add strategy mitogen_linear when installed mitogen (#5985)

* add strategy mitogen_linear when installed mitogen

* add small docs

Rename playbook file

The raw action executes as a regular Mitogen connection, which requires Python on the target, so add strategy: linear to bootstrap-os role playbook.

* add mitogen to  CI test
fix typo

* enable mitogen test on deploy-part1 tests
change version from master to release
download tar.gz archive

* run all CI tests with mitogen

* disable mitogen with upgrade CI tests

* enable mitogen on CI tests via env vars

* disable mitogen on CI test by default, enable on some different OS

* disable mitogen CI test on centos8
(get error  /usr/bin/python: No such file or directory)

.gitlab-ci/packet.yml

@@ -26,11 +26,15 @@ packet_centos7-flannel-containerd-addons-ha:
   extends: .packet
   stage: deploy-part2
   when: on_success
+  variables:
+    MITOGEN_ENABLE: "true"
 
 packet_ubuntu18-crio:
   extends: .packet
   stage: deploy-part2
   when: on_success
+  variables:
+    MITOGEN_ENABLE: "true"
 
 # ### MANUAL JOBS
 
@@ -40,6 +44,7 @@ packet_centos7-weave-upgrade-ha:
   when: on_success
   variables:
     UPGRADE_TEST: basic
+    MITOGEN_ENABLE: "false"
 
 packet_ubuntu16-weave-sep:
   stage: deploy-part2
@@ -95,11 +100,14 @@ packet_debian9-calico-upgrade-once:
   when: on_success
   variables:
     UPGRADE_TEST: graceful
+    MITOGEN_ENABLE: "false"
 
 packet_debian10-containerd:
   stage: deploy-part2
   extends: .packet
   when: on_success
+  variables:
+    MITOGEN_ENABLE: "true"
 
 packet_centos7-calico-ha:
   stage: deploy-part2
@@ -127,6 +135,8 @@ packet_fedora31-flannel:
   stage: deploy-part2
   extends: .packet
   when: on_success
+  variables:
+    MITOGEN_ENABLE: "true"
 
 packet_centos7-kube-router:
   stage: deploy-part2
@@ -172,6 +182,7 @@ packet_debian9-calico-upgrade:
   when: on_success
   variables:
     UPGRADE_TEST: graceful
+    MITOGEN_ENABLE: "false"
 
 packet_ubuntu18-calico-ha-recover:
   stage: deploy-part3