helloService

An example service project outlining our DevOps project setup

Clone this project with

git clone [email protected]:OAODEV/helloService.git

The Service

The hello service runs a TCP server that says hello. The greeting is read from the greeting envar. It will also say who it is from, taking the environment name from the environment it's deployed in.

The service is contained in app/serve_hello.py. This file is heavily documented, describing operations considerations.

The unit tests are in test_hello_service.py. This is nothing unusual and has operations considerations documented.

The Operations Files

The following files are required in the project root to hook into the operations platform.

Dockerfile

This is the file that developers use to create the contained service. For the most part, that means creating the environment, installing dependencies, putting files in place, setting envionment variables, and so on. The platform will use this file to build the container and provide that container with the command to run the service. The Dockerfile in this project has more specific documentation.

More information on docker containers.

Manifest

This file describes the services to herd, offering certain specifics about the service, information the platform requires to work with it. Details are documented in the Manifest file

Each Dockerfile must put the Manifest at /Manifest so that the platform may access it in a known location.

ADD Manifest /Manifest

Version

This file simply holds the semantic version of the application at the commit. Fully optional.

circle.yml

The configuration file for our CI Service. Just copy the file here into your project root, then update the herd_service_name and herd_unittest_cmd lines under machine -> environment

machine:
  services:
    - docker
  environment:
    herd_service_name: <service name>
    herd_unittest_cmd: <unittest cmd>

The unittest cmd and service name should be the same as in the Manifest file.

Config file

This file is not part of the repository. It is passed to the configure command. It should be a file with one <key>=<value> statement per line.

message="Hello World."

Iterating and Deploying with herd

Clone the repo

git clone [email protected]:OAODEV/hello-service.git
cd hello-service

Update tests and code

echo "# `whoami` ran the tutorial on `date`\n" >> app/serve_hello.py
git commit --am "adds importand comment"

Integrate

For details on the herd command integrate see https://github.com/OAODEV/herd#integrate

herd integrate

Note the build name in CircleCI

This is currently a manual process. If the build passes, we go over to CircleCI, click into our build then look for where it says

echo "The build name is in here!!!" r.iadops.com/$herd_service_name:$herd_build_tag

It's in there and should look like this.

r.iadops.com/hello:<semver>_build.<hash>

Configure the Build

First create or locate a config file

echo "greeting=<your personal greeting>" > hello.conf

Then use that to configure the build using the build name you noted earlier. This will result in a Release.

herd configure r.iadops.com/hello:<semver>_build.<hash> ./hello.conf

If this succeeds, it will print out the details of the Release that was created. Note the release number.

Deploy the release

herd deploy <Release Number> <host[:port]>