Kubernetes deployment resource limit - amazon-web-services

Here is my deployment & service file for Django. The 3 pods generated from deployment.yaml works, but the resource request and limits are being ignored.
I have seen a lot of tutorials about applying resource specifications on Pods but not on Deployment files, is there a way around it?
Here is my yaml file:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
app: djangoapi
type: web
name: djangoapi
namespace: "default"
spec:
replicas: 3
template:
metadata:
labels:
app: djangoapi
type: web
spec:
containers:
- name: djangoapi
image: wbivan/app:v0.8.1a
imagePullPolicy: Always
args:
- gunicorn
- api.wsgi
- --bind
- 0.0.0.0:8000
resources:
requests:
memory: "64Mi"
cpu: "250m"
limits:
memory: "128Mi"
cpu: "500m"
envFrom:
- configMapRef:
name: djangoapi-config
ports:
- containerPort: 8000
resources: {}
imagePullSecrets:
- name: regcred
restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
name: djangoapi-svc
namespace: "default"
labels:
app: djangoapi
spec:
ports:
- port: 8000
protocol: TCP
targetPort: 8000
selector:
app: djangoapi
type: web
type: NodePort

There is one extra resource attribute under your container definition after ports.
resources: {}
This overrides original resource definition.
Remove this one and apply it again.

The simple way to avoid such issue is to use a YAML validator.
yamllint Seems like a great tool to validate and parse the YAML.
Once you run the validation, it provides a list of all the wrong things you have been doing.
Example:-
# yamllint file.yml
38:9 error duplication of key "resources" in mapping (key-duplicates)

Related

Google Kubernetes Engine & Github actions deploy deployments.apps "gke-deployment" not found

I've been trying to run Google Kubernetes Engine deploy action for my github repo.
I have made a github workflow job run and everything works just fine except the deploy step.
Here is my error code:
Error from server (NotFound): deployments.apps "gke-deployment" not found
I'm assuming my yaml files are at fault, I'm fairly new to this so I got these from the internet and just edited a bit to fit my code, but I don't know the details.
Kustomize.yaml:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
metadata:
name: arbitrary
# Example configuration for the webserver
# at https://github.com/monopole/hello
commonLabels:
app: videoo-render
resources:
- deployment.yaml
- service.yaml
deployment.yaml (I think the error is here):
apiVersion: apps/v1
kind: Deployment
metadata:
name: the-deployment
spec:
replicas: 3
selector:
matchLabels:
deployment: video-render
template:
metadata:
labels:
deployment: video-render
spec:
containers:
- name: the-container
image: monopole/hello:1
command: ["/video-render",
"--port=8080",
"--enableRiskyFeature=$(ENABLE_RISKY)"]
ports:
- containerPort: 8080
env:
- name: ALT_GREETING
valueFrom:
configMapKeyRef:
name: the-map
key: altGreeting
- name: ENABLE_RISKY
valueFrom:
configMapKeyRef:
name: the-map
key: enableRisky
service.yaml:
kind: Service
apiVersion: v1
metadata:
name: the-service
spec:
selector:
deployment: video-render
type: LoadBalancer
ports:
- protocol: TCP
port: 8666
targetPort: 8080
Using ubuntu 20.04 image, repo is C++ code.
For anyone wondering why this happens:
You have to edit this line to an existing deployment:
DEPLOYMENT_NAME: gke-deployment # TODO: update to deployment name,
to:
DEPLOYMENT_NAME: existing-deployment-name

