echo

Echo

Echo is a simple echo server using elio library.

Prerequisites

Setting Skaffold on WSL

Setting up elio

Before start, set up elio project.

git clone https://github.com/cppis/elio && cd elio
go mod vendor
export ELIO_ROOT=$(pwd)

Now, $ELIO_ROOT is the project root path.

Running app on Host

Using go run

To run echo service, run the following command:

ECHO_IN_URL="0.0.0.0:7001" go run app/echo

You can change the listening url of service echo by changing
environment variable ECHO_IN_URL.

Running app on Kubernetes

Create a Kind cluster

To create a kind, run the following command:

kind create cluster --config app/herald/assets.k8s/kind.cluster.yaml --name elio

To check if the kind cluster is up and running, run the following command:

kubectl config current-context
  kind-elio

To run echo using Skaffold,
run the following command:

skaffold -f app/echo/assets.k8s/skaffold.yaml dev -p dev

Use -vdebug option for debugging.

Or, skaffold debug acts like skaffold dev, but it configures containers in pods
for debugging as required for each container’s runtime technology.

skaffold -f app/echo/assets.k8s/skaffold.yaml debug -p debug

Testing app

You can test echo easily by using telnet.
And, you can end server by send q character.

telnet localhost 7001
  ...
  q<enter>

Ending app

Kubernetes resource cleanup

After running skaffold run or skaffold deploy and deploying your app to a cluster, running skaffold delete will remove all the resources you deployed. Cleanup is enabled by default, it can be turned off by --cleanup=false

Ctrl + C

When running skaffold dev or skaffold debug, pressing Ctrl+C (SIGINT signal) will kick off the cleanup process which will mimic the behavior of skaffold delete. If for some reason the Skaffold process was unable to catch the SIGINT signal, skaffold delete can always be run later to clean up the deployed Kubernetes resources.

To enable image pruning, you can run Skaffold with both --no-prune=false and --cache-artifacts=false:

skaffold dev --no-prune=false --cache-artifacts=false

Delete a Kind cluster

To delete a kind, run the following command:

kind delete cluster --name elio