How to start up the tasks of a nomad job in a specific order

Nomad
1

Hi,

i am new to Nomad and have an application which consists of 3 middleware docker container and 3 docker containers which are my application. I need to have the middleware started before my application starts. I have added the lifecycle block for the middleware tasks like this:

lifecycle {
hook = "prestart"
sidecar = true
}

But my application cannot connect to the middleware when starting.

Any ideas?

Thanks for your help in advance.

Mihael

2

My solution was to use another docker container to wait until that health check for the middleware was good.

task "wait-for-solr" {
	lifecycle {
		hook    = "prestart"
		sidecar = false
	}

	driver = "docker"

	config {
		image   = "badouralix/curl-jq:alpine"
		command = "/bin/sh"
		args = [
			"-c",
			"until curl -fsS http://${NOMAD_ADDR_solr}/api/node/health | jq -e '.status == \"OK\"'; do echo \"Waiting for Solr ...\"; sleep 2; done"
		]
	}
}