diff --git a/dev_docs/kibana_platform_plugin_intro.mdx b/dev_docs/kibana_platform_plugin_intro.mdx index ce8b8b8b54756..bf009a3c5251d 100644 --- a/dev_docs/kibana_platform_plugin_intro.mdx +++ b/dev_docs/kibana_platform_plugin_intro.mdx @@ -7,25 +7,25 @@ date: 2021-01-06 tags: ['kibana','onboarding', 'dev', 'architecture'] --- -From an end user perspective, Kibana is a tool for interacting with Elasticsearch, providing an easy way +From an end user perspective, Kibana is a tool for interacting with Elasticsearch, providing an easy way to visualize and analyze data. From a developer perspective, Kibana is a platform that provides a set of tools to build not only the UI you see in Kibana today, but -a wide variety of applications that can be used to explore, visualize, and act upon data in Elasticsearch. The platform provides developers the ability -to build applications, or inject extra functionality into +a wide variety of applications that can be used to explore, visualize, and act upon data in Elasticsearch. The platform provides developers the ability +to build applications, or inject extra functionality into already existing applications. Did you know that almost everything you see in the Kibana UI is built inside a plugin? If you removed all plugins from Kibana, you'd be left with an empty navigation menu, and a set of developer tools. The Kibana platform is a blank canvas, just waiting for a developer to come along and create something! ![Kibana personas](assets/kibana_platform_plugin_end_user.png) - + ## Platform services Plugins have access to three kinds of public services: - Platform services provided by `core` () - Platform services provided by plugins () - - Shared services provided by plugins, that are only relevant for only a few, specific plugins (e.g. "presentation utils"). + - Shared services provided by plugins, that are only relevant for only a few, specific plugins (e.g. "presentation utils"). The first two items are what make up "Platform services". @@ -37,9 +37,9 @@ clear, and we haven't done a great job of sticking to it. For example, notificat Today it looks something like this. ![Core vs platform plugins vs plugins](assets/platform_plugins_core.png) - + -When the Kibana platform and plugin infrastructure was built, we thought of two types of code: core services, and other plugin services. We planned to keep the most stable and fundamental +When the Kibana platform and plugin infrastructure was built, we thought of two types of code: core services, and other plugin services. We planned to keep the most stable and fundamental code needed to build plugins inside core. In reality, we ended up with many platform-like services living outside of core, with no (short term) intention of moving them. We highly encourage plugin developers to use @@ -54,7 +54,7 @@ In reality, our plugin model ended up being used like micro-services. Plugins ar they desire, without the need to build a plugin. Another side effect of having many small plugins is that common code often ends up extracted into another plugin. Use case specific utilities are exported, - that are not meant to be used in a general manner. This makes our definition of "platform code" a bit trickier to define. We'd like to say "The platform is made up of + that are not meant to be used in a general manner. This makes our definition of "platform code" a bit trickier to define. We'd like to say "The platform is made up of every publically exposed service", but in today's world, that wouldn't be a very accurate picture. We recognize the need to better clarify the relationship between core functionality, platform-like plugin functionality, and functionality exposed by other plugins. @@ -69,19 +69,19 @@ We will continue to focus on adding clarity around these types of services and w ### Core services Sometimes referred to just as Core, Core services provide the most basic and fundamental tools neccessary for building a plugin, like creating saved objects, -routing, application registration, and notifications. The Core platform is not a plugin itself, although +routing, application registration, notifications and . The Core platform is not a plugin itself, although there are some plugins that provide platform functionality. We call these . ### Platform plugins -Plugins that provide fundamental services and functionality to extend and customize Kibana, for example, the +Plugins that provide fundamental services and functionality to extend and customize Kibana, for example, the plugin. There is no official way to tell if a plugin is a platform plugin or not. Platform plugins are _usually_ plugins that are managed by the Platform Group, but we are starting to see some exceptions. ## Plugins -Plugins are code that is written to extend and customize Kibana. Plugin's don't have to be part of the Kibana repo, though the Kibana -repo does contain many plugins! Plugins add customizations by +Plugins are code that is written to extend and customize Kibana. Plugin's don't have to be part of the Kibana repo, though the Kibana +repo does contain many plugins! Plugins add customizations by using provided by . Sometimes people confuse the term "plugin" and "application". While often there is a 1:1 relationship between a plugin and an application, it is not always the case. A plugin may register many applications, or none. @@ -97,7 +97,7 @@ adding it to core's application , +A plugin's public API consists of everything exported from a plugin's , as well as from the top level `index.ts` files that exist in the three "scope" folders: - common/index.ts @@ -113,7 +113,7 @@ Core, and plugins, expose different features at different parts of their lifecyc specifically-named functions on the service definition. Kibana has three lifecycles: setup, start, and stop. Each plugin’s setup function is called sequentially while Kibana is setting up - on the server or when it is being loaded in the browser. The start functions are called sequentially after setup has been completed for all plugins. + on the server or when it is being loaded in the