Easily check your clusters for use of deprecated APIs
Kubernetes 1.16 is slowly starting to roll out, not only across various managed Kubernetes offerings, and with that come a lot of API deprecations1.
Kube No Trouble (kubent) is a simple tool to check whether you're using
any of these API versions in your cluster and therefore should upgrade your
workloads first, before upgrading your Kubernetes cluster.
This tool will be able to detect deprecated APIs depending on how you deploy your resources, as we need the original manifest to be stored somewhere. In particular following tools are supported:
- file - local manifests in YAML or JSON
- kubectl - uses the
kubectl.kubernetes.io/last-applied-configurationannotation - Helm v3 - uses Helm manifests stored as Secrets or ConfigMaps directly in individual namespaces
Additional resources:
- Blog post on K8s deprecated APIs and introduction of kubent: Kubernetes: Deprecated APIs aka Introducing Kube-No-Trouble
Install
Run the following command in your terminal to install kubent using a shell script:
sh -c "$(curl -sSL https://git.io/install-kubent)"(The script will download latest version and unpack to /usr/local/bin).
Manual Installation
You can download the latest release for your platform and unpack manually.
Third-Party Installation
Please note that third-party installation methods are maintained by the community.
The packages may not always be up-to-date with the latest releases of kubent.
Homebrew
kubent is available as a formula
on Homebrew. If you're using macOS or Linux, you can run
the following command to install kubent:
brew install kubentUsage
Configure Kubectl's current context to point to your cluster, kubent will
look for the kube .config file in standard locations (you can point it to custom
location using the -k switch).
kubent will collect resources from your cluster and report on found issues.
Please note that you need to have sufficient permissions to read Secrets in the
cluster in order to use Helm* collectors.
$./kubent
6:25PM INF >>> Kube No Trouble `kubent` <<<
6:25PM INF Initializing collectors and retrieving data
6:25PM INF Retrieved 103 resources from collector name=Cluster
6:25PM INF Retrieved 0 resources from collector name="Helm v3"
6:25PM INF Loaded ruleset name=deprecated-1-16.rego
6:25PM INF Loaded ruleset name=deprecated-1-20.rego
__________________________________________________________________________________________
>>> 1.16 Deprecated APIs <<<
------------------------------------------------------------------------------------------
KIND NAMESPACE NAME API_VERSION
Deployment default nginx-deployment-old apps/v1beta1
Deployment kube-system event-exporter-v0.2.5 apps/v1beta1
Deployment kube-system k8s-snapshots extensions/v1beta1
Deployment kube-system kube-dns extensions/v1beta1
__________________________________________________________________________________________
>>> 1.20 Deprecated APIs <<<
------------------------------------------------------------------------------------------
KIND NAMESPACE NAME API_VERSION
Ingress default test-ingress extensions/v1beta1Arguments
You can list all the configuration options available using --help switch:
$./kubent -h
Usage of ./kubent:
-A, --additional-annotation strings additional annotations that should be checked to determine the last applied config
-a, --additional-kind strings additional kinds of resources to report in Kind.version.group.com format
-c, --cluster enable Cluster collector (default true)
-x, --context string kubeconfig context
-e, --exit-error exit with non-zero code when issues are found
-f, --filename strings manifests to check, use - for stdin
--helm3 enable Helm v3 collector (default true)
-k, --kubeconfig string path to the kubeconfig file
-l, --log-level string set log level (trace, debug, info, warn, error, fatal, panic, disabled) (default "info")
-o, --output string output format - [text|json|csv] (default "text")
-O, --output-file string output file, use - for stdout (default "-")
-t, --target-version string target K8s version in SemVer format (autodetected by default)
-v, --version prints the version of kubent and exits-
--additional-annotationCheck additional annotations for the last applied configuration. This can be useful if a resource was applied with a tool other than kubectl. The flag can be used multiple times. -
-a, --additional-kindTellskubentto flag additional custom resources when found in the specified version. The flag can be used multiple times. The expected format is full Kind.version.group.com form - e.g.-a ManagedCertificate.v1.networking.gke.io. -
-x, --contextSelect context from kubeconfig file (current-contextfrom the file is used by default). -
k, --kubeconfigPath to kubeconfig file to use. This takes precedence overKUBECONFIGenvironment variable, which is also supported and can contain multiple paths, and default~.kube/config. -
-t, --target-versionKubentwill try to detect K8S cluster version and display only relevant findings. This flag allows to override this version for scenarios like use in CI with the file collector only, when detection from an actual cluster is not possible. Expected format ismajor.minor[.patch], e.g.1.16or1.16.3.
Docker Image
We also publish official container image, which can be found at:
ghcr.io/doitintl/kube-no-trouble:latest (also available tagged with each
individual release version).
To run locally, you'll need to provide credentials, e.g. by sharing your kubectl config:
$ docker run -it --rm \
-v "${HOME}/.kube/config:/.kubeconfig" \
ghcr.io/doitintl/kube-no-trouble:latest \
-k /.kubeconfigYou can use kubectl run to run inside a K8S cluster, as a one-off. In that
case the credentials will be picked up via the pod's service account from the
environment, but you'll want to grant relevant permissions first (see
docs/k8s-sa-and-role-example.yaml):
$ kubectl run kubent --restart=Never --rm -i --tty \
--image ghcr.io/doitintl/kube-no-trouble:latest \
--overrides='{"spec": {"serviceAccount": "kubent"}}'Use in CI
Exit codes
kubent will by default return 0 exit code if the program succeeds, even if
it finds deprecated resources, and non-zero exit code if there is an error
during runtime. Because all info output goes to stderr, it's easy to check in
shell if any issues were found:
test -z "$(kubent)" # if stdout output is empty, means no issues were found
# equivalent to [ -z "$(kubent)" ]It's actually better so split this into two steps, in order to differentiate between runtime error and found issues:
if ! OUTPUT="$(kubent)"; then # check for non-zero return code first
echo "kubent failed to run!"
elif [ -n "${OUTPUT}" ]; then # check for empty stdout
echo "Deprecated resources found"
fiYou can also use --exit-error (-e) flag, which will make kubent to exit
with non-zero return code (200) in case any issues are found.
Alternatively, use the json output and smth. like jq to check if the result is
empty:
kubent -o json | jq -e 'length == 0'
Scanning all files in directory
If you want to scan all files in a given directory, you can use the following shell snippet:
FILES=($(ls *.yaml)); kubent ${FILES[@]/#/-f} --helm3=false -c=falseDevelopment
The simplest way to build kubent is:
# Clone the repository
git clone https://github.com/doitintl/kube-no-trouble.git
cd kube-no-trouble/
# Build
go build -o bin/kubent cmd/kubent/main.goOtherwise there's Makefile
$ make
make
all Cean, build and pack
help Prints list of tasks
build Build binary
generate Go generate
release-artifacts Create release artifacts
clean Clean build artifactsCommit messages
We enforce simple version of Conventional Commits in the form:
<type>: <summary>
[optional body]
[optional footer(s)]
Where type is one of:
- build - Affects build and/or build system
- chore - Other non-functional changes
- ci - Affects CI (e.g. GitHub actions)
- dep - Dependency update
- docs - Documentation only change
- feat - A new feature
- fix - A bug fix
- ref - Code refactoring without functionality change
- style - Formatting changes
- test - Adding/changing tests
Use imperative, present tense (Add, not Added), capitalize first letter of
summary, no dot at the and. The body and footer are optional. Relevant GitHub
issues should be referenced in the footer in the form Fixes #123, fixes #456.
Changelog
Changelog is generated automatically based on merged PRs using
changelog-gen. Template can be found in scripts/changelog.tmpl.
PRs are categorized based on their labels, into following sections:
- Announcements -
announcementlabel - Breaking Changes -
breaking-changelabel - Features -
featurelabel - Changes -
changelabel - Fixes -
fixlabel - Internal/Other - everything else
PR can be excluded from changelog with no-release-note label. PR title is
used by default, however, the copy can be customized by including following
block in the PR body:
```release-note
This is an example release note!
```
Issues and Contributions
Please open any issues and/or PRs against github.com/doitintl/kube-no-trouble repository.
Please ensure any contributions are signed with a valid gpg key. We use this to validate that you have committed this and no one else. You can learn how to create a GPG key here.
Feedback and contributions are always welcome!