Add automatic tests to the project

.gitignore

@@ -0,0 +1,2 @@
+.idea
+bats-core/

Jenkinsfile

@@ -57,7 +57,11 @@ pipeline {
                             if(!infra.isTrusted()) {                                
                                 deleteDir()
                                 checkout scm
-                                sh "make build ; docker system prune --force --all"
+                                sh '''
+                                make build
+                                make test
+                                docker system prune --force --all
+                                '''
                             }
                         }
                     }

Makefile

@@ -1,7 +1,37 @@
 ROOT:=$(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
-IMAGE_NAME:=jenkins4eval/jnlp-slave:test
 
-build:
-	docker build -t ${IMAGE_NAME} .
-	docker build -t ${IMAGE_NAME}-alpine -f Dockerfile-alpine .
-	docker build -t ${IMAGE_NAME}-jdk11 -f Dockerfile-jdk11 . 
+IMAGE_NAME:=jenkins4eval/jnlp-slave
+IMAGE_ALPINE:=${IMAGE_NAME}:alpine
+IMAGE_DEBIAN:=${IMAGE_NAME}:test
+IMAGE_JDK11:=${IMAGE_NAME}:jdk11
+
+build: build-alpine build-debian build-jdk11
+
+build-alpine:
+	docker build -t ${IMAGE_ALPINE} --file Dockerfile-alpine .
+
+build-debian:
+	docker build -t ${IMAGE_DEBIAN} --file Dockerfile .
+
+build-jdk11:
+	docker build -t ${IMAGE_JDK11} --file Dockerfile-jdk11 .
+
+bats:
+# The lastest version is v1.1.0
+	@if [ ! -d bats-core ]; then git clone https://github.com/bats-core/bats-core.git; fi
+	@git -C bats-core reset --hard c706d1470dd1376687776bbe985ac22d09780327
+
+.PHONY: test
+test: test-alpine test-debian test-jdk11
+
+.PHONY: test-alpine
+test-alpine: bats
+	@FLAVOR=alpine bats-core/bin/bats tests/tests.bats
+
+.PHONY: test-debian
+test-debian: bats
+	@bats-core/bin/bats tests/tests.bats
+
+.PHONY: test-jdk11
+test-jdk11: bats
+	@FLAVOR=jdk11 bats-core/bin/bats tests/tests.bats

tests/netcat-helper/Dockerfile

@@ -0,0 +1,6 @@
+FROM alpine:3.11
+
+RUN apk update --no-cache \
+  && apk add --no-cache \
+    coreutils \
+    netcat-openbsd

tests/test_helpers.bash

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# check dependencies
+(
+    type docker &>/dev/null || ( echo "docker is not available"; exit 1 )
+)>&2
+
+function printMessage {
+  echo "# ${@}" >&3
+}
+
+# Assert that $1 is the output of a command $2
+function assert {
+    local expected_output
+    local actual_output
+    expected_output="${1}"
+    shift
+    actual_output=$("${@}")
+    if ! [[ "${actual_output}" = "${expected_output}" ]]; then
+        printMessage "Expected: '${expected_output}', actual: '${actual_output}'"
+        false
+    fi
+}
+
+# Retry a command $1 times until it succeeds. Wait $2 seconds between retries.
+function retry {
+    local attempts
+    local delay
+    local i
+    attempts="${1}"
+    shift
+    delay="${1}"
+    shift
+
+    for ((i=0; i < attempts; i++)); do
+        run "${@}"
+        if [[ "${status}" -eq 0 ]]; then
+            return 0
+        fi
+        sleep "${delay}"
+    done
+
+    printMessage "Command '${*}' failed $attempts times. Status: ${status}. Output: ${output}"
+
+    false
+}
+
+function clean_test_container {
+	docker kill "${SLAVE_CONTAINER}" "${NETCAT_HELPER_CONTAINER}" &>/dev/null || :
+	docker rm -fv "${SLAVE_CONTAINER}" "${NETCAT_HELPER_CONTAINER}" &>/dev/null || :
+}
+
+function is_slave_container_running {
+	sleep 1
+	retry 3 1 assert "true" docker inspect -f '{{.State.Running}}' "${SLAVE_CONTAINER}"
+}
+
+function buildNetcatImage() {
+  if ! docker inspect --type=image netcat-helper:latest &>/dev/null; then
+    docker build -t netcat-helper:latest tests/netcat-helper/ &>/dev/null
+  fi
+}

