Exporting Docker Images for Cloud Foundry with Habitat

With Habitat, it’s easy to package and export your applications to any environment, and Cloud Foundry is no exception. Our friends over at Stark & Wayne set up a quick demo to just how easy it can be!

Set up Habitat

First, clone the example Node repo here. Initialize Habitat with the Node Scaffolding by entering the following on the command line at the project root:

$ hab plan init -s node

If you don’t have Habitat installed, get it from here

Next, configure the plan.sh file to have a configurable port:

pkg_origin=myoriginname
pkg_name=expresso
pkg_version=0.1.0
pkg_scaffolding=core/scaffolding-node
pkg_exports=(
    [port]=app.port
)
pkg_exposes(port)

Edit default.toml to include a default value for the port variable:

[app]
port = "3000"

All set!

Package up the app

Enter the Habitat studio, and build the initial Habitat artifact:

$ hab studio enter
[1][default:/src:0]# build .
(...)
[2][default:/src:0]# ls results/*.hart
myoriginname-expresso-0.1.0-20170927132309-x86_64-linux.hart

Cloud Foundry configures applications via injected environment variables. One way to get those variables picked up by the Habitat CLI is via a .toml file that overrides the existing default.toml:

[3][default:/src:0]# cat <

You should be able to see the resulting Docker images like so:

$ docker images
REPOSITORY                          TAG
myoriginname/expresso               cf-0.1.0-20170927132309
myoriginname/expresso               0.1.0-20170927132309
myoriginname/expresso               latest

Deploy to Cloud Foundry

If you are logged in with the cf-CLI to a Cloud Foundry instance that supports Docker containers, deployment is a simple matter of pushing to DockerHub and running via Cloud Foundry.

$ docker push myoriginname/expresso:cf-0.1.0-20170927132309
$ cf app expresso
Showing health and status for app expresso in org test / space habitat as admin...
name:              expresso
requested state:   started
instances:         1/1
usage:             256M x 1 instances
routes:            expresso.local.pcfdev.io
last uploaded:     Sat 10 Mar 12:23:52 CEST 2018
stack:             cflinuxfs2
docker image:      myoriginname/expresso:cf-0.1.0-20170927132309
     state     since                  cpu    memory         disk            details
#0   running   2018-10-03T11:32:48Z   0.2%   44.7 of 256M   556K of 512M

You should now be able to see the page at http://expresso.local.pcfdev.io !

To learn more about using Habitat with Cloud Foundry, check out the Getting Started page here.