So you found a bug in ISC DHCP or plan to develop an extension and want to send us a patch? Great!
This page will explain how to contribute your changes smoothly.
## Writing a patch
We do not require a contributors agreement. By submitting a patch or merge request to this project,
you are agreeing that your code will be covered by the primary license for the project.
ISC DHCP is currently licensed under the MPL2.0 license.
Here's are the steps in contributing a patch:
1.**create account** on [gitlab](https://gitlab.isc.org)
2.**open an issue** in [this project](https://gitlab.isc.org/isc-projects/dhcp/issues/new), make sure
it describes what you want to fix and **why**. ISC DHCP is very mature code, with a large installed base.
We are fairly conservative about making changes unless there is a very good reason.
3.**ask someone from the ISC team to give you a 'project allocation' so you can to fork ISC DHCP in our repo** (ask on the issue - mention @tomek, @vicky, @ondrej
or @godfryd if it seems we haven't noticed your request)
4.**fork the DHCP master branch**: go to the DHCP project page, click the [Fork button](https://gitlab.isc.org/isc-projects/dhcp/forks/new).
If you can't, you didn't complete step 3. It helps to include the issue number and subject in the branch name.
5.**Implement your fix or feature, in your branch**. Make sure it compiles, has unit-tests,
is documented and does what it's supposed to do.
6.**Open Merge Request**: go to the DHCP project [merge requests page](https://gitlab.isc.org/isc-projects/dhcp/merge_requests), and
click [New merge request](https://gitlab.isc.org/isc-projects/dhcp/merge_requests/new). If you
don't see the button, you didn't complete step 3.
7.**Participate in the code review**: Once you submit the MR, someone from ISC will eventually get
to the issue and will review your code. Please make sure you respond to comments. It's likely
you'll be asked to update the code.
See the text below for more details.
## Create an issue
The first step in contributing to ISC DHCP is to [create an issue](https://gitlab.isc.org/isc-projects/dhcp/issues/new), describing the problem, deficiency
or missing feature you want to address. It is important to make it very clear why the specific change
you are proposing should be made. ISC DHCP is very mature code, with a large and somewhat inert installed base.
We are very cautious about introducing changes that could break existing functionalty. If you want to fix
multiple problems, or make multiple changes, please make separate issues for each.
## Plan your changes
Before you start working on a patch or a new feature, it is a good idea to discuss it first with
DHCP developers. You can post your questions to the [dhcp-workers](https://lists.isc.org/mailman/listinfo/dhcp-workers)
or [dhcp-users](https://lists.isc.org/mailman/listinfo/dhcp-users) mailing lists. The dhcp-users is
intended for users who are not interested in the internal workings or development details: it is
OK to ask for feedback regarding new design or the best proposed solution to a certain problem.
This is the best place to get user's feedback. The internal details, questions about the code and
its internals are better asked on dhcp-workers. The dhcp-workers is a very low traffic list.
OK, so you have written a patch? Great! Before you submit it, make sure that your code compiles.
This may seem obvious, but there's more to it. You have surely checked that it compiles on your
system, but ISC DHCP is a portable software. Besides Linux, it is compiled and used on relatively
uncommon systems like OpenBSD. Will your code compile and work there? What about endianness? It is
likely that you used a regular x86 architecture machine to write your patch, but the software is
expected to run on many other architectures. For a complete list of systems we build on, you may
take a look at the [Jenkins build farm report](https://jenkins.isc.org/view/isc-dhcp/).
## Running unit-tests
DHCP developers. You may benefit from reading the [ISC DHCP Developer's Survival Guide](https://gitlab.isc.org/isc-projects/dhcp/wikis/home)
posted on the wiki page for this repo.
You can post questions about development on the [dhcp-workers](https://lists.isc.org/mailman/listinfo/dhcp-workers)
or [dhcp-users](https://lists.isc.org/mailman/listinfo/dhcp-users) mailing lists. Dhcp-users is
intended for users who are not interested in development details: it is appropriate to ask for
feedback regarding the best proposed solution to a certain problem. The internal details,
questions about the code and its internals are better asked on dhcp-workers. The dhcp-workers
list is a very low traffic list.
## Create a branch for your work
These instructions assume you will be making your changes on a branch in the ISC DHCP Gitlab
repository. This is by far the easiest way for us to collaborate with you. While we also maintain a presence
on [Github](https://github.com/isc-projects/dhcp), ISC developers rarely look at Github, which is
just a mirror of our Gitlab system.
