apt-get install samba smbclient cifs-utils heimdal-clients
mcedit /etc/samba/smb.conf

Here we will create one share as read only from guests users
and one share as read/write for a specific user

Create read only Share

[Photos]
comment = "Family Photos"
path = /media/NextCloud/Photos
browseable = yes
read only = yes
guest ok = yes

Create the read/Write Share

[NextCloud]
comment = "All of NextCloud in Garage Server"
path = /media/NextCloud
browseable = yes
read only = no
guest ok = no
force group = users
create mask = 0770
directory mask = 0771
force create mode = 0660
force directory mode = 0770
valid user = michel