The phosphor logging repository provides mechanisms for event and journal logging.
- Building
- Structured Logging
- Event Logs
- Application Specific Error YAML
- Event Log Extensions
- Remote Logging
- Boot Fail on Hardware Errors
To build this package, do the following steps:
- meson builddir
- ninja -c builddir
phosphor-logging provides APIs to add program logging information to the systemd-journal and it is preferred that this logging data is formatted in a structured manner (using the facilities provided by the APIs).
See Structured Logging for more details on this API.
OpenBMC event logs are a collection of D-Bus interfaces owned by
phosphor-log-manager that reside at /xyz/openbmc_project/logging/entry/X
,
where X starts at 1 and is incremented for each new log.
The interfaces are:
- xyz.openbmc_project.Logging.Entry
- The main event log interface.
- xyz.openbmc_project.Association.Definitions
- Used for specifying inventory items as the cause of the event.
- For more information on associations, see here.
- xyz.openbmc_project.Object.Delete
- Provides a Delete method to delete the event.
- xyz.openbmc_project.Software.Version
- Stores the code version that the error occurred on.
On platforms that make use of these event logs, the intent is that they are the common event log representation that other types of event logs can be created from. For example, there is code to convert these into both Redfish and IPMI event logs, in addition to the event log extensions mentioned below.
The logging daemon has the ability to add callout
associations to an event
log based on text in the AdditionalData property. A callout is a link to the
inventory item(s) that were the cause of the event log. See here
for details.
There are two approaches to creating event logs in OpenBMC code. The first makes use of the systemd journal to store metadata needed for the log, and the second is a plain D-Bus method call.
Event logs can be created by using phosphor-logging APIs to commit sdbusplus
exceptions. These APIs write to the journal, and then call a Commit
D-Bus method on the logging daemon to create the event log using the information
it put in the journal.
The APIs are found in <phosphor-logging/elog.hpp>
:
elog()
: Throw an sdbusplus error.commit()
: Catch an error thrown by elog(), and commit it to create the event log.report()
: Create an event log from an sdbusplus error without throwing the exception first.
Any errors passed into these APIs must be known to phosphor-logging, usually
by being defined in <phosphor-logging/elog-errors.hpp>
. The errors must
also be known by sdbusplus, and be defined in their corresponding error.hpp.
See below for details on how get errors into these headers.
Example:
#include <phosphor-logging/elog-errors.hpp>
#include <phosphor-logging/elog.hpp>
#include <xyz/openbmc_project/Common/error.hpp>
...
using InternalFailure =
sdbusplus::xyz::openbmc_project::Common::Error::InternalFailure;
...
if (somethingBadHappened)
{
phosphor::logging::report<InternalFailure>();
}
Alternatively, to throw, catch, and then commit the error:
try
{
phosphor::logging::elog<InternalFailure>();
}
catch (InternalFailure& e)
{
phosphor::logging::commit<InternalFailure>();
}
Metadata can be added to event logs to add debug data captured at the time of
the event. It shows up in the AdditionalData property in the
xyz.openbmc_project.Logging.Entry
interface. Metadata is passed in via the
elog()
or report()
functions, which write it to the journal. The metadata
must be predefined for the error in the metadata YAML
so that the daemon knows to look for it in the journal when it creates the
event log.
Example:
#include <phosphor-logging/elog-errors.hpp>
#include <phosphor-logging/elog.hpp>
#include <xyz/openbmc_project/Control/Device/error.hpp>
...
using WriteFailure =
sdbusplus::xyz::openbmc_project::Control::Device::Error::WriteFailure;
using metadata =
xyz::openbmc_project::Control::Device::WriteFailure;
...
if (somethingBadHappened)
{
phosphor::logging::report<WriteFailure>(metadata::CALLOUT_ERRNO(5),
metadata::CALLOUT_DEVICE_PATH("some path"));
}
In the above example, the AdditionalData property would look like:
["CALLOUT_ERRNO=5", "CALLOUT_DEVICE_PATH=some path"]
Note that the metadata fields must be all uppercase.
As mentioned above, both sdbusplus and phosphor-logging must know about the
event logs in their header files, or the code that uses them will not even
compile. The standard way to do this to define the event in the appropriate
<error-category>.errors.yaml
file, and define any metadata in the
<error-category>.metadata.yaml
file in the appropriate *-dbus-interfaces
repository. During the build, phosphor-logging generates the elog-errors.hpp
file for use by the calling code.
