Scripting the Catalyst: Beyond the Basics

Transcription

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2 Scripting the Catalyst: Beyond the Basics Jeff McLaughlin, Principal TME

3 Cisco Spark How Questions? Use Cisco Spark to communicate with the speaker after the session 1. Find this session in the Cisco Live Mobile App 2. Click Join the Discussion 3. Install Spark or go directly to the space 4. Enter messages/questions in the space cs.co/ciscolivebot# 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

4 Agenda Why programmability? Planning a script Python and Tools Finding and using Models NCClient and YDK-Py REST APIs Completing the script On-Box Python

5 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 5

6 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 6

7 Why Programmability?

8 Why automation and programmability? Administrator Needs to configure hostname switch1 int g0/0 ip address /24 vlan 100,200, hostname switch6 int g0/0 ip address /24 vlan 100,200, Cisco and/or its affiliates. All rights reserved. Cisco Public 8

9 Notepad is the most common automation tool. It s just a very bad automation tool.... Programmability Reason #1 Do repetitive and tedious tasks more easily 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 9

10 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored if error counters too high: then shutdown interface* * pseudo-code Programmability Reason #2 Programmatic Control of network devices 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 10

11 party apps Cisco ISE NETCONF REST API Catalyst switches APIC-EM Programmability Reason #3 Interaction between network devices and other systems 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 11

12 Transactionality int g0/0 ip address /24 no shutdown router bgp router-id bgp log-neighbor-changes neighbor remote-as neighbor remote-as address-family ipv4 unicast neighbor activate network mask exit-address-family Programmability Reason #4 Stop bad configuration being committed to devices 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 12

13 Operational Simplification How to find the red user's switch/port? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 13

14 Operational Simplification # ping # show arp i # show mac address-table address 001a.a24d.5141 # show cdp neighbor g0/1 detail How to find the red user's switch/port? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 14

15 Operational Simplification # show mac address-table address 001a.a24d.5141 # show cdp neighbor g0/10 detail How to find the red user's switch/port? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 15

16 Operational Simplification How to find the red user's switch/port? # show mac address-table address 001a.a24d.5141 # show cdp neighbor g0/10 detail Vlan Mac Address Type Ports a.a24d.5141 DYNAMIC Gi0/ Cisco and/or its affiliates. All rights reserved. Cisco Public 16

17 Operational Simplification Programmability Reason #5 Automate complex troubleshooting tasks 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 17

18 Time for a demo 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

19 1 User types command into Spark 2 Command pulled down by script REST 5 Data posted back to Spark room 3 Script sends NETCONF request 4 Switch replies via NETCONF with data NETCONF Catalyst Cisco and/or its affiliates. All rights reserved. Cisco Public 19

20 Planning Tools Models APIs Development 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 20

21 Planning your script

22 What do I want to do? Catalyst Display the routing table 2. Graph the routing table 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 22

23 What tool to use? CLI CFG MGMT TOOLS PYTHON SCRIPT Advantages: Easy to use Well documented Immediate result Advantages: Device roles Powerful templating Easy to learn Advantages: Numerous libraries Programmable intfs Well supported Disadvantages: Time consuming Tedious Error-prone Disadvantages: Less functionality Disadvantages: Development time 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 23

24 Python: Why not C, Ruby, Perl, TCL, Go, etc.? Easy to Learn Interactive shell Easy to begin with simple scripts Libraries! Extensive libraries, like an app store for developers Read Excel, output PDF, draw graphs, etc. And it s well supported in the networking community! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 24

25 Which tools do I use? Catalyst Cisco and/or its affiliates. All rights reserved. Cisco Public 25

26 Which tools do I use? REST! NETCONF? CLI? SNMP? Catalyst Cisco and/or its affiliates. All rights reserved. Cisco Public 26

27 NETCONF, CLI, SNMP? CLI SNMP NETCONF Venerable/Ancient? Structured Data? Tooling? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 27

28 Which tools do I use? REST! NETCONF! CLI? SNMP? Catalyst Cisco and/or its affiliates. All rights reserved. Cisco Public 28

