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kmsv2: no-op refactor priming logic into its own function
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Signed-off-by: Monis Khan <mok@microsoft.com>
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enj committed Jun 13, 2023
1 parent 15003c6 commit 55b690e
Showing 1 changed file with 51 additions and 47 deletions.
Expand Up @@ -715,53 +715,7 @@ func kmsPrefixTransformer(ctx context.Context, config *apiserverconfig.KMSConfig
// initialize state so that Load always works
probe.state.Store(&envelopekmsv2.State{})

runProbeCheckAndLog := func(ctx context.Context, depth int) error {
if err := probe.check(ctx); err != nil {
klog.VDepth(1+depth, 2).ErrorS(err, "kms plugin failed health check probe", "name", kmsName)
return err
}
return nil
}

blockAndProbeFastUntilSuccess := func(ctx context.Context) {
_ = wait.PollUntilWithContext(
ctx,
kmsv2PluginHealthzNegativeInterval,
func(ctx context.Context) (bool, error) {
return runProbeCheckAndLog(ctx, 1) == nil, nil
},
)
}

// on the happy path where the plugin is healthy and available on server start,
// prime keyID and DEK by running the check inline once (this also prevents unit tests from flaking)
errPrime := runProbeCheckAndLog(ctx, 0)

// if our initial attempt to prime failed, start trying to get to a valid state in the background ASAP
// this prevents a slow start when the external healthz checker is configured to ignore the KMS healthz endpoint
// since we want to support the plugin starting up async with the API server, this error is not fatal
if errPrime != nil {
go blockAndProbeFastUntilSuccess(ctx) // separate go routine to avoid blocking
}

// make sure that the plugin's key ID is reasonably up-to-date
// also, make sure that our DEK is up-to-date to with said key ID (if it expires the server will fail all writes)
// if this background loop ever stops running, the server will become unfunctional after kmsv2PluginWriteDEKMaxTTL
go wait.PollUntilWithContext(
ctx,
kmsv2PluginHealthzPositiveInterval,
func(ctx context.Context) (bool, error) {
if err := runProbeCheckAndLog(ctx, 0); err == nil {
return false, nil
}

// TODO add integration test for quicker error poll on failure
// if we fail, block the outer polling and start a new quicker poll inline
// this limits the chance that our DEK expires during a transient failure
blockAndProbeFastUntilSuccess(ctx)

return false, nil
})
primeAndProbeKMSv2(ctx, probe, kmsName)

transformer := storagevalue.PrefixTransformer{
Transformer: envelopekmsv2.NewEnvelopeTransformer(envelopeService, kmsName, probe.getCurrentState),
Expand All @@ -778,6 +732,56 @@ func kmsPrefixTransformer(ctx context.Context, config *apiserverconfig.KMSConfig
}
}

func primeAndProbeKMSv2(ctx context.Context, probe *kmsv2PluginProbe, kmsName string) {
runProbeCheckAndLog := func(ctx context.Context, depth int) error {
if err := probe.check(ctx); err != nil {
klog.VDepth(1+depth, 2).ErrorS(err, "kms plugin failed health check probe", "name", kmsName)
return err
}
return nil
}

blockAndProbeFastUntilSuccess := func(ctx context.Context) {
_ = wait.PollUntilWithContext(
ctx,
kmsv2PluginHealthzNegativeInterval,
func(ctx context.Context) (bool, error) {
return runProbeCheckAndLog(ctx, 1) == nil, nil
},
)
}

// on the happy path where the plugin is healthy and available on server start,
// prime keyID and DEK by running the check inline once (this also prevents unit tests from flaking)
errPrime := runProbeCheckAndLog(ctx, 0)

// if our initial attempt to prime failed, start trying to get to a valid state in the background ASAP
// this prevents a slow start when the external healthz checker is configured to ignore the KMS healthz endpoint
// since we want to support the plugin starting up async with the API server, this error is not fatal
if errPrime != nil {
go blockAndProbeFastUntilSuccess(ctx) // separate go routine to avoid blocking
}

// make sure that the plugin's key ID is reasonably up-to-date
// also, make sure that our DEK is up-to-date to with said key ID (if it expires the server will fail all writes)
// if this background loop ever stops running, the server will become unfunctional after kmsv2PluginWriteDEKMaxTTL
go wait.PollUntilWithContext(
ctx,
kmsv2PluginHealthzPositiveInterval,
func(ctx context.Context) (bool, error) {
if err := runProbeCheckAndLog(ctx, 0); err == nil {
return false, nil
}

// TODO add integration test for quicker error poll on failure
// if we fail, block the outer polling and start a new quicker poll inline
// this limits the chance that our DEK expires during a transient failure
blockAndProbeFastUntilSuccess(ctx)

return false, nil
})
}

func envelopePrefixTransformer(config *apiserverconfig.KMSConfiguration, envelopeService envelope.Service, prefix string) storagevalue.PrefixTransformer {
baseTransformerFunc := func(block cipher.Block) (storagevalue.Transformer, error) {
gcm, err := aestransformer.NewGCMTransformer(block)
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