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Installation

Installation

With our solution for Monitoring OpenShift, you can start monitoring your clusters in under 10 minutes, including forwarding metadata-enriched container logs, host logs, and metrics.

Features:

Log forwarding is built on native JSON logging driver.
Tiny image, tiny binary. Very low memory, CPU, and disk consumption.
Logs are enriched with OpenShift metadata (container, image, pod, daemon sets, jobs, cron jobs, etc.).
Collect stats and events, allowing you to correlate logs with metrics.
Collects process metrics.
Forwards host logs allows us to monitor main components of the cluster.
Uses HTTP Event Collector to ingest data in Splunk. Requires Splunk version 6.5 or above (talk to us if you need support for an earlier version of Splunk).
Multi-line events support.
Security Monitoring (privileged containers and enabled capabilities).
Capacity Monitoring (Available and allocated resource, CPU Shares, CPU Quotas, Memory Limits for containers).
At least once delivery guarantee.

Splunk configuration

Install Monitoring OpenShift application

Install Monitoring OpenShift from splunkbase. You need to install it on Search Heads only.

Enable HTTP Event Collector in Splunk

Outcold Solutions' Collector sends data to Splunk using HTTP Event Collector. By default, Splunk does not enable HTTP Event Collector. Please read HTTP Event Collector walkthrough to learn more about HTTP Event Collector.

After enabling HTTP Event Collector, you need to find correct Url for HTTP Event Collector and generate an HTTP Event Collector Token. If you are running your Splunk instance on hostname hec.example.com, it listens on port 8088, using SSL and token is B5A79AAD-D822-46CC-80D1-819F80D7BFB0 you can test it with the curl command as in the example below.

$ curl -k https://hec.example.com:8088/services/collector/event/1.0 -H "Authorization: Splunk B5A79AAD-D822-46CC-80D1-819F80D7BFB0" -d '{"event": "hello world"}'
{"text": "Success", "code": 0}

-k is necessary for self-signed certificates.

OpenShift preparation

To be able to use our solution and get all the benefits, you will need to perform preparation on every OpenShift node in your cluster.

Docker logging driver

When you set up your OpenShift cluster, verify that docker uses json-file logging driver.

RHEL by default configures docker with journald. Base on your Linux distribution you can find this configuration in various places. In case of latest RHEL Server 7.4 you can find it under /etc/sysconfig/docker. Replace --log-driver=journald with --log-driver=json-file --log-opt max-size=1M --log-opt max-file=3. It is important to limit the size of the log files and number of them, see Managing Container Logs for details.

$ sed -i 's/--log-driver=journald/--log-driver=json-file --log-opt max-size=1M --log-opt max-file=3/' /etc/sysconfig/docker
$ systemctl restart docker

If you are using Red Hat Container Development Kit, it will pre-setup minishift with journald logging driver. You can change it when you start minishift for the first time with minishift start --docker-opt log-driver=json-file.

Syslog and host logs

RHEL Server distribution might not include rsyslog installed by default. That means that all host logs (including OpenShift components and host logs) are stored only with journalctl. By default, journalctl knows how to forward logs to local syslog server. In most cases you just need to install rsyslog and after that, you will see host logs under /var/log/messages.

$ sudo yum install rsyslog
$ sudo systemctl enable rsyslog
$ sudo systemctl start rsyslog

Verify that you can see syslog messages under /var/log/messages.

$ tail /var/log/messages

Install Collector for OpenShift

Verify that you are in the context of the user who can perform admin operations (cluster-admin role).

$ oc login -u system:admin

Because we are monitoring log files located on the host volumes, collector needs access to host volume. To enable it run (see Use the hostPath Volume Plug-in)

$ oc edit scc privileged

Verify that privileged security context can access host dir volumes and can run privileged containers. By default it has these capabilities.

allowHostDirVolumePlugin: true
allowPrivilegedContainer: true

Use latest OpenShift configuration file collectorforopenshift.yaml. This configuration deploys latest image of collectorforopenshift on all OpenShift nodes as a DaemonSet workload.

Open it in your favorite editor and set the Splunk HTTP Event Collector Url, token, configuration for a certificate if required, and accept a license agreement.

[general]

; acceptEULA = false

...

# Splunk output
[output.splunk]

# Splunk HTTP Event Collector url
; url =

# Splunk HTTP Event Collector Token
; token =

# Allow invalid SSL server certificate
; insecure = false

# Path to CA certificate
; caPath =

# CA Name to verify
; caName =

Based on the example above you will need to modify the lines as in the following.

[general]

acceptEULA = true

...

# Splunk output
[output.splunk]

# Splunk HTTP Event Collector url
url = https://hec.example.com:8088/services/collector/event/1.0

# Splunk HTTP Event Collector Token
token = B5A79AAD-D822-46CC-80D1-819F80D7BFB0

# Allow invalid SSL server certificate
insecure = true

Apply this change to your OpenShift cluster with oc

$ oc apply -f ./collectorforopenshift.yaml

After that, you need to add privileged security context to the Service Account we use for the collector.

$ oc adm policy add-scc-to-user privileged system:serviceaccount:default:collectorforopenshift

If you see an error message the server could not find the requested resource, possible that you are using a mismatched version of the oc tool and the server version. You can accomplish the same by using command oc edit securitycontextconstraints privileged and adding system:serviceaccount:default:collectorforopenshift to the list of users.

If you are using Red Hat certified images from registry.connect.redhat.com, make sure to specify the secret for pulling the image. See instructions on the Configuration Reference page.

Verify that Daemon Set is deployed.

$ oc get daemonsets --all-namespaces

If collectorforopenshift Pods aren't deployed, follow the Troubleshooting steps.

Give it a few moments to download the image and start the container. After all the pods are deployed, go to the Monitoring OpenShift application in Splunk and you should see data on dashboards.

Screencasts

Installation process

Solution Overview

Links

Outcold Solutions provides solutions for monitoring Kubernetes, OpenShift and Docker clusters in Splunk Enterprise and Splunk Cloud. We offer certified Splunk applications, which gives you insights across all containers environments. We are helping businesses reduce complexity related to logging and monitoring by providing easy-to-use and deploy solutions for Linux and Windows containers. We deliver applications, which helps developers monitor their applications and operators to keep their clusters healthy. With the power of Splunk Enterprise and Splunk Cloud, we offer one solution to help you keep all the metrics and logs in one place, allowing you to quickly address complex questions on container performance.

Monitoring OpenShift - Version 3