```ruby
# Add the opscode APT source for chef
default[:apt][:sources] = node[:apt][:sources] | ["opscode"]

# Set the default server version
default[:chef][:server][:version] = "12.0.8-1"

# Set the default client version
default[:chef][:client][:version] = "12.7.2-1"

# A list of gems needed by chef recipes
default[:chef][:gems] = []
```

Update chef client to 12.8.1
user
```ruby
# Add the opscode APT source for chef
default[:apt][:sources] = node[:apt][:sources] | ["opscode"]

# Set the default server version
default[:chef][:server][:version] = "12.0.8-1"

# Set the default client version
default[:chef][:client][:version] = "12.8.1-1"

# A list of gems needed by chef recipes
default[:chef][:gems] = []
```
assistant