Annotation of wikisrc/kyua/import.mdwn, revision 1.4
1.1 jmmv 1: [[!meta title="Kyua: The way into NetBSD"]]
2: [[!toc levels=2]]
4: **Project owner: [Julio Merino](mailto:jmmv@NetBSD.org).**
1.4 ! jmmv 5: **Status: under review by tech-userlevel@ as of 2012-09-01.**
1.1 jmmv 6:
7: The import of Kyua into NetBSD to replace the deprecated ATF tools is
8: planned to happen in NetBSD 7.0. The ATF libraries will remain in place,
9: and as such no changes will happen to the tests that already live in
12: The transition from ATF to Kyua includes steps and tools to offer backwards
13: compatibility with users that may rely on the ATF tools shipped since
14: NetBSD 5.0. These backwards compatibility tools cover the most common use
15: cases but might not be perfect initially. Despite these provisions, this
16: plan should be executed well in advance the creation of the 7.0 branch to
17: ensure there is enough time in NetBSD-current to flesh out any major
1.3 jmmv 20: **Before moving on, please read the
1.2 jmmv 21: [[Kyua: An introduction for NetBSD users|/kyua]] page. You should be
1.1 jmmv 22: familiar with the structure of Kyua and its major components to be able to
1.3 jmmv 23: review this plan.**
1.1 jmmv 24:
25: # Proposed changes
27: The final user visible changes that this project will bring to NetBSD are
28: as follows. Because these change the availability of tools that have
29: already been shipped since 5.0, the modifications are staged to happen
30: across two major releases:
32: ## For NetBSD 7.0
34: * Addition of the new `kyua` command-line tool. This provides the runtime
35: engine for the test programs (`atf-run`'s functionality) and the ability
36: to generate reports of the results in plain text form and HTML form
37: (`atf-report`'s functionality). This tool is able to execute all the
38: existing test programs without modifications.
40: * Replacement of the `Atffile`s files in `/usr/tests` with `Kyuafile`s.
42: * Ability to generate HTML reports right form the base system, with such
43: reports hooked into the various continuous build systems.
45: * Replacement of the `atf-run` and `atf-report` tools with shell scripts
46: that provide backwards compatibility implementations based on `kyua`.
47: These can deal with old-style `Atffile`s so that users with custom test
48: suites can continue to run them.
50: * Introduction of a new `atf2kyua` script to convert old `Atffile`s to
51: `Kyuafile`s. This is used internally by the compatibility `atf-run`
52: script, but can also be invoked by the end user by hand to deal with his
53: own test suites. Could be placed into `libexec` if we do not want to
54: make this public.
56: ## For NetBSD 8.0
58: * Removal of the backwards compatibility `atf-run` and `atf-report`
59: scripts, as well as the supporting `atf2kyua` tool.
1.3 jmmv 61: # Why?
63: As mentioned in [[another page|/kyua]], Kyua should be seen as ATF 2.x even
64: though it carries a different name. It is the evolution of the previous
65: ATF tools (*the tools only*), but written in a more modular and flexible
66: way, and with a more reliable codebase. Therefore, you should consider
67: this project as the update of ATF to a newer version.
69: The `atf-run` and `atf-report` tools have effectively been in maintenance
70: mode for over a year already. None of the desired features (see the list
71: of open PRs) have been implemented on top of them, mostly because doing so
72: is building upon a broken implementation. Additionally, several developers
73: have had to implement their own test results dashboards due to
74: defficiencies in `atf-report`, effectively reinventing the wheel.
76: This update will permit the real removal of the obsolete tools, thus
77: allowing us to build additional features on top of Kyua without having to
78: worry about being compatible with `atf-run` (and thus adjusting this tool
79: to behave in the same manner).
81: Some possible answers to "Why not?" can be found later in this page.
83: ## And why now?
1.1 jmmv 84:
85: Kyua has existed for almost 3 years already, so you may be wondering why
86: this import is being proposed now. The major reasons are:
88: * Since 0.5, Kyua has now feature-parity with ATF. Replacing the ATF tools
89: with Kyua should not introduce functionality regressions.
91: * NetBSD-6 has been branched relatively recently, so we can expect NetBSD-7
92: to be far away enough in the future to provide plenty of time to
93: stabilize Kyua in NetBSD-current.
95: * The existence of the deprecated `atf-run` and `atf-report` tools hinders
96: the development of new features that require changes to the inteface of
97: ATF test programs. As an example: a highly requested feature is the
98: ability to change the timeout settings of the test programs (for the
99: benefit of old, slow platforms); doing this in the ATF codebase is
102: * Some developers continue to add old-style tests to the tree. While this
103: is suboptimal and against the policy dictated by core@, Kyua brings in a
104: mechanism to allow running these tests unmodified (i.e. without adding
105: any ATF calls in their code). This, in turn, will let such developers
106: add their tests more easily, and thus increase the tests coverage.
108: # The plan
110: This section details what the transition plan looks like and an estimate
111: timeline. As all things that depend on free time (opensource software
112: hacking, in this case), take the estimates with a grain of salt.
