I have an Angular 6 application that I'm required to deploy onto a Kubernetes cluster as a Docker container (Nginx Base Image).
Question: How do I accommodate using the same Docker image that's built once, but to be able to run in dev & prod and point to different API_URL?
My Environment Files:
environment.ts
export const environment = {
production: false,
API_URL: 'https://dev-server.domain.com'
};
environment.prod.ts
export const environment = {
production: true,
API_URL: 'https://prod-server.domain.com'
};
My nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
server {
listen 80;
server_name localhost;
root /usr/share/nginx/html;
index index.html index.htm;
include /etc/nginx/mime.types;
gzip on;
gzip_min_length 1000;
gzip_proxied expired no-cache no-store private auth;
gzip_types text/plain text/css application/json application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript;
location / {
try_files $uri $uri/ /index.html;
}
}
}
My Dockerfile:
# base image
FROM nginx:alpine
# private and public mapping
EXPOSE 80
COPY nginx.conf /etc/nginx/nginx.conf
WORKDIR /usr/share/nginx/html
COPY dist/my_project .
At this point, I build my project on my local machine and optimize it for production:
ng build --prod --build-optimizer
So, at this point my file structure looks like the following:
root
|--Dockerfile
|--nginx.conf
|--angular.json
|--dist
|--my_project
|--styles.3ed0e5393a1386f6fc48.css
|--runtime.a66f828dca56eeb90e02.js
|--polyfills.2f5aa8fb3d2aea854d83.js
|--main.2b3e9b16d82428586ae5.js
|--index.html
|--favicon.ico
|--3rdpartylicenses.txt
|--assets
Now, I'm ready to create the docker image:
docker build -t my_application_image .
Then, I push the image to the Docker registry, and then used in Kubernetes.
Now that you know my setup, can you suggest how I can modify this such that different environment files can be used for dev & prod?
One of the ways to solve it would be to add an entrypoint script to your docker image and a default prod env. The use only one environment.ts with something like :
export const environment = {
production: {{production}},
API_URL: '{{api_url}}'
};
Dockerfile with
ENV PRODUCTION=true API_URL=https://prod-server.domain.com
ADD entrypoint.sh /entrypoint.sh
ENTRYPOINT /entrypoint.sh
and finally entrypoint it self
#!/bin/bash
sed -i "s/{{production}}/${PRODUCTION}/g" environment.ts
sed -i "s/{{api_url}}/${API_URL}/g" environment.ts
exec $@