browser. The start functions are called sequentially after setup has been completed for all plugins. The stop functions are called sequentially while Kibana is gracefully shutting down the server or when the browser tab or window is being closed. The table below explains how each lifecycle relates to the state of Kibana. @@ -121,10 +121,10 @@ The table below explains how each lifecycle relates to the state of Kibana. | lifecycle | purpose | server | browser | | ---------- | ------ | ------- | ----- | | setup | perform "registration" work to setup environment for runtime |configure REST API endpoint, register saved object types, etc. | configure application routes in SPA, register custom UI elements in extension points, etc. | -| start | bootstrap runtime logic | respond to an incoming request, request Elasticsearch server, etc. | start polling Kibana server, update DOM tree in response to user interactions, etc.| +| start | bootstrap runtime logic | respond to an incoming request, request Elasticsearch server, etc. | start polling Kibana server, update DOM tree in response to user interactions, etc.| | stop | cleanup runtime | dispose of active handles before the server shutdown. | store session data in the LocalStorage when the user navigates away from Kibana, etc. | -Different service interfaces can and will be passed to setup, start, and stop because certain functionality makes sense in the context of a running plugin while other types +Different service interfaces can and will be passed to setup, start, and stop because certain functionality makes sense in the context of a running plugin while other types of functionality may have restrictions or may only make sense in the context of a plugin that is stopping. ## Extension points @@ -141,4 +141,4 @@ plugins to customize the Kibana experience. Examples of extension points are: ## Follow up material -Learn how to build your own plugin by following \ No newline at end of file +Learn how to build your own plugin by following diff --git a/src/core/README.md b/src/core/README.md index c73c6aa56bfd0..799cdb5c799ae 100644 --- a/src/core/README.md +++ b/src/core/README.md @@ -29,7 +29,7 @@ rules tailored to our needs (e.g. `byteSize`, `duration` etc.). That means that by the "legacy" Kibana may be rejected by the `core` now. ### Logging -`core` has its own [logging system](./server/logging/README.md) and will output log records directly (e.g. to file or terminal) when configured. When no +`core` has its own [logging system](./server/logging/README.mdx) and will output log records directly (e.g. to file or terminal) when configured. When no specific configuration is provided, logs are forwarded to the "legacy" Kibana so that they look the same as the rest of the log records throughout Kibana. diff --git a/src/core/server/logging/README.md b/src/core/server/logging/README.mdx similarity index 94% rename from src/core/server/logging/README.md rename to src/core/server/logging/README.mdx index 0704431c282c9..6fd730f47dc07 100644 --- a/src/core/server/logging/README.md +++ b/src/core/server/logging/README.mdx @@ -1,3 +1,13 @@ +--- +id: kibCoreLogging +slug: /kibana-dev-docs/services/logging +title: Logging system +image: https://source.unsplash.com/400x175/?Logging +summary: Core logging contains the system and service for Kibana logs. +date: 2020-12-02 +tags: ['kibana','dev', 'contributor', 'api docs'] +--- + # Logging - [Loggers, Appenders and Layouts](#loggers-appenders-and-layouts) - [Logger hierarchy](#logger-hierarchy) @@ -16,7 +26,7 @@ - [Log record format changes](#log-record-format-changes) The way logging works in Kibana is inspired by `log4j 2` logging framework used by [Elasticsearch](https://www.elastic.co/guide/en/elasticsearch/reference/current/settings.html#logging). -The main idea is to have consistent logging behaviour (configuration, log format etc.) across the entire Elastic Stack +The main idea is to have consistent logging behaviour (configuration, log format etc.) across the entire Elastic Stack where possible. ## Loggers, Appenders and Layouts @@ -34,16 +44,17 @@ __Layouts__ define how log messages are formatted and what type of information t ## Logger hierarchy -Every logger has its unique context name that follows hierarchical naming rule. The logger is considered to be an +Every logger has its unique context name that follows hierarchical naming rule. The logger is considered to be an ancestor of another logger if its name followed by a `.` is a prefix of the descendant logger name. For example logger with `a.b` context name is an ancestor of logger with `a.b.c` context name. All top-level loggers are descendants of special -logger with `root` context name that resides at the top of the logger hierarchy. This logger always exists and +logger with `root` context name that resides at the top of the logger hierarchy. This logger always exists and fully configured. Developer can configure _log level_ and _appenders_ that should be used within particular context name. If logger configuration -specifies only _log level_ then _appenders_ configuration will be inherited from the ancestor logger. +specifies only _log level_ then _appenders_ configuration will be inherited from the ancestor logger. -__Note:__ in the current implementation log messages are only forwarded to appenders configured for a particular logger +__Note:__ +In the current implementation log messages are only forwarded to appenders configured for a particular logger context name or to appenders of the closest ancestor if current logger doesn't have any appenders configured. That means that we __don't support__ so called _appender additivity_ when log messages are forwarded to _every_ distinct appender within ancestor chain including `root`. @@ -51,8 +62,10 @@ ancestor chain including `root`. ## Log level Currently we support the following log levels: _all_, _fatal_, _error_, _warn_, _info_, _debug_, _trace_, _off_. + Levels are ordered, so _all_ > _fatal_ > _error_ > _warn_ > _info_ > _debug_ > _trace_ > _off_. -A log record is being logged by the