MCollective cheat sheet

mco-cheat-sheet

# MCollective Cheat Sheet

MCollective is a server orchestration tool that is built by Puppet Labs and so is tightly integrated with the puppet infrastructure. Commands a run from the control aka "client" server.  

## Finding/listing hosts

List all

```
mco find
```

With specific puppet classes

```
mco find --with-class apache
mco find --with-class postgres::server
```

With specific fact values

```
mco find --with-fact is_virtual=true --with-fact 'processorcount >= 12'
```

## Ping

mco ping
You can use the same filters as shown above with mco find.

Ping all servers containing "test" in their name

```
mco ping -I /test/
```

## Service

Who's running apache?

```
mco service httpd status
```

Restart a service on all, but avoid thundering herd by splaying in batches, e.g. 3 at a time

```
mco service puppet restart --batch 3 --batch-sleep 3
```


## Process

```
mco process list elasticsearch
mco process list jboss
mco process list httpd
```

## File

Create a file /tmp/fooj on test12

```
mco puppet resource file /tmp/fooj ensure=file mode=0440 owner=root -I test12
```

The filemgr command is probably more suited for file management tasks.  See https://github.com/puppetlabs/mcollective-filemgr-agent

Directory listing

```
mco rpc filemgr status dirlist=true file=/usr/local/java
```

## Yum

See https://github.com/slaney/mcollective-plugins

``` 
sudo mco rpc yum install package=telnet
sudo mco rpc yum update package=rkhunter
```

## Puppet

If you care about the graphs displayed in summary, you'll need to set your putty encoding to utf-8 and use a font like DejaVu.

```
mco puppet summary
mco puppet count
mco puppet status
```

Invoke a puppet run on a specific server

```
mco puppet runonce -I test02
```

It's OK to do puppet runonce on multiple hosts.  By default, puppet will splay its runs to avoid a thundering herd.