callmemaybe: hostname as an interface

Single binary local DNS server that launch commands if you ask for specific hostname

Why?

I have a lot of projects. Switching between them is a pain: some of them use docker, some are started from systemd, some just from cli with arbitrary params. Also you need to memoize that 192.168.1.1:9200 is elasticsearch in one project, and 67.122.34.55:5423 is a postgres on another. And you need to find that dreaded command that creates proxy between your production pod to your local machine. A lot to deal with.

So I wanted to open http://project1 in browser and project1 will be up automagically: no need to run something. And then when I need to connect to database I could just use http://db.project1 as connection string and all ssh/kubernetes port forwarding blabber would be hidden from me.

Installation

$ curl https://i.jpillora.com/slavaGanzin/callmemaybe! | bash
$ sudo callmemaybe

/etc/systemd/system/callmemaybe.service created.

Run it with:
  sudo systemctl start callmemaybe

For autostart run:
  sudo systemctl enable --now callmemaybe


/etc/callmemaybe.yaml created.

Edit it with:
  vim /etc/callmemaybe.yaml


listening:
  udp:
    address: 0.0.0.0
    family: IPv4
    port: 53

Test that everything is working:

$ curl test.callmemaybe

callmemaybe: test

Hello, is it me youre looking for?

# or open it in browser
chromium http://test.callmemaybe

What can you do with it?

Launch proxies only when you need it

zerotier.host:
  ip: [host ip]
  start: systemctl start zerotier-one
openvpn.host:
  ip: [host ip]
  start: openvpn /path/to/config.ovpn
wireguard.host:
  ip: [host ip]
  start: systemctl start wg-quick@wg0

Switch between project branches

project1.local:
  ip: 127.0.0.1
  folder: /path/to/project
  command: git checkout main; docker-compose down; docker-compose up -d
  healthcheck: curl 127.0.0.1

develop.project1.local:
  ip: 127.0.0.1
  folder: /path/to/project
  command: git checkout develop; docker-compose down; docker-compose up -d
  healthcheck: curl 127.0.0.1

use as poorman's adblock

It's a dns server so, why not?

blocklists:
  - http://sbc.io/hosts/hosts #adware + spyware from https://github.com/StevenBlack/hosts#list-of-all-hosts-file-variants

# before
stats.g.doubleclick.net -> 142.250.13.157 142.250.13.156 142.250.13.154 142.250.13.155
# after
blocked: stats.g.doubleclick.net -> 0.0.0.0

Or just by matching urls by hand:

supershady.host:
  ip: 0.0.0.0

Config

Edit /etc/callmemaybe.yaml to add your projects and hosts. BTW, configuration reloads every second - no need to restart callmemaybe everytime you make a change.

settings:
  udp:
    port: 53
    address: 0.0.0.0
    type: "udp4"  #(Must be either "udp4" or "udp6")
  tcp:
    port: 53
    address: 0.0.0.0
    type: "udp4"  #(Must be either "udp4" or "udp6")

  # list of standard hosts files (like one in your /etc/hosts)
  # could be a path to a file or URL to hosts file to download
  # all hosts will be resolved to 0.0.0.0, so it's like poorman's adblock
  # https://en.wikipedia.org/wiki/Domain_Name_System_blocklist
  blocklists: ~
    # - http://sbc.io/hosts/hosts #adware + spyware from https://github.com/StevenBlack/hosts#list-of-all-hosts-file-variants


  resolvers: ~


#loopback
localhost:
  ip: 127.0.0.1

# Place here your own projects/hosts.
# Params and default values
# hostname:                     #hostname of your action
#   ip:          127.0.0.1      #what ip hostname resolve to.
#   healthcheck: ~              #any command that checks that project is up, so there is no need to run start command
#   start:       ~              #command that starts your project
#   folder:      ~              #folder where command will be running
#   user:        ~              #user running command, by default same as user of callmemaybe
#   group:       ~              #group running command


#test endpoint. Feel free to remove
test.callmemaybe:
  start: echo "Hello, is it me you looking for?" | callmemaybe server