29 How do I build it? Catalyst 3850 Read Spark messages Post Spark messages Post PNG image Poll Spark room Parse Spark command Format data from switch Graph data from switch Read the routing table 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 29

30 Setting up Python environment

31 Getting Python Mac Python is probably already installed. Unix/Linux 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 31

32 Getting Python 1 Download and install Python 2.7 or 3 2 PC/Windows Download and install PIP package manager 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 32

33 Python 2 vs 3 Python >>> print "Hello World! Hello World! Python 2 Python 3.6.0a4 >>> print "Hello World!" SyntaxError: Missing parentheses >>> print ("Hello World") Hello World Python 3 Most common version Default installation on Linux Most libraries Losing popularity Several language enhancements Often separate installation Not all libraries supported Commonly used in books/courses Python 2 and 3 are not mutually compatible! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 33

34 PIP Install $ pip install netaddr Downloading/unpacking netaddr Downloading netaddr py2.py3-none-any.whl (1.6MB): 1.6MB downloaded Installing collected packages: netaddr Successfully installed netaddr Cleaning up... PDFrw YDK-Py OpenPy XL Python NCClient 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 34

35 What libraries do we need? 1 Something to do REST (requests) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 35

36 What libraries do we need? NETCONF Catalyst Something to do NETCONF (ncclient) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 36

37 What libraries do we need? 3 Something to do graphing (graphviz) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 37

38 Virtual Environments V-Env1 V-Env2 V-Env3 Python 2.5 Python 2.7 Python 2.7 Requests = NCClient = Jinja2 = Jinja2 = 2.7 NCClient = paramiko = Requests = NCClient = openpyxl = Cisco and/or its affiliates. All rights reserved. Cisco Public 38

39 Installing Virtual Environment $ pip install virtualenv Collecting virtualenv Downloading virtualenv py2.py3-none-any.whl (1.8MB) 100% 1.8MB 658kB/s Installing collected packages: virtualenv Successfully installed virtualenv Install Virtualenv with PIP like any Python library Cisco and/or its affiliates. All rights reserved. Cisco Public 39

40 Using VirtualEnvironments $ mkdir spark_app $ cd spark_app $ virtualenv env New python executable in /Users/jemclaug/Documents/Projects/CL LV 2017//env/bin/python Installing setuptools, pip, wheel...done. $ source env/bin/activate (env) $... (env) $ (env) $ deactivate $ Make a directory for your project Create a virtual environment Activate the virtual environment Do Pythonic stuff like PIP installs Deactivate 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 40

41 Git and version control Cisco and/or its affiliates. All rights reserved. Cisco Public 41

42 Create code Modify code Save code Save code again 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 42

43 Initial Commit BGP over NC Added oper data Fixed nc_get Initial Commit BGP over NC Added oper data Fixed nc_get Version control scenario 1: You make changes and need to track them Version control scenario 2: You work with collaborator(s) and need to track and merge changes to code Cisco and/or its affiliates. All rights reserved. Cisco Public 43

44 Git is a version control system. GitHub is an online source code repository. GitHub provides an easy way to share code and collaborate. It works together with Git Cisco and/or its affiliates. All rights reserved. Cisco Public 44

45 Installing git Install Git using the standard installers on Mac/Windows Use the usual methods on Linux (apt-get, yum, rpm, etc.) Highly Recommended: Install GitHub Desktop! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 45

46 Tracking your project with Git 1 Create.gitignore file $ cat.gitignore.gitignore *.py[co] env/ (Sometimes) Tells git, don't track these files! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 46

47 Tracking your project with Git 2 Initialize the repo JEMCLAUG-M-34E1:spark_app jemclaug$ git init Initialized empty Git repository in /Users/jemclaug/Documents/Projects/CL LV 2017//spark_app/.git/ 3 Add file(s) to be tracked $ echo "My First File" > file.txt $ git add file.txt 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 47

48 Tracking your project with Git 4 Commit your changes $ git commit Aborting commit due to empty commit message. $ git commit -m "Added my first file" [master (root-commit) cba52b5] Added my first file 1 file changed, 1 insertion(+) create mode file.txt 5 View changes in GH Desktop! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 48

