b) Logging and Visualization for Helm Chart oudsm Deployment

Introduction

This section describes how to install and configure logging and visualization for the oudsm Helm chart deployment.

The ELK stack consists of Elasticsearch, Logstash, and Kibana. Using ELK you can gain insights in real-time from the log data from your applications.

  • Elasticsearch is a distributed, RESTful search and analytics engine capable of solving a growing number of use cases. As the heart of the Elastic Stack, it centrally stores your data so you can discover the expected and uncover the unexpected.
  • Logstash is an open source, server-side data processing pipeline that ingests data from a multitude of sources simultaneously, transforms it, and then sends it to your favorite “stash.”
  • Kibana lets you visualize your Elasticsearch data and navigate the Elastic Stack. It gives you the freedom to select the way you give shape to your data. And you don’t always have to know what you’re looking for.

Install Elasticsearch and Kibana

If you do not already have a centralized Elasticsearch (ELK) stack then you must configure this first. For details on how to configure the ELK stack, follow Installing Elasticsearch (ELK) Stack and Kibana

Create the logstash pod

Variables used in this chapter

In order to create the logstash pod, you must create a yaml file. This file contains variables which you must substitute with variables applicable to your ELK environment.

Most of the values for the variables will be based on your ELK deployment as per Installing Elasticsearch (ELK) Stack and Kibana.

The table below outlines the variables and values you must set:

Variable Sample Value Description
<ELK_VER> 8.3.1 The version of logstash you want to install.
<ELK_SSL> true If SSL is enabled for ELK set the value to true, or if NON-SSL set to false. This value must be lowercase.
<ELK_HOSTS> https://elasticsearch.example.com:9200 The URL for sending logs to Elasticsearch. HTTP if NON-SSL is used.
<ELK_USER> logstash_internal The name of the user for logstash to access Elasticsearch.
<ELK_PASSWORD> password The password for ELK_USER.
<ELK_APIKEY> apikey The API key details.

You will also need the BASE64 version of the Certificate Authority (CA) certificate(s) that signed the certificate of the Elasticsearch server. If using a self-signed certificate, this is the self signed certificate of the Elasticsearch server. See Copying the Elasticsearch Certificate for details on how to get the correct certificate. In the example below the certificate is called elk.crt.

Create Kubernetes secrets

  1. Create a Kubernetes secret for Elasticsearch using the API Key or Password.

    a) If ELK uses an API Key for authentication:

    $ kubectl create secret generic elasticsearch-pw-elastic -n <domain_namespace> --from-literal password=<ELK_APIKEY>

    For example:

    $ kubectl create secret generic elasticsearch-pw-elastic -n oudsmns --from-literal password=<ELK_APIKEY>

    The output will look similar to the following:

    secret/elasticsearch-pw-elastic created

    b) If ELK uses a password for authentication:

    $ kubectl create secret generic elasticsearch-pw-elastic -n <domain_namespace> --from-literal password=<ELK_PASSWORD>

    For example:

    $ kubectl create secret generic elasticsearch-pw-elastic -n oudsmns --from-literal password=<ELK_PASSWORD>

    The output will look similar to the following:

    secret/elasticsearch-pw-elastic created

    Note: It is recommended that the ELK Stack is created with authentication enabled. If no authentication is enabled you may create a secret using the values above.

  2. Create a Kubernetes secret to access the required images on hub.docker.com:

    Note: You must first have a user account on hub.docker.com:

    $ kubectl create secret docker-registry "dockercred" --docker-server="https://index.docker.io/v1/" --docker-username="<docker_username>" --docker-password=<password> --docker-email=<docker_email_credentials> --namespace=<domain_namespace>

    For example:

    $ kubectl create secret docker-registry "dockercred" --docker-server="https://index.docker.io/v1/" --docker-username="username" --docker-password=<password> --docker-email=user@example.com --namespace=oudsmns

