# Troubleshooting ## Ingress-Controller Logs and Events There are many ways to troubleshoot the ingress-controller. The following are basic troubleshooting methods to obtain more information. Check the Ingress Resource Events ```console $ kubectl get ing -n NAME HOSTS ADDRESS PORTS AGE cafe-ingress cafe.com 10.0.2.15 80 25s $ kubectl describe ing -n Name: cafe-ingress Namespace: default Address: 10.0.2.15 Default backend: default-http-backend:80 (172.17.0.5:8080) Rules: Host Path Backends ---- ---- -------- cafe.com /tea tea-svc:80 () /coffee coffee-svc:80 () Annotations: kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{},"name":"cafe-ingress","namespace":"default","selfLink":"/apis/extensions/v1beta1/namespaces/default/ingresses/cafe-ingress"},"spec":{"rules":[{"host":"cafe.com","http":{"paths":[{"backend":{"serviceName":"tea-svc","servicePort":80},"path":"/tea"},{"backend":{"serviceName":"coffee-svc","servicePort":80},"path":"/coffee"}]}}]},"status":{"loadBalancer":{"ingress":[{"ip":"169.48.142.110"}]}}} Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 1m nginx-ingress-controller Ingress default/cafe-ingress Normal UPDATE 58s nginx-ingress-controller Ingress default/cafe-ingress ``` Check the Ingress Controller Logs ```console $ kubectl get pods -n NAME READY STATUS RESTARTS AGE nginx-ingress-controller-67956bf89d-fv58j 1/1 Running 0 1m $ kubectl logs -n nginx-ingress-controller-67956bf89d-fv58j ------------------------------------------------------------------------------- NGINX Ingress controller Release: 0.14.0 Build: git-734361d Repository: https://github.com/kubernetes/ingress-nginx ------------------------------------------------------------------------------- .... ``` Check the Nginx Configuration ```console $ kubectl get pods -n NAME READY STATUS RESTARTS AGE nginx-ingress-controller-67956bf89d-fv58j 1/1 Running 0 1m $ kubectl exec -it -n nginx-ingress-controller-67956bf89d-fv58j cat /etc/nginx/nginx.conf daemon off; worker_processes 2; pid /run/nginx.pid; worker_rlimit_nofile 523264; worker_shutdown_timeout 10s; events { multi_accept on; worker_connections 16384; use epoll; } http { .... ``` Check if used Services Exist ```console $ kubectl get svc --all-namespaces NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE default coffee-svc ClusterIP 10.106.154.35 80/TCP 18m default kubernetes ClusterIP 10.96.0.1 443/TCP 30m default tea-svc ClusterIP 10.104.172.12 80/TCP 18m kube-system default-http-backend NodePort 10.108.189.236 80:30001/TCP 30m kube-system kube-dns ClusterIP 10.96.0.10 53/UDP,53/TCP 30m kube-system kubernetes-dashboard NodePort 10.103.128.17 80:30000/TCP 30m ``` Use the `ingress-nginx` kubectl plugin Install [krew](https://github.com/GoogleContainerTools/krew), then run ```console $ kubectl krew install --manifest https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/cmd/plugin/release/ingress-nginx.yaml ``` to install the plugin. Then run ```console $ kubectl ingress-nginx --help ``` to make sure the plugin is properly installed and to get a list of commands. The plugin includes all of the commands present in the `/dbg` tool, plus a more detailed version of `kubectl get ingresses` available by runnning `kubectl ingress-nginx ingresses`. Use the `/dbg` Tool to Check Dynamic Configuration ```console $ kubectl exec -n nginx-ingress-controller-67956bf89d-fv58j /dbg dbg is a tool for quickly inspecting the state of the nginx instance Usage: dbg [command] Available Commands: backends Inspect the dynamically-loaded backends information conf Dump the contents of /etc/nginx/nginx.conf general Output the general dynamic lua state help Help about any command Flags: -h, --help help for dbg Use "dbg [command] --help" for more information about a command. ``` ```console $ kubectl exec -n nginx-ingress-controller-67956bf89d-fv58j /dbg backends Inspect the dynamically-loaded backends information. Usage: dbg backends [command] Available Commands: all Output the all dynamic backend information as a JSON array get Output the backend information only for the backend that has this name list Output a newline-separated list of the backend names Flags: -h, --help help for backends Use "dbg backends [command] --help" for more information about a command. ``` ```console $ kubectl exec -n nginx-ingress-controller-67956bf89d-fv58j /dbg backends list coffee-svc-80 tea-svc-80 upstream-default-backend ``` ```console $ kubectl exec -n nginx-ingress-controller-67956bf89d-fv58j /dbg