In much the same way, sdbusplus uses the event log definitions to generate an error.hpp file that contains the specific exception. The path of the error.hpp matches the path of the YAML file.
For example, if in phosphor-dbus-interfaces there is
xyz/openbmc_project/Control/Device.errors.yaml
, the errors that come from
that file will be in the include:
xyz/openbmc_project/Control/Device/error.hpp
.
In rare cases, one may want one to define their errors in the same repository that uses them. To do that, one must:
- Add the error and metadata YAML files to the repository.
- Run the sdbus++ script within the makefile to create the error.hpp and .cpp files from the local YAML, and include the error.cpp file in the application that uses it. See openpower-occ-control for an example.
- Tell phosphor-logging about the error. This is done by either:
- Following the directions defined in this README, or
- Running the script yourself:
- Run phosphor-logging's
elog-gen.py
script on the local yaml to generate an elog-errors.hpp file that just contains the local errors, and check that into the repository and include it where the errors are needed. - Create a recipe that copies the local YAML files to a place that phosphor-logging can find it during the build. See here for an example.
There is also a D-Bus method to create event logs:
- Service: xyz.openbmc_project.Logging
- Object Path: /xyz/openbmc_project/logging
- Interface: xyz.openbmc_project.Logging.Create
- Method: Create
- Method Arguments:
- Message: The
Message
string property for thexyz.openbmc_project.Logging.Entry
interface. - Severity: The
severity
property for thexyz.openbmc_project.Logging.Entry
interface. Anxyz.openbmc_project.Logging.Entry.Level
enum value. - AdditionalData: The
AdditionalData
property for thexyz.openbmc_project.Logging.Entry
interface, but in a map instead of in a vector of "KEY=VALUE" strings. Example:
- Message: The
- Method Arguments:
std::map<std::string, std::string> additionalData;
additionalData["KEY"] = "VALUE";
Unlike the previous APIs where errors could also act as exceptions that could be thrown across D-Bus, this API does not require that the error be defined in the error YAML in the D-Bus interfaces repository so that sdbusplus knows about it. Additionally, as this method passes in everything needed to create the event log, the logging daemon doesn't have to know about it ahead of time either.
That being said, it is recommended that users of this API still follow some
guidelines for the message field, which is normally generated from a
combination of the path to the error YAML file and the error name itself. For
example, the Timeout
error in xyz/openbmc_project/Common.errors.yaml
will
have a Message property of xyz.openbmc_project.Common.Error.Timeout
.
The guidelines are:
-
When it makes sense, one can still use an existing error that has already been defined in an error YAML file, and use the same severity and metadata (AdditionalData) as in the corresponding metadata YAML file.
-
If creating a new error, use the same naming scheme as other errors, which starts with the domain,
xyz.openbmc_project
,org.open_power
, etc, followed by the capitalized category values, followed byError
, followed by the capitalized error name itself, with everything separated by "."s. For example:xyz.openbmc_project.Some.Category.Error.Name
. -
If creating a new common error, still add it to the appropriate error and metadata YAML files in the appropriate D-Bus interfaces repository so that others can know about it and use it in the future. This can be done after the fact.
- This document captures steps for adding application specific error YAML files and generating local elog-errors.hpp header file for application use.
- Should cater for continuous integration (CI) build, bitbake image build, and local repository build.
- Make is called on the repository that is modified.
- Dependent packages are pulled based on the dependency list specified in the configure.ac script.
- Native recipes copy error YAML files to shared location.
- phosphor-logging builds elog-errors.hpp by parsing the error YAML files from the shared location.
- Copies local error YAML files to the shared location in SDK
- Make generates elog-errors.hpp by parsing the error YAML files from the shared location.
Reference
Modify Makefile.am to export newly added error YAML to shared location
yamldir = ${datadir}/phosphor-dbus-yaml/yaml
nobase_yaml_DATA = \
org/open_power/Host.errors.yaml
- Add a conditional check "GEN_ERRORS"
- Disable the check for recipe bitbake image build
- Enable it for local repository build
- If "GEN_ERRORS" is enabled, build generates elog-errors.hpp header file.
