nginxEstimated reading time: 7 minutes
Official build of Nginx.
GitHub repo: https://github.com/nginxinc/docker-nginx
Supported tags and respective
Where to file issues:
the NGINX Docker Maintainers
Supported Docker versions:
the latest release (down to 1.6 on a best-effort basis)
What is nginx?
Nginx (pronounced “engine-x”) is an open source reverse proxy server for HTTP, HTTPS, SMTP, POP3, and IMAP protocols, as well as a load balancer, HTTP cache, and a web server (origin server). The nginx project started with a strong focus on high concurrency, high performance and low memory usage. It is licensed under the 2-clause BSD-like license and it runs on Linux, BSD variants, Mac OS X, Solaris, AIX, HP-UX, as well as on other *nix flavors. It also has a proof of concept port for Microsoft Windows.
How to use this image
Hosting some simple static content
$ docker run --name some-nginx -v /some/content:/usr/share/nginx/html:ro -d nginx
Alternatively, a simple
Dockerfile can be used to generate a new image that includes the necessary content (which is a much cleaner solution than the bind mount above):
FROM nginx COPY static-html-directory /usr/share/nginx/html
Place this file in the same directory as your directory of content (“static-html-directory”), run
docker build -t some-content-nginx ., then start your container:
$ docker run --name some-nginx -d some-content-nginx
Exposing external port
$ docker run --name some-nginx -d -p 8080:80 some-content-nginx
Then you can hit
http://host-ip:8080 in your browser.
$ docker run --name my-custom-nginx-container -v /host/path/nginx.conf:/etc/nginx/nginx.conf:ro -d nginx
If you wish to adapt the default configuration, use something like the following to copy it from a running nginx container:
$ docker run --name tmp-nginx-container -d nginx $ docker cp tmp-nginx-container:/etc/nginx/nginx.conf /host/path/nginx.conf $ docker rm -f tmp-nginx-container
This can also be accomplished more cleanly using a simple
FROM nginx COPY nginx.conf /etc/nginx/nginx.conf
If you add a custom
CMD in the Dockerfile, be sure to include
-g daemon off; in the
CMD in order for nginx to stay in the foreground, so that Docker can track the process properly (otherwise your container will stop immediately after starting)!
Then build the image with
docker build -t custom-nginx . and run it as follows:
$ docker run --name my-custom-nginx-container -d custom-nginx
Using environment variables in nginx configuration
Out-of-the-box, nginx doesn’t support environment variables inside most configuration blocks. But
envsubst may be used as a workaround if you need to generate your nginx configuration dynamically before nginx starts.
Here is an example using docker-compose.yml:
web: image: nginx volumes: - ./mysite.template:/etc/nginx/conf.d/mysite.template ports: - "8080:80" environment: - NGINX_HOST=foobar.com - NGINX_PORT=80 command: /bin/bash -c "envsubst < /etc/nginx/conf.d/mysite.template > /etc/nginx/conf.d/default.conf && nginx -g 'daemon off;'"
mysite.template file may then contain variable references like this:
Running nginx in debug mode
Images since version 1.9.8 come with
nginx-debug binary that produces verbose output when using higher log levels. It can be used with simple CMD substitution:
$ docker run --name my-nginx -v /host/path/nginx.conf:/etc/nginx/nginx.conf:ro -d nginx nginx-debug -g 'daemon off;'
Similar configuration in docker-compose.yml may look like this:
web: image: nginx volumes: - ./nginx.conf:/etc/nginx/nginx.conf:ro command: [nginx-debug, '-g', 'daemon off;']
Monitoring nginx with Amplify
Amplify is a free monitoring tool that can be used to monitor microservice architectures based on nginx. Amplify is developed and maintained by the company behind the nginx software.
With Amplify it is possible to collect and aggregate metrics across containers, and present a coherent set of visualizations of the key performance data, such as active connections or requests per second. It is also easy to quickly check for any performance degradations, traffic anomalies, and get a deeper insight into the nginx configuration in general.
In order to use Amplify, a small Python-based agent software (Amplify Agent) should be installed inside the container.
For more information about Amplify, please check the official documentation here.
nginx images come in many flavors, each designed for a specific use case.
This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.
This image is based on the popular Alpine Linux project, available in the
alpine official image. Alpine Linux is much smaller than most distribution base images (~5MB), and thus leads to much slimmer images in general.
This variant is highly recommended when final image size being as small as possible is desired. The main caveat to note is that it does use musl libc instead of glibc and friends, so certain software might run into issues depending on the depth of their libc requirements. However, most software doesn’t have an issue with this, so this variant is usually a very safe choice. See this Hacker News comment thread for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
To minimize image size, it’s uncommon for additional related tools (such as
bash) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the
alpine image description for examples of how to install packages if you are unfamiliar).