https://github.com/petems/java-simple-step-apm-minikube
A minikube lab to show out Single Step APM works for a Java app in K8s
https://github.com/petems/java-simple-step-apm-minikube
Last synced: 4 months ago
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A minikube lab to show out Single Step APM works for a Java app in K8s
- Host: GitHub
- URL: https://github.com/petems/java-simple-step-apm-minikube
- Owner: petems
- Created: 2024-04-03T13:16:35.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2024-04-22T18:12:39.000Z (about 1 year ago)
- Last Synced: 2025-01-12T16:37:49.135Z (6 months ago)
- Homepage:
- Size: 5.86 KB
- Stars: 0
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# java-simple-step-apm-minikube
A basic setup showing how Simple Step APM works for Java (aka. Automatic Tracer Injection)
The setup is as follows:
* Minikube
* Datadog Agent
* A Simple Java App without the Datadog tracer in it natively - [petems/datadog-java-apm-demo](https://github.com/petems/datadog-java-apm-demo)
**NB: We're assuming you're running with docker engine on an OSX `arm64` Macbook Pro, but should work on amd64 as I pushed a multi-build version of the image**
Automagically, the [Single Step APM](https://docs.datadoghq.com/tracing/trace_collection/automatic_instrumentation/single-step-apm/?tab=linuxhostorvm) setup will automatically inject the Datadog Java Tracer into the existing image
## Start minikube
```
minikube start
```
## Deploy datadog agent
```
$ kubectl create secret generic datadog-secret --from-literal api-key=YOURKEYHERE
$ helm install datadog-agent -f datadog-values.yaml datadog/datadog
```
## Wait for Datadog agent to confirm healthy
```
$ kubectl get pods -w
NAME READY STATUS RESTARTS AGE
datadog-agent-2bgmt 3/3 Running 0 89s
datadog-agent-cluster-agent-6f446955b4-zjl55 0/1 Running 3 (47s ago) 89s
datadog-agent-cluster-agent-6f446955b4-zjl55 1/1 Running 3 (48s ago) 90s
```
## Run the Java app
```
kubectl apply -f java-app.yaml
```
## Wait for Java app to confirm healthy
```
kubectl get pods datadog-java-apm-demo
NAME READY STATUS RESTARTS AGE
datadog-java-apm-demo 1/1 Running 0 18m
```
## Deploy it as a service
```
$ kubectl expose deployment java-app --type=LoadBalancer --port=8080
service/java-app exposed
$ kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
datadog-agent ClusterIP 10.99.167.139 8125/UDP,8126/TCP 105m
datadog-agent-cluster-agent ClusterIP 10.101.255.109 5005/TCP 105m
datadog-agent-cluster-agent-admission-controller ClusterIP 10.109.153.38 443/TCP 105m
java-app LoadBalancer 10.98.20.110 8080:30800/TCP 4s
kubernetes ClusterIP 10.96.0.1 443/TCP 106m
```
Run it as a minikube service so we can open it in the browser:
```
$ minikube service java-app
|-----------|----------|-------------|---------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|----------|-------------|---------------------------|
| default | java-app | 8080 | http://192.168.49.2:30800 |
|-----------|----------|-------------|---------------------------|
🏃 Starting tunnel for service java-app.
|-----------|----------|-------------|------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|----------|-------------|------------------------|
| default | java-app | | http://127.0.0.1:52838 |
|-----------|----------|-------------|------------------------|
🎉 Opening service default/java-app in default browser...
❗ Because you are using a Docker driver on darwin, the terminal needs to be open to run it.
