Netplan configuration doesn't seem to be taking effect

Question

After configuring a static ip address in /etc/netplan/01-network-manager-all.yaml for my wlan interface, the ip address nor the dns changed.

I used sudo netplan generate and sudo netplan apply, but when I ran ifconfig nothing had changed.

My netplan config:

# Let NetworkManager manage all devices on this system

network:
  version: 2
  renderer: NetworkManager

  wifis:
    wlp6s0:
      dhcp4: no
      dhcp6: no
      addresses: [10.0.0.115/24]
      gateway4: 10.0.0.1
      nameservers:
        addresses: [8.8.8.8, 8.8.4.4]
      access-points:
        XXXXX:
          password: XXXXXXXX

ifconfig output:

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
    inet 127.0.0.1  netmask 255.0.0.0
    inet6 ::1  prefixlen 128  scopeid 0x10<host>
    loop  txqueuelen 1000  (Local Loopback)
    RX packets 2882  bytes 252039 (252.0 KB)
    RX errors 0  dropped 0  overruns 0  frame 0
    TX packets 2882  bytes 252039 (252.0 KB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp6s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 10.0.0.14  netmask 255.255.255.0  broadcast 10.0.0.255
    inet6 fe80::eba8:95b6:70df:fee5  prefixlen 64  scopeid 0x20<link>
    ether 00:17:9a:01:c6:00  txqueuelen 1000  (Ethernet)
    RX packets 12673  bytes 8587304 (8.5 MB)
    RX errors 0  dropped 0  overruns 0  frame 0
    TX packets 11485  bytes 1727699 (1.7 MB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

The ip address stays 10.0.0.14

Solution

You have to decide whether to run with NetworkManager or netplan.

Ubuntu Desktop users should probably use NetworkManager, and use its GUI tools.

Ubuntu Server users should be using netplan.

Your .yaml file is a combination of both NetworkManager and netplan. Can't do that.

If you're going to use NetworkManager, your .yaml should look like this...

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

followed with a:

sudo netplan --debug generate

sudo netplan apply

Then you need to configure /etc/network/interfaces with command syntax similar to, but not exactly, like the remainder of your existing .yaml file. However, rather than editing /etc/network/interfaces just use the NetworkManager GUI tools to configure your wireless networks.