gotjosh
e4afc8d518
The arching goal of this commit is to enable single user synchronisation with LDAP. Also, it included minor fixes of style, error messages and minor bug fixing. The changes are: - bug: The `multildap` package has its own errors when the user is not found. We fixed the conditional branch on this error by asserting on the `multildap` errors as opposed to the `ldap` one - bug: The previous interface usage of `RevokeAllUserTokens` did not work as expected. This replaces the manual injection of the service by leveraging the service injected as part of the `server` struct. - chore: Better error messages around not finding the user in LDAP. - fix: Enable the single sync button and disable it when we receive an error from LDAP. Please note, that you can enable it by dispatching the error. This allows you to try again without having to reload the page. - fix: Move the sync info to the top, then move the sync button above that information and clearfix to have more harmony with the UI.
Backend
This directory contains the code for the Grafana backend. This document gives an overview of the directory structure, and ongoing refactorings.
For more information on developing for the backend:
Central folders of Grafana's backend
| folder | description |
|---|---|
| /pkg/api | HTTP handlers and routing. Almost all handler funcs are global which is something we would like to improve in the future. Handlers should be associated with a struct that refers to all dependencies. |
| /pkg/cmd | The binaries that we build: grafana-server and grafana-cli. |
| /pkg/components | A mix of third-party packages and packages we have implemented ourselves. Includes our packages that have out-grown the util package and don't naturally belong somewhere else. |
| /pkg/infra | Packages in infra should be packages that are used in multiple places in Grafana without knowing anything about the Grafana domain. |
| /pkg/services | Packages in services are responsible for peristing domain objects and manage the relationship between domain objects. Services should communicate with each other using DI when possible. Most of Grafana's codebase still relies on global state for this. Any new features going forward should use DI. |
| /pkg/tsdb | All backend implementations of the data sources in Grafana. Used by both Grafana's frontend and alerting. |
| /pkg/util | Small helper functions that are used in multiple parts of the codebase. Many functions are placed directly in the util folders which is something we want to avoid. Its better to give the util function a more descriptive package name. Ex errutil. |
Central components of Grafana's backend
| package | description |
|---|---|
| /pkg/bus | The bus is described in more details under Communication |
| /pkg/models | This is where we keep our domain model. This package should not depend on any package outside standard library. It does contain some references within Grafana but that is something we should avoid going forward. |
| /pkg/registry | Package for managing services. |
| /pkg/services/alerting | Grafana's alerting services. The alerting engine runs in a separate goroutine and shouldn't depend on anything else within Grafana. |
| /pkg/services/sqlstore | Currently where the database logic resides. |
| /pkg/setting | Anything related to Grafana global configuration should be dealt with in this package. |
Dependency management
Refer to UPGRADING_DEPENDENCIES.md.
Ongoing refactoring
These issues are not something we want to address all at once but something we will improve incrementally. Since Grafana is released at a regular schedule the preferred approach is to do this in batches. Not only is it easier to review, but it also reduces the risk of conflicts when cherry-picking fixes from master to release branches. Please try to submit changes that span multiple locations at the end of the release cycle. We prefer to wait until the end because we make fewer patch releases at the end of the release cycle, so there are fewer opportunities for complications.
Global state
Global state makes testing and debugging software harder and it's something we want to avoid when possible. Unfortunately, there is quite a lot of global state in Grafana.
We want to migrate away from this by using the inject package to wire up all dependencies either in pkg/cmd/grafana-server/main.go or self-registering using registry.RegisterService ex https://github.com/grafana/grafana/blob/master/pkg/services/cleanup/cleanup.go#L25.
Limit the use of the init() function
Only use the init() function to register services/implementations.
Settings refactoring
The plan is to move all settings to from package level vars in settings package to the setting.Cfg struct. To access the settings, services and components can inject this setting.Cfg struct:
Reduce the use of GoConvey
We want to migrate away from using GoConvey. Instead, we want to use stdlib testing, because it's the most common approach in the Go community and we think it will be easier for new contributors. Read more about how we want to write tests in the style guide.
Refactor SqlStore
The sqlstore handlers all use a global xorm engine variable. Refactor them to use the SqlStore instance.
Avoid global HTTP handler functions
Refactor HTTP handlers so that the handler methods are on the HttpServer instance or a more detailed handler struct. E.g (AuthHandler). This ensures they get access to HttpServer service dependencies (and Cfg object) and can avoid global state.
Date comparison
Store newly introduced date columns in the database as epochs if they require date comparison. This permits a unified approach for comparing dates against all the supported databases instead of handling dates differently for each database. Also, by comparing epochs, we no longer need error pruning transformations to and from other time zones.
Provisionable*
All new features that require state should be possible to configure using config files. For example:
Today its only possible to provision data sources and dashboards but this is something we want to support all over Grafana.