Containers in pod won't talk to each other in Kubernetes

I have three containers in a pod: nginx, redis, custom django app. It seems like none of them talk to each other with kubernetes. In docker compose they do but I can't use docker compose in production.
The django container gets this error:
[2022-06-20 21:45:49,420: ERROR/MainProcess] consumer: Cannot connect to redis://redis:6379/0: Error 111 connecting to redis:6379. Connection refused..
Trying again in 32.00 seconds... (16/100)
and the nginx container starts but never shows any traffic. Trying to connect to localhost:8000 gets no reply.
Any idea whats wrong with my yml file?
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
creationTimestamp: null
name: djangonetwork
spec:
ingress:
- from:
- podSelector:
matchLabels:
io.kompose.network/djangonetwork: "true"
podSelector:
matchLabels:
io.kompose.network/djangonetwork: "true"
---
apiVersion: v1
data:
DB_HOST: db
DB_NAME: django_db
DB_PASSWORD: password
DB_PORT: "5432"
DB_USER: user
kind: ConfigMap
metadata:
creationTimestamp: null
labels:
io.kompose.service: web
name: envs--django
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
io.kompose.service: web
name: web
spec:
replicas: 1
selector:
matchLabels:
io.kompose.service: web
strategy:
type: Recreate
template:
metadata:
labels:
io.kompose.network/djangonetwork: "true"
io.kompose.service: web
spec:
containers:
- image: nginx:alpine
name: nginxcontainer
ports:
- containerPort: 8000
- image: redis:alpine
name: rediscontainer
ports:
- containerPort: 6379
resources: {}
- env:
- name: DB_HOST
valueFrom:
configMapKeyRef:
key: DB_HOST
name: envs--django
- name: DB_NAME
valueFrom:
configMapKeyRef:
key: DB_NAME
name: envs--django
- name: DB_PASSWORD
valueFrom:
configMapKeyRef:
key: DB_PASSWORD
name: envs--django
- name: DB_PORT
valueFrom:
configMapKeyRef:
key: DB_PORT
name: envs--django
- name: DB_USER
valueFrom:
configMapKeyRef:
key: DB_USER
name: envs--django
image: localhost:5000/integration/web:latest
name: djangocontainer
ports:
- containerPort: 8000
resources: {}
restartPolicy: Always
status: {}
---
apiVersion: v1
kind: Service
metadata:
labels:
io.kompose.service: web
name: web
spec:
ports:
- name: "8000"
port: 8000
targetPort: 8000
selector:
io.kompose.service: web
You've put all three containers into a single Pod. That's usually not the preferred approach: it means you can't restart one of the containers without restarting all of them (any update to your application code requires discarding your Redis cache) and you can't individually scale the component parts (if you need five replicas of your application, do you also need five reverse proxies and can you usefully use five Redises?).
Instead, a preferred approach is to split these into three separate Deployments (or possibly use a StatefulSet for Redis with persistence). Each has a corresponding Service, and then those Service names can be used as DNS names.
A very minimal example for Redis could look like:
apiVersion: apps/v1
kind: Deployment
metadata:
name: redis
spec:
replicas: 1
template:
metadata:
labels:
service: web
component: redis
spec:
containers:
- name: redis
image: redis
ports:
- name: redis
containerPort: 6379
---
apiVersion: v1
kind: Service
metadata:
name: redis # <-- this name will be a DNS name
spec:
selector: # matches the template: { metadata: { labels: } }
service: web
component: redis
ports:
- name: redis
port: 6379
targetPort: redis # matches a containerPorts: [{ name: }]
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: app
spec:
...
env:
- name: REDIS_HOST
value: redis # matches the Service
If all three parts are in the same Pod, then the Service can't really distinguish which part it's talking to. In principle, between these containers, they share a network namespace and need to talk to each other as localhost; the containers: [{ name: }] have no practical effect.