tests/tests.bats

@@ -0,0 +1,94 @@
+#!/usr/bin/env bats
+
+DOCKERFILE=Dockerfile
+JDK=8
+SLAVE_IMAGE=jenkins-jnlp-slave
+SLAVE_CONTAINER=bats-jenkins-jnlp-slave
+NETCAT_HELPER_CONTAINER=netcat-helper
+
+if [[ -z "${FLAVOR}" ]]
+then
+  FLAVOR="debian"
+elif [[ "${FLAVOR}" = "jdk11" ]]
+then
+  DOCKERFILE+="-jdk11"
+  JDK=11
+  SLAVE_IMAGE+=":jdk11"
+  SLAVE_CONTAINER+="-jdk11"
+else
+  DOCKERFILE+="-alpine"
+  SLAVE_IMAGE+=":alpine"
+  SLAVE_CONTAINER+="-alpine"
+fi
+
+load test_helpers
+
+clean_test_container
+
+buildNetcatImage
+
+function teardown () {
+  clean_test_container
+}
+
+@test "[${FLAVOR}] build image" {
+  cd "${BATS_TEST_DIRNAME}"/.. || false
+  docker build -t "${SLAVE_IMAGE}" -f "${DOCKERFILE}" .
+}
+
+@test "[${FLAVOR}] image has installed jenkins-agent in PATH" {
+  docker run -d -it --name "${SLAVE_CONTAINER}" -P "${SLAVE_IMAGE}" /bin/bash
+
+  is_slave_container_running
+
+  run docker exec "${SLAVE_CONTAINER}" which jenkins-slave
+  [ "/usr/local/bin/jenkins-slave" = "${lines[0]}" ]
+
+  run docker exec "${SLAVE_CONTAINER}" which jenkins-agent
+  [ "/usr/local/bin/jenkins-agent" = "${lines[0]}" ]
+}
+
+@test "[${FLAVOR}] image starts jenkins-agent correctly" {
+  docker run -d -it --name netcat-helper netcat-helper:latest /bin/sh
+
+  docker run -d --link netcat-helper --name "${SLAVE_CONTAINER}" "${SLAVE_IMAGE}" -url http://netcat-helper:5000 aaa bbb
+
+  run docker exec netcat-helper /bin/sh -c "timeout 10s nc -l 5000"
+
+  # The GET request ends with a '\r'
+  [ $'GET /tcpSlaveAgentListener/ HTTP/1.1\r' = "${lines[0]}" ]
+}
+
+@test "[${FLAVOR}] use build args correctly" {
+  cd "${BATS_TEST_DIRNAME}"/.. || false
+
+  local ARG_TEST_VERSION
+  local TEST_VERSION="3.36"
+  local TEST_USER="root"
+
+	if [[ "${FLAVOR}" = "debian" ]]
+  then
+    ARG_TEST_VERSION="${TEST_VERSION}-1"
+  elif [[ "${FLAVOR}" = "jdk11" ]]
+  then
+    ARG_TEST_VERSION="${TEST_VERSION}-1-jdk11"
+  else
+    ARG_TEST_VERSION="${TEST_VERSION}-1-alpine"
+  fi
+
+  docker build \
+    --build-arg "version=${ARG_TEST_VERSION}" \
+    --build-arg "user=${TEST_USER}" \
+    -t "${SLAVE_IMAGE}" \
+    -f "${DOCKERFILE}" .
+
+  docker run -d -it --name "${SLAVE_CONTAINER}" -P "${SLAVE_IMAGE}" /bin/sh
+
+  is_slave_container_running
+
+  run docker exec "${SLAVE_CONTAINER}" sh -c "java -cp /usr/share/jenkins/agent.jar hudson.remoting.jnlp.Main -version"
+  [ "${TEST_VERSION}" = "${lines[0]}" ]
+
+  run docker exec "${SLAVE_CONTAINER}" sh -c "id -u -n ${TEST_USER}"
+  [ "${TEST_USER}" = "${lines[0]}" ]
+}