1. Samsung Open Source Group 1 https://social.samsunginter.net/@rzr
Up/Down Stream Flows
Harmony in community not “Far West” !
<https://www.meetup.com/fr-FR/Rennes-Embedded/>
#RennesEmbedded, Rennes France <2019-04-11>
Philippe Coval
Samsung Open Source Group / SRUK
p.coval@samsung.com

2. Samsung Open Source Group 2 https://social.samsunginter.net/@rzr
$ who am i
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Software engineer at Samsung OSG
– Belong to SRUK team based in Rennes, France
– Currently working on “Privacy by Design” Web of Things,
– Interest: Free Libre Open Source, OpenData, OpenDesign...
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Ping me on the fediverse:
– https://social.samsunginter.net/@rzr

3. Samsung Open Source Group 3
“Without trust there's no cooperation.
And without cooperation there's no progress.
History stops.”
~ Rick Yancey, The Last Star

4. Samsung Open Source Group 4 https://social.samsunginter.net/@rzr
Types of FLOSS models
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Built with OSS:
– Some libs are used in products
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+ patches (shared or not)
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Built on OSS: Custom code on top
– Free OSS base and un-free extensions
– The base is shared to/with community
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Behind doors / Inner source
– Public on releases (Code drop)
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not development branches or metadata
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May not review community contribs
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To open development:
– Governance models
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Community is involved
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Meritocracy
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decision making, roadmaps
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Constitution, CoC
– may help in case of conflicts
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To OpenSource foundations
– Copyright holders
– Neutral entity founded by members

5. Samsung Open Source Group 5 https://social.samsunginter.net/@rzr
Avoid Pitfalls
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FLOSS is gratis (if your time has no value)
– Freeriders (taking without giving)’s back draft: Reputation, Community Support…
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FLOSS Code will evolve with or without you!
– Your base is already open, and will improve if used (by others)
– You will never catch up, it will affect your quality (and users’ security)
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Better focus on your value and build a better common base:
– Design smart, isolate elements:
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UNIX philosophy & KISS principle not “Not Invented here”
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Be a good and smarter citizen since day one
– Comply licenses, Separate upstream and downstream works

6. Samsung Open Source Group 6 https://social.samsunginter.net/@rzr
How to maximize efficiency of FLOSS use
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Improve culture & skills:
– Dedicate experts with FLOSS Culture: Tech & Legal background
– Part of company and involved in communities
– Scale: Learn and Teach
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Setup infrastructure: Listen to developers requirements
– To use their most productive environments:
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GNU/Linux desktop, any flavours, root
– To reach communities
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IRC, mailing lists etc
– Transparent proxies/firewall, Flexible Email (IMAP/SMTP), bandwidth (setup cache)

7. Samsung Open Source Group 7 https://social.samsunginter.net/@rzr
Tooling
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Adopt upstream tools: SCM (git), build system
– Switch to git: The sooner, the better
– Eventually use bridge like git-svn (but it will create more confusion)
– git is flexible, not github (how will you export reviews and PR?)
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CI may help too (if not required)
– Can be self hosted on site or outsourced

8. Samsung Open Source Group 8 https://social.samsunginter.net/@rzr
Cooperation
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Forward patches to upstream first
– Maybe you are doing it wrong? Or upstream may suggest better way.
– Could be merged in stable version (safer)
– Small changes are faster to review
– Easier to apply to several branches (less conflicts) and revert
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Then merge downstream:
– Adjust delay according to your policies (eg: 48h to 7days)
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Keep an eye on it, try to reduce gap
– Technical debt is growing (until it’s upstreamed)

9. Samsung Open Source Group 9 https://social.samsunginter.net/@rzr
History >>> Code
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Mixing code randomly is a risky behavior and not future proof
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Don’t break “evolution chain”
– use external dependencies:
– fork project in last resort but keep history
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Preserve history/authorship:
– Avoid to import/copy code for other tree (public or private)
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Helpful commit messages:
git commit -sam ‘context: Add X for feature Y...
Because of Z reason...
Bug: url://upstream/project/bug/42
’

10. Samsung Open Source Group 10 https://social.samsunginter.net/@rzr
Linking to contexts
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Trackers might be updated after commits (xlinks, regressions etc)
– Origin: $url (Where patch was published first)
– Forwarded: $url (Where upstream will review it)
– Bug: $url (Upstream context)
– Bug-$downstream: $url or $id (downstream context)
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Bug-Debian: #42 (DEP3)
– Relate-to: $url
– Change-id: I1dbadc0de… (unique id to track or search)