49 Cloning repo's from GitHub $ git clone Cloning into 'pyfabric'... remote: Counting objects: 89, done. remote: Total 89 (delta 0), reused 0 (delta 0), pack-reused 89 Unpacking objects: 100% (89/89), done. $ cd pyfabric/ $ virtualenv env New python executable in /Users/jemclaug/pyfabric/env/bin/python Installing setuptools, pip, wheel...done. $ source env/bin/activate (env) $ pip install -r requirements.txt Collecting cffi==1.9.1 (from -r requirements.txt (line 1)) Using cached cffi cp27-cp27m-macosx_10_10_intel.whl Collecting cryptography==1.7.1 (from -r requirements.txt (line 2)) Using cached cryptography cp27-cp27m-macosx_10_10_intel.whl 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 49

50 Planning Tools Models APIs Development 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 50

51 Data Models

52 Human-Oriented Interface Machine-Oriented Interface 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 52

53 Machines using human-oriented interfaces can be highly inefficient! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 53

54 CLI YANG Models Human Oriented Interface Machine Oriented Interface 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 54

55 Structured vs Unstructured Data Un-structured Structured John Smith What is this? His age? The year he graduated college? Meaning of life, the universe & everything? Name: Age: Phone: Keys John Smith Values 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 55

56 Hierarchical Structured Data (XML-like) First User Second User { { <user1> <name>john Smith</name> <age>42</age> <phone> </phone> </user1> <user2> <name>sarah Kim</name> <age>27</age> <phone> </phone> </user2> 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 56

57 Ancient unstructured data COULDYOUREADITIFWEWROTELIKETHIS WITHNOPUNCTUATIONITISHARDTOFIGUR EOUTWHEREONEWORDORSENTENCEBE GINSORENDSANDITISNOTEASYTOSEPAR ATEOUTALLTHEELEMENTSOFTHETEXTTH ANKGOODNESSSOMEONECAMEUPWITHA BETTERWAY 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 57

58 Note inconsistent key format! switch1# sh int e1/10 Ethernet1/10 is up Hardware: 1000/10000 Ethernet, address: d (bia d0.9331) Description: To UCS-11 MTU 1500 bytes, BW Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Switchport monitor is off EtherType is 0x8100 Last link flapped 8week(s) 2day(s) Last clearing of "show interface" counters 1d02h 30 seconds input rate 944 bits/sec, 118 bytes/sec, 0 packets/sec 30 seconds output rate bits/sec, bytes/sec, 5221 packets/sec CLI = Unstructured Data 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 58

59 What we need: Standard, structured way to represent configuration and operational data. <ipv4 xmlns=" <addresses> <address> <ip> </ip> <config> <ip> </ip> <prefix-length>24</prefix-length> </config> </address> </addresses> </ipv4> 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 59

60 The train to Paris leaves at 11:30. Le train à Paris part à 11: Cisco and/or its affiliates. All rights reserved. Cisco Public 60

61 XML vs JSON <interfaces xmlns:= [ ]yang:ietf-interfaces > <interface> <name>eth0</name> <type>ethernetcsmacd</type> <location>0</location> <enabled>true</enabled> <if-index>2</if-index> </interface> </interfaces> NETCONF/RESTCONF { } "ietf-interfaces:interfaces": { "interface": [ { "name": "eth0, "type": "ethernetcsmacd, "location": "0, "enabled": true, "if-index": 2 } ] } RESTCONF 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 61

62 Error! Sends <interface>gigabit 1/0</interface> <ifaddr> /24</ifaddr> Expecting Expecting: <interface> <name>gigabit 1/0</name> <address> /24</address> </interface> 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 62

63 So why do we need YANG? <interface>ethernet 0/0</interface> <name>switch1 to UCS1</name> <ipaddr> /24</ipaddr> <name>ethernet 0/0</name> <descr>switch1 to UCS1</descr> <ip> /24</ip> Question: Which of these is correct? Answer: They all are! <ifname>ethernet 0/0</ifname> <ifalias>switch1 to UCS1</ifalias> <ifaddr> /24</ifaddr> 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 63