backends get coffee-svc-80 { "endpoints": [ { "address": "10.1.1.112", "port": "8080" }, { "address": "10.1.1.119", "port": "8080" }, { "address": "10.1.1.121", "port": "8080" } ], "load-balance": "ewma", "name": "coffee-svc-80", "noServer": false, "port": 0, "secureCACert": { "caFilename": "", "pemSha": "", "secret": "" }, "service": { "metadata": { "creationTimestamp": null }, "spec": { .... ``` ## Debug Logging Using the flag `--v=XX` it is possible to increase the level of logging. This is performed by editing the deployment. ```console $ kubectl get deploy -n NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE default-http-backend 1 1 1 1 35m nginx-ingress-controller 1 1 1 1 35m $ kubectl edit deploy -n nginx-ingress-controller # Add --v=X to "- args", where X is an integer ``` - `--v=2` shows details using `diff` about the changes in the configuration in nginx - `--v=3` shows details about the service, Ingress rule, endpoint changes and it dumps the nginx configuration in JSON format - `--v=5` configures NGINX in [debug mode](http://nginx.org/en/docs/debugging_log.html) ## Authentication to the Kubernetes API Server A number of components are involved in the authentication process and the first step is to narrow down the source of the problem, namely whether it is a problem with service authentication or with the kubeconfig file. Both authentications must work: ``` +-------------+ service +------------+ | | authentication | | + apiserver +<-------------------+ ingress | | | | controller | +-------------+ +------------+ ``` **Service authentication** The Ingress controller needs information from apiserver. Therefore, authentication is required, which can be achieved in two different ways: 1. _Service Account:_ This is recommended, because nothing has to be configured. The Ingress controller will use information provided by the system to communicate with the API server. See 'Service Account' section for details. 2. _Kubeconfig file:_ In some Kubernetes environments service accounts are not available. In this case a manual configuration is required. The Ingress controller binary can be started with the `--kubeconfig` flag. The value of the flag is a path to a file specifying how to connect to the API server. Using the `--kubeconfig` does not requires the flag `--apiserver-host`. The format of the file is identical to `~/.kube/config` which is used by kubectl to connect to the API server. See 'kubeconfig' section for details. 3. _Using the flag `--apiserver-host`:_ Using this flag `--apiserver-host=http://localhost:8080` it is possible to specify an unsecured API server or reach a remote kubernetes cluster using [kubectl proxy](https://kubernetes.io/docs/user-guide/kubectl/kubectl_proxy/). Please do not use this approach in production. In the diagram below you can see the full authentication flow with all options, starting with the browser on the lower left hand side. ``` Kubernetes Workstation +---------------------------------------------------+ +------------------+ | | | | | +-----------+ apiserver +------------+ | | +------------+ | | | | proxy | | | | | | | | | apiserver | | ingress | | | | ingress | | | | | | controller | | | | controller | | | | | | | | | | | | | | | | | | | | | | | | | service account/ | | | | | | | | | | kubeconfig | | | | | | | | | +<-------------------+ | | | | | | | | | | | | | | | | | +------+----+ kubeconfig +------+-----+ | | +------+-----+ | | |<--------------------------------------------------------| | | | | | +---------------------------------------------------+ +------------------+ ``` ### Service Account If using a service account to connect to the API server, Dashboard expects the file `/var/run/secrets/kubernetes.io/serviceaccount/token` to be present. It provides a secret token that is required to authenticate with the API server. Verify with the following commands: ```console # start a container that contains curl $ kubectl run test --image=tutum/curl -- sleep 10000 # check that container is running $ kubectl get pods NAME READY STATUS RESTARTS AGE test-701078429-s5kca 1/1 Running 0 16s # check if secret exists $ kubectl exec test-701078429-s5kca ls /var/run/secrets/kubernetes.io/serviceaccount/ ca.crt namespace token # get service IP of master $ kubectl get services NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes 10.0.0.1 443/TCP 1d # check base connectivity from cluster inside $ kubectl exec test-701078429-s5kca -- curl -k https://10.0.0.1 