Docker-vhoster

Listens on the docker socket for containers to start/end and adds entries for them to your /etc/hosts file.

This is designed to be used alongside a tool like jwilder/nginx-proxy which creates vhost entries for running services.
If you follow its pattern for setting VIRTUAL_HOST environment variables that program nginx, this will allow those same variables to also control your /etc/hosts file.

One time setup:

We need to give your user permission to modify the /etc/hosts file. This is done differently on different OS.

On MacOS, run in terminal:

sudo chmod +a "user:$(whoami) allow read,write,append,readattr,writeattr,readextattr,writeextattr,readsecurity" /etc/hosts

On Windows... Powershell is too complex for me to understand how to do it as a script, so in the UI:

• Navigate in Explorer to C:\Windows\System32\drivers\etc
• Right click the hosts file -> Properties
• Security -> Edit
• Add...
• Enter your user name
• Check Names
• Ok
• Check "Full Control" box
• Ok, Ok

On Linux: Do nothing, this just works

Options

Options: All options can be set as cli arguments or as env vars

argument	env var	default	description
-h, --host-file-location <path>	HOST_FILE_LOCATION	/etc/hosts	The path to the hosts file to modify
-e, --env-var-name <string>	ENV_VAR_NAME	VIRTUAL_HOST,ETC_HOST	The comma separated env vars used to look up the host name on a per-container basis
-v, --vhost-ip-addr <ip address>	VHOST_IP_ADDR	127.0.0.1	The IP address to set in the /etc/hosts file

Required file/volume mount!

You must use this on a machine/container where /var/run/docker.sock is available

Running it

The most common way this is meant to be used is to run inside of docker alongside containers. Typically, if you're running docker-vhoster inside of docker, this is done as: docker run -v /var/run/docker.sock:/var/run/docker.sock:ro -v /etc/hosts:/tmp/hosts itaylor/docker-vhoster -h /tmp/hosts

Example using docker-compose

See the example/ folder.

cd example/
docker-compose up

Once the containers start you'll be able to open a browser to http://web-example.fake.com and have it display a hello world message.

Note if using Docker for windows, you'll have to change the example/docker-compose.yml to have the correct path to Windows' etc/hosts file.

Changelog

0.2.3: Republish of 0.2.2 which was somehow not being picked up? 0.2.2: Fixes duplication of etc host content that can occur on initial start 0.2.1: Fix host file to truncate when writing 0.2.0: Allows multiple env vars to be used to determine host names to set. New default is VIRTUAL_HOST,ETC_HOST so either (or both) env vars can be used on containers to control the etc/hosts entries. Also adds additional handling to prevent race conditions writing to /etc/hosts files. Updates to build with Rust 1.60. 0.1.0: Initial release