64 YANG Data Models container ip { list vrf { leaf rd } } vrf red rd 1:1 <vrf>red</vrf> <rd>1:1</rd> YANG Model Data XML Data YANG models do not contain data or XML. YANG models are like templates used to generate consistent XML Cisco and/or its affiliates. All rights reserved. Cisco Public 64

65 YANG Data Models <vrf>red</vrf> <rd>1:1</rd> container ip { list vrf { leaf rd } } vrf red rd 1:1 XML YANG Model Data { vrf : red rd : 1:1 } JSON YANG models can be used as a template for generating structured data in many different formats Cisco and/or its affiliates. All rights reserved. Cisco Public 65

66 YANG Configuration Model Example* container ip { YANG list vrf { description "Configure an IP VPN Routing/Forwarding instance"; } } leaf name { type string; } leaf rd { description "Specify Route Distinguisher"; type rd-type; } <ip> <vrf> <name>vrf_red</name> <rd>65000:1</rd> </vrf> <vrf> <name>vrf_green</name> <rd>65000:2</rd> </vrf> </ip> ip vrf vrf_red rd 65001:1! ip vrf vrf_green rd 65001:2! XML CLI * Note: YANG model simplified for clarity 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 66

67 So why is this: <ip> <vrf> <name>vrf_red</name> <rd>65000:1</rd> </vrf> <vrf> <name>vrf_green</name> <rd>65000:2</rd> </vrf> </ip>...better than this? ip vrf vrf_red rd 65001:1! ip vrf vrf_green rd 65001:2! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 67

68 CLI ip vrf vrf_red rd 65001:1! ip vrf vrf_green rd 65001:2! Good for human consumption Unstructured from a machine perspective 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 68

69 YANG-structured data <ip> <vrf> <name>vrf_red</name> <rd>65000:1</rd> </vrf> <vrf> <name>vrf_green</name> <rd>65000:2</rd> </vrf> </ip> Designed for machine consumption Directly convertible to/from Python dicts! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 69

70 Where are YANG models? Models installed on device automatically with IOS-XE. On some devices/versions, can be updated independently Also can be downloaded from GitHub Cisco and/or its affiliates. All rights reserved. Cisco Public 70

71 Who defines the YANG models? Vendors Standards Bodies Only work on specific vendor devices Greater feature coverage Can be OS-unique (IOS-XE, XR, etc.) Multi-vendor support More limited feature coverage Allow vendor-specific extensions 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 71

72 Important Point! Cisco s data models and IETF/OpenConfig data models are just two ways of doing the same thing. <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"> <interface> <name>gigabitethernet 1/0/24</name> <description>configured by NETCONF!</description> </interface> </interfaces> IETF-defined model Both of these do exactly the same thing! <native xmlns=" <interface> <GigabitEthernet> <name>1/0/24</name> <description>configured by NETCONF!</description> </GigabitEthernet> </interface> </native> Cisco-defined native model 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 72

73 Important Point! Cisco s data models and IETF/OpenConfig data models are just two ways of doing the same thing. <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"> <interface> <name>gigabitethernet 1/0/24</name> <description>configured by NETCONF!</description> </interface> </interfaces> switch# show run interface g1/0/24 interface Both of these GigabitEthernet do exactly the 1/0/24 same thing! description Configured by NETCONF! <native xmlns=" <interface> <GigabitEthernet> <name>1/0/24</name> <description>configured by NETCONF!</description> </GigabitEthernet> </interface> </native> IETF-defined model Cisco-defined native model 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 73

74 Configuration vs. Operational data Configuration data tells the device what to do. It is data that you see in a show run. Operational data tells us how a device is operating, from show commands other than show run. # sh run int g0/0 interface GigabitEthernet0/0 description Management Interface vrf forwarding Mgmt-vrf ip address # sh int g0/0 GigabitEthernet0/0 is up, line protocol up Hardware is RP management port Description: Management Interface We can write configuration data (think conf t ), and we can read configuration data (think show run ). Operational data is read-only. Some data can be read either as config data or operational data! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 74

