Service not automatically registered with consul

[ervikrant06]

Deployed consul on K8 using helm charts, after that added the sync section in values.yaml file and performed the upgrade of helm deployment.

+syncCatalog:
+  enabled: true
+

• Following consul members are reported after it. I believe vehement-zebu-consul-6rzsj it appeared after adding the syncCatalog section because it was not present earlier.

$ kubectl exec -it vehement-zebu-consul-server-0 consul members
Node                           Address           Status  Type    Build  Protocol  DC   Segment
vehement-zebu-consul-server-0  172.17.0.6:8301   alive   server  1.2.2  2         dc1  <all>
vehement-zebu-consul-server-1  172.17.0.9:8301   alive   server  1.2.2  2         dc1  <all>
vehement-zebu-consul-server-2  172.17.0.3:8301   alive   server  1.2.2  2         dc1  <all>
vehement-zebu-consul-6rzsj     172.17.0.14:8301  alive   client  1.2.2  2         dc1  <default>

• Created the deployment and service using following manifest.

cat <<EOF | kubectl delete -f -
apiVersion: v1
kind: Service
metadata:
  name: my-nginx
  labels:
    run: my-nginx
  annotations:
    "vehement-zebu-consul-server.default.svc.cluster.local/service-name": nginxservice    
spec:
  ports:
  - port: 80
    protocol: TCP
  selector:
    run: my-nginx
  type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
spec:
  selector:
    matchLabels:
      run: my-nginx
  replicas: 2
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 80
EOF

I changed the service type to NodePort after the deployment.

• I don't see this service getting registered in the consul UI. Nothing is appearing in the consul client logs.

• However I can register this service manually.

/ # cat agent1payload.json
{
  "Name": "nginx",
  "address": "my-nginx.default.svc.cluster.local",
  "port": 80,
  "Check": {
     "http": "http://my-nginx.default.svc.cluster.local",
     "interval": "5s"
  }
}
/ # curl --request PUT --data @agent1payload.json http://172.17.0.12:8500/v1/agent/service/register

As per my understanding purpose of consul sync is to automatically register the service in consul as soon it's started in kubernetes. Not sure why it's not getting registered automatically?

[ervikrant06]

@mitchellh I teared down the minikube setup and created it again by enabling the core-dns instead of kube-dns.

/ # dig @consul-server.default.svc.cluster.local -p 8600 consul.service.consul

; <<>> DiG 9.11.2-P1 <<>> @consul-server.default.svc.cluster.local -p 8600 consul.service.consul
; (3 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19190
;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 4
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;consul.service.consul.		IN	A

;; ANSWER SECTION:
consul.service.consul.	0	IN	A	172.17.0.13
consul.service.consul.	0	IN	A	172.17.0.12
consul.service.consul.	0	IN	A	172.17.0.11

;; ADDITIONAL SECTION:
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="

;; Query time: 7 msec
;; SERVER: 172.17.0.11#8600(172.17.0.11)
;; WHEN: Fri Oct 05 17:16:50 UTC 2018
;; MSG SIZE  rcvd: 206

Created the following deployment and NodePort service.

at <<EOF | kubectl create -f -
apiVersion: v1
kind: Service
metadata:
  name: my-nginx
  labels:
    run: my-nginx
  annotations:
    "consul-server.default.svc.cluster.local/service-name": nginxservice
spec:
  ports:
  - port: 80
    protocol: TCP
  selector:
    run: my-nginx
  type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
spec:
  selector:
    matchLabels:
      run: my-nginx
  replicas: 2
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 80
EOF
service "my-nginx" created
deployment "my-nginx" created

I don't see this service getting registered in the consul. Am I missing anything here? There is no proper how to make this work hence I feel that I am doing something silly.

$ kubectl exec -it consul-server-0 consul catalog services
consul

For sync of service from K8 to consul - is stub zone entry required? I took the following CM from hashicorp official blog.

kubectl describe cm kube-dns -n kube-system
Name:         kube-dns
Namespace:    kube-system
Labels:       addonmanager.kubernetes.io/mode=EnsureExists
Annotations:  kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","data":{"stubDomains":"{\"consul\": [\"10.103.165.156\"]}\n"},"kind":"ConfigMap","metadata":{"annotations":{},"labels":{"addonmanage...

Data
====
stubDomains:
----
{"consul": ["10.103.165.156"]}

Events:  <none>

But I don't think stub is working for me. If it was configured properly then it should have shown the output for command / # dig consul.service.consul..

