imagetest_harness_docker: export configurable variables to start container and run tests in the same network

[Dentrax]

This proposal aims to enrich the developer experience of imagetest_harness_docker module.

Abstract

By extending the capabilities of imagetest_harness_docker to handle multiple variables, we eliminate the need to manually write docker container run <ARGS> in each test script. Additionally, running the tests within the same network removes the necessity to execute networking-related tests in a separate container, which currently requires passing --network container:"${CONTAINER_NAME}".

Current Flow

resource "imagetest_harness_docker" "docker" {
  name      = "test"
  inventory = data.imagetest_inventory.this

  mounts = [{
    source      = path.module
    destination = "/tests"
  }]

  envs = {
    IMAGE_NAME : var.digest
  }
}

Then we need to run the container inside the test script first:

0. Add required tools
apk add curl jq nodejs npm

1. Run the container first
docker run \
  -d --rm \
  -p 8080:8080 \
  -p 9090:9090 \
  -e FOO=BAR \
  --name "${CONTAINER_NAME}" \
  "${IMAGE_NAME}"

2. If you need to access ports, you need to set network
curl() {
  docker run --network container:"${CONTAINER_NAME}" curl "$@"
}

3. Run tests

curl http://localhost:8080/health | jq -e '.status == "UP"'
curl http://localhost:9090/health | jq -e '.status == "UP"'

docker run --network container:"${CONTAINER_NAME}" node  bash -c "/usr/local/bin/npm install -g tool && tool --address localhost:9090 status"

Proposed Flow

Expose some variables to pass docker container run:

resource "imagetest_harness_docker" "docker" {
  ...

  ports = [8080, 9090]
  read_only = true
  platform = ["linux/x86_64"]

  ...
}

In the test script:

• Required testing tools are provided by default, so we don't need to apk add for common tools.
• imagetest_harness_docker will run the container by exposing the ports, etc.
• Wait until container to be running state
• We can able to run network-related tests without needing to execute them inside a container using --network container:"${CONTAINER_NAME}".

resource "imagetest_feature" "docker" {
  name    = "camunda-zeebe-docker-test"
  harness = imagetest_harness_docker.docker

  steps = [{
    name = "Smoke test"
    cmd  = <<EOF
curl http://localhost:8080/health | jq -e '.status == "UP"'
curl http://localhost:9090/health | jq -e '.status == "UP"'
npm install -g tool && tool --address localhost:9090 status"
EOF
  }]
}

Current Behavior

curl: (7) Failed to connect to localhost port 8080 after 0 ms: Could not connect to server
curl: (7) Failed to connect to localhost port 9090 after 0 ms: Could not connect to server