Application observability via container build-time injection

Inject OneAgent code modules into a container during its build process.

This method of application instrumentation has limitations in linking Kubernetes workloads with monitored containers/processes. To achieve proper relationships and linking, consider using automatic application-only injection.

Prerequisites

Deploy

To integrate OneAgent into the application image, follow the steps below.

  1. Sign in to Docker with your Dynatrace environment ID as username and access token as password.

    docker login -u <environmentID> -p <accessToken> <environmentURL>
  2. Add the following lines of code to the application image, after the last FROM command:

    COPY --from=<environment>/linux/oneagent-codemodules:<technology> / /
    ENV LD_PRELOAD /opt/dynatrace/oneagent/agent/lib64/liboneagentproc.so
    • <technology>—OneAgent code module required for your application. Available options are all, java, apache, nginx, nodejs, dotnet, php, go, and sdk. You can specify several code modules, separated by hyphen (-), for example java-go. Including specific technology-support options, rather than support for all technology options, results in a smaller OneAgent package.

Dynatrace OneAgent supports Alpine Linux based environments.

COPY --from=<ACTIVEGATE-ADDRESS>/linux/oneagent-codemodules-musl:<TECHNOLOGY> / /
ENV LD_PRELOAD /opt/dynatrace/oneagent/agent/lib64/liboneagentproc.so

Valid options here are: all, dotnet, php, java, apache, nginx, nodejs, and go.

  1. Build your application image.

    Build the Docker image from your Dockerfile to use it in your Kubernetes environment.

    docker build -t yourapp .

You can monitor your application containers with a different Dynatrace environment.

For OneAgent version 1.139+, if you have an existing application image where you've already added the OneAgent code modules for a specific Dynatrace environment, you can have the OneAgent report to another Dynatrace environment without rebuilding your application image.
For this, you need to make a call to the REST endpoint of your second Dynatrace environment. Don't forget to adapt the respective placeholders <environmentID> and <token>.

curl "https://<environmentID>.live.dynatrace.com/api/v1/deployment/installer/agent/connectioninfo?Api-Token=<token>"

In return, you get a JSON object that covers the required information that needs to be passed as an environment variable to the application container.
Make sure you set the environment variables of the application container as described below:

  • DT_TENANT: equals tenantUUID
  • DT_TENANTTOKEN: equals tenantToken
  • DT_CONNECTION_POINT: semi-colon separated list of communicationEndpoints
  1. optional Configure network zones

You can configure network zones as an environment variable:

  • DT_NETWORK_ZONE: equals your.network.zone

See network zones for more information.

  1. optional Configure a proxy address

    In case you run an environment with proxy, you need to set the DT_PROXY environment variable in the application container to pass the proxy credentials to OneAgent.

    For Alpine Linux-based containers, you might need to update the wget shipped with the Alpine image to allow for proxy authentication for the download of OneAgent.

Update

You need to manually update OneAgent by rebuilding the container image every time a new version of a code module is needed.

Uninstall

To uninstall OneAgent from application-only monitoring

  1. Remove the two lines of code from the application image.

    COPY --from=<ACTIVEGATE-ADDRESS>/linux/oneagent-codemodules:<TECHNOLOGY> / /
    ENV LD_PRELOAD /opt/dynatrace/oneagent/agent/lib64/liboneagentproc.so
  2. Rebuild the application image.

    docker build -t yourapp .