ISC's Gitlab has been a target for spammers, so it is set up defensively. New users need permission
from ISC to create new projects. We gladly do this for anyone who asks and provides a good reason.
"I'd like to fix bug X or develop feature Y" is an excellent reason. To request a project
allocation in ISC's Gitlab, just ask for it in a comment in your issue. Make sure
you tag someone at ISC (@tomek, @godfryd, @vicky or @ondrej). When you write a comment in an issue or
merge request and add a name tag on it, the user is automatically notified.
Once you are given a 'project allocation' in our Gitlab, you can fork ISC DHCP and create a branch.
This is your copy of ISC DHCP and is where you will make your changes. Go to the DHCP project page,
click the [Fork button](https://gitlab.isc.org/isc-projects/dhcp/forks/new) and you will be prompted
to name your branch. It helps to include the issue number and subject in the branch name. You can make
changes to this branch without worrying that you will impact the master branch - commit priviliges
are restricted so you cannot accidentally alter the master branch.
Please read the [Gitlab How-To](https://gitlab.isc.org/isc-projects/dhcp/wikis/processes/gitlab-howto) for ISC DHCP.
## Implement your change
Please try to conform to the project's coding standards. ISC DHCP uses the same [coding standards](https://gitlab.isc.org/isc-projects/bind9/blob/master/doc/dev/style.md) as the BIND 9 project. https://gitlab.isc.org/isc-projects/bind9/blob/master/doc/dev/style.md
## Compile your code
We don't yet have continuous integration set up for ISC DHCP, so you have to check the compilation manually.
ISC DHCP is used on a wide array of UNIX and Linux operating systems. Will your code compile and work there?
What about endianness? It is likely that you used a regular x86 architecture machine to write your
patch, but the software is expected to run on many other architectures. .
## Run unit-tests
One of the ground rules in all ISC projects is that every piece of code has to be tested. For newer
projects, such as Kea, we require unit-test for almost every line of code. For older code, such as
projects, we require a unit-test for almost every line of code. For older code, such as
ISC DHCP, that was not developed with testability in mind, it's unfortunately impractical to require
extensive unit-tests. Having said that, please think thoroughly if there is any way to develop
unit-tests. The long term goal is to improve the situation.
Where unit tests are not practical, supplying us with things like configuration file(s), lease file(s),
PCAPS, and step-by-step on how you tested the changes would be a big help. This will aid us in
creating and adding system tests to the build farm.
You should have also conducted some sort of system testing to verify that your changes do what you
want. It would be extremely helpful if you can attach any configuration files (dhcpd and or
dhclient), along with a step-by-step procedure to carry out the test(s). This will help us verify
your changes as extend our own system tests.
Building ISC DHCP code from the repository is slightly different than the release tarballs. One
major difference is that it does not have BIND source bundled inside and those have to be
downloaded separately. Fortunately, there's an easy to use script for that:
```bash
sh util/bind.sh v4_4
./configure --with-atf
make
```
Make sure you have ATF (Automated Test Framework) installed in your system. For more information
about ATF, please refer to <dhcpsourcetree>/doc/devel/atf.dox. Note, running "make devel" in this
directory will generate the documentation. To run the unit-tests, simply run:
```bash
./configure --with-atf
make
make check
```
...
...
@@ -66,37 +128,19 @@ can be obtained with the command:
./configure --help
```
## Create an issue
## Create a Merge Request
Since you want to change something in ISC DHCP, there's a problem, deficiency or a missing feature.
Quite often it is not clear why specific change is being made. The best way to explain it is to
[create an issue here](https://gitlab.isc.org/isc-projects/dhcp/issues/new). We prefer the original
submitter fill them as he or she has the best understanding of the purpose of the change and may
have any extra information, e.g. "this patch fixes compilation issue on FreeBSD 10.1". If there there
is no MR and no gitlab issue, we will create one. Depending on the subjective importance and urgency
as perceived by the ISC engineer, the issue and/or MR will be assigned to one of the milestones.
## Merge Request (also known as sending your patch the right way)
The first step in writing the patch or new feature should be to get the source code from our Git
repository. The procedure is very easy and is [explained here](https://gitlab.isc.org/isc-projects/dhcp/wikis/gitlab-howto).
While it is possible to provide a patch against the latest stable release, it makes the review
process much easier if it is for latest code from the Git master branch.
