#!/bin/bash
#
# A tool to wipe the by-products of a cluster bringup from a bootstrap
# node but leave the bootstrap node and related roles, nodes, clients
# etc undamaged
#
# Usage cluster_nuke.sh <environment>
#
if [[ -z "$1" ]] {
    echo "Usage : $0 'environment'"
    echo "did nothing..."
    exit
}
setglobal ENVIRONMENT = $1
if [[ ! -f "cluster.txt" ]] {
    echo "I am a bear of very little brain so I couldn't find the cluster.txt file. No clusters were harmed in the making of this error message"
    exit
}
if [[ ! -f "environments/${ENVIRONMENT}.json" ]] {
    echo "You are scaring me now, I don't see the environment file you asked for. Not doing nothing"
    exit
}
while read HOSTNAME MACADDR IPADDR ILOIPADDR DOMAIN ROLE {
    if [[ "$ROLE" = "bootstrap" ]] {
	setglobal BOOTSTRAP_NODE = $HOSTNAME
	setglobal BCPC_HYPERVISOR_DOMAIN = $DOMAIN
	echo "Ignoring $HOSTNAME - bootstrap node to be retained"
    } elif [[ "$ROLE" = "work" || "$ROLE" = "head" ]] {
	#
	# Build a list of entries to remove from the databag.
        #
        # Extend the above test if there are other roles that cluster
	# members can have
	setglobal CLUSTER_MEMBERS = ""$(CLUSTER_MEMBERS) $(HOSTNAME)""
    } else {
	echo "Ignoring $HOSTNAME - unknown role"
    }
} < cluster.txt
if [[ -z "$BOOTSTRAP_NODE" ]] {
    echo "No bootstrap node found, unsafe to continue. Are you nuts?"
    exit
}

# cross check that what I think is the bootstrap node for this domain
# based on the cluster definition file cluster appears correctly as a
# node in the databag
setglobal BOOT_FQDN = ""$(BOOTSTRAP_NODE).$(BCPC_HYPERVISOR_DOMAIN)""
echo "BOOT FQDN = $(BOOT_FQDN)"
setglobal MATCH = $[knife node list | grep $BOOT_FQDN]
if [[ ! -z "$MATCH" ]] {
    echo "Plausible level of consistency present : it looks to me like I should delete all nodes and clients except $MATCH..."
} else {
    echo "$BOOT_FQDN not found in data bag, unsafe to continue. Can't fool me that way!"
    exit
}
echo "Making safety copy of $(ENVIRONMENT) configs..."
setglobal DATABAG_BACKUP = ""~/$ENVIRONMENT.databag.$Pid""
knife data bag show configs $(ENVIRONMENT) >> $(DATABAG_BACKUP)
echo "Databag configs for $(ENVIRONMENT) dumped to $(DATABAG_BACKUP)"

echo "Deleting data bag configs..."
knife data bag delete --yes configs

echo "Removing clients and nodes..."
for CLIENT in [$CLUSTER_MEMBERS] {
    knife client delete --yes "$(CLIENT).$(BCPC_HYPERVISOR_DOMAIN)"
    knife node   delete --yes "$(CLIENT).$(BCPC_HYPERVISOR_DOMAIN)"
}

echo "reload knife data..."
knife role from file roles/*.json
knife cookbook upload -a -o cookbooks
knife environment from file "environments/$(ENVIRONMENT).json"

echo "Removing cobbler systems..."
for CLIENT in [$(CLUSTER_MEMBERS)] {
    setglobal SOMETHING = $(CLIENT)
    sudo cobbler system remove --name=$(CLIENT)
}

if [[ ! -z "$SOMETHING" ]] {
    echo "Sync cobbler..."
    sudo cobbler sync
}

echo "Removing cobbler profile..."
sudo cobbler profile remove --name=bcpc_host
sudo cobbler sync

# Prevent stale kickstart being installed
echo "Hiding stale kickstart in case Chef goes all wibbly..."
setglobal KICKSTART_FILE = '"/var/lib/cobbler/kickstarts/bcpc_ubuntu_host.preseed'"
sudo mv $(KICKSTART_FILE) "$(KICKSTART_FILE).old.$Pid"

echo "Rerunning Chef client ..."
sudo chef-client
sudo chef-client
sudo chef-client

echo "Checking results ..."
setglobal CHECK = $[knife data bag show configs $(ENVIRONMENT) | grep -i cobbler-root]
if [[ -z "$CHECK" ]] {
    echo "Warning, no cobbler-root found. I'm so sorry."
    exit
} else {
    echo "Cobbler-root found : $(CHECK)"
}

echo "Verifying kickstarts..."
setglobal CHECK = $[sudo cobbler profile dumpvars --name=bcpc_host | grep kickstart | grep bcpc]
if [[ -z "$CHECK" ]] {
    echo "Warning, no BCPC kickstart data found. Duh!"
    exit
} else {
    echo "Found BCPC kickstart : $(CHECK)"
}

echo "Succesfully took off and nuked the site from orbit. It's the only way to be sure."