logger if its level is higher than or equal to the level of its logger. Otherwise, + +A log record is being logged by the logger if its level is higher than or equal to the level of its logger. Otherwise, the log record is ignored. The _all_ and _off_ levels can be used only in configuration and are just handy shortcuts that allow developer to log every @@ -61,15 +74,15 @@ log record or disable logging entirely for the specific context name. ## Layouts Every appender should know exactly how to format log messages before they are written to the console or file on the disk. -This behaviour is controlled by the layouts and configured through `appender.layout` configuration property for every +This behaviour is controlled by the layouts and configured through `appender.layout` configuration property for every custom appender (see examples in [Configuration](#configuration)). Currently we don't define any default layout for the custom appenders, so one should always make the choice explicitly. -There are two types of layout supported at the moment: `pattern` and `json`. +There are two types of layout supported at the moment: `pattern` and `json`. ### Pattern layout With `pattern` layout it's possible to define a string pattern with special placeholders `%conversion_pattern` (see the table below) that -will be replaced with data from the actual log message. By default the following pattern is used: +will be replaced with data from the actual log message. By default the following pattern is used: `[%date][%level][%logger]%meta %message`. Also `highlight` option can be enabled for `pattern` layout so that some parts of the log message are highlighted with different colors that may be quite handy if log messages are forwarded to the terminal with color support. @@ -111,7 +124,7 @@ Example of `%meta` output: ##### date Outputs the date of the logging event. The date conversion specifier may be followed by a set of braces containing a name of predefined date format and canonical timezone name. -Timezone name is expected to be one from [TZ database name](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). +Timezone name is expected to be one from [TZ database name](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). Timezone defaults to the host timezone when not explicitly specified. Example of `%date` output: @@ -130,7 +143,7 @@ Example of `%date` output: Outputs the process ID. ### JSON layout -With `json` layout log messages will be formatted as JSON strings that include timestamp, log level, context name, message +With `json` layout log messages will be formatted as JSON strings that include timestamp, log level, context name, message text and any other metadata that may be associated with the log message itself. ## Appenders @@ -160,7 +173,7 @@ logging: type: size-limit size: 50mb strategy: - //... + //... layout: type: pattern ``` @@ -188,7 +201,7 @@ logging: interval: 10s modulate: true strategy: - //... + //... layout: type: pattern ``` @@ -202,10 +215,10 @@ How often a rollover should occur. The default value is `24h` - `modulate` - + Whether the interval should be adjusted to cause the next rollover to occur on the interval boundary. - -For example, when true, if the interval is `4h` and the current hour is 3 am then the first rollover will occur at 4 am + +For example, when true, if the interval is `4h` and the current hour is 3 am then the first rollover will occur at 4 am and then next ones will occur at 8 am, noon, 4pm, etc. The default value is `true`. @@ -332,8 +345,8 @@ Here is what we get with the config above: | metrics.ops | console | debug | -The `root` logger has a dedicated configuration node since this context name is special and should always exist. By -default `root` is configured with `info` level and `default` appender that is also always available. This is the +The `root` logger has a dedicated configuration node since this context name is special and should always exist. By +default `root` is configured with `info` level and `default` appender that is also always available. This is the configuration that all custom loggers will use unless they're re-configured explicitly. For example to see _all_ log messages that fall back on the `root` logger configuration, just add one line to the configuration: @@ -392,8 +405,8 @@ The message contains some high-level information, and the corresponding log meta ## Usage -Usage is very straightforward, one should just get a logger for a specific context name and use it to log messages with -different log level. +Usage is very straightforward, one should just get a logger for a specific context name and use it to log messages with +different log level. ```typescript const logger = kibana.logger.get('server'); @@ -436,7 +449,7 @@ All log messages handled by `root` context are forwarded to the legacy logging s root appenders, make sure that it contains `default` appender to provide backward compatibility. **Note**: If you define an appender for a context name, the log messages aren't handled by the `root` context anymore and not forwarded to the legacy logging service. - + #### logging.dest By default logs in *stdout*. With new Kibana logging you can use pre-existing `console` appender or define a custom one. @@ -446,7 +459,7 @@ logging: - name: plugins.myPlugin appenders: [console] ``` -Logs in a *file* if given file path. You should define a custom appender with `type: file` +Logs in a *file* if given file path. You should define a custom appender with `type: file` ```yaml logging: @@ -459,13 +472,13 @@ logging: loggers: - name: plugins.myPlugin appenders: [file] -``` +``` #### logging.json Defines the format of log output. Logs in JSON if `true`. With new logging config you can adjust the output format with [layouts](#layouts). #### logging.quiet -Suppresses all logging output other than error messages. With new logging, config can be achieved +Suppresses all logging output other than error messages. With new logging, config can be achieved with adjusting minimum required [logging level](#log-level). ```yaml loggers: