The Helm plugin that comes in handy while identifying configuration drifts (mostly due to in-place edits) from the deployed Helm charts.
Deploying resources on Kubernetes through the Helm package manager offers simplicity, but maintaining them can be challenging.
While Helm ideally manages all resources, manual interventions are sometimes necessary, leading to configuration discrepancies from the deployed Helm charts.
These changes risk being overwritten by subsequent Helm releases, potentially resulting in lost configurations.
The Helm Drift plugin aims to address this issue by validating resources associated with a specific chart or release against Kubernetes. Leveraging kubectl diff functionality, it identifies any discrepancies or drifts in configurations.
For further insights into the motivation behind creating this plugin, check out the accompanying blog post blog.
# rendering summary to table would render drifts in below format.
helm drift run prometheus-standalone example/chart/sample/ -f ~/path/to/example/chart/sample/override-config.yaml --skip-cleaning
KIND | NAME | DRIFT
-----------------|-----------------------|---------
ServiceAccount | sample | NO
Service | sample | NO
DaemonSet | fluentd-elasticsearch | NO
Pod | nginx | NO
Pod | nginx-2 | NO
ReplicaSet | frontend | NO
Deployment | sample | NO
StatefulSet | web | YES
Job | pi | NO
CronJob | hello | NO
-----------------|-----------------------|---------
STATUS | FAILED
------------------------|---------
Namespace: 'sample' Release: 'sample'
# Invoking command without any output format would render detailed drifts as below.
helm drift run prometheus-standalone example/chart/sample/ -f ~/path/to/example/chart/sample/override-config.yaml --skip-cleaning
# executing above command would yield results something like below:
--------------------------------------------------------------------------------------------------
Release : sample
------------------------------------------------------------------------------------
Identified drifts in: 'StatefulSet' 'web'
-----------
diff -u -N /var/folders/dm/40_kbx_56psgqt29q0wh2cxh0000gq/T/LIVE-1098999488/apps.v1.StatefulSet.sample.web /var/folders/dm/40_kbx_56psgqt29q0wh2cxh0000gq/T/MERGED-836230905/apps.v1.StatefulSet.sample.web
--- /var/folders/dm/40_kbx_56psgqt29q0wh2cxh0000gq/T/LIVE-1098999488/apps.v1.StatefulSet.sample.web 2024-07-07 18:39:33
+++ /var/folders/dm/40_kbx_56psgqt29q0wh2cxh0000gq/T/MERGED-836230905/apps.v1.StatefulSet.sample.web 2024-07-07 18:39:33
@@ -5,7 +5,7 @@
meta.helm.sh/release-name: sample
meta.helm.sh/release-namespace: sample
creationTimestamp: "2024-07-07T11:32:21Z"
- generation: 3
+ generation: 4
labels:
app.kubernetes.io/managed-by: Helm
name: web
@@ -15,7 +15,7 @@
spec:
minReadySeconds: 10
podManagementPolicy: OrderedReady
- replicas: 2
+ replicas: 3
revisionHistoryLimit: 10
selector:
matchLabels:
@@ -28,7 +28,7 @@
app: nginx
spec:
containers:
- - image: k8s.gcr.io/nginx-slim:0.9
+ - image: k8s.gcr.io/nginx-slim:0.8
imagePullPolicy: IfNotPresent
name: nginx
ports:
-----------
------------------------------------------------------------------------------------
OOPS...! DRIFTS FOUND
------------------------------------------------------------------------------------
Total time spent on identifying drifts : 0.383524375
Total number of drifts found : YES
Status : FAILED
------------------------------------------------------------------------------------Try using the drift plugin with a custom diff tool instead for better results. Ex: diff tool, dyff, This can be used by setting the flag --custom-diff
helm drift run prometheus-standalone -n monitoring --from-release --custom-diff "dyff between --omit-header --set-exit-code"helm plugin install https://github.com/nikhilsbhat/helm-driftUse the executable just like any other go-cli application.
helm drift [command] [flags]Make sure the appropriate command is used for the actions. To check the available commands and flags, use helm drift --help
Identifies configuration drifts (mostly due to in-place edits) in the Kubernetes workloads provisioned via Helm charts.
Usage:
drift [command] [flags]
Available Commands:
all Identifies drifts from all releases from the cluster.
completion Generate the autocompletion script for the specified shell
help Help about any command
run Identifies drifts from a selected chart or release.
version Command to fetch the version of helm-drift installed
Flags:
--concurrency int the value to be set for flag --concurrency of 'kubectl diff' (default 1)
-h, --help help for drift
-l, --log-level string log level for the plugin helm drift (defaults to info) (default "info")
--no-color enabling this would render output with no color
--revision int revision of your release from which the drifts to be detected
--set stringArray set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--set-file stringArray set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
--set-string stringArray set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--skip-crds setting this would set '--skip-crds' for helm template command while generating templates
--skip-tests setting this would set '--skip-tests' for helm template command while generating templates
--validate setting this would set '--validate' for helm template command while generating templates
-f, --values ValueFiles specify values in a YAML file (can specify multiple) (default [])
--version string specify a version constraint for the chart version to use, the value passed here would be used to set --version for helm template command while generating templates
Use "drift [command] --help" for more information about a command.It lists all configuration drifts that are part of the specified chart or release, if one exists.