    The output will look similar to the following:

    secret/dockercred created

Enable logstash

  1. Navigate to the $WORKDIR/kubernetes/helm directory and create a logging-override-values.yaml file as follows:

    elk:
  imagePullSecrets:
    - name: dockercred
  IntegrationEnabled: true
  logStashImage: logstash:<ELK_VER>
  logstashConfigMap: false
  esindex: oudsmlogs-00001
  sslenabled: <ELK_SSL>
  eshosts: <ELK_HOSTS>
  # Note: We need to provide either esuser,espassword or esapikey
  esuser: <ELK_USER>
  espassword: elasticsearch-pw-elastic
  esapikey: elasticsearch-pw-elastic
    • Change the <ELK_VER>, <ELK_SSL>, <ELK_HOSTS>, and <ELK_USER>, to match the values for your environment.
    • If using SSL, replace the elk.crt in $WORKDIR/kubernetes/helm/oudsm/certs/ with the elk.crt for your ElasticSearch server.
    • If using API KEY for your ELK authentication, leave both esuser: and espassword: with no value.
    • If using a password for ELK authentication, leave esapi_key: but delete elasticsearch-pw-elastic.
    • If no authentication is used for ELK, leave esuser, espassword, and esapi_key with no value assigned.
    • The rest of the lines in the yaml file should not be changed.

    For example:

    elk:
  imagePullSecrets:
    - name: dockercred
  IntegrationEnabled: true
  logStashImage: logstash:8.3.1
  logstashConfigMap: false
  esindex: oudsmlogs-00001
  sslenabled: true   
  eshosts: https://elasticsearch.example.com:9200
  # Note: We need to provide either esuser,espassword or esapikey
  esuser: logstash_internal
  espassword: elasticsearch-pw-elastic
  esapikey:

Upgrade oudsm deployment with ELK configuration

  1. Run the following command to upgrade the oudsm deployment with the ELK configuration:

    $ helm upgrade --namespace <namespace> --values <valuesfile.yaml> <releasename> oudsm --reuse-values

    For example:

    $ helm upgrade --namespace oudsmns --values logging-override-values.yaml oudsm oudsm --reuse-values

    The output should look similar to the following:

    Release "oudsm" has been upgraded. Happy Helming!
NAME: oudsm
LAST DEPLOYED: <DATE>
NAMESPACE: oudsmns
STATUS: deployed
REVISION: 2
TEST SUITE: None

Verify the pods

  1. Run the following command to check the logstash pod is created correctly:

    $ kubectl get pods -n <namespace>

    For example:

    $ kubectl get pods -n oudsmns

    The output should look similar to the following:

    NAME                              READY   STATUS    RESTARTS   AGE
oudsm-1                           1/1     Running   0          51m
oudsm-logstash-56dbcc6d9f-mxsgj   1/1     Running   0          2m7s

    Note: Wait a couple of minutes to make sure the pod has not had any failures or restarts. If the pod fails you can view the pod log using:

    $ kubectl logs -f oudsm-logstash-<pod> -n oudsmns

    Most errors occur due to misconfiguration of the logging-override-values.yaml. This is usually because of an incorrect value set, or the certificate was not pasted with the correct indentation.

    If the pod has errors, view the helm history to find the last working revision, for example:

    $ helm history oudsm -n oudsmns

    The output will look similar to the following:

    REVISION        UPDATED       STATUS          CHART           APP VERSION     DESCRIPTION
1               <DATE>        superseded      oudsm-0.1       12.2.1.4.0      Install complete
2               <DATE>        deployed        oudsm-0.1       12.2.1.4.0      Upgrade complete

    Rollback to the previous working revision by running:

    $ helm rollback <release> <revision> -n <domain_namespace>

    For example:

    helm rollback oudsm 1 -n oudsmns

    Once you have resolved the issue in the yaml files, run the helm upgrade command outlined earlier to recreate the logstash pod.

Verify and access the Kibana console

To access the Kibana console you will need the Kibana URL as per Installing Elasticsearch (ELK) Stack and Kibana.

For Kibana 7.7.x and below:

  1. Access the Kibana console with http://<hostname>:<port>/app/kibana and login with your username and password.

  2. From the Navigation menu, navigate to Management > Kibana > Index Patterns.

  3. In the Create Index Pattern page enter oudsmlogs* for the Index pattern and click Next Step.

  4. In the Configure settings page, from the Time Filter field name drop down menu select @timestamp and click Create index pattern.

  5. Once the index pattern is created click on Discover in the navigation menu to view the OUDSM logs.

For Kibana version 7.8.X and above:

  1. Access the Kibana console with http://<hostname>:<port>/app/kibana and login with your username and password.

  2. From the Navigation menu, navigate to Management > Stack Management.

  3. Click Data Views in the Kibana section.

  4. Click Create Data View and enter the following information:

    • Name: oudsmlogs*
    • Timestamp: @timestamp

  5. Click Create Data View.

  6. From the Navigation menu, click Discover to view the log file entries.

  7. From the drop down menu, select oudsmlogs* to view the log file entries.