None persistent Prometheus metrics on Kubernetes

I'm collecting Prometheus metrics from a uwsgi application hosted on Kubernetes, the metrics are not retained after the pods are deleted. Prometheus server is hosted on the same kubernetes cluster and I have assigned a persistent storage to it.
How do I retain the metrics from the pods even after they deleted?
The Prometheus deployment yaml:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: prometheus
namespace: default
spec:
replicas: 1
template:
metadata:
labels:
app: prometheus
spec:
containers:
- name: prometheus
image: prom/prometheus
args:
- "--config.file=/etc/prometheus/prometheus.yml"
- "--storage.tsdb.path=/prometheus/"
- "--storage.tsdb.retention=2200h"
ports:
- containerPort: 9090
volumeMounts:
- name: prometheus-config-volume
mountPath: /etc/prometheus/
- name: prometheus-storage-volume
mountPath: /prometheus/
volumes:
- name: prometheus-config-volume
configMap:
defaultMode: 420
name: prometheus-server-conf
- name: prometheus-storage-volume
persistentVolumeClaim:
claimName: azurefile
---
apiVersion: v1
kind: Service
metadata:
labels:
app: prometheus
name: prometheus
spec:
type: LoadBalancer
loadBalancerIP: ...
ports:
- port: 80
protocol: TCP
targetPort: 9090
selector:
app: prometheus
Application deployment yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: api-app
spec:
replicas: 2
selector:
matchLabels:
app: api-app
template:
metadata:
labels:
app: api-app
spec:
containers:
- name: nginx
image: nginx
lifecycle:
preStop:
exec:
command: ["/usr/sbin/nginx","-s","quit"]
ports:
- containerPort: 80
protocol: TCP
resources:
limits:
cpu: 50m
memory: 100Mi
requests:
cpu: 10m
memory: 50Mi
volumeMounts:
- name: app-api
mountPath: /var/run/app
- name: nginx-conf
mountPath: /etc/nginx/conf.d
- name: api-app
image: azurecr.io/app_api_se:opencv
workingDir: /app
command: ["/usr/local/bin/uwsgi"]
args:
- "--die-on-term"
- "--manage-script-name"
- "--mount=/=api:app_dispatch"
- "--socket=/var/run/app/uwsgi.sock"
- "--chmod-socket=777"
- "--pyargv=se"
- "--metrics-dir=/storage"
- "--metrics-dir-restore"
resources:
requests:
cpu: 150m
memory: 1Gi
volumeMounts:
- name: app-api
mountPath: /var/run/app
- name: storage
mountPath: /storage
volumes:
- name: app-api
emptyDir: {}
- name: storage
persistentVolumeClaim:
claimName: app-storage
- name: nginx-conf
configMap:
name: app
tolerations:
- key: "sku"
operator: "Equal"
value: "test"
effect: "NoSchedule"
---
apiVersion: v1
kind: Service
metadata:
labels:
app: api-app
name: api-app
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: api-app
Your issue is with the wrong type of controller used to deploy Prometheus. The Deployment controller is wrong choice in this case (it's meant for Stateless applications, that don't need to maintain any persistence identifiers between Pods rescheduling - like persistence data).
You should switch to StatefulSet kind*, if you require persistence of data (metrics scraped by Prometheus) across Pod (re)scheduling.
*This is how Prometheus is deployed by default with prometheus-operator.
With this configuration for a volume, it will be removed when you release a pod. You are basically looking for a PersistentVolumne, documentation and example.
Also check, PersistentVolumeClaim.

