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diff --git a/docs/content/introduction/design.md b/docs/content/introduction/design.md new file mode 100644 index 0000000000..e236b47d6f --- /dev/null +++ b/docs/content/introduction/design.md @@ -0,0 +1,148 @@ +--- +title: "Design" +weight: 3 +--- + +# Design + +FD.io CSIT system design needs to meet continuously expanding requirements of +FD.io projects including VPP, related sub-systems (e.g. plugin applications, +DPDK drivers) and FD.io applications (e.g. DPDK applications), as well as +growing number of compute platforms running those applications. With CSIT +project scope and charter including both FD.io continuous testing AND +performance trending/comparisons, those evolving requirements further amplify +the need for CSIT framework modularity, flexibility and usability. + +## Design Hierarchy + +CSIT follows a hierarchical system design with SUTs and DUTs at the bottom level +of the hierarchy, presentation level at the top level and a number of functional +layers in-between. The current CSIT system design including CSIT framework is +depicted in the figure below. + +{{< svg "static/csit_design_picture.svg" >}} + +A brief bottom-up description is provided here: + +1. SUTs, DUTs, TGs + - SUTs - Systems Under Test; + - DUTs - Devices Under Test; + - TGs - Traffic Generators; +2. Level-1 libraries - Robot and Python + - Lowest level CSIT libraries abstracting underlying test environment, SUT, + DUT and TG specifics; + - Used commonly across multiple L2 KWs; + - Performance and functional tests: + - L1 KWs (KeyWords) are implemented as RF libraries and Python + libraries; + - Performance TG L1 KWs: + - All L1 KWs are implemented as Python libraries: + - Support for TRex only today; + - CSIT IXIA drivers in progress; + - Performance data plane traffic profiles: + - TG-specific stream profiles provide full control of: + - Packet definition - layers, MACs, IPs, ports, combinations thereof + e.g. IPs and UDP ports; + - Stream definitions - different streams can run together, delayed, + one after each other; + - Stream profiles are independent of CSIT framework and can be used + in any T-rex setup, can be sent anywhere to repeat tests with + exactly the same setup; + - Easily extensible - one can create a new stream profile that meets + tests requirements; + - Same stream profile can be used for different tests with the same + traffic needs; + - Functional data plane traffic scripts: + - Scapy specific traffic scripts; +3. Level-2 libraries - Robot resource files: + - Higher level CSIT libraries abstracting required functions for executing + tests; + - L2 KWs are classified into the following functional categories: + - Configuration, test, verification, state report; + - Suite setup, suite teardown; + - Test setup, test teardown; +4. Tests - Robot: + - Test suites with test cases; + - Performance tests using physical testbed environment: + - VPP; + - DPDK-Testpmd; + - DPDK-L3Fwd; + - Tools: + - Documentation generator; + - Report generator; + - Testbed environment setup ansible playbooks; + - Operational debugging scripts; + +5. Test Lifecycle Abstraction + +A well coded test must follow a disciplined abstraction of the test +lifecycles that includes setup, configuration, test and verification. In +addition to improve test execution efficiency, the commmon aspects of +test setup and configuration shared across multiple test cases should be +done only once. Translating these high-level guidelines into the Robot +Framework one arrives to definition of a well coded RF tests for FD.io +CSIT. Anatomy of Good Tests for CSIT: + +1. Suite Setup - Suite startup Configuration common to all Test Cases in suite: + uses Configuration KWs, Verification KWs, StateReport KWs; +2. Test Setup - Test startup Configuration common to multiple Test Cases: uses + Configuration KWs, StateReport KWs; +3. Test Case - uses L2 KWs with RF Gherkin style: + - prefixed with {Given} - Verification of Test setup, reading state: uses + Configuration KWs, Verification KWs, StateReport KWs; + - prefixed with {When} - Test execution: Configuration KWs, Test KWs; + - prefixed with {Then} - Verification of Test execution, reading state: uses + Verification KWs, StateReport KWs; +4. Test Teardown - post Test teardown with Configuration cleanup and + Verification common to multiple Test Cases - uses: Configuration KWs, + Verification KWs, StateReport KWs; +5. Suite Teardown - Suite post-test Configuration cleanup: uses Configuration + KWs, Verification KWs, StateReport KWs; + +## RF Keywords Functional Classification + +CSIT RF KWs are classified into the functional categories matching the test +lifecycle events described earlier. All CSIT RF L2 and L1 KWs have been grouped +into the following functional categories: + +1. Configuration; +2. Test; +3. Verification; +4. StateReport; +5. SuiteSetup; +6. TestSetup; +7. SuiteTeardown; +8. TestTeardown; + +## RF Keywords Naming Guidelines + +Readability counts: "..code is read much more often than it is written." +Hence following a good and consistent grammar practice is important when +writing Robot Framework KeyWords and Tests. All CSIT test cases +are coded using Gherkin style and include only L2 KWs references. L2 KWs are +coded using simple style and include L2 KWs, L1 KWs, and L1 python references. +To improve readability, the proposal is to use the same grammar for both +Robot Framework KW styles, and to formalize the grammar of English +sentences used for naming the Robot Framework KWs. Robot +Framework KWs names are short sentences expressing functional description of +the command. They must follow English sentence grammar in one of the following +forms: + +1. **Imperative** - verb-object(s): *"Do something"*, verb in base form. +2. **Declarative** - subject-verb-object(s): *"Subject does something"*, verb in + a third-person singular present tense form. +3. **Affirmative** - modal_verb-verb-object(s): *"Subject should be something"*, + *"Object should exist"*, verb in base form. +4. **Negative** - modal_verb-Not-verb-object(s): *"Subject should not be + something"*, *"Object should not exist"*, verb in base form. + +Passive form MUST NOT be used. However a usage of past participle as an +adjective is okay. See usage examples provided in the Coding guidelines +section below. Following sections list applicability of the above +grammar forms to different Robot Framework KW categories. Usage +examples are provided, both good and bad. + +## Coding Guidelines + +Coding guidelines can be found on +[Design optimizations wiki page](https://wiki.fd.io/view/CSIT/Design_Optimizations).
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