Description of problem:
SELinux is preventing snap from 'connectto' accesses on the unix_stream_socket /run/snapd.socket.

*****  Plugin catchall_boolean (89.3 confidence) suggests   ******************

If you want to allow daemons to enable cluster mode
Then você deve informar o SELinux sobre isso habilitando o booleano 'daemons_enable_cluster_mode'.

Do
setsebool -P daemons_enable_cluster_mode 1

*****  Plugin catchall (11.6 confidence) suggests   **************************

If you believe that snap should be allowed connectto access on the snapd.socket unix_stream_socket by default.
Then você deve informar que este é um erro.
Você pode gerar um módulo de política local para permitir este acesso.
Do
allow this access for now by executing:
# ausearch -c 'snap' --raw | audit2allow -M my-snap
# semodule -X 300 -i my-snap.pp

Additional Information:
Source Context                system_u:system_r:snappy_t:s0
Target Context                system_u:system_r:snappy_t:s0
Target Objects                /run/snapd.socket [ unix_stream_socket ]
Source                        snap
Source Path                   snap
Port                          <Desconhecido>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           
Policy RPM                    selinux-policy-3.13.1-283.26.fc27.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 4.15.8-300.fc27.x86_64 #1 SMP Fri
                              Mar 9 18:11:36 UTC 2018 x86_64 x86_64
Alert Count                   1
First Seen                    2018-03-15 17:16:54 -03
Last Seen                     2018-03-15 17:16:54 -03
Local ID                      9f16d87c-7ba0-4db7-b605-8e648b058618

Raw Audit Messages
type=AVC msg=audit(1521145014.975:436): avc:  denied  { connectto } for  pid=10060 comm="snap" path="/run/snapd.socket" scontext=system_u:system_r:snappy_t:s0 tcontext=system_u:system_r:snappy_t:s0 tclass=unix_stream_socket permissive=1


Hash: snap,snappy_t,snappy_t,unix_stream_socket,connectto

Version-Release number of selected component:
selinux-policy-3.13.1-283.26.fc27.noarch

Additional info:
component:      selinux-policy
reporter:       libreport-2.9.3
hashmarkername: setroubleshoot
kernel:         4.15.8-300.fc27.x86_64
type:           libreport