https://github.com/swdotcom/update-and-apply-kubernetes-configs
Apply kubernetes configuration files from source control
https://github.com/swdotcom/update-and-apply-kubernetes-configs
Last synced: about 1 year ago
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Apply kubernetes configuration files from source control
- Host: GitHub
- URL: https://github.com/swdotcom/update-and-apply-kubernetes-configs
- Owner: swdotcom
- License: apache-2.0
- Created: 2020-08-21T22:38:06.000Z (almost 6 years ago)
- Default Branch: main
- Last Pushed: 2023-04-11T00:51:15.000Z (about 3 years ago)
- Last Synced: 2025-03-07T21:48:10.573Z (about 1 year ago)
- Size: 10.7 KB
- Stars: 11
- Watchers: 6
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Update and Apply Kubernetes Configurations
Composite Github action to update k8 configurations with environment variables and then apply them with kubectl.
This requires that kubectl be installed and configured. [Github's hosted runners](https://docs.github.com/en/actions/reference/software-installed-on-github-hosted-runners) already have kubectl installed. If you're using StrongDM to manage access to your k8 cluster, then checkout [configure-kubectl-with-strongdm](https://github.com/marketplace/actions/configure-kubectl-with-strongdm).
# Usage
See [action.yaml](action.yaml)
## Example usage
Given kubernetes configurations that are committed to the codebase.
`k8/deployment.yaml`
```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-app-deployment
labels:
app: my-app
annotations:
kubernetes.io/change-cause: ${CHANGE_CAUSE}
spec:
replicas: 3
selector:
matchLabels:
app: my-app
template:
metadata:
labels:
app: my-app
spec:
containers:
- name: api
image: xxxxxxxxxxxx.dkr.ecr.us-west-2.amazonaws.com/unicorn/my-app:${IMAGE_TAG}
ports:
- containerPort: 80
```
`k8/config-staging.yaml`
```yaml
kind: ConfigMap
apiVersion: v1
metadata:
name: my-app
namespace: default
data:
APP_ENV: 'staging'
SOME_CONFIG: 'hello'
```
This action uses `envsubst` to replace values in form `$VARIABLE` or `${VARIABLE}` that are found in the list of configuration files. See below for the different replacement options. The k8 templates do not need to define any replacements, like the `k8/config-staging.yaml` above. It's still useful to apply these during the deployment so that configurations can be managed through git.
The order that you list the files for `k8-config-file-paths` is the order that they will be applied to your cluster. So, you probably want to apply any configMap updates before applying the deployment.
**The files will be applied to kubectl's current-context, so make sure to set it to the correct one before this action runs.**
```yaml
- name: Switch to staging cluster
run: kubectl config use-context staging
- uses: swdotcom/update-and-apply-kubernetes-configs@v1
with:
k8-config-file-paths: |
k8/config-staging.yaml
k8/deployment.yaml
replacement-method: defined
env:
IMAGE_TAG: ${{ github.sha }}
CHANGE_CAUSE: ${{ github.event.release.tag_name }}
```
Config files can also be defined on one line with a space delimiter.
```yaml
- name: Switch to staging cluster
run: kubectl config use-context staging
- uses: swdotcom/update-and-apply-kubernetes-configs@v1
with:
k8-config-file-paths: k8/config-staging.yaml k8/deployment.yaml
replacement-method: defined
env:
IMAGE_TAG: ${{ github.sha }}
CHANGE_CAUSE: ${{ github.event.release.tag_name }}
```
### Replacement Method - **defined (Default)**
Any value matching the format `$VARIABLE` or `${VARIABLE}` will be replaced by a matching ENV variable. If no ENV variable is defined with that name, it will be unmodified.
### Replacement Method - **list**
Any value matching the format `$VARIABLE` or `${VARIABLE}` will be replaced by a matching ENV variable. If the ENV variable is not in the predefined list of replacement, it will be unmodified. This is useful for situations where you have a legitimate value that matches `$VAR` or `${VAR}` and you want it to be applied exactly as is to kubernetes.
```yaml
- uses: swdotcom/update-and-apply-kubernetes-configs@v1
with:
k8-config-file-paths: k8/config-staging.yaml k8/deployment.yaml
replacement-method: list
env-replacement-list: |
ONLY_ME
env:
ONLY_ME: hi
```
### Replacement Method - **all**
Any value matching the format `$VARIABLE` or `${VARIABLE}` will be replaced by a matching ENV variable. If no ENV variable is defined with that name, it will be replaced with nothing. So, it would be best practice to wrap ENV vars in quotes to avoid errors when applying an invalid configuration to kubernetes.
## Applying Resources to a Namespace
The `namespace` option allows you to apply the list of files to a specific namespace. This is useful when you need to apply a shared configMap to multiple namespaces. Your k8 resource definition must not have a namespace specified for this to work. If a namespace is specified in your file, then it will take precedence. Once this action completes, the namespace will be returned to the original namespace if it was set, otherwise will be returned to `default`.
```yaml
- uses: swdotcom/update-and-apply-kubernetes-configs@v1
with:
namespace: custom-namespace
k8-config-file-paths: k8/config-staging.yaml
```
`k8/config-staging.yaml`
```yaml
kind: ConfigMap
apiVersion: v1
metadata:
name: my-app
data:
APP_ENV: 'staging'
SOME_CONFIG: 'hello'
```