Gitiles
Code Review Sign In
gerrit.openbmc.org / openbmc / bmcweb / d02420b2600a8a8636c1a9a7e3981e57a545d1f3
commitd02420b2600a8a8636c1a9a7e3981e57a545d1f3[log] [tgz]
authorEd Tanous <edtanous@google.com>Mon Jun 06 11:06:13 2022 -0700
committerEd Tanous <ed@tanous.net>Mon Jun 13 15:54:47 2022 +0000
treed94e4f1159907dcd32be961926b0922adc5be1e4
parent2c615dffdb6baf7e0bdd5772a39f4b97d1e38a2c [diff]
Document common error of replacing the json object

Prior to having query params and aggregation supported, this wasn't much
of an issue, but now that we have these features, we need to code
against doing multiple things in parallel.  We have had cases in the
past prior to these new features, but these were generally localized to
a single handler, so the fixes tended to go under the radar.

This commit documents this common pitfall, and propose a solution.  The
commit below has already done most of the work to make the codebase
consistent in this regard.  Documenting this will hopefully ensure that
regressions don't happen again, or if they do, we have documentation
that we can point to.

1476687d Remove brace initialization of json objects

Tested: Documentation only.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Id9e761987fd90955218fbb232b277a08b0227339
1 file changed
tree: d94e4f1159907dcd32be961926b0922adc5be1e4
  1. .github/
  2. http/
  3. include/
  4. redfish-core/
  5. scripts/
  6. src/
  7. static/
  8. subprojects/
  9. .clang-format
  10. .clang-ignore
  11. .clang-tidy
  12. .dockerignore
  13. .gitignore
  14. .shellcheck
  15. bmcweb.service.in
  16. bmcweb.socket.in
  17. bmcweb_config.h.in
  18. build_x86.sh
  19. build_x86_docker.sh
  20. CLIENTS.md
  21. COMMON_ERRORS.md
  22. DEVELOPING.md
  23. Dockerfile
  24. Dockerfile.base
  25. HEADERS.md
  26. LICENSE
  27. MAINTAINERS
  28. meson.build
  29. meson_options.txt
  30. OEM_SCHEMAS.md
  31. OWNERS
  32. pam-webserver
  33. README.md
  34. Redfish.md
  35. run-ci
  36. setup.cfg
  37. TESTING.md
README.md

OpenBMC webserver

This component attempts to be a "do everything" embedded webserver for openbmc.

Capabilities

At this time, the webserver implements a few interfaces:

  • Authentication middleware that supports cookie and token based authentication, as well as CSRF prevention backed by linux PAM authentication credentials.
  • An (incomplete) attempt at replicating phosphor-dbus-rest interfaces in C++. Right now, a few of the endpoint definitions work as expected, but there is still a lot of work to be done. The portions of the interface that are functional are designed to work correctly for phosphor-webui, but may not yet be complete.
  • Replication of the rest-dbus backend interfaces to allow bmc debug to logged in users.
  • An initial attempt at a read-only redfish interface. Currently the redfish interface targets ServiceRoot, SessionService, AccountService, Roles, and ManagersService. Some functionality here has been shimmed to make development possible. For example, there exists only a single user role.
  • SSL key generation at runtime. See the configuration section for details.
  • Static file hosting. Currently, static files are hosted from the fixed location at /usr/share/www. This is intended to allow loose coupling with yocto projects, and allow overriding static files at build time.
  • Dbus-monitor over websocket. A generic endpoint that allows UIs to open a websocket and register for notification of events to avoid polling in single page applications. (this interface may be modified in the future due to security concerns.

Configuration

BMCWeb is configured by setting -D flags that correspond to options in bmcweb/meson_options.txt and then compiling. For example, meson <builddir> -Dkvm=disabled ... followed by ninja in build directory. The option names become C++ preprocessor symbols that control which code is compiled into the program.

Compile bmcweb with default options:

meson builddir
ninja -C builddir

Compile bmcweb with yocto defaults:

meson builddir -Dbuildtype=minsize -Db_lto=true -Dtests=disabled
ninja -C buildir

If any of the dependencies are not found on the host system during configuration, meson automatically gets them via its wrap dependencies mentioned in bmcweb/subprojects.

Enable/Disable meson wrap feature

meson builddir -Dwrap_mode=nofallback
ninja -C builddir

Enable debug traces

meson builddir -Dbuildtype=debug
ninja -C builddir

Generate test coverage report:

meson builddir -Db_coverage=true -Dtests=enabled
ninja -C builddir test
ninja -C builddir coverage

When BMCWeb starts running, it reads persistent configuration data (such as UUID and session data) from a local file. If this is not usable, it generates a new configuration.

When BMCWeb SSL support is enabled and a usable certificate is not found, it will generate a self-sign a certificate before launching the server. The keys are generated by the secp384r1 algorithm. The certificate

  • is issued by C=US, O=OpenBMC, CN=testhost,
  • is valid for 10 years,
  • has a random serial number, and
  • is signed using the SHA-256 algorithm.