# Generate phosphor-logging/elog-errors.hpp
if GEN_ERRORS
ELOG_MAKO ?= elog-gen-template.mako.hpp
ELOG_DIR ?= ${OECORE_NATIVE_SYSROOT}${datadir}/phosphor-logging/elog
ELOG_GEN_DIR ?= ${ELOG_DIR}/tools/
ELOG_MAKO_DIR ?= ${ELOG_DIR}/tools/phosphor-logging/templates/
YAML_DIR ?= ${OECORE_NATIVE_SYSROOT}${datadir}/phosphor-dbus-yaml/yaml
phosphor-logging/elog-errors.hpp:
@mkdir -p ${YAML_DIR}/org/open_power/
@cp ${top_srcdir}/org/open_power/Host.errors.yaml \
${YAML_DIR}/org/open_power/Host.errors.yaml
@mkdir -p `dirname $@`
@chmod 777 $(ELOG_GEN_DIR)/elog-gen.py
$(AM_V_at)$(PYTHON) $(ELOG_GEN_DIR)/elog-gen.py -y ${YAML_DIR} \
-t ${ELOG_MAKO_DIR} -m ${ELOG_MAKO} -o $@
endif
- Append elog-errors.hpp to BUILT_SOURCES list and put it in conditional check GEN_ERRORS so that the elog-errors.hpp is generated only during local repository build.
if GEN_ERRORS
nobase_nodist_include_HEADERS += \
phosphor-logging/elog-errors.hpp
endif
if GEN_ERRORS
BUILT_SOURCES += phosphor-logging/elog-errors.hpp
endif
- As the same Makefile is used both for recipe image build and native recipe build, add a conditional to ensure that only installation of error yaml files happens during native build. It is not required to build repository during native build.
if !INSTALL_ERROR_YAML
endif
Reference
-
Install error yaml option(argument) is enabled for native recipe build and disabled for bitbake build.
-
When install error yaml option is disabled do not check for target specific packages in autotools configure script.
AC_ARG_ENABLE([install_error_yaml],
AS_HELP_STRING([--enable-install_error_yaml],
[Enable installing error yaml file]),[], [install_error_yaml=no])
AM_CONDITIONAL([INSTALL_ERROR_YAML],
[test "x$enable_install_error_yaml" = "xyes"])
AS_IF([test "x$enable_install_error_yaml" != "xyes"], [
..
..
])
AC_ARG_ENABLE([gen_errors],
AS_HELP_STRING([--enable-gen_errors], [Enable elog-errors.hpp generation ]),
[],[gen_errors=yes])
AM_CONDITIONAL([GEN_ERRORS], [test "x$enable_gen_errors" != "xno"])
Reference
- https://github.com/openbmc/openbmc/blob/master/meta-openbmc-machines\ /meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector.bb
- Extend the recipe for native and native SDK builds
BBCLASSEXTEND += "native nativesdk"
- Native recipe caters only for copying error yaml files to shared location.
- For native and native SDK build remove dependency on packages that recipe build depends
DEPENDS_remove_class-native = "phosphor-logging"
DEPENDS_remove_class-nativesdk = "phosphor-logging"
- Add package config to enable/disable install_error_yaml feature.
PACKAGECONFIG ??= "install_error_yaml"
PACKAGECONFIG[install_error_yaml] = " \
--enable-install_error_yaml, \
--disable-install_error_yaml, ,\
"
PACKAGECONFIG_add_class-native = "install_error_yaml"
PACKAGECONFIG_add_class-nativesdk = "install_error_yaml"
PACKAGECONFIG_remove_class-target = "install_error_yaml"
- Disable gen_errors argument for bitbake image build as the application uses the elog-errors.hpp generated by phosphor-logging
- Argument is enabled by default for local repository build in the configure script of the local repository.
XTRA_OECONF += "--disable-gen_errors"
- During local build use --prefix=/usr for the configure script.
Reference
The extension concept is a way to allow code that creates other formats of error logs besides phosphor-logging's event logs to still reside in the phosphor-log-manager application.
The extension code lives in the extensions/<extension>
subdirectories,
and is enabled with a --enable-<extension>
configure flag. The
extension code won't compile unless enabled with this flag.
Extensions can register themselves to have functions called at the following points using the REGISTER_EXTENSION_FUNCTION macro.
- On startup
- Function type void(internal::Manager&)
- After an event log is created
- Function type void(args)
- The args are:
- const std::string& - The Message property
- uin32_t - The event log ID
- uint64_t - The event log timestamp
- Level - The event level
- const AdditionalDataArg& - the additional data
- const AssociationEndpointsArg& - Association endpoints (callouts)
- Before an event log is deleted, to check if it is allowed.
- Function type void(std::uint32_t, bool&) that takes the event ID
- After an event log is deleted
- Function type void(std::uint32_t) that takes the event ID
Using these callback points, they can create their own event log for each OpenBMC event log that is created, and delete these logs when the corresponding OpenBMC event log is deleted.
