This is an experimental Prometheus setup for monitoring Kubernetes services that expose prometheus-friendly metrics through address http://service_address:service_port/metrics.
The purpose of the setup is to gather performance-related metrics during load tests and analyze them to find and fix bottlenecks.
- Pick a local directory for promdash. It can be any directory, preferably one which is stable and which you don't mind keeping around. Then (in our case, we use /mnt/promdash, just run this docker command
docker run -v /mnt/promdash:/mnt/promdash -e DATABASE_URL=sqlite3:/mnt/promdash/file.sqlite3 prom/promdash ./bin/rake db:migrate
. In the future, we might use mysql as the promdash database, however, in any case, this 1 time db setup step is required.
Now quickly confirm that /mnt/promdash/file.sqlite3 exists, and has a non-zero size, and make sure its permissions are open so that containers can read from it. For example:
[jay@rhbd kubernetes]$ ls -altrh /mnt/promdash/
total 20K
drwxr-xr-x. 6 root root 4.0K May 6 23:12 ..
-rwxrwxrwx 1 root root 12K May 6 23:33 file.sqlite3
Looks open enough :).
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Now, you can start this pod, like so
kubectl create -f contrib/prometheus/prometheus-all.json
. This ReplicationController will maintain both prometheus, the server, as well as promdash, the visualization tool. You can then configure promdash, and next time you restart the pod - you're configuration will be remain (since the promdash directory was mounted as a local docker volume). -
Finally, you can simply access localhost:3000, which will have promdash running. Then, add the prometheus server (locahost:9090)to as a promdash server, and create a dashboard according to the promdash directions.
You can launch prometheus easily, by simply running.
kubectl create -f contrib/prometheus/prometheus-all.json
Then (edit the publicIP field in prometheus-service to be a public ip on one of your kubelets),
and run
kubectl create -f contrib/prometheus/prometheus-service.json
Now, you can access the service wget 10.0.1.89:9090
, and build graphs.
This is a v1 api based, containerized prometheus ReplicationController, which scrapes endpoints which are readable on the KUBERNETES service (the internal kubernetes service running in the default namespace, which is visible to all pods).
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Use kubectl to handle auth & proxy the kubernetes API locally, emulating the old KUBERNETES_RO service.
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The list of services to be monitored is passed as a command line aguments in the yaml file.
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The startup scripts assumes that each service T will have 2 environment variables set
T_SERVICE_HOST
andT_SERVICE_PORT
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Each can be configured manually in yaml file if you want to monitor something that is not a regular Kubernetes service. For example, you can add comma delimted endpoints which can be scraped like so...
- -t
- KUBERNETES_RO,MY_OTHER_METRIC_SERVICE
For regular Kubernetes services the env variables are set up automatically and injected at runtime.
By default the metrics are written to a temporary location (that can be changed in the the volumes section of the yaml file). Prometheus' UI is available at port 9090.
- We should publish this image into the kube/ namespace.
- Possibly use postgre or mysql as a promdash database.
- push gateway (https://github.com/prometheus/pushgateway) setup.
- stop using kubectl to make a local proxy faking the old RO port and build in real auth capabilities.