DNSMASQ in OSX

Installing Dnsmasq

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    brew up && brew install dnsmasq

The installation process will output several commands that you can use to start Dnsmasq automatically with a default configuration. I used the following commands but you should use whichever commands brew tells you to:

Configuring Dnsmasq

Now that you have Dnsmasq installed and running, it’s time to configure it! The configuration file lives at /usr/local/etc/dnsmasq.conf by default, so open this file in your favourite editor.

One the many, many things that Dnsmasq can do is compare DNS requests against a database of patterns and use these to determine the correct response. I use this functionality to match any request which ends in .dev and send 10.200.200.10 in response. The Dnsmasq configuration directive to do this is very simple:

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    address=/dev/10.200.200.10

Insert this into your /usr/local/etc/dnsmasq.conf file (I put it near the example address=/double-click.net/127.0.0.1 entry just to keep them all together) and save the file.

You may need to restart Dnsmasq to get it to recognise this change. Restarting Dnsmasq is the same as any other service running under launchd:

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    sudo launchctl stop homebrew.mxcl.dnsmasq
    sudo launchctl start homebrew.mxcl.dnsmasq

You can test Dnsmasq by sending it a DNS query using the dig utility. Pick a name ending in dev and use dig to query your new DNS server:

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    dig local.site.dev @127.0.0.1

You should get back a response something like:

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    ;; ANSWER SECTION:
    local.site.dev. 0 IN    A   10.200.200.10

Configuring OS X

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    sudo mkdir -p /etc/resolver
    # Create file for domain .dev
    sudo tee /etc/resolver/dev >/dev/null <<EOF
    nameserver 127.0.0.1
    EOF

Testing.

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    # Make sure you haven't broken your DNS.
    ping -c 1 www.google.com
    # Check that .dev names work
    ping -c 1 this.is.a.test.dev
    ping -c 1 iam.the.walrus.dev