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Explore Kuma with the Universal demo app
To start learning how Kuma works, you can download and run a simple demo application that consists of two services:
demo-app: web application that lets you increment a numeric counter
redis: data store for the counter
This guide also introduces some of the tools Kuma provides to help you control and monitor traffic, track resource status, and more.
demo-app service listens on port 5000. When it starts, it expects to find a zone key in Redis that specifies the name of the datacenter (or cluster) where the Redis instance is running. This name is displayed in the browser.
The zone key is purely static and arbitrary. Different zone values for different Redis instances let you keep track of which Redis instance stores the counter if you manage routes across different zones, clusters, and clouds.
- Redis installed
- Kuma installed
git clone https://github.com/kumahq/kuma-counter-demo.git
redisas a daemon on port 26379 and set a default zone name:
redis-server --port 26379 --daemonize yes redis-cli -p 26379 set zone local
Install and start
demo-appon the default port 5000:
npm install --prefix=app/ npm start --prefix=app/
Create a token for Redis and a token for the app:
kumactl generate dataplane-token --name=redis > kuma-token-redis kumactl generate dataplane-token --name=app > kuma-token-app
Create a data plane proxy for each service
kuma-dp run \ --cp-address=https://localhost:5678/ \ --dns-enabled=false \ --dataplane-token-file=kuma-token-redis \ --dataplane=" type: Dataplane mesh: default name: redis networking: address: 127.0.0.1 inbound: - port: 16379 servicePort: 26379 serviceAddress: 127.0.0.1 tags: kuma.io/service: redis kuma.io/protocol: tcp admin: port: 9901"
And for the demo app:
kuma-dp run \ --cp-address=https://localhost:5678/ \ --dns-enabled=false \ --dataplane-token-file=kuma-token-app \ --dataplane=" type: Dataplane mesh: default name: app networking: address: 127.0.0.1 outbound: - port: 6379 tags: kuma.io/service: redis inbound: - port: 15000 servicePort: 5000 serviceAddress: 127.0.0.1 tags: kuma.io/service: app kuma.io/protocol: http admin: port: 9902"
Navigate to 127.0.0.1:5000 and increment the counter.
Explore the mesh
You can view the sidecar proxies that are connected to the Kuma control plane:
Kuma ships with a read-only GUI that you can use to retrieve Kuma resources. By default the GUI listens on the API port and defaults to
You can navigate to
127.0.0.1:5681/meshes/default/dataplanes to see the connected dataplanes.
Enable Mutual TLS and Traffic Permissions
By default the network is unsecure and not encrypted. We can change this with Kuma by enabling the Mutual TLS policy to provision a dynamic Certificate Authority (CA) on the
default Mesh resource that will automatically assign TLS certificates to our services (more specifically to the injected dataplane proxies running alongside the services).
We can enable Mutual TLS with a
builtin CA backend by executing:
cat <<EOF | kumactl apply -f - type: Mesh name: default mtls: enabledBackend: ca-1 backends: - name: ca-1 type: builtin EOF
Once Mutual TLS has been enabled, Kuma will not allow traffic to flow freely across our services unless we explicitly have a Traffic Permission policy that describes what services can be consumed by other services. By default, a very permissive traffic permission is created.
For the sake of this demo we will delete it:
kumactl delete traffic-permission allow-all-default
You can try to make requests to the demo application at
127.0.0.1:5000/ and you will notice that they will not work.
Now let’s add back the default traffic permission:
cat <<EOF | kumactl apply -f - type: TrafficPermission name: allow-all-default mesh: default sources: - match: kuma.io/service: '*' destinations: - match: kuma.io/service: '*' EOF
By doing so every request we now make on our demo application at
127.0.0.1:5000/ is not only working again, but it is automatically encrypted and secure.
As usual, you can visualize the Mutual TLS configuration and the Traffic Permission policies we have just applied via the GUI, the HTTP API or
Explore Traffic Metrics
With Traffic Metrics we can leverage Prometheus and Grafana to provide powerful dashboards that visualize the overall traffic activity of our application and the status of the service mesh.
cat <<EOF | kumactl apply -f - type: Mesh name: default mtls: enabledBackend: ca-1 backends: - name: ca-1 type: builtin metrics: enabledBackend: prometheus-1 backends: - name: prometheus-1 type: prometheus conf: skipMTLS: true EOF
This will enable the
prometheus metrics backend on the
default Mesh and automatically collect metrics for all of our traffic.
Increment the counter to generate traffic, and access the dashboard at 127.0.0.1:3000 with default credentials for both the username (
admin) and the password (
Kuma automatically installs three dashboard that are ready to use:
Kuma Mesh: to visualize the status of the overall Mesh.
Kuma Dataplane: to visualize metrics for a single individual dataplane.
Kuma Service to Service: to visualize traffic metrics for our services.
You can now explore the dashboards and see the metrics being populated over time.