```
## Observe the Single Step APM Settings
Do some pod describes so you can see the automatic injection working:
```
$ kubectl describe pod datadog-java-apm-demo | grep Volumes -C 14
DD_ENTITY_ID: (v1:metadata.uid)
DD_DOGSTATSD_URL: unix:///var/run/datadog/dsd.socket
DD_TRACE_AGENT_URL: unix:///var/run/datadog/apm.socket
JAVA_TOOL_OPTIONS: -javaagent:/datadog-lib/dd-java-agent.jar -XX:OnError=/datadog-lib/continuousprofiler/tmp/dd_crash_uploader.sh -XX:ErrorFile=/datadog-lib/continuousprofiler/tmp/hs_err_pid_%p.log
Mounts:
/datadog-lib from datadog-auto-instrumentation (rw)
/var/run/datadog from datadog (ro)
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-w82b6 (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kube-api-access-w82b6:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional:
DownwardAPI: true
datadog:
Type: HostPath (bare host directory volume)
Path: /var/run/datadog
HostPathType: DirectoryOrCreate
datadog-auto-instrumentation:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit:
```
You can see the `datadog-auto-instrumentation` volume set as an `EmptyDir` that shares the pods lifetime
We can also see the environment variables that add the `JAVA_TOOL_OPTIONS ` has worked as well:
```
$ kubectl describe pod datadog-java-apm-demo | grep Environment -C 9
Finished: Wed, 03 Apr 2024 13:53:40 +0100
Ready: True
Restart Count: 0
Limits:
cpu: 50m
memory: 20971520
Requests:
cpu: 50m
memory: 20971520
Environment:
DD_INSTRUMENTATION_INSTALL_ID: c75eace2-f3dd-4484-a5a8-f03056ccc739
DD_INSTRUMENTATION_INSTALL_TIME: 1712147422
DD_ENTITY_ID: (v1:metadata.uid)
DD_DOGSTATSD_URL: unix:///var/run/datadog/dsd.socket
DD_TRACE_AGENT_URL: unix:///var/run/datadog/apm.socket
Mounts:
/datadog-lib from datadog-auto-instrumentation (rw)
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-w82b6 (ro)
Containers:
--
Container ID: docker://703cff397f2736d41048e0949e69427fb1825457b24852968bea192344e5d562
Image: petems/datadog-java-apm-demo
Image ID: docker-pullable://petems/datadog-java-apm-demo@sha256:7ad25e7c0aa4c0104f3d98a8cb46bad8ec31619e8d7e471c3fe4eed25d67fc2a
Port: 8080/TCP
Host Port: 0/TCP
State: Running
Started: Wed, 03 Apr 2024 13:53:49 +0100
Ready: True
Restart Count: 0
Environment:
DD_INSTRUMENTATION_INSTALL_TYPE: k8s_lib_injection
DD_INSTRUMENTATION_INSTALL_ID: c75eace2-f3dd-4484-a5a8-f03056ccc739
DD_INSTRUMENTATION_INSTALL_TIME: 1712147422
DD_ENTITY_ID: (v1:metadata.uid)
DD_DOGSTATSD_URL: unix:///var/run/datadog/dsd.socket
DD_TRACE_AGENT_URL: unix:///var/run/datadog/apm.socket
JAVA_TOOL_OPTIONS: -javaagent:/datadog-lib/dd-java-agent.jar -XX:OnError=/datadog-lib/continuousprofiler/tmp/dd_crash_uploader.sh -XX:ErrorFile=/datadog-lib/continuousprofiler/tmp/hs_err_pid_%p.log
Mounts:
/datadog-lib from datadog-auto-instrumentation (rw)
```
We can also look at the logs for the app to see the Datadog tracer is running:
```
$ kubectl logs datadog-java-apm-demo | grep dd-java-agent.jar
Defaulted container "java-service" out of: java-service, datadog-lib-java-init (init)
Picked up JAVA_TOOL_OPTIONS: -javaagent:/datadog-lib/dd-java-agent.jar -XX:OnError=/datadog-lib/continuousprofiler/tmp/dd_crash_uploader.sh -XX:ErrorFile=/datadog-lib/continuousprofiler/tmp/hs_err_pid_%p.log
```
## Jump into the Java app to create some traces
Now we know the tracer has been injected, we can create some traces:
```
$ kubectl exec -it datadog-java-apm-demo /bin/sh
# apk add curl
(1/5) Installing ca-certificates (20240226-r0)
(2/5) Installing brotli-libs (1.0.9-r6)
(3/5) Installing nghttp2-libs (1.47.0-r2)
(4/5) Installing libcurl (8.5.0-r0)
(5/5) Installing curl (8.5.0-r0)
Executing busybox-1.35.0-r17.trigger
Executing ca-certificates-20240226-r0.trigger
OK: 325 MiB in 22 packages
/ # curl localhost:8080/success
/ # curl localhost:8080/failure
{"timestamp":"2024-04-03T12:57:52.478+00:00","status":500,"error":"Internal Server Error","path":"/failure"}/ # exit
```
## Confirm Traces are showing in Datadog
* Go to the APM page and see the traces
## TODO
* Add curl into the image
* Get the logs sending as well
* Better annotations and labelling
## Attributions
Built heavily on the work by @nilushancosta - https://medium.com/@nilushancosta/how-to-automatically-add-datadog-apm-libraries-for-java-into-containers-on-kubernetes-8ab0db2606bb