$ amtool alert
Alertname        Starts At                Summary
Test_Alert       2017-08-02 18:30:18 UTC  This is a testing alert!
Test_Alert       2017-08-02 18:30:18 UTC  This is a testing alert!
Check_Foo_Fails  2017-08-02 18:30:18 UTC  This is a testing alert!
Check_Foo_Fails  2017-08-02 18:30:18 UTC  This is a testing alert!

amtool -o extended alert
Labels                                        Annotations                                                    Starts At                Ends At                  Generator URL
alertname="Test_Alert" instance="node0"       link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local
alertname="Test_Alert" instance="node1"       link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local
alertname="Check_Foo_Fails" instance="node0"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local
alertname="Check_Foo_Fails" instance="node1"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local

$ amtool -o extended alert query alertname="Test_Alert"
Labels                                   Annotations                                                    Starts At                Ends At                  Generator URL
alertname="Test_Alert" instance="node0"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local
alertname="Test_Alert" instance="node1"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local

$ amtool -o extended alert query instance=~".+1"
Labels                                        Annotations                                                    Starts At                Ends At                  Generator URL
alertname="Test_Alert" instance="node1"       link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local
alertname="Check_Foo_Fails" instance="node1"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local

$ amtool -o extended alert query alertname=~"Test.*" instance=~".+1"
Labels                                   Annotations                                                    Starts At                Ends At                  Generator URL
alertname="Test_Alert" instance="node1"  link="https://example.com" summary="This is a testing alert!"  2017-08-02 18:31:24 UTC  0001-01-01 00:00:00 UTC  http://my.testing.script.local

$ amtool silence add alertname=Test_Alert
b3ede22e-ca14-4aa0-932c-ca2f3445f926

$ amtool silence add alertname="Test_Alert" instance=~".+0"
e48cb58a-0b17-49ba-b734-3585139b1d25

$ amtool silence query
ID                                    Matchers              Ends At                  Created By  Comment
b3ede22e-ca14-4aa0-932c-ca2f3445f926  alertname=Test_Alert  2017-08-02 19:54:50 UTC  kellel

$ amtool silence query instance=~".+0"
ID                                    Matchers                            Ends At                  Created By  Comment
e48cb58a-0b17-49ba-b734-3585139b1d25  alertname=Test_Alert instance=~.+0  2017-08-02 22:41:39 UTC  kellel

$ amtool silence expire b3ede22e-ca14-4aa0-932c-ca2f3445f926

$ amtool silence query instance=~".+0"
ID                                    Matchers                            Ends At                  Created By  Comment
e48cb58a-0b17-49ba-b734-3585139b1d25  alertname=Test_Alert instance=~.+0  2017-08-02 22:41:39 UTC  kellel

$ amtool silence expire $(amtool silence -q query instance=~".+0")

$ amtool silence query instance=~".+0"

$ amtool silence expire $(amtool silence query -q)