… (#3734)

* separate out some util packages

Signed-off-by: Kevin Minehart <kmineh0151@gmail.com>

* use goimports with -local

Signed-off-by: Kevin Minehart <kmineh0151@gmail.com>

* refactor: reduce the number of transitive imports when using math and logging functions

Signed-off-by: Kevin Minehart <kmineh0151@gmail.com>

* add deprecation warning to pkg/log/log.go

Signed-off-by: Kevin Minehart <kmineh0151@gmail.com>

* Remove util.Logger and move util.InitLogger to util/log package.

Signed-off-by: Peter Štibraný <peter.stibrany@grafana.com>

* Review feedback.

Signed-off-by: Peter Štibraný <peter.stibrany@grafana.com>

* Chore: Upgrade weaveworks/common

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Add changelog entries

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Use instrument.NewHistogramCollector

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Use tracing.ExtractSampledTraceID

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Add tenant resolver package

This implements the multi tenant resolver as described by the [proposal]
for multi tenant query-federation.

By default it behaves like before, but it's implementation can be
swapped out.

[proposal]: cortexproject/cortex#3364

Signed-off-by: Christian Simon <simon@swine.de>

* Replace usages of `ExtractOrgID`

Use TenantID or UserID depending on which of the methods are meant to be
used.

Signed-off-by: Christian Simon <simon@swine.de>

* Replace usages of `ExtractOrgIDFromHTTPRequest`

This is replaced by ExtractTenantIDFromHTTPRequest, which makes sure
that exactly one tenant ID is set.

Signed-off-by: Christian Simon <simon@swine.de>

* Add methods to `tenant` package to use resolver directly

Signed-off-by: Christian Simon <simon@swine.de>

* Remove UserID method from Resolver interface

We need a better definition for what we are trying to achieve with
UserID before we can add it to the interface

Signed-off-by: Christian Simon <simon@swine.de>

* Update comment on the TenantID/TenantIDs

Signed-off-by: Christian Simon <simon@swine.de>

* Improve performance of NormalizeTenantIDs

- reduce allocations by reusing the input slice during de-duplication

Signed-off-by: Christian Simon <simon@swine.de>

* Add tenant query federation

This experimental feature allows queries to cover data from more than a
single Cortex tenant and can be activated by supplying
`-tenant-federation.enabled` to all cortex instances.

To query multiple tenants a `|` separated tenant list can be specified
in the `X-Scope-OrgID` header. The source tenant of a metric will be
exposed in the label `__tenant_id__`.

Signed-off-by: Christian Simon <simon@swine.de>

* Aggregate the limit of maxQueriers correctly

This ensures the limit is aggregated correctly of the setting of each
individual tenant. It also implements the logic for the v2 query
frontend.

Signed-off-by: Christian Simon <simon@swine.de>

* Fix tenant labels and make LabelNames more efficient

Signed-off-by: Christian Simon <simon@swine.de>

* Use tsdb_errors for error handling

Signed-off-by: Christian Simon <simon@swine.de>

* Fix uninitialized label matcher

Regexp matcher need to be initialized, this adds a test for regexp
matcher and fixes the underlying issue.

Signed-off-by: Christian Simon <simon@swine.de>

* Use map for filterValuesByMatchers to reduce allocations

Signed-off-by: Christian Simon <simon@swine.de>

* Address review suggestions

Signed-off-by: Christian Simon <simon@swine.de>

* Add validation.SmallestPositiveNonZeroIntPerTenant to avoid code duplication

Signed-off-by: Christian Simon <simon@swine.de>

* Add limitations and experimental status to docs

Signed-off-by: Christian Simon <simon@swine.de>

* Remove unnecessary cast of defaultTenantLabel

Signed-off-by: Christian Simon <simon@swine.de>

* Handle query-range limits for multi tenant queries

Signed-off-by: Christian Simon <simon@swine.de>

* Skip results cache, if multi tenants query

Signed-off-by: Christian Simon <simon@swine.de>

* Add failint to ensure query path supports multiple tenants

To avoid any future regressions in the multi tenant support within the
query path, a faillint command tests if TenantID is used and if it
finds one, it suggestest using TenantIDs instead>

Signed-off-by: Christian Simon <simon@swine.de>

* Align CHANGELOG line with the flag description

Signed-off-by: Christian Simon <simon@swine.de>

* Add a limitation about missing results cache

Signed-off-by: Christian Simon <simon@swine.de>

This prevents paths generated from TenantIDs to become vulnerable to
path traversal attacks. CVE-2021-36157

Signed-off-by: Christian Simon <simon@swine.de>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>