NGINX Documentation

Building Ingress Controller Image

This document explains how to build an Ingress Controller image. Note that for NGINX, we provide the image though DockerHub. For NGINX Plus, you need to build the image.

Prerequisites

Before you can build the image, make sure that the following software is installed on your machine:

  • Docker
  • GNU Make
  • git
  • OpenSSL, optionally, if you would like to generate a self-signed certificate and a key for the default server.
  • For NGINX Plus, you must have the NGINX Plus license – the certificate (nginx-repo.crt) and the key (nginx-repo.key).

Although the Ingress controller is written in golang, golang is not required, as the Ingress controller binary will be built in a Docker container.

Building the Image and Pushing It to the Private Registry

We build the image using the make utility and the provided Makefile. Let’s create the controller binary, build an image and push the image to the private registry.

  1. Make sure to run the docker login command first to login to the registry. If you’re using Google Container Registry, you don’t need to use the docker command to login – make sure you’re logged into the gcloud tool (using the gcloud auth login command) and set the variable PUSH_TO_GCR=1 when running the make command.

  2. Clone the Ingress controller repo:

    $ git clone https://github.com/nginxinc/kubernetes-ingress/
    $ git checkout v1.6.1
    
  3. Build the image:

    • For NGINX:

      $ make clean
      $ make PREFIX=myregistry.example.com/nginx-ingress
      

      myregistry.example.com/nginx-ingress defines the repo in your private registry where the image will be pushed. Substitute that value with the repo in your private registry.

      As the result, the image myregistry.example.com/nginx-ingress:1.6.0 is built and pushed to the registry. Note that the tag 1.6.0 comes from the VERSION variable, defined in the Makefile.

    • For NGINX Plus, first, make sure that the certificate (nginx-repo.crt) and the key (nginx-repo.key) of your license are located in the root of the project:

      $ ls nginx-repo.*
      nginx-repo.crt  nginx-repo.key
      

      Then run:

      $ make clean
      $ make DOCKERFILE=DockerfileForPlus PREFIX=myregistry.example.com/nginx-plus-ingress
      

      myregistry.example.com/nginx-plus-ingress defines the repo in your private registry where the image will be pushed. Substitute that value with the repo in your private registry.

      As the result, the image myregistry.example.com/nginx-plus-ingress:1.6.0 is built and pushed to the registry. Note that the tag 1.6.0 comes from the VERSION variable, defined in the Makefile.

Next you will find the details about available Makefile targets and variables.

Makefile Targets

The Makefile we provide has the following targets:

  • test: runs unit tests.
  • nginx-ingress: creates the controller binary.
  • container: builds a Docker image.
  • push: pushes the image to the private Docker registry.
  • all (the default target): executes the four targets above in the order listed. If one of the targets fails, the execution process stops, reporting an error.

Makefile Variables

The Makefile contains the following main variables for you to customize (either by changing the Makefile or by overriding the variables in the make command):

  • PREFIX – the name of the image. The default is nginx/nginx-ingress.
  • VERSION – the current version of the controller.
  • TAG – the tag added to the image. It’s set to the value of the VERSION variable by default.
  • PUSH_TO_GCR. If you’re running your Kubernetes in GCE and using Google Container Registry, make sure that PUSH_TO_GCR = 1. This means using the gcloud docker push command to push the image, which is convenient when pushing images to GCR. By default, the variable is unset and the regular docker push command is used to push the image to the registry.
  • DOCKERFILE – the path to a Dockerfile. We provide five Dockerfiles:
    1. Dockerfile, for building a debian-based image with NGINX. It’s used by default.
    2. DockerfileForAlpine, for building an alpine-based image with NGINX.
    3. DockerfileForPlus, for building an debian-based image with NGINX Plus.
    4. DockerfileWithOpentracing, for building a debian-based image with NGINX, opentracing module and the Jaeger tracer.
    5. DockerfileWithOpentracingForPlus, for building a debian-based image with NGINX Plus, opentracing module and the Jaeger tracer.
  • GENERATE_DEFAULT_CERT_AND_KEY - The Ingress controller requires a certificate and a key for the default HTTP/HTTPS server. You can reference them in a TLS Secret in a command-line argument to the Ingress controller. As an alternative, you can add a file in the PEM format with your certificate and key to the image as /etc/nginx/secrets/default. Optionally, you can generate a self-signed certificate and a key during the build process. Set GENERATE_DEFAULT_CERT_AND_KEY to 1 to generate a certificate and a key in the default.pem file. Note that you must add the ADD instruction in the Dockerfile to copy the cert and the key to the image. The default value of GENERATE_DEFAULT_CERT_AND_KEY is 0.
  • DOCKER_BUILD_OPTIONS – the options for the docker build command. For example, --pull.
  • BUILD_IN_CONTAINER – By default, to compile the controller we use the golang container that we run as part of the building process. If you want to compile the controller using your local golang environment:
    1. Make sure that the Ingress controller repo is in your $GOPATH.
    2. Specify BUILD_IN_CONTAINER=0 when you run the make command.