Kubernetes 1.4 SSL Termination on AWS

I have 6 HTTP micro-services. Currently they run in a crazy bash/custom deploy tools setup (dokku, mup).
I dockerized them and moved to kubernetes on AWS (setup with kop). The last piece is converting my nginx config.
I'd like
All 6 to have SSL termination (not in the docker image)
4 need websockets and client IP session affinity (Meteor, Socket.io)
5 need http->https forwarding
1 serves the same content on http and https
I did 1. SSL termination setting the service type to LoadBalancer and using AWS specific annotations. This created AWS load balancers, but this seems like a dead end for the other requirements.
I looked at Ingress, but don't see how to do it on AWS. Will this Ingress Controller work on AWS?
Do I need an nginx controller in each pod? This looked interesting, but I'm not sure how recent/relevant it is.
I'm not sure what direction to start in. What will work?
Mike
You should be able to use the nginx ingress controller to accomplish this.
SSL termination
Websocket support
http->https
Turn off the http->https redirect, as described in the link above
The README walks you through how to set it up, and there are plenty of examples.
The basic pieces you need to make this work are:
A default backend that will respond with 404 when there is no matching Ingress rule
The nginx ingress controller which will monitor your ingress rules and rewrite/reload nginx.conf whenever they change.
One or more ingress rules that describe how traffic should be routed to your services.
The end result is that you will have a single ELB that corresponds to your nginx ingress controller service, which in turn is responsible for routing to your individual services according to the ingress rules specified.
There may be a better way to do this. I wrote this answer because I asked the question. It's the best I could come up with Pixel Elephant's doc links above.
The default-http-backend is very useful for debugging. +1
Ingress
this creates an endpoint on the node's IP address, which can change depending on where the Ingress Container is running
note the configmap at the bottom. Configured per environment.
(markdown placeholder because no ```)
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: "nginx"
name: all-ingress
spec:
tls:
- hosts:
- admin-stage.example.io
secretName: tls-secret
rules:
- host: admin-stage.example.io
http:
paths:
- backend:
serviceName: admin
servicePort: http-port
path: /
---
apiVersion: v1
data:
enable-sticky-sessions: "true"
proxy-read-timeout: "7200"
proxy-send-imeout: "7200"
kind: ConfigMap
metadata:
name: nginx-load-balancer-conf
App Service and Deployment
the service port needs to be named, or you may get "upstream default-admin-80 does not have any active endpoints. Using default backend"
(markdown placeholder because no ```)
apiVersion: v1
kind: Service
metadata:
name: admin
spec:
ports:
- name: http-port
port: 80
protocol: TCP
targetPort: http-port
selector:
app: admin
sessionAffinity: ClientIP
type: ClusterIP
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: admin
spec:
replicas: 1
template:
metadata:
labels:
app: admin
name: admin
spec:
containers:
- image: example/admin:latest
name: admin
ports:
- containerPort: 80
name: http-port
resources:
requests:
cpu: 500m
memory: 1000Mi
volumeMounts:
- mountPath: /etc/env-volume
name: config
readOnly: true
imagePullSecrets:
- name: cloud.docker.com-pull
volumes:
- name: config
secret:
defaultMode: 420
items:
- key: admin.sh
mode: 256
path: env.sh
- key: settings.json
mode: 256
path: settings.json
secretName: env-secret
Ingress Nginx Docker Image
note default-ssl-certificate at bottom
logging is great -v below
note the Service will create an ELB on AWS which can be used to configure DNS.
(markdown placeholder because no ```)
apiVersion: v1
kind: Service
metadata:
name: nginx-ingress-service
spec:
ports:
- name: http-port
port: 80
protocol: TCP
targetPort: http-port
- name: https-port
port: 443
protocol: TCP
targetPort: https-port
selector:
app: nginx-ingress-service
sessionAffinity: None
type: LoadBalancer
---
apiVersion: v1
kind: ReplicationController
metadata:
name: nginx-ingress-controller
labels:
k8s-app: nginx-ingress-lb
spec:
replicas: 1
selector:
k8s-app: nginx-ingress-lb
template:
metadata:
labels:
k8s-app: nginx-ingress-lb
name: nginx-ingress-lb
spec:
terminationGracePeriodSeconds: 60
containers:
- image: gcr.io/google_containers/nginx-ingress-controller:0.8.3
name: nginx-ingress-lb
imagePullPolicy: Always
readinessProbe:
httpGet:
path: /healthz
port: 10254
scheme: HTTP
livenessProbe:
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
timeoutSeconds: 1
# use downward API
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
ports:
- name: http-port
containerPort: 80
hostPort: 80
- name: https-port
containerPort: 443
hostPort: 443
# we expose 18080 to access nginx stats in url /nginx-status
# this is optional
- containerPort: 18080
hostPort: 18080
args:
- /nginx-ingress-controller
- --default-backend-service=$(POD_NAMESPACE)/default-http-backend
- --default-ssl-certificate=default/tls-secret
- --nginx-configmap=$(POD_NAMESPACE)/nginx-load-balancer-conf
- --v=2
Default Backend (this is copy/paste from .yaml file)
apiVersion: v1
kind: Service
metadata:
name: default-http-backend
labels:
k8s-app: default-http-backend
spec:
ports:
- port: 80
targetPort: 8080
protocol: TCP
name: http
selector:
k8s-app: default-http-backend
---
apiVersion: v1
kind: ReplicationController
metadata:
name: default-http-backend
spec:
replicas: 1
selector:
k8s-app: default-http-backend
template:
metadata:
labels:
k8s-app: default-http-backend
spec:
terminationGracePeriodSeconds: 60
containers:
- name: default-http-backend
# Any image is permissable as long as:
# 1. It serves a 404 page at /
# 2. It serves 200 on a /healthz endpoint
image: gcr.io/google_containers/defaultbackend:1.0
livenessProbe:
httpGet:
path: /healthz
port: 8080
scheme: HTTP
initialDelaySeconds: 30
timeoutSeconds: 5
ports:
- containerPort: 8080
resources:
limits:
cpu: 10m
memory: 20Mi
requests:
cpu: 10m
memory: 20Mi
This config uses three secrets:
tls-secret - 3 files: tls.key, tls.crt, dhparam.pem
env-secret - 2 files: admin.sh and settings.json. Container has start script to setup environment.
cloud.docker.com-pull

Why can Kubernetes not route a service on public ELB on AWS?

I've been trying to follow the example (guestbook) to reproduce another application which has to be available on a public interface.
This is my Kubernetes configuration (YAML):
apiVersion: v1
kind: Service
metadata:
name: my-app-server
labels:
app: my-app-server
tier: backend
spec:
type: LoadBalancer
ports:
- port: 80
targetPort: 3000
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-app-server
spec:
replicas: 3
template:
metadata:
labels:
app: my-app-server
tier: backend
spec:
containers:
- name: ppm-server
image: docker/container:tag
imagePullPolicy: Always
resources:
requests:
cpu: 100m
memory: 100Mi
env:
- name: GET_HOSTS_FROM
value: dns
ports:
- containerPort: 3000
imagePullSecrets:
- name: myregistrykey
Not sure why this is not working.
The guestbook all-in-one example seems to work just fine though.
I tried using the exact same configuration file while just changing the variables in the configuration.