Prepare v0.56.0 release (#6202)

Signed-off-by: Johan Fylling <[email protected]>

Author: johanfylling

CHANGELOG.md

@@ -3,18 +3,99 @@
 All notable changes to this project will be documented in this file. This
 project adheres to [Semantic Versioning](http://semver.org/).
 
-## Unreleased
+## 0.56.0
+
+This release contains a mix of new features, bugfixes and a new builtin function.
+
+### Support for General References in Rule Heads (Experimental)
+
+A new experimental feature in OPA is support for general refs in rule heads. Where a general ref is a reference with variables at arbitrary locations.
+
+```rego
+package example
+
+import future.keywords
+
+# Converting a flat list of users to a mapping by "role" and then "id".
+users_by_role[role][id] := user if {
+    some user in data.users
+    id := user.id
+    role := user.role
+}
+
+# Explicit "admin" key override to the above mapping.
+users_by_role.admin[id] := user if {
+    some user in data.admins
+    id := user.id
+}
+
+# Leaf entries can be multi-value.
+users_by_country[country] contains user.id if {
+    some user in data.users
+    country := user.country
+}
+```
+
+General refs are currently not supported by the OPA planner, making this feature unsupported for Wasm and IR.
+
+Note: this feature is disabled by default, and needs to be enabled by setting the `EXPERIMENTAL_GENERAL_RULE_REFS` environment variable (once the feature is complete - supports Wasm and IR - this requirement will be dropped).
+
+Authored by @johanfylling.
+
+### New Built-In Function: `numbers.range_step`
+
+Similar to the `numbers.range` built-in function, `numbers.range_step` returns an array of numbers in a given range. The new built-in function also allows you to control the _step between each entry_.
+
+See [the documentation on the new built-in](https://www.openpolicyagent.org/docs/v0.56.0/policy-reference/#builtin-numbers-numbersrange_step)
+for all the details.
+
+Authored by @sspaink.
+
+### New Ecosystem page on The Website
+
+The OPA Ecosystem of related integrations has been refreshed and moved to a more prominent location on [the website](https://www.openpolicyagent.org/ecosystem/). 
+
+If you're interested to add any new integrations you've been working on, please see the [docs here](https://github.com/open-policy-agent/opa/tree/main/docs#opa-ecosystem) (updates to existing integrations are very welcome too!).
+
+### Runtime, Tooling, SDK
+
+- ast: Update strict error check message for unused args ([#6125](https://github.com/open-policy-agent/opa/pull/6125)) authored by @ashutosh-narkar
+- ast: Remove unnecessary nil check ([#6155](https://github.com/open-policy-agent/opa/pull/6155)) authored by @Juneezee
+- cmd: Make `opa test -z` fail with failing tests ([#6126](https://github.com/open-policy-agent/opa/issues/6126)) authored by @fdaguin
+- cmd: Fix `opa test` `--ignore` when used together with `--bundle` ([#6185](https://github.com/open-policy-agent/opa/pull/6185)) authored by @joaobrandt
+- cmd: Adding `--fail-non-empty` flag to `opa exec` ([#6153](https://github.com/open-policy-agent/opa/pull/6153)) authored by @Ronnie-personal
+- download: Add `opa_no_oci` flag to build without containerd ([#6159](https://github.com/open-policy-agent/opa/pull/6159)) authored by @slonka
+- download: Remove not required basedir for oci bundles & add test to verify signature verification ([#6145](https://github.com/open-policy-agent/opa/pull/6145)) authored by @gitu
+- fmt: Trim trailing whitespace in comments ([#6161](https://github.com/open-policy-agent/opa/issues/6161)) authored by @anderseknert
+- fmt: Remove dedup comment function in opa fmt ([#6165](https://github.com/open-policy-agent/opa/pull/6165)) authored by @anderseknert
+- runtime: Always read .tar.gz file provided in argument as a bundle ([#5879](https://github.com/open-policy-agent/opa/issues/5879)) authored by @yogisinha
+- server/authorizer: Inline readBody ([#6156](https://github.com/open-policy-agent/opa/pull/6156)) authored by @srenatus
+- test: Bind test server to localhost interface ([#6162](https://github.com/open-policy-agent/opa/issues/6162)) authored by @anderseknert
+
+### Topdown and Rego
+
+- ast: Including "child" rules when fetching rules by ref ([#6182](https://github.com/open-policy-agent/opa/issues/6182)) authored by @johanfylling
+- ast: Making partial object key rules contribute to dynamic portion of object type ([#6138](https://github.com/open-policy-agent/opa/issues/6138)) authored by @johanfylling
+- rego: Expose PrepareOption, add BuiltinFuncs ([#6188](https://github.com/open-policy-agent/opa/pull/6188)) authored by @srenatus
+- topdown: Support force cache even when server doesn't set the Date header ([#6175](https://github.com/open-policy-agent/opa/pull/6175)) authored by @c2zwdjnlcg
+- topdown: Partial-eval for partial object/set ref head rules ([#6094](https://github.com/open-policy-agent/opa/issues/6094)) authored by @johanfylling
+
+### Miscellaneous
+
+- Updates to Documentation and Website (authored by: @anderseknert, @ashutosh-narkar, @atkrad, @charlieegan3, @hmoazzem, @johndbro1, @Pushkarm029, @srenatus and @testwill)
+- Dependency updates; notably:
+  - golang: from 1.20.6 to 1.21 (authored by @ashutosh-narkar amd @srenatus)
+  - golang.org/x/net from 0.12.0 to 0.14.0
+  - google.golang.org/grpc from 1.56.2 to 1.57.0
+  - oras.land/oras-go/v2 from 2.2.1 to 2.3.0
+  - Replace ghodss/yaml with sigs.k8s.io/yaml ([#6195](https://github.com/open-policy-agent/opa/pull/6195)) authored by @mrueg
 
 ### Breaking changes
 
 Since its introduction in 0.34.0, the `--exit-zero-on-skipped` option always made the `opa test` command return an exit code 0. When used, it now returns the exit code 0 only if no failed tests were found.
 
 Test runs on existing projects using `--exit-zero-on-skipped` will fail if any failed tests were inhibited by this behavior.
 
-### Tooling, SDK, and Runtime
-
-- `opa test`: Fix `--exit-zero-on-skipped` behavior to make test runs fail with failing test rules ([#6126](https://github.com/open-policy-agent/opa/issues/6126)) reported and authored by @fdaguin
-
 ## 0.55.0
 
 > **_NOTES:_**