From 820b2bc8f1ee3af1e61a2b499596190152980a17 Mon Sep 17 00:00:00 2001 From: Charlie Voiselle <464492+angrycub@users.noreply.github.com> Date: Tue, 29 Oct 2019 16:53:25 -0400 Subject: [PATCH] Updating Nomad Consul Connect info --- .../docs/connect/platform/nomad.html.md | 197 +----------------- 1 file changed, 11 insertions(+), 186 deletions(-) diff --git a/website/source/docs/connect/platform/nomad.html.md b/website/source/docs/connect/platform/nomad.html.md index 071410573..7190d80ad 100644 --- a/website/source/docs/connect/platform/nomad.html.md +++ b/website/source/docs/connect/platform/nomad.html.md @@ -11,193 +11,18 @@ description: |- Connect can be used with [Nomad](https://www.nomadproject.io) to provide secure service-to-service communication between Nomad jobs and task groups. The ability to use the [dynamic port](https://www.nomadproject.io/docs/job-specification/network.html#dynamic-ports) -feature of Nomad makes Connect particularly easy to use. +feature of Nomad makes Connect particularly easy to use. For more information +about using Consul Connect with Nomad, you might find the following resources +useful. -Using Connect with Nomad today requires manually specifying the Connect -sidecar proxy and managing intentions directly via Consul (outside of Nomad). -The Consul and Nomad teams are working together towards a more automatic -and unified solution in an upcoming Nomad release. +For a step-by-step guide to introduce you to using Consul Connect with Nomad: -~> **Important security note:** As of Nomad 0.8.4, Nomad doesn't yet support network namespacing -for tasks in a task group. As a result, running Connect with Nomad should -assume the same [security checklist](/docs/connect/security.html#prevent-non-connect-traffic-to-services) as running directly on a machine without namespacing. +- [Nomad Consul Connect Guide](https://www.nomadproject.io/guides/integrations/consul-connect/index.html) --> **Envoy Support:** Using the [Envoy Connect integration](/docs/connect/proxies/envoy.html) -with Nomad is not currently possible following this guide. This guide relies on some features -of the built-in proxy that are not possible via Envoy. +For reference information about configuring Nomad jobs to use Consul Connect: -## Requirements - -To use Connect with Nomad, the following requirements must be first be -satisfied: - - - * **Nomad 0.8.3 or later.** - The server and clients of the Nomad cluster - must be running version 0.8.3 or later. This is the earliest version that - was verified to work with Connect. It is possible to work with earlier - versions but it is untested. - - * **Consul 1.2.0 or later.** - A Consul cluster must be setup and running with - version 1.2.0 or later. - Nomad must be [configured to use this Consul cluster](https://www.nomadproject.io/docs/service-discovery/index.html). - -## Accepting Connect for an Existing Service - -The job specification below shows a job that is configured with Connect. -The example uses `raw_exec` for now just to show how it can be used locally -but the Docker driver or any other driver could easily be used. The example -will be updated to use the official Consul Docker image following release. - -The example below shows a hypothetical database being configured to listen -with Connect only. Explanations of the various sections follow the example. - -```hcl -job "db" { - datacenters = ["dc1"] - - group "db" { - task "db" { - driver = "raw_exec" - - config { - command = "/usr/local/bin/my-database" - args = ["-bind", "127.0.0.1:${NOMAD_PORT_tcp}"] - } - - resources { - network { - port "tcp" {} - } - } - } - - task "connect-proxy" { - driver = "raw_exec" - - config { - command = "/usr/local/bin/consul" - args = [ - "connect", "proxy", - "-service", "db", - "-service-addr", "${NOMAD_ADDR_db_tcp}", - "-listen", ":${NOMAD_PORT_tcp}", - "-register", - ] - } - - resources { - network { - port "tcp" {} - } - } - } - } -} -``` - -The job specification contains a single task group "db" with two tasks. -By placing the two tasks in the same group, the Connect proxy will always -be colocated directly next to the database, and has access to information -such as the dynamic port it is running on. - -For the "db" task, there are a few important configurations: - - * The `-bind` address for the database is loopback only and listening on - a dynamic port. This prevents non-Connect connections from outside of - the node that the database is running on. - - * The `tcp` port is dynamic. This removes any static constraints on the port, - allowing Nomad to allocate any available port for any allocation. - - * The database is _not_ registered with Consul using a `service` block. - This isn't strictly necessary, but since we won't be connecting directly - to this service, we also don't need to register it. We recommend registering - the source service as well since Consul can then know the health of the - target service, which is used in determining if the proxy should - receive requests. - -Next, the "connect-proxy" task is colocated next to the "db" task. This is -using "raw_exec" executing Consul directly. In the future this example will -be updated to use the official Consul Docker image. - -The important configuration for this proxy: - - * The `-service` and `-service-addr` flag specify the name of the service - the proxy is representing. The address is set to the interpolation - `${NOMAD_ADDR_db_tcp}` which allows the database to listen on any - dynamic address and the proxy can still find it. - - * The `-listen` flag sets up a public listener (TLS) to accept connections - on behalf of the "db" service. The port this is listening on is dynamic, - since service discovery can be used to find the service ports. - - * The `-register` flag tells the proxy to self-register with Consul. Nomad - doesn't currently know how to register Connect proxies with the `service` - stanza, and this causes the proxy to register itself so it is discoverable. - -Following running this job specification, the DB will be started with a -Connect proxy. The only public listener from the job is the proxy. This means -that only Connect connections can access the database from an external node. - -## Connecting to Upstream Dependencies - -In addition to accepting Connect-based connections, services often need -to connect to upstream dependencies that are listening via Connect. For -example, a "web" application may need to connect to the "db" exposed -in the example above. - -The job specification below shows an example of this scenario: - -```hcl -job "web" { - datacenters = ["dc1"] - - group "web" { - task "web" { - # ... typical configuration. - - env { - DATABASE_URL = "postgresql://${NOMAD_ADDR_proxy_tcp}/db" - } - } - - task "proxy" { - driver = "raw_exec" - - config { - command = "/usr/local/bin/consul" - args = [ - "connect", "proxy", - "-service", "web", - "-upstream", "db:${NOMAD_PORT_tcp}", - ] - } - - resources { - network { - port "tcp" {} - } - } - } - } -} -``` - -Starting with the "proxy" task, the primary difference to accepting -connections is that the service address, `-listen`, and `-register` flag -are not specified. This prevents the proxy from registering itself as -a valid listener for the given service. - -The `-upstream` flag is specified to configure a private listener to -connect to the service "db" as "web". The port is dynamic. The listener -will bind to a loopback address only. - -Finally, the "web" task is configured to use the localhost address to -connect to the database. This will establish a connection to the remote -DB using Connect. Interpolation is used to retrieve the address dynamically -since the port is dynamic. - --> **Both -listen and -upstream can be specified** for services that both -accept Connect connections as well as have upstream dependencies. Additionally, -multiple `-upstream` flags can be specified for multiple upstream dependencies. This -can be done on a single proxy instance rather than having multiple. +- [Nomad Job Specification - `connect`](https://www.nomadproject.io/docs/job-specification/connect.html) +- [Nomad Job Specification - `sidecar_service`](https://www.nomadproject.io/docs/job-specification/sidecar_service.html) +- [Nomad Job Specification - `sidecar_task`](https://www.nomadproject.io/docs/job-specification/sidecar_task.html) +- [Nomad Job Specification - `proxy`](https://www.nomadproject.io/docs/job-specification/proxy.html) +- [Nomad Job Specification - `upstreams`](https://www.nomadproject.io/docs/job-specification/upstreams.html)