75 Models and structured data are particularly important for efficiently reading operational data Cisco and/or its affiliates. All rights reserved. Cisco Public 75

76 PID Runtime(ms) Invoked usecs 5Sec 1Min 5Min TTY Process % 0.00% 0.00% 0 Chunk Manager % 0.01% 0.00% 0 Load Meter Challenge: Write a Python script to go through the list of nearly 500 running processes and print the names of only those with runtime of 10 seconds or greater. Regex hard to understand Tied directly to table layout 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 76

77 Regular Expressions -Stackexchange user 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 77

78 PID Runtime(ms) Invoked usecs 5Sec 1Min 5Min TTY Process % 0.00% 0.00% 0 Chunk Manager % 0.01% 0.00% 0 Load Meter Challenge: Write a Python script to go through the list of nearly 500 running processes and print the names of only those with runtime of 10 seconds or greater. XML easily rendered as Python dict Uses YANG data models Intuitive nomenclature 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 78

79 NETCONF vs. YANG Communication Protocol NETCONF Data Description YANG SNMP MIB/ASN Cisco and/or its affiliates. All rights reserved. Cisco Public 79

80 NETCONF protocol stack CONTENT XML (based on YANG) OPERATIONS GET, EDIT-CONFIG, ETC MESSAGES RPC SECURE TRANSPORT SSH 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 80

81 Enabling NETCONF: 3 Steps C3850-1#conf t Enter configuration commands, one per line. End with CNTL/Z. C3850-1(config)#aaa new-model C3850-1(config)#aaa authentication login default local C3850-1(config)#aaa authorization exec default local C3850-1(config)#username admin password cisco C3850-1(config)#line vty 0 15 C3850-1(config-line)#transport input all C3850-1(config)#netconf-yang C3850-1(config)# Enable AAA Enable SSH Enable NETCONF 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 81

82 Finding and using YANG models

83 What are we looking for? Extract route and next hop interface or IP from routing table NO regular expressions!!! Open model if possible 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 83

84 YangExplorer: A Cisco tool for exploring models Available at: -explorer Or just Google: "cisco yangexplorer" 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 84

85 YangExplorer: A Cisco tool for exploring models Models on device Models subscribed on YangExplorer 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 85

86 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 86

87 Finding a model, method 1 Either scroll through the model list or search for a specific model. Click RPC. The XML is displayed Cisco and/or its affiliates. All rights reserved. Cisco Public 87

88 Finding a model, method 2 Pull the config from an existing device. Select get-config for the hierarchy you need. Click Run RPC. The XML is displayed Cisco and/or its affiliates. All rights reserved. Cisco Public 88

89 Planning Tools Models APIs Development 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 89

90 Python NETCONF Libraries

91 NCClient Python Library Raw XML NETCONF NCClient 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 91

92 NCClient "Get" Example 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 92

93 YANG Developer Kit (YDK) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 93

94 NCClient: YDK: <interface> <GigabitEthernet> <name>1/0/14</name> <description>to_core_switch</description> <ip> <address> <primary> <address> </address> <mask> </mask> </primary> </address> </ip> </GigabitEthernet> </interface> gigabitethernet= interface.gigabitethernet() gigabitethernet.name = "1/0/14" gigabitethernet.description = "To_Core_Switch" gigabitethernet.ip.address.primary.address = " " gigabitethernet.ip.address.primary.mask = " " ip_add.gigabitethernet.append(gigabitethernet) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 94

95 REST APIs

96 Consider some of the things you can do with an app like Spark Cisco and/or its affiliates. All rights reserved. Cisco Public 96

97 Add a user to a room 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 97

98 Read a message 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 98

99 API s allow you to do same things with a script instead of by clicking.. Create a space Add a user to a space Read a message 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 99

100 REST API calls use HTTP methods like GET, PUT and POST Cisco and/or its affiliates. All rights reserved. Cisco Public 100

101 ...and like a web page, REST APIs use URLs Cisco and/or its affiliates. All rights reserved. Cisco Public 101

