dimedrol/python-jaeger repository overview

⁠OpenTelemetry Demo w/Python

This is sample demo Python project which illustrates how Open Telemetry works. (Source code at GitHub⁠). As an OpenTelemetry API implementation in our case is Jaeger⁠.

To simplify the demo we'll use free DNS names from noip.com⁠.

Let's use NoIP's "hopto.org" zone for our demo purposes.

⁠Principal schema

⁠Hosts

In this demo we will use 3 hosts:

• localhost (for starting python-jaeger application from sources or docker)
• remoteservice.hopto.org (for starting 2nd instance if python-jaeger application, i.e. some remote service to call from the 1st service, which is running on localhost) and
• jaegerdemo.hopto.org (Jaeger UI, data collector)

⁠Docker

Everything which is needed for this demo is available as Docker images, so we'll use Docker to run Jaeger and python-jaeger applications.

⁠Why "localhost" is needed?

In this demo we will use 2 instances of python-jaeger application. The 1st instance will be running on localhost (from sources or Docker container) and the 2nd instance will be running on remote host (remoteservice.hopto.org). The 1st instance may report all activities to Jaeger collector directly (e.g. calling it's /v1/worker endpoint) or demonstrate a "cascade-call", calling /v1/remotecall with configured environment variable -e REMOTE_URL_TO_CALL=http://remoteservice.hopto.org/api/v1/worker calling the 2nd instance as a demo of complex multi-worker microservice architecture. We may use either localhost or remoteservice.hopto.org* for simple demo, but we need both for more complex demo. We will see the result (report) of this "cascade-call" in Jaeger UI width 2 spans (1st span is for the 1st instance and 2nd span is for the 2nd instance).

⁠How to run

⁠1. Jaeger

Go to jaegerdemo.hopto.org (having Docker service installed there, firewall opened) and run Jaeger collector and UI:

docker run -it --net=host jaegertracing/all-in-one:latest

Let's use --net=host for easier TCP/UDP ports management (N.B. security is out of this demo scope)

⁠2. Localhost

On the localhost machine run python-jaeger application either from Docker image or from sources. If we want to check the "cascade-call", start the optional 2nd python-jaeger instance (see below the 3rd option)

Running from sources on Windows machine may look like this:

g:\Projects\python-jaeger>set OTEL_EXPORTER_JAEGER_AGENT_HOST=jaegerdemo.hopto.org

g:\Projects\python-jaeger>set OTEL_EXPORTER_JAEGER_AGENT_PORT=6831

g:\Projects\python-jaeger>set REMOTE_URL_TO_CALL=http://remoteservice.hopto.org/api/v1/worker

g:\Projects\python-jaeger>python app/main.py
 * Serving Flask app "main" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)

Application will be available at http://localhost:8080

Pay attention to the environment variables: for Jaeger collector we use OTEL_EXPORTER_JAEGER_AGENT_HOST and OTEL_EXPORTER_JAEGER_AGENT_PORT (UDP port).

In case of Docker usage we may run it like this:

docker run -it --net=host -e REMOTE_URL_TO_CALL=remoteservice.hopto.org -e OTEL_EXPORTER_JAEGER_AGENT_HOST=jaegerdemo.hopto.org -e OTEL_EXPORTER_JAEGER_AGENT_PORT=6831 dimedrol/python-jaeger

REMOTE_URL_TO_CALL environment variable is optional, if it's not set, the "https://en.wikipedia.org/wiki/Tracing_(software)⁠" value will be used for demo purposes.

⁠3. Remote service (optional)

(Optional) On the remoteservice.hopto.org machine (having Docker service installed there, firewall opened) and run dockerized python-jaeger application:

docker run -it --net=host -e OTEL_EXPORTER_JAEGER_AGENT_HOST=jaegerdemo.hopto.org -e OTEL_EXPORTER_JAEGER_AGENT_PORT=6831 dimedrol/python-jaeger

Using --net=host here as well. Pay attention to the environment variables: for Jaeger collector we use OTEL_EXPORTER_JAEGER_AGENT_HOST and OTEL_EXPORTER_JAEGER_AGENT_PORT (UDP port).

⁠4. Ready

Make some requests from Swagger UI http://localhost:8080/api/ and/or http://remoteservice.hopto.org/api/ and check the results in Jaeger UI http://jaegerdemo.hopto.org:16686/

eof