doc: add a new contributor 'hints' guide

Keeping this in glusterfs Repo for glusterfs specific improvements.
There would be a link to this page, and some more similar pages from
docs.gluster.org

updates: bz#1193929
Change-Id: Ie98670cc32e62951f1b1880b1ae39f5cc2b45329
Signed-off-by: Amar Tumballi <amarts@redhat.com>

doc/developer-guide/README.md

@@ -18,11 +18,9 @@ code check-in.
     the GPL v2 and the LGPL v3 or later
 -   [GlusterFS Coding Standards](./coding-standard.md)
 
-Developing
-----------
+-   If you are not sure of where to start, and what to do, we have a small
+    write-up on what you can pick. [Check it out](./options-to-contribute.md)
 
--   [Language Bindings](./Language Bindings.md) - Connect to
-    GlusterFS using various language bindings
 
 Adding File operations
 ----------------------

doc/developer-guide/options-to-contribute.md

@@ -0,0 +1,212 @@
+# A guide for contributors
+
+While you have gone through 'how to contribute' guides, if you are
+not sure what to work on, but really want to help the project, you
+have now landed on the right document :-)
+
+### Basic
+
+Instead of planning to fix **all** the below issues in one patch,
+we recommend you to have a a constant, continuous flow of improvements
+for the project. We recommend you to pick 1 file (or just few files) at
+a time to address below issues.
+Pick any `.c` (or `.h`) file, and you can send a patch which fixes **any**
+of the below themes. Ideally, fix all such occurrences in the file, even
+though, the reviewers would review even a single line change patch
+from you.
+
+1. Check for variable definitions, and if there is an array definition,
+which is very large at the top of the function, see if you can re-scope
+the variable to relevant sections (if it helps).
+
+Most of the time, some of these arrays may be used for 'error' handling,
+and it is possible to use them only in that scope.
+
+Reference: https://review.gluster.org/20846/
+
+
+2. Check for complete string initialization at the beginning of a function.
+Ideally, there is no reason to initialize a string. Fix it across the file.
+
+Example:
+
+`char new_path_name[PATH_MAX] = {0};` to `char new_path_name[PATH_MAX];`
+
+
+3. Change `calloc()` to `malloc()` wherever it makes sense.
+
+In a case of allocating a structures, where you expect certain (or most of)
+variables to be 0 (or NULL), it makes sense to use calloc(). But otherwise,
+there is an extra cost to `memset()` the whole object after allocating it.
+While it is not a significant improvement in performance, code which gets
+hit 1000s of times in a second, it would add some value.
+
+Reference: https://review.gluster.org/20878/
+
+
+4. You can consider using `snprintf()`, instead of `strncpy()` while dealing
+with strings.
+
+strncpy() won't null terminate if the dest buffer isn't big enough; snprintf()
+does. While most of the string operations in the code is on array, and larger
+size than required, strncpy() does an extra copy of 0s at the end of
+string till the size of the array. It makes sense to use `snprintf()`,
+which doesn't suffer from that behavior.
+
+Also check the return value from snprintf() for buffer overflow and handle
+accordingly
+
+Reference: https://review.gluster.org/20925/
+
+
+5. Now, pick a `.h` file, and see if a structure is very large, and see
+if re-aligning them as per [coding-standard](./conding-standard.md) gives any size benefit,
+if yes, go ahead and change it. Make sure you check all the structures
+in the file for similar pattern.
+
+Reference: [Check this section](https://github.com/gluster/glusterfs/blob/master/doc/developer-guide/coding-standard.md#structure-members-should-be-aligned-based-on-the-padding-requirements
+
+
+### If you are up for more :-)
+
+Good progress! Glad you are interested to know more. We are surely interested
+in next level of contributions from you!
+
+#### Coverity
+
+Visit [Coverity Dashboard](https://scan.coverity.com/projects/gluster-glusterfs?tab=overview).
+
+Now, if the number of defect is not 0, you have an opportunity to contribute.
+
+You get all the detail on why the particular defect is mentioned there, and
+most probable hint on how to fix it. Do it!
+
+Reference: https://review.gluster.org/21394/
+
+Use the same reference Id (789278) as the patch, so we can capture it is in
+single bugzilla.
+
+#### Clang-Scan
+
+Clang-Scan is a tool which scans the .c files and reports the possible issues,
