Add extra_hosts integration test.

Author: shishir-a412ed

example/extra_hosts.nomad

@@ -0,0 +1,21 @@
+job "extra_hosts" {
+  datacenters = ["dc1"]
+
+  group "extra_hosts-group" {
+    task "extra_hosts-task" {
+      driver = "containerd-driver"
+      config {
+        image           = "docker.io/library/ubuntu:16.04"
+        extra_hosts     = ["postgres:127.0.1.1", "redis:127.0.1.2"]
+        host_network    = true
+        command         = "sleep"
+        args            = ["600s"]
+      }
+
+      resources {
+        cpu    = 500
+        memory = 256
+      }
+    }
+  }
+}

tests/007-test-extra-hosts.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+
+source $SRCDIR/utils.sh
+
+job_name=extra_hosts
+
+test_extra_hosts_nomad_job() {
+    pushd ~/go/src/github.com/Roblox/nomad-driver-containerd/example
+
+    echo "INFO: Starting nomad $job_name job using nomad-driver-containerd."
+    nomad job run $job_name.nomad
+
+    # Even though $(nomad job status) reports job status as "running"
+    # The actual container process might not be running yet.
+    # We need to wait for actual container to start running before trying exec.
+    echo "INFO: Wait for ${job_name} container to get into RUNNING state, before trying exec."
+    is_container_active ${job_name} true
+
+    echo "INFO: Checking status of $job_name job."
+    job_status=$(nomad job status -short $job_name|grep Status|awk '{split($0,a,"="); print a[2]}'|tr -d ' ')
+    if [ "$job_status" != "running" ];then
+        echo "ERROR: Error in getting ${job_name} job status."
+        return 1
+    fi
+
+    echo "INFO: Checking extra hosts info in /etc/hosts."
+    output=$(nomad alloc exec -job ${job_name} cat /etc/hosts)
+    for host in "127.0.1.1	postgres" "127.0.1.2	redis" ; do
+        echo -e "$output" |grep "$host" &>/dev/null
+        if [ $? -ne 0 ];then
+           echo "ERROR: extra host $host not found."
+           return 1
+        fi
+    done
+
+    echo "INFO: Stopping nomad ${job_name} job."
+    nomad job stop ${job_name}
+    job_status=$(nomad job status -short ${job_name}|grep Status|awk '{split($0,a,"="); print a[2]}'|tr -d ' ')
+    if [ $job_status != "dead(stopped)" ];then
+        echo "ERROR: Error in stopping ${job_name} job."
+        exit 1
+    fi
+
+    echo "INFO: purge nomad ${job_name} job."
+    nomad job stop -purge ${job_name}
+    popd
+}
+
+test_extra_hosts_nomad_job