Dr. SaltStack or: How I Learned to Stop Worrying and Replace the Cron

Salt Stack is at it's heart a remote execution system which also does configuration management very well. Using recent additional to the 2014.7 release, this talk will demonstrate how Salt can be used to replace Cron for command scheduling. The talk will also include a brief introduction to Salt and some basic examples.

Transcript

1. Dr. SaltStack or: How I Learned to Stop Worrying and Replace the Cron
2. Gareth J. Greenaway • Founder & organizer of SoCal Linux Expo • Core contributor to Salt Stack project • http://www.twitter.com/garethgreenaway
3. Scheduling Jobs *under Un*x like operating systems.
4. 1. Easily schedule a job. 2. Easy notification of job completion. 3. Different notification depending on job. 4. Schedule remotely across many nodes. 5. Enable, Disable, and Move Jobs. What We Want
5. A few different options
6. at
7. echo "cc -o foo foo.c" | at 1145 jan 31
8. • Available on most Linux & *BSD systems, even Windows and OS X. • Simple syntax to schedule jobs • Management tools: at,atq, and atrm • Notifications via email Pros
9. Cons • One time run. • Node specific management.
10. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. 4. Remotely across many nodes. 5. Enable, Disable, and Move Jobs.
11. cron
12. MAILTO: user@example.com 00 20 * * * /home/user/command.sh
13. Pros • Also available on most Linux & *BSD systems, and Windows and OS X. • Relatively simple syntax to schedule jobs • Management tools: crontab • Notification
14. Cons • Still node specific management. • Having to check the man page for which column is which
15. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. 4. Remotely across many nodes. 5. Enable, Disable, and Move Jobs.
16. Alternatives
17. Manage ‘at’ jobs with Salt
18. What is Salt?
19. Remote Execution System
20. ‘at’ jobs
21. salt '*' at.at <timespec> <cmd> [tag=<tag>] [runas=<user>] Example: salt 'node1' at.at 12:05am '/sbin/reboot' tag=reboot Schedule ‘at’ job
22. Configuration Management System
23. States
24. Puppet: Manifests Chef: Recipes Ansible: Playbooks CFEngine: Promises
25. ‘at’ jobs
26. rose: at.present: - job: 'echo "I love saltstack" > love' - timespec: '9:9 11/09/13' - tag: love - user: jam Schedule ‘at’ job.
27. Manage ‘cron’ with Salt
28. Similar execution and state modules for cron
29. Still Limitations of both at and cron
30. Simply Use Salt
31. Disclaimer: Many features presented currently available in future releases or develop branch of Salt.
32. Powerful Scheduler
33. schedule: job1: function: state.sls seconds: 3600 args: - httpd kwargs: test: True Schedule Configured on Minion
34. schedule: job1: function: state.sls cron: '*/5 * * * *' args: - httpd kwargs: test: True More precise by mimicking Cron.
35. schedule: job1: function: state.sls when: 'Monday 8:15pm' args: - httpd kwargs: test: True Even more precise. And more clear.
36. Multiple runs. schedule: job1: function: state.sls when: - ‘Monday 8:15pm' - ‘Tuesday 3:00pm’ args: - httpd kwargs: test: True
37. What We Want 1. Easily schedule a job. 2. Notification of job completion. ? 3. Different notification depending on job. ? 4. Remotely across many nodes. ? 5. Enable, Disable, and Move Jobs. ?
38. Notifications
39. Salt Returners
40. Examples of returners: MySQL, PostgreSQL, Redis SMTP, XMPP, HipChat
41. Scheduler + Returners
42. schedule: job1: function: state.sls when: 'Monday 8:15pm' args: - httpd kwargs: test: True returner: xmpp Notifications
43. Returner Configuration on Minion
44. xmpp.recipient: to-jid@gmail.com xmpp.jid: from-jid@gmail.com/salt xmpp.password: 12345 XMPP Returner Configuration
45. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. ? 4. Remotely across many nodes. ? 5. Enable, Disable, and Move Jobs. ?
46. Different Notifications
47. Alternative Returner Configuration
48. alt.xmpp.recipient: different-jid@gmail.com alt.xmpp.jid: from-jid@gmail.com/salt alt.xmpp.password: 12345 XMPP Returner Configuration
49. schedule: job1: function: state.sls when: 'Monday 8:15pm' args: - httpd kwargs: test: True returner: xmpp return_config: alt Notifications
50. xmpp.jid: from-jid@gmail.com/salt xmpp.password: 12345 alt.xmpp.recipient: to-jid@gmail.com diff.xmpp.recipient: two-jid@gmail.com XMPP Returner Configuration
51. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. 4. Remotely across many nodes. ? 5. Enable, Disable, and Move Jobs. ?
52. Remotely Across Many Nodes
53. Remote Execution System
54. salt '*' schedule.add job1 function='test.ping' seconds=3600 salt 'node1' schedule.add job1 function='test. ping' when=’Thursday 9:15pm’ salt 'node2' schedule.add job1 function='test. ping' when=”[’Thursday 9:15pm’,’Friday 10: 15am’]” Schedule Jobs
55. Configuration Management System
56. job2: schedule.present: - function: test.ping - seconds: 15 Schedule Jobs
57. Schedule Jobs job1: schedule.present: - function: state.sls - args: - httpd - kwargs: test: True - when: - Monday 5:00pm - Tuesday 3:00pm - Wednesday 5:00pm
58. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. 4. Remotely across many nodes. 5. Enable, Disable, and Move Jobs. ?
59. Disable, Enable and Move
60. Schedule Execution Module
61. schedule.disable_job
62. salt ‘node’ schedule.disable_job job1
63. schedule.enable_job
64. salt ‘node’ schedule.enable_job job1
65. schedule.move_job
66. salt ‘node’ schedule.move_job job1 target-node
67. Other Available Functions • schedule.copy • schedule.delete • schedule.disable • schedule.enable • schedule.list • schedule.modify • schedule.purge • schedule.reload • schedule.save • schedule.run_job
68. What We Want 1. Easily schedule a job. 2. Notification of job completion. 3. Different notification depending on job. 4. Remotely across many nodes. 5. Enable, Disable, and Move Jobs.
70. So what can you schedule?
71. Salt has almost 300* modules and roughly 1200* module functions. * not all modules and functions available on all systems.
72. Other Interesting Scheduler Features
73. Splay
74. schedule: job1: function: state.sls seconds: 3600 args: - httpd kwargs: test: True splay: 15
75. schedule: job1: function: state.sls seconds: 3600 args: - httpd kwargs: test: True splay: start: 10 end: 15
76. Range
77. schedule: job1: function: state.sls seconds: 3600 args: - httpd kwargs: test: True range: start: 8:00am end: 5:00pm
78. Inverted Range
79. schedule: job1: function: state.sls seconds: 3600 args: - httpd kwargs: test: True range: invert: True start: 8:00am end: 5:00pm
80. Scheduling Jobs with Salt Stack
81. Thank You!
82. Any questions?