Add options for configuring file limits in swift

Options have been added to allow a deployer to control the
hard, soft, and fs.file-max limits on swift specific nodes.

Change-Id: Ia5dd51fa360745a9776d58d0bf49d8e1201d3139
Closes-Bug: #1595290
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

defaults/main.yml

@@ -113,6 +113,11 @@ statsd_default_sample_rate: 1.0
 statsd_sample_rate_factor: 1.0
 statsd_metric_prefix:
 
+# Set the file limits
+swift_hard_open_file_limits: 10240
+swift_soft_open_file_limits: 4096
+swift_max_file_limits: "{{ swift_hard_open_file_limits * 24 }}"
+
 ## Keystone authentication middleware
 swift_keystone_auth_plugin: "password"
 

releasenotes/notes/swift-fs-file-limits-a57ab8b4c3c944e4.yaml

@@ -0,0 +1,11 @@
+---
+features:
+  - The ``os_swift`` role has 3 new variables that will allow a
+    deployer to change the hard, soft and fs.file-max limits. the
+    hard and soft limits are being added to the limits.conf file for
+    the swift system user. The fs.file-max settings are added to
+    storage hosts via kernel tuning. The new options are
+    ``swift_hard_open_file_limits`` with a default of 10240
+    ``swift_soft_open_file_limits`` with a default of 4096
+    ``swift_max_file_limits`` with a default of 24 times the value
+    of ``swift_hard_open_file_limits``.

tasks/swift_pre_install.yml

@@ -109,3 +109,23 @@
     group: "root"
   tags:
     - swift-crond
+
+- name: Configure soft file limits
+  lineinfile:
+    dest: "/etc/security/limits.conf"
+    regexp: "^{{ swift_system_user_name }}.*soft.*nofile.*"
+    state: "present"
+    line: "{{ swift_system_user_name }}\tsoft\tnofile\t\t{{ swift_soft_open_file_limits }}"
+    insertbefore: "^# End of file"
+  tags:
+    - swift-config
+
+- name: Configure hard file limits
+  lineinfile:
+    dest: "/etc/security/limits.conf"
+    regexp: "^{{ swift_system_user_name }}.*hard.*nofile.*"
+    state: "present"
+    line: "{{ swift_system_user_name }}\thard\tnofile\t\t{{ swift_hard_open_file_limits }}"
+    insertbefore: "^# End of file"
+  tags:
+    - swift-config

tasks/swift_storage_hosts_setup.yml

@@ -26,6 +26,14 @@
     sysctl_set: yes
   delegate_to: "{{ physical_host }}"
 
+- name: "Set sysctl file-max"
+  sysctl:
+    name: "fs.file-max"
+    state: present
+    value: "{{ swift_max_file_limits }}"
+    sysctl_set: yes
+  delegate_to: "{{ physical_host }}"
+
 - name: "Put /etc/rsyncd.conf in place"
   template:
     src: "rsyncd.conf.j2"