Run a Wavefront proxy in a Kubernetes container and customize it.

VMware Aria Operations for Applications (formerly known as Tanzu Observability by Wavefront) supports setting up the Wavefront proxy to run in a Kubernetes container. However, you cannot rely on a single wavefront.conf file. Instead, a ConfigMap file governs deployment.

  1. Create a custom ConfigMap file that contains the custom setup, for example preprocessing rules, for your proxy configuration. This doc page creates a 00_proxy-preprocessor-config.yaml file.
  2. Edit wavefront.yaml so it points to the ConfigMap file.
  3. Test your setup.

Example: Use a Custom ConfigMap to Include Preprocessor Rules

This section illustrates how to use a custom ConfigMap to block traffic for some metrics via preprocessor rules. You can use the same approach to, for example, have the Wavefront proxy use an HTTPS proxy.

In this section, we first create a custom ConfigMap (00_proxy-preprocessor-config.yaml) that includes preprocessor rules to block metrics. Then we customize the wavefront.yaml so it points to our Operations for Applications service instance, includes the proxy authentication, and points to the ConfigMap file.

1. Create a file called 00_proxy-preprocessor-config.yaml with content like the following. This sample file includes some examples of preprocessor rules that block certain metrics.

apiVersion: v1 kind: ConfigMap metadata:   name: proxy-preprocessor-config   namespace: default data:   preprocessor_rules.yaml: |     # preprocessor rule to drop tag service with empty values     '2878':       - rule      : filter-metric-by-name         action    : block         if:           equals:             scope: metricName             value: ["illegal.metric"]        - rule      : filter-metric-by-ip         action    : block         if:           any:             - startsWith:                 scope: sourceName                 value: "127.0.0."             - startsWith:                 scope: ip                 value: "127.0.0."

2. Update your wavefront.yaml (your deployment yaml for Wavefront proxy).

# Change <your_instance> and the values for the proxy authentication parameters depending on your subscription type.  apiVersion: apps/v1 # Kubernetes versions after 1.9.0 should use apps/v1 # Kubernetes version 1.8.x should use apps/v1beta2 # Kubernetes versions before 1.8.0 should use apps/v1beta1 kind: Deployment metadata:   labels:     app: wavefront-proxy     name: wavefront-proxy   name: wavefront-proxy   namespace: default spec:   replicas: 1   selector:     matchLabels:       app: wavefront-proxy   template:     metadata:       labels:         app: wavefront-proxy     spec:       containers:       - name: wavefront-proxy         image: wavefronthq/proxy:latest         imagePullPolicy: Always         env:         - name: WAVEFRONT_URL           value: <https://<your_instance>.wavefront.com/api/         - name: WAVEFRONT_PROXY_ARGS           value: --preprocessorConfigFile /preprocessor-config/preprocessor_rules.yaml --histogramDistListenerPorts 40000 --traceListenerPorts 2878         ports:         - containerPort: 2878           protocol: TCP         # Uncomment the below lines to consume Zipkin/Istio traces         #- containerPort: 9411         #  protocol: TCP         - containerPort: 40000           protocol: TCP         volumeMounts:         - name: proxy-preprocessor-config           mountPath: /preprocessor-config/           readOnly: true         securityContext:           privileged: false       volumes:       - name: proxy-preprocessor-config         configMap:           name: proxy-preprocessor-config --- apiVersion: v1 kind: Service metadata:   name: wavefront-proxy   labels:     app: wavefront-proxy   namespace: default spec:   ports:   - name: wavefront     port: 2878     protocol: TCP   # Uncomment the below lines to consume Zipkin/Istio traces   #- name: http   #  port: 9411   #  targetPort: 9411   #  protocol: TCP   - name: traces     port: 30000     protocol: TCP   - name: histogram     port: 40000     protocol: TCP   selector:     app: wavefront-proxy

3. Notice these settings in this wavefront.yaml file:

 volumes: - name: proxy-preprocessor-config   configMap:     name: proxy-preprocessor-config
The volumes (coming from the ConfigMap) and volume mounts inside the container that mounts it on as /preprocessor-config/preprocessor_rules.yaml 
 - name: WAVEFRONT_PROXY_ARGS   value: --preprocessorConfigFile /preprocessor-config/preprocessor_rules.yaml
The WAVEFRONT_PROXY_ARGS environment variable sets --preprocessorConfigFile to /preprocessor-config/preprocessor_rules.yaml to let the proxy know how find the preprocessor_rules.yaml file.

4. To apply the updated YAML file run kubectl apply -f.

Test Your Setup

To test your setup, look at the log first, then send some data to the proxy.

Look at the Log

1. To get the log of the proxy, run kubectl logs wavefront-proxy-<id>

2. Check if there are errors during loading of the preprocessor rules. If everything works, you see messages like this:

2021-11-16 16:21:20,017 INFO  [PreprocessorConfigManager:loadFromStream] Loaded 2 rules for port :: 2878 2021-11-16 16:21:20,018 INFO  [PreprocessorConfigManager:loadFromStream] Loaded Preprocessor rules for port key :: "2878" 2021-11-16 16:21:20,018 INFO  [PreprocessorConfigManager:loadFromStream] Total Preprocessor rules loaded :: 2 2021-11-16 16:21:20,022 INFO  [proxy:initPreprocessors] Preprocessor configuration loaded from /preprocessor-config/preprocessor_rules.yaml

Send Data to the Proxy

Run an Ubuntu container and send some data to the proxy via the Netcat utility, as follows:

1. Create a file named ubuntu.yaml and enter the following:

apiVersion: v1 kind: Pod metadata:   name: ubuntu spec:   containers:   - name: ubuntu     image: ubuntu:latest     # Just spin & wait forever     command: [ "/bin/bash", "-c", "--" ]     args: [ "while true; do sleep 300; done;" ]

2. Run the following commands to

  • Run the Ubuntu container indefinitely
  • Install Netcat (nc)

  • Send metrics to the proxy (This is a crude approach but fine for testing).

    a. Start:

       exec

    b. Get a shell prompt:

       kubectl exec -it ubuntu /bin/bash

    c. Install Netcat:

       apt-get update    apt-get install -y netcat

    d. Use a simple command like this to send data into proxy:

       echo 'test.metric 123 source=test' | nc -C wavefront-proxy 2878

    The command sends a metric called test-metric with source source-test. e. Test that the preprocessor rule picks up and blocks data:

       echo 'illegal.metric 234 source=secret' | nc -C wavefront-proxy 2878    echo 'test.metric 351 source=127.0.0.1' | nc -C wavefront-proxy 2878

Learn More!

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