/ # dig @consul-dns.default.svc.cluster.local consul.service.consul

; <<>> DiG 9.11.2-P1 <<>> @consul-dns.default.svc.cluster.local consul.service.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28412
;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 4
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;consul.service.consul.		IN	A

;; ANSWER SECTION:
consul.service.consul.	0	IN	A	172.17.0.13
consul.service.consul.	0	IN	A	172.17.0.11
consul.service.consul.	0	IN	A	172.17.0.12

;; ADDITIONAL SECTION:
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="

;; Query time: 5 msec
;; SERVER: 10.103.165.156#53(10.103.165.156)
;; WHEN: Fri Oct 05 17:35:21 UTC 2018
;; MSG SIZE  rcvd: 206

/ # dig consul.service.consul

; <<>> DiG 9.11.2-P1 <<>> consul.service.consul
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 21301
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;consul.service.consul.		IN	A

;; AUTHORITY SECTION:
.			30	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2018100500 1800 900 604800 86400

;; Query time: 159 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Fri Oct 05 17:35:45 UTC 2018
;; MSG SIZE  rcvd: 125

/ # cat /etc/resolv.conf
nameserver 10.96.0.10
search default.svc.cluster.local svc.cluster.local cluster.local
options ndots:5
/ # curl consul.service.consul
curl: (6) Could not resolve host: consul.service.consul

[ervikrant06]

I managed to fix the stub zone configuration issue following K8 official documentation. Now the dig is working:

/ # dig consul.service.consul

; <<>> DiG 9.11.2-P1 <<>> consul.service.consul
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46198
;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 4
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;consul.service.consul.		IN	A

;; ANSWER SECTION:
consul.service.consul.	0	IN	A	172.17.0.12
consul.service.consul.	0	IN	A	172.17.0.13
consul.service.consul.	0	IN	A	172.17.0.11

;; ADDITIONAL SECTION:
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="
consul.service.consul.	0	IN	TXT	"consul-network-segment="

;; Query time: 13 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Fri Oct 05 17:56:42 UTC 2018
;; MSG SIZE  rcvd: 332

I recreated the service after modifying the annotation as per

 annotations:
    "consul.hashicorp.com/service-name": nginxservice

Still it's not registered in consul.

[s3than]

Same issue, DNS provider working as expected however sync not displaying.

No error messages received upsert as expected in the catalog logs, not recording any logs in consul cluster on the attempt to register service.

[adilyse]

@ervikrant06 Is there a catalog sync pod being created? It would have consul-sync-catalog in its name and its logs might shed some light on the service sync status. Because this is specific to the Kubernetes integration, it won't be listed when using the consul members command.

[ervikrant06]

@adilyse Nope this POD is not created. I tried multiple times but never managed to see that container. I believe following is the only change which we need to make in values.yaml file.

+syncCatalog:
+  enabled: true
+

[adilyse]

One thing that I've run into is if a cluster doesn't have enough resources (usually CPU), some of the pods defined by the Helm chart won't get scheduled. This could explain why the catalog sync pod isn't being created for you and without this pod, the catalog sync functionality won't work.

I'll look into updating the documentation to include information about resource requirements.

[ervikrant06]

Thanks. i don't it's a resource related issue otherwise POD should stuck in Pending state but I don't see any trace for it.. Also the helm chart deployment is completed successfully I believe it should also have shown the failure.

Note: I am using minikube which is single node setup.

[hsmade]

I do have the sync pod, and it logs:

2018-11-13T15:25:35.375Z [INFO ] to-k8s/sink: upsert: key=kube-system/consul-ui
2018-11-13T15:25:35.375Z [INFO ] to-k8s/sink: upsert: key=kube-system/traefik-ingress-service
2018-11-13T15:25:35.375Z [INFO ] to-k8s/sink: upsert: key=kube-system/traefik-web-ui
2018-11-13T15:25:35.375Z [INFO ] to-k8s/sink: upsert: key=kube-system/kube-dns

But still, no services in consul (except the consul service).

[adilyse]

@hsmade Could you provide some additional information about your setup? Specifically, what are the sync settings in the values.yaml and what are the kubernetes service types of the services you are trying to sync?

I'm curious about the helm chart sync settings because the logs you've included start with to-k8s, which are about syncing Consul services into kubernetes as external services. To figure out why kubernetes services aren't showing up in Consul, the to-consul-prefaced logs would be more helpful.

As for the service types, currently we are only able to sync NodePort or LoadBalancer type services (docs), so if your services are defined as ClusterIP services, they won't show up in Consul.

[adilyse]

@ervikrant06 I just realized that you said you are experiencing this problem after doing an "upgrade of [a] helm deployment". I've run into some issues trying to upgrade a helm chart in place. If you delete the current helm chart and install it fresh with the sync enabled, are you able to get a catalog sync pod?

[adilyse]

For folks running on Minikube, we've added a new guide for running Consul on Minikube that might have some helpful information.

[adilyse]

We've released several versions since this issue was last commented on, the latest being v0.8.1 last week. I'm going to go ahead and close this since it's likely out of date now. If folks run into similar issues with the latest release, please feel free to file a new issue.