This is a quick and dirty interface to update-alternatives on Centos/Redhat/Ubuntu for puppet. Seems to work well and doesn't require any modules.
class my_alternatives {
# Manipulates alternatives using update-alternatives.
# Supports RHEL, Centos and Suse.
# Ubuntu not tested (yet).
#
# If multiple matches are available, picks the first one.
#
# There is rudimentary alternatives support in the java class,
# but it's rather limited and doesn't support most platforms and java versions.
define update (
$item = $title, # the item to manage, ie "java"
$versiongrep, # string to pass to grep to select an alternative, ie '1.8' (1.8.*openjdk would also work)
$optional = true, # if false, execution will fail if the version is not found
$altcmd = 'update-alternatives' # command to use
) {
case $::osfamily {
'RedHat','SuSE': {
if ! $optional {
# verify that we have exactly 1 matching alternatives, unless it's optional
exec { "check alternatives for ${item}":
path => ['/sbin','/bin','/usr/bin','/usr/sbin'],
command => "echo Alternative for ${item} version containing ${versiongrep} was not found, or multiple found ; false",
unless => "test $(${altcmd} --display ${item} | grep '^/' | grep -- '$versiongrep' | wc -l) -eq 1",
before => Exec["update alternatives for ${item} to ${versiongrep}"],
}
}
# Runs the update alternatives command
# - unless it reports that it's already set to that version
# - unless that version is not found via grep
exec { "update alternatives for ${item} to ${versiongrep}":
path => ['/sbin','/bin','/usr/bin','/usr/sbin'],
command => "${altcmd} --set ${item} $( ${altcmd} --display ${item} | grep '^/' | grep -- '$versiongrep' | head -n 1 | sed 's/ .*$//' ) ",
unless => "test -x \"$(${altcmd} --display ${item} | grep 'currently points' | grep -- '$versiongrep' | awk '{print \$NF}')\"",
onlyif => "${altcmd} --display ${item} | grep '^/' | grep -- '$versiongrep' ", # check that there is one (if optional and not found, this won't run)
}
}
# Leave Ubuntu alone, this probably won't work there anyway
}
}
}
