pod-manager

Pod Manager

The pod-manager tool is intended to provide a CLI Tool to handle some of the administrivia of managing a Redis Pod in Sentinel.

For example, normally to remove the pod 'p2' from your bank of sentinels, you would have to iterate over each sentinel, and issue a 'sentinel remove p2' command to each one.

With pod-manager you run `pod-manager pod remove p2'.

There are several other sub-commands such as 'validatesentinels', 'failover', and 'reset'.

Operational Requirements

When built with sentinel config file support, pod-manager requires read access to said config file. It will also need connectivity to the Sentinels in the cluster (it will build the list from the config file). Finally, for node-specific actions it will need access to the Redis instances in the pod.

Example Usage

Displaying information about the Pod 'p2':

# pod-manager pod info p2
Podname: p2
========================
Master: 127.0.0.1:6400
Quorum: 2
Auth Token: foo
Known Sentinels: 
        127.0.0.1:26380 
        127.0.0.1:26381 
        127.0.0.1:26379 
Known Slaves: 
        127.0.0.1:6401

Settings: 
cli string: redis-cli -h 127.0.0.1 -p 6400 -a foo

The same, but with JSON instead:

# pod-manager pod info -j p2
{"Name":"p2","MasterIP":"127.0.0.1","MasterPort":"6400","Authpass":"foo","KnownSentinels":["127.0.0.1:26380","127.0.0.1:26381","127.0.0.1:26379"],"KnownSlaves":["127.0.0.1:6401"],"Settings":null,"Quorum":"2","BadDirectives":null}

Removing a pod from the sentinel cluster:

pod-manager pod remove pod1

##Validating Authentication By passing the '-authcheck' flag pod-manager will attempt to conenct to the master and every KnownSlave and issue a ping, authenticating with the auth-pass entry. If any instances fail the check results of all checks will be displayed.

#Sentinel Validation By using the validatesentinels subcommand you can have pod-manager connect to each sentinel in the config file and request the master info from them. If any of the KnownSentinels do not have the pod in their list (ie. returning null or some other error) or are unreachable, pod-manager will tell you how many sentinels were validated vs how many were expected.

This is useful for checking the number of sentinels Sentinel must have a majority of in order to elect a leader in the event of an +odown event on a master.

Which Pod Tool?

Why pod-connector and pod-manager? Pod Connector's primary purpose is to provide connectivity to the specified pod, with a bit of info available. Pod Manager, however, is designed to make changes to sentinel and in some cases directly to the instances in the pod.

You might give access to pod-connector people whom you are willing to allow connectivity to the pod, but reserve pod-manager access for those who manage sentinel and the pod. Different needs, different tools. This is much simpler than yet another user system in a tool.

Bash Completion

Add the pod-manager_completion file to your bash completions directory (or source it directly) to add bash completion for pod-manager.