Merge pull request #39446 from fraenkel/env_secrets

Automatic merge from submit-queue (batch tested with PRs 39446, 40023, 36853)

Create environment variables from secrets

Allow environment variables to be populated from entire secrets.

**Release note**:
```release-note
Populate environment variables from a secrets.
```

federation/apis/openapi-spec/swagger.json

@@ -10101,6 +10101,10 @@
      "prefix": {
       "description": "An optional identifer to prepend to each key in the ConfigMap. Must be a C_IDENTIFIER.",
       "type": "string"
+     },
+     "secretRef": {
+      "description": "The Secret to select from",
+      "$ref": "#/definitions/v1.SecretEnvSource"
      }
     }
    },
@@ -11598,6 +11602,15 @@
      }
     }
    },
+   "v1.SecretEnvSource": {
+    "description": "SecretEnvSource selects a Secret to populate the environment variables with.\n\nThe contents of the target Secret's Data field will represent the key-value pairs as environment variables.",
+    "properties": {
+     "name": {
+      "description": "Name of the referent. More info: http://kubernetes.io/docs/user-guide/identifiers#names",
+      "type": "string"
+     }
+    }
+   },
    "v1.SecretKeySelector": {
     "description": "SecretKeySelector selects a key of a Secret.",
     "required": [