# Rough command structure:
mdb tag get <hostname> <tag>         -- get value of tag from hostname
mdb tag list <hostname>              -- list tags attached to hostname
mdb tag find <tag>[=<value>]         -- find hosts with tag (or with tag=value)
mdb tag set <hostname> <tag> <value> -- set a value for tag on host
mdb tag delete <hostname> <tag>      -- delete tag from host
mdb tag edit <hostname> <tag>        -- edit tag on host in text editor

mdb endpoint create <hostname>
mdb endpoint delete <hostname>


# Rough 'filesystem' layout:
  /mdb/endpoints/
     ./hostname.example.com/
        ./tags/
           ./tagname1 ./tagname2 ./tagname3


# To build (this will get better):
$ brew install etcd
$ brew services start etcd
$ go get github.com/spf13/cobra github.com/coreos/etcd/client github.com/ \
  mitchellh/go-homedir github.com/spf13/viper github.com/coreos/etcd/error
$ go build


# quick demo:
# setup (add build directory to your path, then cut&paste): 
mdb endpoint create db01.example.com
mdb endpoint create db02.example.com
mdb endpoint create db03.example.com

mdb tag set db01.example.com role db
mdb tag set db01.example.com shard 1
mdb tag set db01.example.com dbrole master

mdb tag set db02.example.com role db
mdb tag set db02.example.com shard 1
mdb tag set db02.example.com dbrole slave
mdb tag set db02.example.com dbmaster db01.example.com

mdb tag set db03.example.com role db
mdb tag set db03.example.com shard 1
mdb tag set db03.example.com dbrole slave
mdb tag set db03.example.com dbmaster db01.example.com


# get info (command + output):

# list all my hosts
$ mdb endpoints list
db03.example.com
db01.example.com
db02.example.com

# show the tags for a host
$ mdb tags list db01.example.com
dbrole
role
shard

# What shard is this host in?
$ mdb tags get db01.example.com shard
1

# What hosts are slaves of db01?
$ mdb tags find dbmaster=db01.example.com
db02.example.com
db03.example.com

# What is the master of shard 1?
# Doesn't work yet! Pretend.
$ mdb tags find dbrole=master,&shard=1
db01.example.com