`stern customer -c customer` runs but no logs are streamed down

[jerzy-wachowiak]

Setup Win 10 / Virtual Box / openshift v3.11.0+6c2b013-59) / minishift v1.26.1+1e20f27

Referce to https://redhat-developer-demos.github.io/istio-tutorial/istio-tutorial/1.0.0/2deploy-microservices.html#deploycustomer stern customer -c customer run as admin/admin

Issue The command stern customer -c customer runs but no logs are streamed down

Solution the command should be stern customer-1-7bml8 -c customer -n tutorial where customer-1-7bml8 is the pod name selected by oc get pods -n tutorial | grep -E "STATUS|Running"

[lordofthejars]

@jerzy-wachowiak I have tried to reproduce in MacOs but no luck, it worked perfectly. In fact, reading stern docs I see that says that the pod can be a pod query, so I am not sure if it can be the version of stern you are using or something like that. I have created a PR https://github.com/redhat-developer-demos/istio-tutorial/pull/169 can you review to see if it works in your case? If it works then I will merge the change.

[jerzy-wachowiak]

@lordofthejars [1 ] I use https://github.com/wercker/stern/releases/download/1.10.0/stern_windows_amd64.exe and there is an option "-n" for k8s namespace

λ stern -h
Tail multiple pods and containers from Kubernetes

Usage:
  stern pod-query [flags]

Flags:
      --all-namespaces             If present, tail across all namespaces. A specific namespace is ignored even if specified with --namespace.
      --color string               Color output. Can be 'always', 'never', or 'auto' (default "auto")
      --completion string          Outputs stern command-line completion code for the specified shell. Can be 'bash' or 'zsh'
  -c, --container string           Container name when multiple containers in pod (default ".*")
      --container-state string     If present, tail containers with status in running, waiting or terminated. Default to running. (default "running")
      --context string             Kubernetes context to use. Default to current context configured in kubeconfig.
  -e, --exclude strings            Regex of log lines to exclude
  -E, --exclude-container string   Exclude a Container name
  -h, --help                       help for stern
      --kubeconfig string          Path to kubeconfig file to use
  -n, --namespace string           Kubernetes namespace to use. Default to namespace configured in Kubernetes context
  -o, --output string              Specify predefined template. Currently support: [default, raw, json] (default "default")
  -l, --selector string            Selector (label query) to filter on. If present, default to ".*" for the pod-query.
  -s, --since duration             Return logs newer than a relative duration like 5s, 2m, or 3h. Defaults to 48h.
      --tail int                   The number of lines from the end of the logs to show. Defaults to -1, showing all logs. (default -1)
      --template string            Template to use for log lines, leave empty to use --output flag
  -t, --timestamps                 Print timestamps
  -v, --version                    Print the version and exit

[2] You can skip in stern the -n option if you before have selected the "tutorial" namespace. You can reproduce it this way

λ oc login -u admin -p a
Login successful.

You have access to the following projects and can switch between them with 'oc project <projectname>':

    default
    istio-operator
    istio-system
    kube-dns
    kube-proxy
    kube-public
    kube-system
  * myproject
    openshift
    openshift-apiserver
    openshift-controller-manager
    openshift-core-operators
    openshift-infra
    openshift-node
    openshift-service-cert-signer
    openshift-web-console
    tutorial

Using project "myproject".

C:\Tools
λ oc get pods -n tutorial
NAME                        READY     STATUS      RESTARTS   AGE
customer-1-7bml8            2/2       Running     6          1d
customer-1-build            0/1       Completed   0          1d
preference-v1-1-build       0/1       Completed   0          23h
preference-v1-1-jhldg       2/2       Running     6          23h
recommendation-v1-1-7clfx   2/2       Running     6          23h
recommendation-v1-1-build   0/1       Completed   0          23h
C:\Tools
λ stern customer-1-7bml8 -c customer

C:\Tools
λ stern customer-1-7bml8 -c customer -n tutorial
+ customer-1-7bml8 › customer
customer-1-7bml8 customer Starting the Java application using /opt/run-java/run-java.sh ...
customer-1-7bml8 customer exec java -Xms128m -Xmx256m -Djava.net.preferIPv4Stack=true -javaagent:/opt/jolokia/jolokia.jar=config=/opt/jolokia/etc/jolokia.properties -javaagent:/opt/prometheus/jmx_prometheus_javaagent.jar=9779:/opt/prometheus/prometheus-config.yml -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MinHeapFreeRatio=20 -XX:MaxHeapFreeRatio=40 -XX:+ExitOnOutOfMemoryError -cp . -jar /deployments/customer.jar
...

If you do this

C:\Tools
λ oc project tutorial
Now using project "tutorial" on server "https://192.168.5.100:8443".

C:\Tools
λ stern customer-1-7bml8 -c customer
+ customer-1-7bml8 › customer
customer-1-7bml8 customer Starting the Java application using /opt/run-java/run-java.sh ...
customer-1-7bml8 customer exec java -Xms128m -Xmx256m -Djava.net.preferIPv4Stack=true -javaagent:/opt/jolokia/jolokia.jar=config=/opt/jolokia/etc/jolokia.properties -javaagent:/opt/prometheus/jmx_prometheus_javaagent.jar=9779:/opt/prometheus/prometheus-config.yml -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MinHeapFreeRatio=20 -XX:MaxHeapFreeRatio=40 -XX:+ExitOnOutOfMemoryError -cp . -jar /deployments/customer.jar
customer-1-7bml8 customer I> No access restrictor found, access to any MBean is allowed
...

it works as the namespace "tutorial" is set implicit by the command before

[lordofthejars]

Ok, but in my case also it works when I do not specify the pod name, but a pod-query stern customer -c customer