Usage:
drift run [RELEASE] [CHART] [flags]
Examples:
helm drift run prometheus-standalone path/to/chart/prometheus-standalone -f ~/path/to/override-config.yaml
helm drift run prometheus-standalone --from-release
Flags:
--consider-hooks when this is enabled, the flag 'ignore-hooks' holds no value
--custom-diff KUBECTL_EXTERNAL_DIFF custom diff command to use instead of default, the command passed here would be set under KUBECTL_EXTERNAL_DIFF.More information can be found here https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#diff
-d, --disable-error-on-drift enabling this would disable exiting with error if drifts were identified
--from-release enable the flag to identify drifts from a release instead (disabled by default, works with command 'run' not with 'all')
-h, --help help for run
--ignore-hooks strings list of hooks to ignore while identifying the drifts (default [hook-succeeded,hook-failed])
--ignore-hpa-changes when enabled, the drifts caused on workload due to hpa scaling would be ignored
--kind strings kubernetes resource names to limit the drift identification (--kind takes higher precedence over --name)
--name string name of the kubernetes resource to limit the drift identification
-o, --output string the format to which the output should be rendered to, it should be one of yaml|json|table, if nothing specified it sets to default
--regex string regex used to split helm template rendered (default "---\\n# Source:\\s.*.")
--skip strings kubernetes resource names to skip the drift identification (ex: --skip Deployments)
--skip-cleaning enable the flag to skip cleaning the manifests rendered on to disk
--skip-validation enable the flag if prerequisite validation needs to be skipped
--temp-path string path on disk where the helm templates would be rendered on to (the same would be used be used by 'kubectl diff') (default "/Users/nikhil.bhat/.helm-drift/templates")
Global Flags:
--concurrency int the value to be set for flag --concurrency of 'kubectl diff' (default 1)
-l, --log-level string log level for the plugin helm drift (defaults to info) (default "info")
--no-color enabling this would render output with no color
--revision int revision of your release from which the drifts to be detected
--set stringArray set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--set-file stringArray set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
--set-string stringArray set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--skip-crds setting this would set '--skip-crds' for helm template command while generating templates
--skip-tests setting this would set '--skip-tests' for helm template command while generating templates
--validate setting this would set '--validate' for helm template command while generating templates
-f, --values ValueFiles specify values in a YAML file (can specify multiple) (default [])
--version string specify a version constraint for the chart version to use, the value passed here would be used to set --version for helm template command while generating templatesIt lists all configuration drifts that are part of various releases present in the cluster.
Do note that this is expensive operation since multiple kubectl command would be executed in parallel.
Usage:
drift all [flags]
Examples:
helm drift all --kube-context k3d-sample
helm drift all --kube-context k3d-sample -n sample
Flags:
--consider-hooks when this is enabled, the flag 'ignore-hooks' holds no value
--custom-diff KUBECTL_EXTERNAL_DIFF custom diff command to use instead of default, the command passed here would be set under KUBECTL_EXTERNAL_DIFF.More information can be found here https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#diff
-d, --disable-error-on-drift enabling this would disable exiting with error if drifts were identified
-h, --help help for all
--ignore-hooks strings list of hooks to ignore while identifying the drifts (default [hook-succeeded,hook-failed])
--ignore-hpa-changes when enabled, the drifts caused on workload due to hpa scaling would be ignored
--is-default-namespace set this flag if drifts have to be checked specifically in 'default' namespace
--kind strings kubernetes resource names to limit the drift identification (--kind takes higher precedence over --name)
--name string name of the kubernetes resource to limit the drift identification
-o, --output string the format to which the output should be rendered to, it should be one of yaml|json|table, if nothing specified it sets to default
--regex string regex used to split helm template rendered (default "---\\n# Source:\\s.*.")
--skip strings kubernetes resource names to skip the drift identification (ex: --skip Deployments)
--skip-cleaning enable the flag to skip cleaning the manifests rendered on to disk
--skip-release stringArray list of helm releases to be skipped for identifying helm drifts, ex: ReleaseName=Namespace | ReleaseName=Namespace
--skip-validation enable the flag if prerequisite validation needs to be skipped
--temp-path string path on disk where the helm templates would be rendered on to (the same would be used be used by 'kubectl diff') (default "/Users/nikhil.bhat/.helm-drift/templates")
Global Flags:
--concurrency int the value to be set for flag --concurrency of 'kubectl diff' (default 1)
-l, --log-level string log level for the plugin helm drift (defaults to info) (default "info")
--no-color enabling this would render output with no color
--revision int revision of your release from which the drifts to be detected
--set stringArray set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--set-file stringArray set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
--set-string stringArray set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
--skip-crds setting this would set '--skip-crds' for helm template command while generating templates
--skip-tests setting this would set '--skip-tests' for helm template command while generating templates
--validate setting this would set '--validate' for helm template command while generating templates
-f, --values ValueFiles specify values in a YAML file (can specify multiple) (default [])
--version string specify a version constraint for the chart version to use, the value passed here would be used to set --version for helm template command while generating templatesUpdated documentation on all available commands and flags can be found here.
Identifying drifts on CRDs would be tricky, and the plugin might not respond with the correct data.
If helm hooks are defined in the chart with hook-succeeded or hook-failed, one might always find drifts when identifying drifts from charts.
Things would work perfectly when identifying drifts from the installed release.
Support for adding a flag to skip helm hooks if required, is under development.