Unauthorized # connect using tokens $ TOKEN_VALUE=$(kubectl exec test-701078429-s5kca -- cat /var/run/secrets/kubernetes.io/serviceaccount/token) $ echo $TOKEN_VALUE eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3Mi....9A $ kubectl exec test-701078429-s5kca -- curl --cacert /var/run/secrets/kubernetes.io/serviceaccount/ca.crt -H "Authorization: Bearer $TOKEN_VALUE" https://10.0.0.1 { "paths": [ "/api", "/api/v1", "/apis", "/apis/apps", "/apis/apps/v1alpha1", "/apis/authentication.k8s.io", "/apis/authentication.k8s.io/v1beta1", "/apis/authorization.k8s.io", "/apis/authorization.k8s.io/v1beta1", "/apis/autoscaling", "/apis/autoscaling/v1", "/apis/batch", "/apis/batch/v1", "/apis/batch/v2alpha1", "/apis/certificates.k8s.io", "/apis/certificates.k8s.io/v1alpha1", "/apis/extensions", "/apis/extensions/v1beta1", "/apis/policy", "/apis/policy/v1alpha1", "/apis/rbac.authorization.k8s.io", "/apis/rbac.authorization.k8s.io/v1alpha1", "/apis/storage.k8s.io", "/apis/storage.k8s.io/v1beta1", "/healthz", "/healthz/ping", "/logs", "/metrics", "/swaggerapi/", "/ui/", "/version" ] } ``` If it is not working, there are two possible reasons: 1. The contents of the tokens are invalid. Find the secret name with `kubectl get secrets | grep service-account` and delete it with `kubectl delete secret `. It will automatically be recreated. 2. You have a non-standard Kubernetes installation and the file containing the token may not be present. The API server will mount a volume containing this file, but only if the API server is configured to use the ServiceAccount admission controller. If you experience this error, verify that your API server is using the ServiceAccount admission controller. If you are configuring the API server by hand, you can set this with the `--admission-control` parameter. > Note that you should use other admission controllers as well. Before configuring this option, you should read about admission controllers. More information: - [User Guide: Service Accounts](http://kubernetes.io/docs/user-guide/service-accounts/) - [Cluster Administrator Guide: Managing Service Accounts](http://kubernetes.io/docs/admin/service-accounts-admin/) ## Kube-Config If you want to use a kubeconfig file for authentication, follow the [deploy procedure](deploy/index.md) and add the flag `--kubeconfig=/etc/kubernetes/kubeconfig.yaml` to the args section of the deployment. ## Using GDB with Nginx [Gdb](https://www.gnu.org/software/gdb/) can be used to with nginx to perform a configuration dump. This allows us to see which configuration is being used, as well as older configurations. Note: The below is based on the nginx [documentation](https://docs.nginx.com/nginx/admin-guide/monitoring/debugging/#dumping-nginx-configuration-from-a-running-process). 1. SSH into the worker ```console $ ssh user@workerIP ``` 2. Obtain the Docker Container Running nginx ```console $ docker ps | grep nginx-ingress-controller CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES d9e1d243156a quay.io/kubernetes-ingress-controller/nginx-ingress-controller "/usr/bin/dumb-init …" 19 minutes ago Up 19 minutes k8s_nginx-ingress-controller_nginx-ingress-controller-67956bf89d-mqxzt_kube-system_079f31ec-aa37-11e8-ad39-080027a227db_0 ``` 3. Exec into the container ```console $ docker exec -it --user=0 --privileged d9e1d243156a bash ``` 4. Make sure nginx is running in `--with-debug` ```console $ nginx -V 2>&1 | grep -- '--with-debug' ``` 5. Get list of processes running on container ```console $ ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 20:23 ? 00:00:00 /usr/bin/dumb-init /nginx-ingres root 5 1 0 20:23 ? 00:00:05 /nginx-ingress-controller --defa root 21 5 0 20:23 ? 00:00:00 nginx: master process /usr/sbin/ nobody 106 21 0 20:23 ? 00:00:00 nginx: worker process nobody 107 21 0 20:23 ? 00:00:00 nginx: worker process root 172 0 0 20:43 pts/0 00:00:00 bash ``` 7. Attach gdb to the nginx master process ```console $ gdb -p 21 .... Attaching to process 21 Reading symbols from /usr/sbin/nginx...done. .... (gdb) ``` 8. Copy and paste the following: ```console set $cd = ngx_cycle->config_dump set $nelts = $cd.nelts set $elts = (ngx_conf_dump_t*)($cd.elts) while ($nelts-- > 0) set $name = $elts[$nelts]->name.data printf "Dumping %s to nginx_conf.txt\n", $name append memory nginx_conf.txt \ $elts[$nelts]->buffer.start $elts[$nelts]->buffer.end end ``` 9. Quit GDB by pressing CTRL+D 10. Open nginx_conf.txt ```console cat nginx_conf.txt ```