based on https://github.com/crosbymichael/slex uses https://github.com/MattAitchison/envconfig uses https://gist.github.com/MattAitchison/ea7664793653b8fa88dd

Usage: remotectl <flags> <query> [--] <cmd>

Providers:
[do]

Environment Vars:
REMOTECTL_USER=""          # user to connect as
REMOTECTL_PROVIDER="do"        # comma-sep list of provider modules to use for selecting hosts
REMOTECTL_NAMESPACE=""         # namespace is a prefix which is matched and removed from hosts
REMOTECTL_PREFIX="{{.Name}}: " # prefix template for host log output
REMOTECTL_PORT="22"            # port used to connect to each host
SSH_AUTH_SOCK=""               # ssh agent socket
REMOTECTL_IDENTITY=""          # file from which the identity (private key) for public key authentication is read.

Flags:
  -help
    	show this help message
  -list
    	lists selected ips and names. /etc/hosts friendly output
  -profile string
    	bash profile to source for env config
  -version
    	show version

# run uptime on all hosts
remotectl -- uptime

# run uptime on all hosts tagged foo
remotectl foo uptime

# list all hosts
remotectl -list

# add hosts tagged "app" into /etc/hosts
remotectl -list app >> /etc/hosts

# show configuration using a profile (no query or cmd)
remotectl -profile myprofile

go template prefix for host output.

• .Name - name of host
• .IP - ip of host
• .Index - numerical index of host in run
• .Group - group index (if groups mode is used)

Providers may implement different query string semantics. However, there is an ideal convention set forth by builtin providers:

Queries are treated as "tag" lookups first. If no hosts exist with
this tag, query is treated as a "name" lookup. This optimizes for
primary use case of multiple hosts, but still works to reference
individual hosts.

Key-value attributes can be provided in the form `<key>:<value>`.
Providers implement more detailed semantics around this convention.

• DO_ACCESS_TOKEN
• REMOTECTL_NAMESPACE will limit to DO hosts prefixed with namespace. Allows queries within a namespace since DO has no tags/attributes/vpcs.

Use with clients. Public mentions on Twitter.

• -verbose, -v shows status output more like capistrano or fabric. otherwise, focuses only on output of remote hosts.

• -env, -e <key=value> sets environment variable to be set in remote shell.

• -local, -L doesn't use ssh, but shells out locally to run . replaces string "{}" in with each host ip. used for rsync, etc. also allows using system ssh.

• -first, -1 limits list of hosts returned to just the first host. can be combined with --random to pick random host.

• REMOTECTL_BASHENV
• REMOTECTL_AGENT
• REMOTECTL_PREFIX
• REMOTECTL_NAMESPACE
• REMOTECTL_SHELLENV file to copy and source on remote side
• REMOTECTL_AGENT boolean to forward agent. defaults to true?

• ec2
  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY
  • EC2_FILTER apply ec2 filters
  • EC2_IPDOMAIN public / private which ip to use (ie, private when using bastion/gateway)

# broadcast docker image to hosts tagged "app" via stdin
docker save myimage | remotectl app docker load

# wait for all "app" hosts to be ssh reachable
remotectl --wait app

Screencast!

- Bastion/gateway
- Modes
- Random flag

• Wait flag

• REMOTECTL_GATEWAY selector to use as bastion host. optional prefix "@" to specify bastion user.

• REMOTECTL_MODE execution mode options (based on ruby sshkit):

  • parallel runs commands in parallel. default.

  • sequence[:<wait-duration>] runs in sequence with option duration between. ex: REMOTECTL_MODE=sequence:2s

  • groups:<limit>[:<wait-duration>] runs in parallel on hosts, grouped sequential. ex: REMOTECTL_MODE=group:4:2s

• --random, -r randomizes the list of hosts returned from query from any sorting or bias of the provider.

• --timeout, -t <wait-duration> global timeout val

• --wait, -w polls hosts until they're all ready to receive ssh commands. can be used with or without . is only performed when all hosts are ready.

MIT