11. Samsung Open Source Group 11 https://social.samsunginter.net/@rzr
Attribution
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Respect authors (and their works or time), in commit messages:
– Author: ...
– Thanks-to:, Credit-to:, Reported-by:, Suggested-by: ...
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Author is the most knowledgeable why or how the change was made:
– (Current or Future) License may require attributions (ex: BSD-3-Clause-Attribution)
– May be contacted afterwards for project interest (regressions etc)
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Commits may be signed
– Per project policy: to ensure integrity or authorship
– Comply with project’s license
– Ensure code is not “borrowed” from random source

12. Samsung Open Source Group 12 https://social.samsunginter.net/@rzr
Legal & Security
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FLOSS is not public domain: Rights and duties
– Different philosophies:
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Author/User, Business/Community, OSI/FSF, Permissive/Copyleft…
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SPDX: Software Package Data Exchange
– Standard (namespace) for licensing
– SPDX Header in source:
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SPDX-License-Identifier: GPL-2.0
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Never assume that random public code is safe
– Minimal chain of trust to author should be established

13. Samsung Open Source Group 13 https://social.samsunginter.net/@rzr
Security matters
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Scan for vulnerability and legal compliance
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Upstream code is exposed
– it can be scanned by bots:
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Fossa, FOSSology, OpenHub/Black duck, github alerts...
– And vulnerabilities reported (1st private, then public)
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Downstream code maybe not
– Patches may fix ? or add more vulnerabilities
– Scanning code, verifying code is long and costly
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Usually: gratis for FLOSS / pay for private code

14. Samsung Open Source Group 14 https://social.samsunginter.net/@rzr
Git chain is robust if well linked
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git cherry-pick upstream’s changes
– Eg: Apply fixes from release branches
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Or rebase your tree on upstream:
– CONTINUOUSLY on post release branches
– Follow versions: git rebase -i $tag
– Adapt your changes on conflict:
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Hint: may split changes and upstream progressively
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Other useful commands: git blame, git bissect
– Prefer git rebase over git merge

15. Samsung Open Source Group 15 https://social.samsunginter.net/@rzr
Moving forward & Sustainability
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OSS Foundations
– Neutral and Legal entity
– Funded by companies and
individuals
– Provides infrastructure
– Training and certifications
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Originally seeded by 1 project:
– Linux Foundation:
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From kernel to many projects:
– OS: Tizen, Yocto, AGL
– Middlewares:
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IoTivity, LFEdge. Onap,
OpenJS
– Similar to:
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Apache, Eclipse, Document,
OpenStack, FSF, Mozilla, Debian/
SPI, ROS, Python, Pi, OW2 ...

16. Samsung Open Source Group 16 https://social.samsunginter.net/@rzr
Prefer Co-maintenance
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Inactive upstream
– Upstream is not your contractor
– Shift to co-maintenance ?
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Abandonware Organization:
– https://abandonware.github.io/
– Community maintained packages
– Maximize benefit, minimize effort
– No trade off on security

17. Samsung Open Source Group 17 https://social.samsunginter.net/@rzr
Summary
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Avoid “Not invented here”
– It’s easy to start a new project. It’s harder to maintain it
– Join an existing project / Reduce duplication
– Review changes, minimize downstream changes
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Be part of chain of trust
– Bigger Adoption => More checks and test => care about interoperability
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Establish Long term strategy with opensource foundations:
– Scale, Comply license, involve community...

18. Samsung Open Source Group 18 https://social.samsunginter.net/@rzr
References:
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https://www.SoftwareHeritage.org/
– 88M projects 2019-04-08
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https://wiki.iotivity.org/contribute
– Example: Contrubution tips for IoTivity project
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https://social.samsunginter.net/@rzr/101640930444343920
– tizen-upstream-coop-tdc2014-pcoval
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Samsung’s Open Source portal
– https://opensource.samsung.com/
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https://youtu.be/2KDFRiSNSX8
– OSI’s Simon Phipps at OW2 2018

19. 19
https://social.samsunginter.net/@rzrSamsung Open Source Group
Thanks !
https://Social.SamsungInter.net/@rzr