vmx

Remote instances management tool over SSH written in Go

$ vmx
NAME:
   vmx -
vmx is a tool for interacting with cloud instances (like AWS EC2, for example) over SSH


USAGE:
   vmx [global options] command [command options] [arguments...]

VERSION:
   1.0.0

AUTHOR:
   Aliaksandr Kazlou

COMMANDS:
     run      Run custom command
     list     List available custom commands
     help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --profile value, -p value  profile to use to read hosts and commands from
   --help, -h                 show help
   --version, -v              print the version

Table of Contents

• Installation
• Config
• Profiles
• Commands
  • run command
    • "commands" file
    • Command with the confirmation
    • Pass extra arguments to the command
    • Running the ad-hoc command
  • list command
• Hosts
  • Ad-hoc host name
• Defaults
• Bash auto completion
• Credits

Installation

Use the go command:

$ go get github.com/zshamrock/vmx

Config

All the control files commands, defaults, hosts, etc. are looking for in the $VMX_HOME directory if defined, otherwise in directory $HOME/.vmx (so for unix like systems it would be enough to put them in the ~/.vmx).

Profiles

vmx supports profiles, similar to the aws CLI from Amazon. So you can pass either -p or --profile to specify which profile to use. If not specified, it will also check for the value of the env var $VMX_DEFAULT_PROFILE.

If any of those set that profile will be used, otherwise the "default" one.

What profile really means, is that the configuration files will be read from $VMX_HOME/<profile>, instead of $VMX_HOME.

Commands

There are 2 available commands: list and run.

run command

run command is the core of the tool, it is main purpose.

run runs the commands described in the commands file

"commands" file

commands is the ini file with the following syntax:

[command-name]
workingdir=
command=
follow=

where command-name is the command name which will be used in the run command, i.e. vmx run host-name command-name.

workingdir is optional, i.e. you can provide the working dir to change before running the command.

follow is also the optional key, boolean value is expected there, like 1|0, true|false, yes|no, which has the same meaning as --follow CLI argument, i.e. follows the output of the command execution. The purpose of this key is to define the "follow" flag as part of the command definition in the file and not specify it very time over --profile when command is run.

command is the required field.

Ex.:

[mem]
command=df -h

or

[rest-logs]
workingdir=/opt/app
command=tail -f -n 10 logs/rest.log

which could be run as following:

• vmx run host-name mem or
• vmx run host-name rest-logs

For the rest-logs run command it will change the working directory to the /opt/apt first before running the command.

Command with the confirmation

If you put the ! in the end of the command name, i.e. [redeploy!] then when running this command (by using the command name without the !), the app will ask the confirmation before running the command on the host, i.e.

# commands file
...
[redeploy!]
command=./redeploy.sh
...

and

vmx run host-name redeploy

and

vmx run dev redeploy
Confirm to run "redeploy" command on [host-name] - yes/no or y/n:

Pass extra arguments to the command

Any extra arguments passed to the the run command will be then passed to the actual command to run replacing the substitution %s in the command name from the config file.

Here is the example:

# commands file
...
[logs]
workingdir=/opt/app/logs
command=tail -n 10 %s
...

And when running:

vmx run host-name logs -f rest.log

it will be interpreted as tail -n 10 -f rest.log (i.e. all extra arguments are passed to the command defined in the commands file, more precisely replacing the %s placeholder, so it can be in any place of the command, not only in the end).

Running the ad-hoc command

It is also possible to run the ad-hoc command, i.e. the command which is not defined in the commands file.

Ex.:

vmx run host-name df -h

with no df command definition in the commands file, will be interpreted as the "ad-hoc" command, and will be executed on the host as it is, i.e. df -h.

list command

list command simply prints all available run commands, i.e.:

$ vmx list

app-logs
check-version
less-logs
logs
mem
redeploy (!)
rest-logs
stop (!)
view-docker-compose

Hosts

Hosts configuration is based on the notion of host groups, exactly the same configuration concept as Ansible has.

Hosts are defined in the $VMX_HOME/hosts (or otherwise in ~/.vmx/hosts), and they are tightly coupled with the $VMX_SSH_CONFIG_HOME/config (or ~/.ssh/config otherwise).

Here the syntax for the hosts file:

[group-name]
host1
host2
etc.

[group-name:children]
group-name1
group-name2

There is also the special hosts group named all.

The actual hostname, user, identity file, etc. are necessary for SSH to know are defined in the $VMX_SSH_CONFIG_HOME/config file.

Example:

# ~/.ssh/config
Host rest-prod1
    User ubuntu
    Hostname 1.2.3.4

Host rest-prod2
    User ubuntu
    Hostname 5.6.7.8
    IdentityFile ~/.ssh/rest_prod2_id_rsa

and the corresponding section of the hosts file:

# ~/.vmx/hosts
[rest-prod]
rest-prod1
rest-prod2

And so the to execute the run command for both rest-prod instances:

vmx run rest-prod redeploy

Ad-hoc host name

If host name used in the run command is not defined in the hosts file it is then looked in the ~/.ssh/config directly instead. So, if you don't have hosts to group you don't need then to configure hosts at all, and utilize yours ~/.ssh/config instead.

Defaults

You can configure default values per host groups in the $VMX_HOME/defaults, and also supports all hosts group.

The only supported value in the defaults is workingdir, i.e.:

[all]
workingdir=/opt/app

[rest-prod]
workingdir=/opt/app/rest

Bash auto completion

To enable Bash completion, copy autocomplete/vmx file into /etc/bash_completion.d/ directory. Then either restart the current shell, or source that added auto completion file.

Credits

• ssh_config
• go-ini
• cli