Fixes
- https://github.com/linkerd/linkerd2/issues/2962
- https://github.com/linkerd/linkerd2/issues/2545
### Problem
Field omissions for workload objects are not respected while marshaling to JSON.
### Solution
After digging a bit into the code, I came to realize that while marshaling, workload objects have empty structs as values for various fields which would rather be omitted. As of now, the standard library`encoding/json` does not support zero values of structs with the `omitemty` tag. The relevant issue can be found [here](https://github.com/golang/go/issues/11939). To tackle this problem, the object declaration should have _pointer-to-struct_ as a field type instead of _struct_ itself. However, this approach would be out of scope as the workload object declaration is handled by the k8s library.
I was able to find a drop-in replacement for the `encoding/json` library which supports zero value of structs with the `omitempty` tag. It can be found [here](https://github.com/clarketm/json). I have made use of this library to implement a simple filter like functionality to remove empty tags once a YAML with empty tags is generated, hence leaving the previously existing methods unaffected
Signed-off-by: Mayank Shah <mayankshah1614@gmail.com>
Fixes#3356
1.16 removes some api groups that were already deprecated. From k8s blog
post (https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/):
```
- PodSecurityPolicy: will no longer be served from extensions/v1beta1 in
v1.16.
Migrate to the policy/v1beta1 API, available since v1.10. Existing
persisted data can be retrieved/updated via the policy/v1beta1 API.
- DaemonSet, Deployment, StatefulSet, and ReplicaSet: will no longer be
served from extensions/v1beta1, apps/v1beta1, or apps/v1beta2 in v1.16.
Migrate to the apps/v1 API, available since v1.9. Existing persisted
data can be retrieved/updated via the apps/v1 API.
```
Previous PRs had already made this change at the Helm templates level,
but we still needed to do it at the API calls and tests.
The integration tests ran fine for k8s 1.12 and 1.15. They fail on 1.16
because the upgrade integration test tries to install linkerd 2.5 which is not
compatible with 1.16.
Signed-off-by: Alejandro Pedraza <alejandro@buoyant.io>
When changing templates, it's can be pretty time-intensive to
repair all test fixtures.
This change instruments CLI tests with two flags, `-update` and
`-pretty-diff` that control how test fixtures are diffed. When the
`-update` flag is set, the tests fixtures are overwritten as tests
execute. The `-pretty-diff` flag causes the full text of the fixture
to be printed on mismatch.
linkerd only routes TCP data, but `linkerd inject` does not warn when it
injects into pods with ports set to `protocol: UDP`.
Modify `linkerd inject` to warn when injected into a pod with
`protocol: UDP`. The Linkerd sidecar will still be injected, but the
stderr output will include a warning.
Also add stderr checking on all inject unit tests.
Part of #1516.
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
Mayank Shah
Alejandro Pedraza
Oliver Gould
Andrew Seigner