kubectl version --short
Client Version: v1.22.2
Server Version: v1.21.1
This Dockerfile give "Readiness probe failed":
# syntax=docker/dockerfile:1
FROM golang:1.17.2-alpine as builder
WORKDIR /source
COPY ./src/go.mod ./
# COPY ./src/go.sum ./
RUN go mod download
COPY ./src ./
# COPY src/*.go ./
# output app in app folder
RUN go build -o /app
FROM golang:1.16-alpine
COPY --from=builder /app /app
EXPOSE 80
# execute app
CMD [ "/app" ]
Deploying a simple knative service:
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
name: helloworld-go
namespace: default
spec:
template:
spec:
containers:
- image: gcr.io/<projid>/dockerfile-micro-depend:latest
kubectl describe pod dockerfile-micro-depend-dhv8n-deployment-796484d788-hwpmm
Name: dockerfile-micro-depend-dhv8n-deployment-796484d788-hwpmm
Namespace: default
Priority: 0
Node: kind-control-plane/172.18.0.2
Start Time: Fri, 10 Dec 2021 17:37:26 +0100
Labels: app=dockerfile-micro-depend-dhv8n
pod-template-hash=796484d788
serving.knative.dev/configuration=dockerfile-micro-depend
serving.knative.dev/configurationGeneration=1
serving.knative.dev/revision=dockerfile-micro-depend-dhv8n
serving.knative.dev/revisionUID=053a72d2-c506-43cd-9c3c-bbd3e7296295
serving.knative.dev/service=dockerfile-micro-depend
Annotations: serving.knative.dev/creator: kubernetes-admin
Status: Running
IP: 10.244.0.12
IPs:
IP: 10.244.0.12
Controlled By: ReplicaSet/dockerfile-micro-depend-dhv8n-deployment-796484d788
Containers:
user-container:
Container ID: containerd://c90f6129263426a5ec58fc2f4286a6b5ae85faa82f86f50e05c5126ca8082e4c
Image: gcr.io/<projid>/dockerfile-micro-depend@sha256:dc9b331e5e63af3067578652c8822af91c73c19226541c3495080d0049328452
Image ID: gcr.io/<projid>/dockerfile-micro-depend@sha256:dc9b331e5e63af3067578652c8822af91c73c19226541c3495080d0049328452
Port: 8080/TCP
Host Port: 0/TCP
State: Running
Started: Fri, 10 Dec 2021 17:37:32 +0100
Ready: True
Restart Count: 0
Environment:
PORT: 8080
K_REVISION: dockerfile-micro-depend-dhv8n
K_CONFIGURATION: dockerfile-micro-depend
K_SERVICE: dockerfile-micro-depend
K_INTERNAL_POD_NAME: dockerfile-micro-depend-dhv8n-deployment-796484d788-hwpmm (v1:metadata.name)
K_INTERNAL_POD_NAMESPACE: default (v1:metadata.namespace)
Mounts:
/var/log from knative-var-log (rw)
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-plmnm (ro)
queue-proxy:
Container ID: containerd://4448ee3b78b9a18ef7f2132eb444c943fd6cc471dd36f04cee6ce3aa4b685bc5
Image: gcr.io/knative-releases/knative.dev/serving/cmd/queue@sha256:713bd548700bf7fe5452969611d1cc987051bd607d67a4e7623e140f06c209b2
Image ID: gcr.io/knative-releases/knative.dev/serving/cmd/queue@sha256:713bd548700bf7fe5452969611d1cc987051bd607d67a4e7623e140f06c209b2
Ports: 8022/TCP, 9090/TCP, 9091/TCP, 8012/TCP
Host Ports: 0/TCP, 0/TCP, 0/TCP, 0/TCP
State: Running
Started: Fri, 10 Dec 2021 17:37:32 +0100
Ready: False
Restart Count: 0
Requests:
cpu: 25m
Readiness: exec [/ko-app/queue -probe-period 0] delay=0s timeout=10s period=1s #success=1 #failure=3
Environment:
SERVING_NAMESPACE: default
SERVING_SERVICE: dockerfile-micro-depend
SERVING_CONFIGURATION: dockerfile-micro-depend
SERVING_REVISION: dockerfile-micro-depend-dhv8n
QUEUE_SERVING_PORT: 8012
CONTAINER_CONCURRENCY: 0
REVISION_TIMEOUT_SECONDS: 300
SERVING_POD: dockerfile-micro-depend-dhv8n-deployment-796484d788-hwpmm (v1:metadata.name)
SERVING_POD_IP: (v1:status.podIP)
SERVING_LOGGING_CONFIG: {
"level": "info",
"development": false,
"outputPaths": ["stdout"],
"errorOutputPaths": ["stderr"],
"encoding": "json",
"encoderConfig": {
"timeKey": "ts",
"levelKey": "level",
"nameKey": "logger",
"callerKey": "caller",
"messageKey": "msg",
"stacktraceKey": "stacktrace",
"lineEnding": "",
"levelEncoder": "",
"timeEncoder": "iso8601",
"durationEncoder": "",
"callerEncoder": ""
}
}
SERVING_LOGGING_LEVEL:
SERVING_REQUEST_LOG_TEMPLATE:
SERVING_REQUEST_METRICS_BACKEND: prometheus
TRACING_CONFIG_BACKEND: none
TRACING_CONFIG_ZIPKIN_ENDPOINT:
TRACING_CONFIG_STACKDRIVER_PROJECT_ID:
TRACING_CONFIG_DEBUG: false
TRACING_CONFIG_SAMPLE_RATE: 0.1
USER_PORT: 8080
SYSTEM_NAMESPACE: knative-serving
METRICS_DOMAIN: knative.dev/internal/serving
DOWNWARD_API_LABELS_PATH: /etc/podinfo/labels
SERVING_READINESS_PROBE: {"tcpSocket":{"port":8080,"host":"127.0.0.1"},"successThreshold":1}
ENABLE_PROFILING: false
SERVING_ENABLE_PROBE_REQUEST_LOG: false
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-plmnm (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
knative-var-log:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
kube-api-access-plmnm:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 82s default-scheduler Successfully assigned default/dockerfile-micro-depend-dhv8n-deployment-796484d788-hwpmm to kind-control-plane
Normal Pulling 81s kubelet Pulling image "gcr.io/<projid>/dockerfile-micro-depend@sha256:dc9b331e5e63af3067578652c8822af91c73c19226541c3495080d0049328452"
Normal Pulled 77s kubelet Successfully pulled image "gcr.io/<projid>/dockerfile-micro-depend@sha256:dc9b331e5e63af3067578652c8822af91c73c19226541c3495080d0049328452" in 4.6859265s
Normal Created 76s kubelet Created container user-container
Normal Started 76s kubelet Started container user-container
Normal Pulled 76s kubelet Container image "gcr.io/knative-releases/knative.dev/serving/cmd/queue@sha256:713bd548700bf7fe5452969611d1cc987051bd607d67a4e7623e140f06c209b2" already present on machine
Normal Created 76s kubelet Created container queue-proxy
Normal Started 76s kubelet Started container queue-proxy
Warning Unhealthy 5s (x7 over 66s) kubelet Readiness probe failed:
Then I found this "official" example and used the Dockerfile, and it worked. Do you know why?
Clearly it has to do with some health checking on the pod, but I have no idea why the first Dockerfile is not working.
It looks like your application runs on port 80 (based on the EXPOSE 80 line in your Dockerfile), but the default for Knative is to run on 8080 (exposed as $PORT to your container).
You can override this by setting a (single) containerPort in your yaml to point Knative at the port your application serves on.