Increase amount of MaxSessions

For running bigger amount of ansible forks, we need to increase
ssh MaxSessions parameter for lxc hosts, since
all connections to lxc containers occur through hosts

Depends-On: https://review.opendev.org/758399
Change-Id: Ib3e850ba79658a42995cd782a11342aca6858342

handlers/main.yml

@@ -93,6 +93,12 @@
     name: it_does_not_matter
     daemon_reload: yes
 
+- name: Restart sshd
+  service:
+    name: sshd
+    state: "restarted"
+    enabled: yes
+
 - name: Remove rootfs archive
   file:
     path: "/tmp/{{ cache_basename }}"

tasks/lxc_post_install.yml

@@ -63,6 +63,17 @@
   tags:
     - lxc-config
 
+- name: Set sshd MaxSessions
+  lineinfile:
+    dest: /etc/ssh/sshd_config
+    state: present
+    regexp: "^#?MaxSessions.*$"
+    line: "MaxSessions 50"
+  notify:
+    - Restart sshd
+  tags:
+    - lxc-config
+
 # NOTE(hwoarang): The previous task only affected newly created services.
 # However, for particular systemd versions like v228 the default one for
 # started scopes is 512