Code on Micha Kops' Tech Notes

C4 Modeling with PlantUML and AsciiDoc

Tue, 01 Nov 2022 00:00:00 +0100

C4 models allow us to visualize software architecture by decomposition in containers and components.

Viewpoints are organized in hierarchical levels:

Context Diagrams (Level 1)
Container Diagrams (Level 2)
Component Diagrams (Level 3)
Code Diagrams (Level 4)

C4-PlantUML offers a variety of macros and stereotypes that make modeling fun.

An example in PlantUML:

sample.puml

@startuml
!include <c4/C4_Context.puml>
!include <c4/C4_Container.puml>

left to right direction

Person(user, "User")

System_Ext(auth, "AuthService", "Provides authentication and authorization via OIDC")

System_Boundary(zone1, "Some system boundary") {


    System(lb, "Load Balancer")

    System_Boundary(az, "App Cluster") {
        System(app, "App Servers") {
            Container(app1, "App1", "Docker", "Does stuff")
            Container(app2, "App1", "Docker", "Does stuff")

            ContainerDb(dbSess, "Session DB", "Redis")
            ContainerDb(db1, "RBMS 1", "AWS RDS Postgres")
            ContainerDb(db2, "RBMS 2", "AWS RDS Postgres")

            ' both app servers sync sessions via redis
            Rel(app1, dbSess, "Uses", "Sync Session")
            Rel(app2, dbSess, "Uses", "Sync Session")

            ' both app servers persist data in RDBMS
            Rel(app1, db1, "Uses", "Persist/query relational data")
            Rel(app2, db2, "Uses", "Persist/query relational data")
        }
    }
}

Rel(user, lb, "call")
Rel(lb, app1, "delegate")
Rel(lb, app2, "delegate")
Rel(app1, auth, "Verify", "User auth")
Rel(app2, auth, "Verify", "User auth")

SHOW_FLOATING_LEGEND()

@enduml

Prettier Code Formatter Configuration

Fri, 14 May 2021 00:00:00 +0200

Goals

Setup Prettier for different environments / IDEs
Run Prettier via git hooks

Install Prettier

Install via npm

npm install --save-dev --save-exact prettier

Add empty configuration file

echo {}> .prettierrc.json

Create Prettier ignore file .prettierignore:

# Ignore artifacts:
build
coverage

Format all project files with Prettier:

npx prettier --write .

Git Hooks

Adding the following lines to the project’s package-json makes ESLint and Prettier run before each commit:

{
  "husky": {
    "hooks": {
      "pre-commit": "lint-staged"
    }
  },
  "lint-staged": {
    "**/*": "prettier --write --ignore-unknown"
  }
}

Whitesource Snippets

Sun, 11 Nov 2018 00:00:00 +0100

Whitesource Configuration for GitLab Pipeline

The following configuration derives values from predefined GitLab Variables

whitesource.conf

# Providing project information from GitLab CI
wss_project_name="$CI_PROJECT_NAME"
wss_project_version="$CI_JOB_ID"
wss_project_tag="$CI_COMMIT_TAG"

# Providing product information
wss_product_name="The Product Name"
wss_product_version="$POM_VERSION"

# Analyze the Maven POM and its transitive dependencies only, no file-system check
# Use this only if you don't have any extra checked in jar-files or stuff like that!
fileSystemScan=false
includes=pom.xml

# Only scanning the Maven project
resolveAllDependencies=false
maven.resolveDependencies=true

Generating Java Source Files with JavaPoet

Sat, 28 Feb 2015 00:00:00 +0100

For the most of us developers, generating Java source files is an occasionally happening task and we’re dealing with it e.g. when writing annotation processors, writing tools or interacting with meta-data files.

JavaPoet is a nice library to simplify such tasks, offering an intuitive fluent-builder API to generate source files in no time.

In the following tutorial I’d like to share a few examples by writing code generators with the help of this library.