The CI/CD and DevOps Blog

Build A GCE (Google Compute Engine) VM image using Packer

This tutorial explains how to manually create a GCE VM image using Packer. Before you start, you should be familiar with the following concepts:

The best way to get started is to install Packer and run scripts manually on your local machine to create a VM image. Once you understand the mechanics of it, you should consider automating your workflow by following our documentation on Automated creation of GCE image using Packer.

Kubernetes Tutorial: how to pull a private docker image in a pod

Docker images that comprise a production application are often deployed to private repositories in Docker registries. Kubernetes provides a feature called imagePullSecrets that allows pods to pull private docker images. In this blog, we demonstrate how you can easily hookup imagePullSecrets to your pod using Shippable.


Creating an imagePullSecrets secret

imagePullSecrets is a type of a Kubernete Secret whose sole purpose is to pull private images from a Docker registry. It allows you to specify the Url of the docker registry, credentials for logging in and the image name of your private docker image.

There are two ways an imagePullSecrets can be created.

1. kubectl create secret docker-registry command. We use this approach in our blog.

ambarishs-MacBook-Pro:gke ambarish$ kubectl create secret docker-registry private-registry-key --docker-username="devopsrecipes" --docker-password="xxxxxx" --docker-email="" --docker-server=""
secret "private-registry-key" created


2. Creating the secret via a yml.

In this approach, a config.json file is created for the private registry. Its contents are then base64 encoded and specified in the .dockerconfigjson property.

apiVersion: v1
kind: Secret
  name: private-registry-key
  namespace: default
  .dockerconfigjson: UmVhbGx5IHJlYWxseSByZWVlZWVlZWVlZWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGx5eXl5eXl5eXl5eXl5eXl5eXl5eSBsbGxsbGxsbGxsbGxsbG9vb29vb29vb29vb29vb29vb29vb29vb29vb25ubm5ubm5ubm5ubm5ubm5ubm5ubm5ubmdnZ2dnZ2dnZ2dnZ2dnZ2dnZ2cgYXV0aCBrZXlzCg==


Kubernetes Tutorial: Using Secrets In Your Application

Applications deployed to a Kubernetes cluster often need access to sensitive information such as credentials to access a database and authentication tokens to make authenticated API calls to services. Kubernetes allows you to specify such sensitive information cleanly in an object called a Secret. This avoids putting sensitive data in a Pod defintion or a docker image. In this blog, we demonstrate how you can easily hookup Kubernetes Secrets to your pod using Shippable.


Creating a Kubernetes Secret

Secrets are defined in a yml file in a Secret object. A Secret object can specifiy multiple secrets in name-value pairs. Each secret has to be base64 encoded before specifying it in the yml.

Let's define an API token as a secret for a fake token xxx-xxx-xxx.

1. Base 64 encode the token.

ambarishs-MacBook-Pro:sources ambarish$ echo -n "xxx-xxx-xxx" | base64

2. Create the secrets yml called create-secret.yml.

apiVersion: v1
kind: Secret
  name: auth-token-secret
type: Opaque

3. Create the secret in the kubernetes cluster using kubectl.

$ kubectl create -f secrets.yml
secret "auth-token" created

Kubernetes Tutorial: Attaching A Volume Mount To Your Application

Kubernetes allows you to package multiple containers into a pod. All containers in the pod run on the same Nodeshare the IP address and port space, and can find each other via localhost. To share data between pods, Kubernetes has an abstraction called Volumes. In this blog, we demonstrate how you can  easily hookup Kubernetes Volumnes to your pod and define the containers in the pod using Shippable.


Kuberetes Volumes

A Volume is a directory with data that is accessible to all containers running in a pod and gets mounted into each containers filesystem. Its lifetime is identical to the lifetime of the pod. Decoupling the volume lifetime from the container lifetime allows the volume to persist across container crashes and restarts. Volumes further can be backed by host's filesystem, by persistent block storage volumes such as AWS EBS or a distributed file system. The complete list of the different types of volumes that Kubernetes supports can be found here.

Shippable supports mounting all the types of volumes that Kubernetes supports via the dockerOptions resource. However, the specific volume type that we demonstrate in this blog is a gitRepo volume. A gitRepo volume mounts a directory into each containers filesystem and clones a git repository into it. 

Declarative Continuous Deployment Pipelines with Docker

Everyone agrees that continuous deployment helps accelerate innovation. However, Continuous Deployment (CD) today is synonymous with fragile homegrown solutions made of disjointed tools cobbled together with thousands of lines of imperative scripts. Avi Cavale walks you through the CD maturity model and demos an end to end continuous deployment with declarative pipelines for Docker applications.

This video was taken at the Docker Seattle Meetup, hosted by Tune.