In addition, an extension has the option of disabling phosphor-logging's default error log capping policy so that it can use its own. The macro DISABLE_LOG_ENTRY_CAPS() is used for that.
The reason for adding support for extensions inside the phosphor-log-manager daemon as opposed to just creating new daemons that listen for D-Bus signals is to allow interactions that would be complicated or expensive if just done over D-Bus, such as:
- Allowing for custom old log retention algorithms.
- Prohibiting manual deleting of certain logs based on an extension's requirements.
- Add a new flag to configure.ac to enable the extension:
AC_ARG_ENABLE([foo-extension],
AS_HELP_STRING([--enable-foo-extension],
[Create Foo logs]))
AM_CONDITIONAL([ENABLE_FOO_EXTENSION],
[test "x$enable_foo_extension" == "xyes"])
- Add the code in
extensions/<extension>/
. - Create a makefile include to add the new code to phosphor-log-manager:
phosphor_log_manager_SOURCES += \
extensions/foo/foo.cpp
- In
extensions/extensions.mk
, add the makefile include:
if ENABLE_FOO_EXTENSION
include extensions/foo/foo.mk
endif
- In the extension code, register the functions to call and optionally disable log capping using the provided macros:
DISABLE_LOG_ENTRY_CAPS();
void fooStartup(internal::Manager& manager)
{
// Initialize
}
REGISTER_EXTENSION_FUNCTION(fooStartup);
void fooCreate(const std::string& message, uint32_t id, uint64_t timestamp,
Entry::Level severity, const AdditionalDataArg& additionalData,
const AssociationEndpointsArg& assocs)
{
// Create a different type of error log based on 'entry'.
}
REGISTER_EXTENSION_FUNCTION(fooCreate);
void fooRemove(uint32_t id)
{
// Delete the extension error log that corresponds to 'id'.
}
REGISTER_EXTENSION_FUNCTION(fooRemove);
The supported extensions are:
- OpenPower PELs
- Enabled with --enable-openpower-pel-extension
- Detailed information can be found here
The BMC has the ability to stream out local logs (that go to the systemd journal) via rsyslog (https://www.rsyslog.com/).
The BMC will send everything. Any kind of filtering and appropriate storage will have to be managed on the rsyslog server. Various examples are available on the internet. Here are few pointers : https://www.rsyslog.com/storing-and-forwarding-remote-messages/ https://www.rsyslog.com/doc/rsyslog%255Fconf%255Ffilter.html https://www.thegeekdiary.com/understanding-rsyslog-filter-options/
The BMC is an rsyslog client. To stream out logs, it needs to talk to an rsyslog server, to which there's connectivity over a network. REST API can be used to set the remote server's IP address and port number.
The following presumes a user has logged on to the BMC (see https://github.com/openbmc/docs/blob/master/rest-api.md).
Set the IP:
curl -b cjar -k -H "Content-Type: application/json" -X PUT \
-d '{"data": <IP address>}' \
https://<BMC IP address>/xyz/openbmc_project/logging/config/remote/attr/Address
Set the port:
curl -b cjar -k -H "Content-Type: application/json" -X PUT \
-d '{"data": <port number>}' \
https://<BMC IP address>/xyz/openbmc_project/logging/config/remote/attr/Port
curl -b cjar -k \
https://<BMC IP address>/xyz/openbmc_project/logging/config/remote
Rsyslog can store logs separately for each host. For this reason, it's useful to provide a unique hostname to each managed BMC. Here's how that can be done via a REST API :
curl -b cjar -k -H "Content-Type: application/json" -X PUT \
-d '{"data": "myHostName"}' \
https://<BMC IP address>//xyz/openbmc_project/network/config/attr/HostName
Remote logging can be disabled by writing 0 to the port, or an empty string("") to the IP.
When switching to a new server from an existing one (i.e the address, or port, or both change), it is recommended to disable the existing configuration first.
phosphor-logging supports a setting, which when set, will result in the software looking at new phosphor-logging entries being created, and if a CALLOUT* is found within the entry, ensuring the system will not power on.
The full design for this can be found here
To enable this function:
busctl set-property xyz.openbmc_project.Settings /xyz/openbmc_project/logging/settings xyz.openbmc_project.Logging.Settings QuiesceOnHwError b true
To check if an entry is blocking the boot:
obmcutil listbootblock
Resolve or clear the corresponding entry to allow the system to boot.