Since you won't get write access to the ISC DHCP repository, you should fork it and then commit
your changes to your own repo. How you organize the work depends entirely on you, but it seems
reasonable to create a branch rather than working on your master. Once you feel that your patch
is ready, please commit your changes and push it to your copy of ISC DHCP repo. Then go to DHCP project
Once you feel that your patch is ready, go to the DHCP project
and [submit a Merge Request](https://gitlab.isc.org/isc-projects/dhcp/merge_requests/new).
TODO: I don't think this is necessary. If you can't access this link or don't see New Merge Request
button on the [merge requests page](https://gitlab.isc.org/isc-projects/dhcp/merge_requests)
or the link gives you 404 error, please ask on dhcp-users and someone will help you out.
If you can't access this link or don't see New Merge Request button on the [merge requests
page](https://gitlab.isc.org/isc-projects/dhcp/merge_requests), please ask on dhcp-workers and someone
will help you out.
Once you submit it, someone from the DHCP development team will look at it and will get back to you.
The dev team is very small, so it may take a while...
## If you really can't do MR on gitlab...
## If you really can't do a merge request on ISC's Gitlab...
Well, you are out of luck. There are other ways, but those are really awkward and the chances of
your patch being ignored are really high. Anyway, here they are:
...
...
@@ -116,23 +160,23 @@ your patch being ignored are really high. Anyway, here they are:
## Going through a review
Once the MR is in the system, the action is on one of the ISC (and possibly other trusted) engineers.
Once the merge request (MR) is in the system, the action is on one of the core developers.
Sooner or later, one of these engineers will do the review. Unfortunately, we have a small team
and we have a lot of users to support, so it may take a while for us to get to your patch.
Having said that, we value external contributions very much and will do whatever we
can to review patches in a timely manner.
Sooner or later, one of ISC engineers will do the review. Here's the tricky part. One of ISC DHCP
developers will review your patch, but it may not happen immediately. Unfortunately, developers
are usually working under a tight schedule, so any extra unplanned review work may take a while
sometimes. Having said that, we value external contributions very much and will do whatever we
can to review patches in a timely manner. Don't get discouraged if your patch is not accepted
after first review. To keep the code quality high, we use the same review processes for external
patches as we do for internal code. It may take some cycles of review/updated patch submissions
before the code is finally accepted. The nature of the review process is that it emphasizes areas
that need improvement. If you are not used to the review process, you may get the impression that
the feedback is negative. It is not: even the ISC developers seldom see reviews that say "All OK
please merge".
Don't get discouraged if your patch is not accepted on the first review. To keep the code
quality high, we use the same review processes for external patches as we do for internal code.
It may take some cycles of review/updated patch submissions before the code is finally accepted.
The nature of the review process is that it emphasizes areas that need improvement. If you are
not used to the review process, you may get the impression that the feedback is negative. It
is not: even the core developers seldom see reviews that say "All OK please merge".
If we happen to have any comments that you as submitter are expected to address (and in the
overwhelming majority of cases, we have), you will be asked to update your MR. It is not
uncommon to see several rounds of such reviews, so this can get very complicated very quickly.
overwhelming majority of cases, we have), you will be asked to update your MR. It is common
to see several rounds of such reviews.
Once the process is almost complete, the developer will likely ask you how you would like to be
credited. The typical answers are by first and last name, by nickname, by company name or
...
...
@@ -143,18 +187,10 @@ notes.
Sadly, we sometimes see patches that are submitted and then the submitter never responds to our
comments or requests for an updated patch. Depending on the nature of the patch, we may either fix
the outstanding issues on our own and get another ISC engineer to review them or the ticket may end
the outstanding issues on our own and get another engineer to review them or the ticket may end
up in our Outstanding milestone. When a new release is started, we go through the tickets in
Outstanding, select a small number of them and move them to whatever the current milestone is. Keep
that in mind if you plan to submit a patch and forget about it. We may accept it eventually, but
it's much, much faster process if you participate in it.
## Extra steps
it's a much, much faster process if you participate in it.
If you are interested in knowing the results of more in-depth testing, you are welcome to visit the
ISC Jenkins page: https://jenkins.isc.org This is a live result page with all tests being run on
various systems. Besides basic unit-tests, we also have reports from valgrind (memory debugger),
cppcheck and clang-analyzer (static code analyzers), Lettuce system tests and more. Although it
is not possible for non ISC employees to run tests on that farm, it is possible that your
contributed patch will end up there sooner or later. We also have ISC Forge tests running and other
additional tests, but currently those test results are not publicly available.
#### Thank you for contributing your time and expertise to the ISC DHCP Project.
