refactor(kubernetes): Look up CRD details on-demand #4033
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On account creation, we iterate over all kinds in the account and call registerKind. Since we only have the name of the kind and no other information, we just assume the kind is namespaced and pass true. Since the kind registry will return a set of default properties (including isNamespaced set to true) for something not in the registry, skip the needless call to register these kinds with default properties.
Each account has a set of custom resources that are statically defined in the account config. We register each of these into the KubernetesKindRegistry, but currently do so in a somewhat opaque way, by depending on a side-effect of the KubernetesResourceProperties.fromCustomResource function we use when creating a different property on the account. Remove the side effect from the fromCustomResource function and instead pass the list of custom resources to the constructor for KubernetesKindRegistry, allowing it to register resources there.
The current logic for reading CRD details is full of unsafe casts and is hard to read. Define a class that has the fields we expect on a CRD and use ObjectMapper to convert the manifest back from the cluster into a typed object.
To avoid needing to pre-register all CRDs into the kind registry, the registry should be able to look up kind information in the cluster if it comes across a kind that it does not have any information about. When creating a KubernetesKindRegistry, the caller can provide a Function<KubernetesKind, Optional<KubernetesKindProperties>>; when looking up a kind that is not in the registry, the registry will call that function to try to resolve the kind properties. If the function returns a result, the properties are recorded in the registry (so subsequent lookups of the same kind don't call the function again). If the function returns an empty Optional, we return a set of default properties as before. This commit does not actually use the new functionality; this will come in a later commit.
Create a new function getCrdProperties that on-demand looks up the properties of a CRD and pass this to the constructor for the kind registry. This removes the need to pre-register kinds that are fround when listing CRDs as the registry will look up any kinds it needs, and also removes the last remaining side-effect of calling liveCrdSupplier. The only call to getCrds is from the unregistered CRD caching agent. Given that this happens once per caching cycle (along with a lot of other lookups) there's no real benefit to memoizing the result with a timed expiration. Remove the memoization and just have getCrds do a live lookup.
The term registered is confusing, and also somewhat redundant given that the method is on a kind regsitry. (It's also not entirely correct as the function can also live lookup properties and register them.) Let's rename the function getKindProperties to be more in line with what it does.
maggieneterval
approved these changes
Sep 17, 2019
...netflix/spinnaker/clouddriver/kubernetes/v2/description/manifest/KubernetesKindRegistry.java
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Co-Authored-By: Maggie Neterval <mneterval@google.com>
Calling get() returns null when no resource is found rather than throwing an exception. We should return Optional.empty() in that case (rather than try to dereference the null in the following logic) just as we do when we run into an exception. Also add visibility by logging any exceptions in the exception block.
plumpy
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Sep 17, 2019
plumpy
approved these changes
Sep 17, 2019
The logic in an earlier commit to look up CRD properties was incorrect as it was looking up CRDs via the command kubectl get crd kind.apigroup; we need to use the *plural* version of the kind in this command (as a CRD's name is based on the plural kind). There's unfortunately no good way to directly look up a CRD based on the singular name. This commit works around it by just listing all CRDs and filtering based on the name to the one we're interested in. To avoid the performance implications of too many lookups of the entire list of CRDs, also re-introduce memoizing.
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refactor(kubernetes): Remove useless call to register kind
On account creation, we iterate over all kinds in the account and call registerKind. Since we only have the name of the kind and no other information, we just assume the kind is namespaced and pass true.
Since the kind registry will return a set of default properties
(including isNamespaced set to true) for something not in the registry, skip the needless call to register these kinds with default properties.
refactor(kubernetes): Pass custom resources to registry constructor
Each account has a set of custom resources that are statically defined in the account config. We register each of these into the KubernetesKindRegistry, but currently do so in a somewhat opaque way, by depending on a side-effect of the KubernetesResourceProperties.fromCustomResource function we use when creating a different property on the account.
Remove the side effect from the fromCustomResource function and instead pass the list of custom resources to the constructor for KubernetesKindRegistry, allowing it to register resources there.
refactor(kubernetes): Use ObjectMapper to parse CRD
The current logic for reading CRD details is full of unsafe casts and is hard to read. Define a class that has the fields we expect on a CRD and use ObjectMapper to convert the manifest back from the cluster into a typed object.
refactor(kubernetes): Allow KubernetesKindRegistry to look up CRDs
To avoid needing to pre-register all CRDs into the kind registry, the registry should be able to look up kind information in the cluster if it comes across a kind that it does not have any information about.
When creating a KubernetesKindRegistry, the caller can provide a Function<KubernetesKind, Optional>; when looking up a kind that is not in the registry, the registry will call that function to try to resolve the kind properties. If the function returns a result, the properties are recorded in the registry
(so subsequent lookups of the same kind don't call the function again). If the function returns an empty Optional, we return a set of default properties as before.
This commit does not actually use the new functionality; this will come in a later commit.
refactor(kubernetes): Look up CRD details on-demand
Create a new function getCrdProperties that on-demand looks up the properties of a CRD and pass this to the constructor for the kind registry. This removes the need to pre-register kinds that are fround when listing CRDs as the registry will look up any kinds it needs, and also removes the last remaining side-effect of calling liveCrdSupplier.
The only call to getCrds is from the unregistered CRD caching agent. Given that this happens once per caching cycle (along with a lot of other lookups) there's no real benefit to memoizing the result with a timed expiration. Remove the memoization and just have getCrds do a live lookup.
refactor(kubernetes): Rename getRegisteredKind to getKindProperties
The term registered is confusing, and also somewhat redundant given that the method is on a kind regsitry. (It's also not entirely correct as the function can also live lookup properties and register them.)
Let's rename the function getKindProperties to be more in line with what it does.