Most notably, this is only L4 resources.

Most of the API is fairly straight forward.
However, one interesting aspect is how these policies associate with workloads.
Istio's AuthorizationPolicy has label selectors.
However, we intentionally do not send those as part of the Workload API, in order to keep the size low.

The obvious solution to this is to put the list of selected workloads into the policy itself.

f(3.1415, true)
Point{1, 2}
m["foo"]
s[i : j + 1]
obj.color
f.p[i].x()
</pre>


<h3 id="Selectors">Selectors</h3>

<p>
For a <a href="#Primary_expressions">primary expression</a> <code>x</code>
that is not a <a href="#Package_clause">package name</a>, the
<i>selector expression</i>
</p>

<pre>
x.f
</pre>

<p>

  optional int32 replicas = 1;

  // selector is the label query over pods that should match the replicas count. This is same
  // as the label selector but in the string format to avoid introspection
  // by clients. The string will be in the same format as the query-param syntax.
  // More info about label selectors: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/
  // +optional

}

// NetworkPolicyPeer describes a peer to allow traffic to/from. Only certain combinations of
// fields are allowed
message NetworkPolicyPeer {
  // podSelector is a label selector which selects pods. This field follows standard label
  // selector semantics; if present but empty, it selects all pods.
  //
  // If namespaceSelector is also set, then the NetworkPolicyPeer as a whole selects

  // on whether the namespace for that object matches the selector. If the
  // object itself is a namespace, the matching is performed on
  // object.metadata.labels. If the object is another cluster scoped resource,
  // it never skips the policy.
  //
  // For example, to run the webhook on any objects whose namespace is not
  // associated with "runlevel" of "0" or "1";  you will set the selector as
  // follows:
  // "namespaceSelector": {

  // matchExpressions is a list of label selector requirements. The requirements are ANDed.
  // +optional
  repeated LabelSelectorRequirement matchExpressions = 2;
}

// A label selector requirement is a selector that contains values, a key, and an operator that
// relates the key and values.
message LabelSelectorRequirement {
  // key is the label key that the selector applies to.
  // +patchMergeKey=key

    This particularly-subtle bug was caused by us assigning each `OkHttpClient` instance its own
    `NullProxySelector` when an explicit proxy is configured. But we don't share connections when
    the proxy selectors are different. Ugh!


## Version 4.2.0

_2019-09-10_

 *  New: API to decode a certificate and private key to create a `HeldCertificate`. This accepts a

 *  Fix: Don't retry requests that failed due to timeouts.
 *  Fix: Cache 302s and 308s that include appropriate response headers.
 *  Fix: Improve pooling of connections that use proxy selectors.
 *  Fix: Don't leak connections when using ALPN on the desktop.
 *  Fix: Update Jetty ALPN to `7.1.2.v20141202` (Java 7) and `8.1.2.v20141202` (Java 8).

f(3.1415, true)
Point{1, 2}
m["foo"]
s[i : j + 1]
obj.color
f.p[i].x()
</pre>


<h3 id="Selectors">Selectors</h3>

<p>
For a <a href="#Primary_expressions">primary expression</a> <code>x</code>
that is not a <a href="#Package_clause">package name</a>, the
<i>selector expression</i>
</p>

<pre>
x.f
</pre>

<p>

* restore ability to run against secured etcd ([#21535](https://github.com/kubernetes/kubernetes/pull/21535), [@AdoHe](https://github.com/AdoHe))

### Other notable changes

* validate that daemonsets don't have empty selectors on creation ([#23530](https://github.com/kubernetes/kubernetes/pull/23530), [@mikedanese](https://github.com/mikedanese))