+similar to coverity, but a different tool. Over the years we have seen, they
+both report very different set of issues, and hence there is a value in fixing it.
+
+GlusterFS project gets tested with clang-scan job every night, and the report is
+posted in the [job details page](https://build.gluster.org/job/clang-scan/lastCompletedBuild/clangScanBuildBugs/).
+As long as the number is not 0 in the report here, you have an opportunity to
+contribute! Similar to coverity dashboard, click on 'Details' to find out the
+reason behind that report, and send a patch.
+
+Reference: https://review.gluster.org/21025
+
+Again, you can use reference Id (1622665) for these patches!
+
+
+### I am good with programming, I would like to do more than above!
+
+#### Locked regions / Critical sections
+
+In the file you open, see if the lock is taken only to increment or decrement
+a flag, counter etc. If yes, then recommend you to convert it to ATOMIC locks.
+It is simple activity, but, if you know programing, you would know the benefit
+here.
+
+NOTE: There may not always a possibility to do this! You may have to check
+with developers first before going ahead.
+
+Reference: https://review.gluster.org/21221/
+
+
+#### ASan (address sanitizer)
+
+[The job](https://build.gluster.org/job/asan/) runs regression with asan builds,
+and you can also run glusterfs with asan on your workload to identify the leaks.
+If there are any leaks reported, feel free to check it, and send us patch.
+
+You can also run `valgrind` and let us know what it reports.
+
+Reference: https://review.gluster.org/21397
+
+
+#### Porting to different architecture
+
+This is something which we are not focusing right now, happy to collaborate!
+
+Reference: https://review.gluster.org/21276
+
+
+#### Fix 'TODO/FIXME' in codebase
+
+There are few cases of pending features, or pending validations, which are
+pending from sometime. You can pick them in the given file, and choose to
+fix it.
+
+
+### I don't know C, but I am interested to contribute in some way!
+
+You are most welcome! Our community is open for your contribution! First thing
+which comes to our mind is **documentation**. Next is, **testing** or validation.
+
+If you have some hardware, and want to run some performance comparisons with
+different version, or options, and help us to tune better is also a great help.
+
+
+#### Documentation
+
+1. We have some documentation in [glusterfs repo](../), go through these, and
+see if you can help us to keep up-to-date.
+
+2. The https://docs.gluster.org is powered by https://github.com/gluster/glusterdocs
+repo. You can check out the repo, and help in keeping that up-to-date.
+
+3. [Our website](https://gluster.org) is maintained by https://github.com/gluster/glusterweb
+repo. Help us to keep this up-to-date, and add content there.
+
+4. Write blogs about Gluster, and your experience, and make world know little
+more about Gluster, and your use-case, and how it helped to solve the problem.
+
+
+#### Testing
+
+1. There is a regression test suite in glusterfs, which runs with every patch, and is
+triggered by just running `./run-tests.sh` from the root of the project repo.
+
+You can add more test case to match your use-case, and send it as a patch, so you
+can make sure all future patches in glusterfs would keep your usecase intact.
+
+2. [Glusto-Tests](https://github.com/gluster/glusto-tests): This is another testing
+framework written for gluster, and makes use of clustered setup to test different
+use-cases, and helps to validate many bugs.
+
+
+#### Ansible
+
+Gluster Organization has rich set of ansible roles, which are actively maintained.
+Feel free to check them out here - https://github.com/gluster/gluster-ansible
+
+
+#### Monitoring
+
+We have prometheus repo, and are actively working on adding more metrics. Add what
+you need @ https://github.com/gluster/gluster-prometheus
+
+
+#### Health-Report
+
+This is a project, where at any given point in time, you want to run some set of
+commands locally, and get an output to analyze the status, it can be added.
+Contribute @ https://github.com/gluster/gluster-health-report
+
+
+### All these C/bash/python is old-school, I want something in containers.
+
+We have something for you too :-)
+
+Please visit our https://github.com/gluster/gcs repo for checking how you can help,
+and how gluster can help you in container world.
+
+
+### Note
+
+For any queries, best way is to contact us through mailing-list, <mailto:gluster-devel@gluster.org>