Checks if a specific pod is running, by matching the state and labels
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A POSIX shell script based container: It that calls the Kubernetes API to check running Pods matching the desired Labels.
GitHub Source: https://github.com/piscue/pod-running-checker
Useful as InitContainer in Kubernetes to create dependencies between deployments, as it could check if another deployment is Running by matching labels and status, before starting to rollout the dependency
It will check for pods running with certain labels
LABELS="app=alpine,pod-template-hash=7b421232"
It supports for WAIT_TIME and default is 10 seconds
WAIT_TIME=10
It will not time out, useful to keep the default timeout of a deplomyent or a helm update
In order to be able to operate, this pod needs to have some permissions and query the Kubernetes API, this could be done by creating a Service Account and Cluster Role
Is already a deprecrated way to use ClusterRole and ClusterRoleBinding since v1.17
Be aware about the namespace where you define it
apiVersion: v1
kind: ServiceAccount
metadata:
name: pod-running-checker
namespace: default
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: pod-running-checker
rules:
- apiGroups:
- ""
resources:
- pods
- services
- endpoints
verbs:
- get
- list
- watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: system:serviceaccount:pod-running-checker:default
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: pod-running-checker
subjects:
- kind: ServiceAccount
name: pod-running-checker
namespace: default
This nginx-deployment will rollout when at least one Pod with labels app=alpine and pod-template-hash=7b421232 is on Running state
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
serviceAccountName: pod-running-checker
initContainers:
- name: pod-running-checker
securityContext:
{}
image: piscue/pod-running-checker:0.1.2
imagePullPolicy: IfNotPresent
env:
- name: LABELS
value: "app=alpine,pod-template-hash=7b421232"
containers:
- name: nginx
image: nginx:latest
ports:
- name: http
containerPort: 80
protocol: TCP
Content type
Image
Digest
sha256:18b9f2f56…
Size
4.2 MB
Last updated
over 3 years ago
docker pull piscue/pod-running-checker