Diagnose your Configuration with Istioctl Analyze

6 minute read

istioctl analyze is a diagnostic tool that can detect potential issues with your Istio configuration. It can run against a live cluster or a set of local configuration files. It can also run against a combination of the two, allowing you to catch problems before you apply changes to a cluster.

Getting started in under a minute

You can analyze your current live Kubernetes cluster by running:

$ istioctl analyze --all-namespaces

And that’s it! It’ll give you any recommendations that apply.

For example, if you forgot to enable Istio injection (a very common issue), you would get the following warning:

Warn [IST0102](Namespace default) The namespace is not enabled for Istio injection. Run 'kubectl label namespace default istio-injection=enabled' to enable it, or 'kubectl label namespace default istio-injection=disabled' to explicitly mark it as not needing injection

Analyzing live clusters, local files, or both

Analyze the current live cluster, simulating the effect of applying additional yaml files like bookinfo-gateway.yaml and destination-rule-all.yaml in the samples/bookinfo/networking directory:

$ istioctl analyze @samples/bookinfo/networking/bookinfo-gateway.yaml@ @samples/bookinfo/networking/destination-rule-all.yaml@

Analyze the entire networking folder:

$ istioctl analyze samples/bookinfo/networking/

Analyze all yaml files in the networking folder:

$ istioctl analyze samples/bookinfo/networking/*.yaml

The above examples are doing analysis on a live cluster. The tool also supports performing analysis of a set of local Kubernetes yaml configuration files, or on a combination of local files and a live cluster. When analyzing a set of local files, the file-set is expected to be fully self-contained. Typically, this is used to analyze the entire set of configuration files that are intended to be deployed to a cluster. To use this feature, simply add the --use-kube=false flag.

Analyze all yaml files in the networking folder:

$ istioctl analyze --use-kube=false samples/bookinfo/networking/*.yaml

You can run istioctl analyze --help to see the full set of options.

Advanced

Enabling validation messages for resource status

Starting with Istio 1.5, Galley can be set up to perform configuration analysis alongside the configuration distribution that it is primarily responsible for, via the istiod.enableAnalysis flag. This analysis uses the same logic and error messages as when using istioctl analyze. Validation messages from the analysis are written to the status subresource of the affected Istio resource.

For example. if you have a misconfigured gateway on your “ratings” virtual service, running kubectl get virtualservice ratings would give you something like:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"networking.istio.io/v1alpha3","kind":"VirtualService","metadata":{"annotations":{},"name":"ratings","namespace":"default"},"spec":{"hosts":["ratings"],"http":[{"route":[{"destination":{"host":"ratings","subset":"v1"}}]}]}}
  creationTimestamp: "2019-09-04T17:31:46Z"
  generation: 11
  name: ratings
  namespace: default
  resourceVersion: "12760039"
  selfLink: /apis/networking.istio.io/v1alpha3/namespaces/default/virtualservices/ratings
  uid: dec86702-cf39-11e9-b803-42010a8a014a
spec:
  gateways:
  - bogus-gateway
  hosts:
  - ratings
  http:
  - route:
    - destination:
        host: ratings
        subset: v1
status:
  validationMessages:
  - code: IST0101
    level: Error
    message: 'Referenced gateway not found: "bogus-gateway"'

enableAnalysis runs in the background, and will keep the status field of a resource up to date with its current validation status. Note that this isn’t a replacement for istioctl analyze:

Not all resources have a custom status field (e.g. Kubernetes namespace resources), so messages attached to those resources won’t show validation messages.
enableAnalysis only works on Istio versions starting with 1.5, while istioctl analyze can be used with older versions.
While it makes it easy to see what’s wrong with a particular resource, it’s harder to get a holistic view of validation status in the mesh.

You can enable this feature with:

$ istioctl install --set values.global.istiod.enableAnalysis=true

Ignoring specific analyzer messages via CLI

Sometimes you might find it useful to hide or ignore analyzer messages in certain cases. For example, imagine a situation where a message is emitted about a resource you don’t have permissions to update:

$ istioctl analyze -k --all-namespaces
Warn [IST0102] (Namespace frod) The namespace is not enabled for Istio injection. Run 'kubectl label namespace frod istio-injection=enabled' to enable it, or 'kubectl label namespace frod istio-injection=disabled' to explicitly mark it as not needing injection
Error: Analyzers found issues.
See https://istio.io/docs/reference/config/analysis for more information about causes and resolutions.

Because you don’t have permissions to update the namespace, you cannot resolve the message by annotating the namespace. Instead, you can direct istioctl analyze to suppress the above message on the resource:

$ istioctl analyze -k --all-namespaces --suppress "IST0102=Namespace frod"
✔ No validation issues found.

The syntax used for suppression is the same syntax used throughout istioctl when referring to resources: <kind> <name>.<namespace>, or just <kind> <name> for cluster-scoped resources like Namespace. If you want to suppress multiple objects, you can either repeat the --suppress argument or use wildcards:

$ # Suppress code IST0102 on namespace frod and IST0107 on all pods in namespace baz
$ istioctl analyze -k --all-namespaces --suppress "IST0102=Namespace frod" --suppress "IST0107=Pod *.baz"

Ignoring specific analyzer messages via annotations

You can also ignore specific analyzer messages using an annotation on the resource. For example, to ignore code IST0107 (MisplacedAnnotation) on resource deployment/my-deployment:

$ kubectl annotate deployment my-deployment galley.istio.io/analyze-suppress=IST0107

To ignore multiple codes for a resource, separate each code with a comma:

$ kubectl annotate deployment my-deployment galley.istio.io/analyze-suppress=IST0107,IST0002

Helping us improve this tool

We’re continuing to add more analysis capability and we’d love your help in identifying more use cases. If you’ve discovered some Istio configuration “gotcha”, some tricky situation that caused you some problems, open an issue and let us know. We might be able to automatically flag this problem so that others can discover and avoid the problem in the first place.

To do this, open an issue describing your scenario. For example:

Look at all the virtual services
For each, look at their list of gateways
If some of the gateways don’t exist, produce an error

We already have an analyzer for this specific scenario, so this is just an example to illustrate what kind of information you should provide.

Q&A

What Istio release does this tool target?
Like other istioctl tools, we generally recommend using a downloaded version that matches the version deployed in your cluster.
For the time being, analysis is generally backwards compatible, so that you can, for example, run the 1.4 version of istioctl analyze against a cluster running Istio 1.1 and expect to get useful feedback. Analysis rules that are not meaningful with an older Istio release will be skipped.
If you decide to use the latest istioctl for analysis purposes on a cluster running an older Istio version, we suggest that you keep it in a separate folder from the version of the binary used to manage your deployed Istio release.
What analyzers are supported today?
We’re still working to documenting the analyzers. In the meantime, you can see all the analyzers in the Istio source.
You can also see what configuration analysis messages are supported to get an idea of what is currently covered.
Can analysis do anything harmful to my cluster?
Analysis never changes configuration state. It is a completely read-only operation that will never alter the state of a cluster.
What about analysis that goes beyond configuration?
Today, the analysis is purely based on Kubernetes configuration, but in the future we’d like to expand beyond that. For example, we could allow analyzers to also look at logs to generate recommendations.
Where can I find out how to fix the errors I’m getting?
The set of configuration analysis messages contains descriptions of each message along with suggested fixes.