114: ## Discuss this plan in tech-userlevel@
116: If you are here it's possibly because a review request for this plan has
1.4 ! jmmv 117: already been published and thus the plan has already begun.
1.1 jmmv 118:
119: This plan will be sent to the tech-userlevel@ mailing list asking for
120: comments. **Two weeks shall be allowed for initial discussion.** Depending
121: on the outcome, the plan and/or the software will need to be adjusted
122: (which in turn may require significant amounts of time not yet accounted
123: for). I'll be optimistic for now.
125: ## Get core@ approval
127: By policy, the import of any new software component into src requires core@
128: approval. Even though this will have been discussed at length in
129: tech-userlevel@ (as per the previous step), the final decider on this issue
130: will be core@. The corollary of this is that, if no consensus can be
131: reached in tech-userlevel@ regarding this plan, core@ will be asked to come
132: up with a decision.
134: If core@ approves the plan, the next steps shall start immediately. If
135: core@ disagrees, core@ will be asked to provide advice on the corrections
136: that should be made before the plan can be approved.
1.4 ! jmmv 138: It is hard to tell how long this step will last, but possibly account for 2
! 139: to 4 weeks.
1.1 jmmv 141: ## Import Kyua into src
1.2 jmmv 143: As the [[introductory page to Kyua|/kyua]] describes, Kyua has been
144: available in pkgsrc for a while and can be readily installed and used to
145: run the tests from `/usr/tests`.
1.1 jmmv 146:
147: However, because ATF lives in src, and because NetBSD aims to provide the
148: best environment for testing "out of the box", Kyua should be imported into
149: src just like ATF was. The major reasons for this, as have been explained
150: in the past, are: first, to allow any new deployment of NetBSD to be
151: validated right after installation and continuously afterwards; and,
152: second, to permit the execution of tests during development without having
153: to install any additional software.
155: The specific steps to perform this import are:
157: 1. Import Lutok into `external/bsd/lutok/`. This is a shared library that
158: wraps the native Lua C interface in C++. Lutok was originally part of
159: Kyua, and was split into its own package per the request of some users
160: that found this component useful on its own.
162: 1. Import Kyua into `external/bsd/kyua-cli/`. This yields a new kyua
163: binary in `/usr/bin`, a lot of test programs in `/usr/tests/kyua-cli`
164: (around 100) and some auxiliary files in `/usr/share/kyua`.
166: 1. Protect all products of Lutok and Kyua with the existing `MKATF` knob.
167: If desired, these could instead be protected by a new and separate
168: `MKKYUA` knob, but because the transition is only temporary, I do not
169: think it's worth the effort.
171: 1. Update `bsd.test.mk` to generate `Kyuafile`s *in addition to*
174: There is no real need to do this import in a branch given that this import
175: only adds new functionality without touching existing stuff.
177: All the preparatory work for the import can be done offline (in about two
178: weeks at most, given that I have mot of this ready). Aside from the code
179: changes, this will involve the validation of NetBSD/amd64, NetBSD/i386 and
180: NetBSD/macppc builds (which are the ports I have access to). If you
181: consider that some other tricky architecture should be build-tested
182: (sparc64?), let me know and I'll include it in the list.
184: The submission step to CVS, once all the code changes are ready locally,
185: and any post-commit validation checks will take a few hours. Any build
186: breakage should be addressed in a timely manner (and can possibly be
187: worked-around by setting `MKATF=no`).
189: ## Update documentation
1.2 jmmv 191: The [[Kyua: An introduction for NetBSD users|/kyua]] wiki page will be
1.1 jmmv 192: updated to explain how Kyua is bundled in NetBSD and how to use the bundled
1.2 jmmv 195: The [[Creating atf-based tests for NetBSD src|/tutorials/atf]] wiki page
196: will be updated to account for the differences in test programs execution
197: with Kyua instead of ATF.
1.1 jmmv 198:
199: The afterboot(8) and tests(7) manpages will be adjusted to mention `kyua`
200: instead of the ATF tools.
202: ## Adjust continuous testing systems to use Kyua
204: With `kyua` being part of the release sets, it is possible to adjust the
205: continuous test systems to make use of this tool in the test environments
206: without having to take any additional step.
208: I'll work with gson@ and pgoyette@ to adapt their continuous testing
209: machines to use the new built-in `kyua` binary instead of `atf-run` and
210: `atf-report`. I'm planning to do the necessary work to change `anita`
211: myself, and I expect to help them deploy the changes to their own systems.
212: Because Kyua and ATF will cohexist in the base system at this point,
213: migrating the continuous testing systems to Kyua can happen at its own
216: It might happen that Kyua misses some little detail needed by these
217: systems. In that case, this may require a new release of Kyua and a
218: reimport into the tree. Incremental imports with new features are much
219: easier than the original import described in here. Also, it will be
220: possible to cherry-pick any external changes into the tree without a
221: reimport (as has often been done in ATF).
1.4 ! jmmv 223: This step can take a few weeks of time, mostly due to the back and forth
! 224: between different people in different timezones.
1.1 jmmv 226: ## User validation period
228: At this stage, **at least one month shall be given to the community** to
229: test the new tools and the new test results dashboards. Collect feedback
230: and address requests as appropriate.
