sko0F0RUJnrzLXOdtvDfNu7Ff+tRNb4PwrU3inbm2YJRnOoZI9vIsv/9DwsMm9d+YIIOz/7y5jLGhZ34nXzhmI6cJO92+Ve5ubhbbpKUFQAh2L1PP6A+I7jHvoWHToSaZlt+DCN4Kg+JlZuf2FXk8MeHkEc6qWWHQTFF8/ArKew== archvsync@syowa -----BEGIN PGP SIGNATURE----- iHUEARYJAB0WIQRlU8JZ1ISAlY6/xTT0TupTmP8ZlgUCYmeDUwAKCRD0TupTmP8Z lkBLAQCbcDkL77iDOtpildPE334qHcjaKlnMimpZ/MIkI4YgEQD/cKxEv6GnVuXD Fz7eaN0W/O7fwpAFPLrpASseraXILwE= =fayr -----END PGP SIGNATURE----- ``` ### Releases trigger key ```none -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA384 Ubuntu Releases trigger SSH key for Canonical. SSH key fingerprint: ff:79:41:eb:c7:7d:00:d4:78:34:28:d1:d2:f0:ae:90 no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,command="~/releases-sync &",from="91.189.88.156,185.125.188.81" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA7l6nWM6Z2KfR4KmwF29Fv9nAgTLwHM5H/TWhinl7DZDG+Jn+TC9kll3cuyGByhwh/mNTwbyvsyiDSXFtbglowQoPSW4rhOEVy6s+/lDjDBGTDsgk8wyBqlNJRlppODsl+kqX0IqAIc3XJ9luDl894tD5rxhiXzqXL3c8r8CuhPkGdUCCMbWU4OUAIjIAs8DClYzjrAZ54IVbk5gTjDYUtlSLNXjm1rZ788h65waKBn4/LV+8nEaFIPA9FxPZI6VLmKGO/RQqZrLPNKOzotmkofV1jV2OmQNHzIwu2seV6HGYqZc3U9jE2+Eat86C6IMYS7KPxVoQd6AnHjRMlhyb6Q== archvsync@syowa -----BEGIN PGP SIGNATURE----- iHUEARYJAB0WIQRlU8JZ1ISAlY6/xTT0TupTmP8ZlgUCYmeDvgAKCRD0TupTmP8Z ltuCAQDnzCcZ5wTOV+Pxg+YQQihC5R64kslnjVI+CnGMzLeuzQD7B5pkoeRneVJp JR9bXlpTBqjGCTaLVRFF4faLrLef5Qk= =cdwz -----END PGP SIGNATURE----- ``` ### HTTP triggers While SSH triggers (above) are the preferred trigger method, it is also possible for the primary Ubuntu Archive to send HTTP triggers. HTTP triggers can be nearly any format, for example: ```none http://ubuntu-archive:8BBsmDsLXpjJvSjM4nZv@cctld.mirrors.example.com/trigger http://ubuntu-releases:zT99CGf9V499RH9SQFtV@cctld.mirrors.example.com/trigger ``` or: ```none http://cctld.mirrors.example.com/ubuntu-archive/53cfa724-f75d-44a1-b9d2-a14e637887bc/trigger http://cctld.mirrors.example.com/ubuntu-releases/f4b95974-9862-40ba-a476-f751c30c5f31/trigger ``` The first example uses usernames and (long random) passwords to a trigger destination, and would decide which component to begin syncing based on the authenticated username. The second example places the component name and (long random) UUID in the path itself. Treat these URLs as sensitive, to avoid outside users triggering unnecessary syncs. It is up to the mirror administrator to build logic into the HTTP endpoint which authenticates the primary Ubuntu Archive and begins a sync. This logic varies wildly based on your specific platform. Output format is undefined; the primary simply loads the URL and moves on without examining the output.