6 FD.io CSIT system design needs to meet continuously expanding
7 requirements of FD.io projects including VPP, related sub-systems (e.g.
8 plugin applications, DPDK drivers) and FD.io applications (e.g. DPDK
9 applications), as well as growing number of compute platforms running
10 those applications. With CSIT project scope and charter including both
11 FD.io continuous testing AND performance trending/comparisons, those
12 evolving requirements further amplify the need for CSIT framework
13 modularity, flexibility and usability.
18 CSIT follows a hierarchical system design with SUTs and DUTs at the
19 bottom level of the hierarchy, presentation level at the top level and a
20 number of functional layers in-between. The current CSIT system design
21 including CSIT framework is depicted in the figure below.
29 \graphicspath{{../_tmp/src/csit_framework_documentation/}}
30 \includegraphics[width=0.90\textwidth]{csit_design_picture}
31 \label{fig:csit_design_picture}
36 .. figure:: csit_design_picture.svg
37 :alt: FD.io CSIT system design
40 *FD.io CSIT system design*
42 A brief bottom-up description is provided here:
46 - SUTs - Systems Under Test;
47 - DUTs - Devices Under Test;
48 - TGs - Traffic Generators;
50 #. Level-1 libraries - Robot and Python
52 - Lowest level CSIT libraries abstracting underlying test environment, SUT,
54 - Used commonly across multiple L2 KWs;
55 - Performance and functional tests:
57 - L1 KWs (KeyWords) are implemented as RF libraries and Python
60 - Performance TG L1 KWs:
62 - All L1 KWs are implemented as Python libraries:
64 - Support for TRex only today;
65 - CSIT IXIA drivers in progress;
67 - Performance data plane traffic profiles:
69 - TG-specific stream profiles provide full control of:
71 - Packet definition – layers, MACs, IPs, ports, combinations thereof
72 e.g. IPs and UDP ports;
73 - Stream definitions - different streams can run together, delayed,
75 - Stream profiles are independent of CSIT framework and can be used
76 in any T-rex setup, can be sent anywhere to repeat tests with
77 exactly the same setup;
78 - Easily extensible – one can create a new stream profile that meets
80 - Same stream profile can be used for different tests with the same
83 - Functional data plane traffic scripts:
85 - Scapy specific traffic scripts;
87 #. Level-2 libraries - Robot resource files:
89 - Higher level CSIT libraries abstracting required functions for executing
91 - L2 KWs are classified into the following functional categories:
93 - Configuration, test, verification, state report;
94 - Suite setup, suite teardown;
95 - Test setup, test teardown;
99 - Test suites with test cases;
100 - Functional tests using VIRL environment:
105 - Performance tests using physical testbed environment:
111 - VPP Container K8s orchestrated topologies;
115 - Documentation generator;
117 - Testbed environment setup ansible playbooks;
118 - Operational debugging scripts;
120 Test Lifecycle Abstraction
121 --------------------------
123 A well coded test must follow a disciplined abstraction of the test
124 lifecycles that includes setup, configuration, test and verification. In
125 addition to improve test execution efficiency, the commmon aspects of
126 test setup and configuration shared across multiple test cases should be
127 done only once. Translating these high-level guidelines into the Robot
128 Framework one arrives to definition of a well coded RF tests for FD.io
129 CSIT. Anatomy of Good Tests for CSIT:
131 #. Suite Setup - Suite startup Configuration common to all Test Cases in suite:
132 uses Configuration KWs, Verification KWs, StateReport KWs;
133 #. Test Setup - Test startup Configuration common to multiple Test Cases: uses
134 Configuration KWs, StateReport KWs;
135 #. Test Case - uses L2 KWs with RF Gherkin style:
137 - prefixed with {Given} - Verification of Test setup, reading state: uses
138 Configuration KWs, Verification KWs, StateReport KWs;
139 - prefixed with {When} - Test execution: Configuration KWs, Test KWs;
140 - prefixed with {Then} - Verification of Test execution, reading state: uses
141 Verification KWs, StateReport KWs;
143 #. Test Teardown - post Test teardown with Configuration cleanup and
144 Verification common to multiple Test Cases - uses: Configuration KWs,
145 Verification KWs, StateReport KWs;
146 #. Suite Teardown - Suite post-test Configuration cleanup: uses Configuration
147 KWs, Verification KWs, StateReport KWs;
149 RF Keywords Functional Classification
150 -------------------------------------
152 CSIT RF KWs are classified into the functional categories matching the test
153 lifecycle events described earlier. All CSIT RF L2 and L1 KWs have been grouped
154 into the following functional categories:
165 RF Keywords Naming Guidelines
166 -----------------------------
168 Readability counts: "..code is read much more often than it is written."
169 Hence following a good and consistent grammar practice is important when
170 writing :abbr:`RF (Robot Framework)` KeyWords and Tests. All CSIT test cases
171 are coded using Gherkin style and include only L2 KWs references. L2 KWs are
172 coded using simple style and include L2 KWs, L1 KWs, and L1 python references.
173 To improve readability, the proposal is to use the same grammar for both
174 :abbr:`RF (Robot Framework)` KW styles, and to formalize the grammar of English
175 sentences used for naming the :abbr:`RF (Robot Framework)` KWs. :abbr:`RF (Robot
176 Framework)` KWs names are short sentences expressing functional description of
177 the command. They must follow English sentence grammar in one of the following
180 #. **Imperative** - verb-object(s): *"Do something"*, verb in base form.
181 #. **Declarative** - subject–verb–object(s): *"Subject does something"*, verb in
182 a third-person singular present tense form.
183 #. **Affirmative** - modal_verb-verb-object(s): *"Subject should be something"*,
184 *"Object should exist"*, verb in base form.
185 #. **Negative** - modal_verb-Not-verb-object(s): *"Subject should not be
186 something"*, *"Object should not exist"*, verb in base form.
188 Passive form MUST NOT be used. However a usage of past participle as an
189 adjective is okay. See usage examples provided in the Coding guidelines
190 section below. Following sections list applicability of the above
191 grammar forms to different :abbr:`RF (Robot Framework)` KW categories. Usage
192 examples are provided, both good and bad.
197 Coding guidelines can be found on `Design optimizations wiki page
198 <https://wiki.fd.io/view/CSIT/Design_Optimizations>`_.