102 REST API URLs determine what resource is being accessed. POST POST POST Cisco and/or its affiliates. All rights reserved. Cisco Public 102

103 The headers of the request contain basic information such as an authentication token, while the body of the request contains the data to send Cisco and/or its affiliates. All rights reserved. Cisco Public 103

104 How do I find REST APIs? REST APIs are useless unless they are documented Cisco and/or its affiliates. All rights reserved. Cisco Public 104

105 Headers for call Content needed API Test Button! 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 105

106 Often you don t need to know REST to use REST! Libraries make the calls easy Cisco and/or its affiliates. All rights reserved. Cisco Public 106

107 Our script will use a library I created, spark.py... Example: Post a message: Easier than Cisco and/or its affiliates. All rights reserved. Cisco Public 107

108 Pulling it all together

109 Planning Tools Models APIs Development 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 109

110 Script Flow 1 What Pull messages from Spark How Spark library Example 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 110

111 Script Flow 2 What Parse message How Python conditions Example* * simple, but can be improved using NLP 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 111

112 Script Flow 3 What Collect routes How NETCONF w/ NCClient Example 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 112

113 Script Flow 4 (Optional) What Graph Routes How Graphviz Library Example 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 113

114 Script Flow 5 What Post response to Spark How Spark library Example (With graph) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 114

115 On-Box Scripting

116 Off-box Python Scripting NETCONF* Off-box scripts run on an external server and communicate with the switch over the network using NETCONF or other protocols. * or other protocol 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 116

117 On-box Python Scripting CLI NETCONF Syslog On-box Python scripts run in a container on the device itself. They can communicate with the network or the device itself. Guestshell Container 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 117

118 Advantages On-Box Access CLI directly on device Trigger syslog messages Interact with Embedded Event Manager Access device bootflash Zero Touch Provisioning Use interactive Python shell 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 118

119 Embedded Event Manager EEM takes certain actions based on triggering events. Events: cli temperature IPSLA Etc Trigger Actions: cli python reload syslog Etc 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 119

120 3 Spark posts diff to room 4 Python script diffs configs and sends diff to Spark Catalyst User changes device config EEM 2 Change detected by EEM 3 EEM Triggers on-box Python script 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 120

121 Wrapping Up

122 How do I learn Python? Automate the Boring Stuff with Python, Al Sweigart Great introduction to Python focused on automation. (Not specifically network automation.) Covers Python 3.0 only. Assumes zero knowledge. Read Excel docs, generate PDFs, etc. Highly recommended. Real Python. Three-part course. Begins with basics assuming no knowledge. Covers Python 2.7 and 3.0. Parts II and III focus on web development with Python. Covers flask, Django, jinja2 templates. Many resources on the web site for free Cisco and/or its affiliates. All rights reserved. Cisco Public 122

123 Cisco DevNet Learning Labs Sandboxes API Documentation Python, YDK, REST And More! Cisco and/or its affiliates. All rights reserved. Cisco Public 123

124 "If a thing is worth doing, it is worth doing badly." - G.K. Chesterton 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 124

125 Work in the USB lab Identify one problem you can solve with a script Start small Copy and mod scripts from DevNet (developer.cisco.com) 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 125

126 Cisco Spark How Questions? Use Cisco Spark to communicate with the speaker after the session 1. Find this session in the Cisco Live Mobile App 2. Click Join the Discussion 3. Install Spark or go directly to the space 4. Enter messages/questions in the space cs.co/ciscolivebot# 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

127 Please complete your Online Session Evaluations after each session Complete 4 Session Evaluations & the Overall Conference Evaluation (available from Thursday) to receive your Cisco Live T-shirt All surveys can be completed via the Cisco Live Mobile App or the Communication Stations Complete Your Online Session Evaluation Don t forget: Cisco Live sessions will be available for viewing on-demand after the event at Cisco and/or its affiliates. All rights reserved. Cisco Public

128 Continue Your Education Demos in the Cisco campus Walk-in Self-Paced Labs Tech Circle Meet the Engineer 1:1 meetings Related sessions 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 128

129 Thank you

130