1.4 ! jmmv 232: *Because the old `atf-run` and `atf-report` tools have not yet been dropped
! 233: at this point, we can spend as much time as necessary on this phase to get
! 234: things right.*
1.1 jmmv 236: ## Replace atf-run and atf-report with kyua-atf-compat
238: Import the Kyua-based `atf-run` and `atf-report` compatibility tools and
239: stop building the deprecated versions of these. The compatibility versions
240: are shipped in a separate `kyua-atf-compat` package, and thus this will be
241: imported into `external/bsd/kyua-atf-compat/`.
243: Once this is done, change `bsd.test.mk` to not generate `Atffile`s any
244: more, as the compatibility tools do not need them.
246: ## Drop atf-run and atf-report's code
248: Delete the native `atf-run` and `atf-report` utilities from the source tree
249: (and from the upstream repository). This also gets rid of a lot of
250: supporting helper code, which makes the various ATF libraries leaner (and
251: therefore benefits all test programs!).
253: ## Get rid of some ATF wrappers as a proof of concept
255: There are some test programs (e.g. the ones in the ipf test suite) that are
256: not ATF-based. To plug them into the NetBSD test suite, we have
257: implemented ATF-based wrappers that invoke the original plain tests. This
258: is certainly suboptimal, as this level of indirection hinders readability
259: and makes development harder. (In particular, it prevents some key
260: developers from contributing tests in the first place.)
262: Because Kyua has the ability to run these "plain" (non-ATF) test programs
263: directly, and because a bunch of developers are really looking forward to
264: this feature, I will convert a few tests to not include ATF wrappers as a
265: proof of concept of this feature. The ipf tests are probably a good choice
266: for this.
268: ## Remove atf-run and atf-report compatibility tools
270: This is still really far away in the future (needs to happen after NetBSD
271: 7.0 is branched), but I'm listing it for completeness of the plan. The
272: idea is to get rid of any ATF compatibility scripts by NetBSD 8.0. This
273: gives end users a full release cycle (that of 7) to adapt to Kyua while at
274: the same time being able to use the old-style tools.
276: # Possible concerns
278: This section attempts to collect the list of possible concerns and/or
279: objections that may come up during the review, together with an attempt of
280: rebuttal from my side.
282: ## Increased compilation time
284: The addition of any new component to src increases the build time of the
285: whole system. In the case of Kyua, this increase might be noticeable
286: *because of the large amount of test programs provided (roughly 100)*, all
287: of which are in C++.
289: Note that ATF also had a relatively large codebase and a bunch of tests
290: (although not as many). The "trick" was that the majority of these tests
291: were written in shell, and as such they did not increase the build time by
292: much. However, they significantly increased the run time of the test
293: suite, and they were less detailed (mostly integration tests, few unit
294: tests) than the Kyua tests.
296: In order to mitigate this issue, the build of all pieces of Kyua will be
297: protected by `MKATF` so that people allergic to C++ can avoid the whole
298: thing. Even more, there are some other additional provisions described
301: ## Introduction of more C++ code in base
303: First of all, why did I use C++? To make the implementation simpler and
304: safer (the RAII programming pattern is really useful in avoiding memory and
305: resource leaks with minimal effort). And C++ is part of the base system
306: and a supported language, so there was no reason not to do so. But that's
1.4 ! jmmv 307: not the point of this item: if you dislike like C++, this is not going to
! 308: make you think I did right.
1.1 jmmv 309:
310: It's true that, if we count the number of lines, Kyua brings in more C++
311: code than what will eventually be dropped by the removal of the ATF tools.
312: However, because ATF was also C++, the import of Kyua itself does not make
313: the situation significantly worse.
315: Additionally, the two compilers we can really use (GCC and LLVM) already
316: use, or will soon use, C++ in their code base. It is unlikely that we will
317: be able to remove all C++ support from base anytime soon due to this, while
318: at the same time keeping support for all the ports that NetBSD has.
1.4 ! jmmv 320: Long term, if the use of C++ proves to be a problem, there are a couple of
! 321: major things that can be done to slowly get rid of C++. These ideas have
! 322: merits of their own (not only remove C++). The first is to split the
! 323: execution engine of a single test case into a separate binary and, because
! 324: this would be performance-critical, write it in plain C. The second is the
! 325: rewrite of most user-interface code in Lua, which in itself would bring
! 326: some extensibility advantages to the program; I haven't pursued this yet
! 327: because my knowledge of Lua is very limited. Both options will be
! 328: investigated separtely when the time permits. In the meantime, the
! 329: replacement of ATF with Kyua does not make things worse; it just changes
! 330: one chunk of code with another.
1.1 jmmv 331:
332: ## No need for Lutok as a public library
334: Kyua depends on Lutok, which is a C++ interface to Lua. The code of this
335: library was originally part of Kyua, but I split it into its own project
336: because some users asked for it.
338: If there is no desire to ship Lutok as a shared library in `/usr/lib`, we
339: can build Lutok as a static private library and link Kyua against it.
340: There is no need to install this as a shared library.
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