What are hotfixes
---

Hotfixes are small updates that do not change anything major about the image. 
Thus they can be applied without a reboot. When you apply a hotfix, the Web UI 
is shut down and replaced. Then the new version of the Web UI is started 
automatically. No reboot is needed. All rules stay the way they are, even rule 
and port counters remain unaffected.


Advantages of hotfixes
---

* No need for reboots

* No traffic interruption (the counters do not reset)

* No risk: the worst thing that can happen is that the webserver does not come 
up again


Requirements
---

Hotfixes can only apply to the matching major image versions.

The image version is:

* Starting with 2.2.2 the number after the dash ("-") in the version string, 
e.g. for "2.3.4-5" the image version in "5" and for "6.7.8-9.1" it is "9.1". If
there is no dot then the version is the major version, if there is a dot then
the part before the dot is the major image version and the other part the minor
image version.

* The image version of 2.2.1.4 is 1.

* The image version for all previous update versions is 0. Note that there will
be no public hotfixes for those versions since we can only guarantee that the
hotfixes work for specific older versions.

* Before version 2.2.2 the hotfixes can only be applied through the shell (CLI)
and not the web UI.

* Before version 2.2.2 the rules/groups need to made permanent (button on rule
table page) for the names/descriptions to be kept.


How to apply using shell (CLI)
---

Once you made sure that the requirements are met, download the hotfix package
onto the "/mnt/flash" ("~") folder. You can do that using e.g. "wget":

    echo 'nameserver 8.8.8.8' >/etc/resolv.conf
    wget http://www.cubro.net/cubro/update/ex12/hotfixes/EX12hotfix_2.2.2-1.1.tar.gz

Then unpack the archive:

    tar xzf EX12hotfix_2.2.2-1.tar.gz

And apply the hotfix:

   ./hotfix_setup.sh

Wait some time (longer with HTTPS enabled) and the web UI should be accessible
again.


How to apply using Web UI
---

Only possible after version 2.2.2.

Apply just like any upgrade. Any possible messages about rebooting refer to
standard upgrades and do not apply here.


Known issues
---

* Applying the hotfix using the web UI before version 2.2.2 is not possible.

* Before version 2.2.2 it is necessary that the rules/groups are made permanent
  for the rule/group names/descriptions to be restored.

* On devices with image versions below 2 the original version number is
  displayed on some places, e.g. login.

* If applied through the web UI no error message is displayed on the web UI that
  applying the hotfix failed e.g. because there is no space left on the device.

* Version 2.2.2 of EX5-2 did not allow applying hotfixes through the web UI.