apiVersion: v1
kind: Pod
metadata:
  name: init-demo
spec:
  # Init-контейнери
  initContainers:
    - name: init-step-1
      image: busybox:1.36
      command: ["sh", "-c", "echo Init step 1 && sleep 2"]
    
    - name: init-step-2
      image: busybox:1.36
      command: ["sh", "-c", "echo Init step 2 && sleep 2"]
  
  # Основні контейнери
  containers:
    - name: app
      image: nginx:1.27

apiVersion: v1
kind: Pod
metadata:
  name: wait-for-db
spec:
  initContainers:
    - name: wait-for-postgres
      image: busybox:1.36
      command:
        - sh
        - -c
        - |
          echo "Waiting for PostgreSQL..."
          until nc -z postgres 5432; do
            echo "PostgreSQL is not ready yet, waiting..."
            sleep 2
          done
          echo "PostgreSQL is ready!"
  
  containers:
    - name: app
      image: myapp:1.0
      env:
        - name: ConnectionStrings__DefaultConnection
          value: "Host=postgres;Database=mydb;Username=user;Password=pass"

apiVersion: v1
kind: Pod
metadata:
  name: config-loader
spec:
  volumes:
    - name: config
      emptyDir: {}
  
  initContainers:
    - name: download-config
      image: alpine:3.19
      volumeMounts:
        - name: config
          mountPath: /config
      command:
        - sh
        - -c
        - |
          echo "Downloading configuration..."
          # Симуляція завантаження конфігурації
          cat > /config/appsettings.json <<EOF
          {
            "Logging": {
              "LogLevel": {
                "Default": "Information"
              }
            },
            "DatabaseSettings": {
              "ConnectionString": "Host=postgres;Database=mydb"
            }
          }
          EOF
          echo "Configuration downloaded!"
  
  containers:
    - name: app
      image: myapp:1.0
      volumeMounts:
        - name: config
          mountPath: /app/config
          readOnly: true

public class Todo
{
    public int Id { get; set; }
    public string Title { get; set; } = string.Empty;
    public bool IsCompleted { get; set; }
}

using Microsoft.EntityFrameworkCore;

public class AppDbContext : DbContext
{
    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
    {
    }

    public DbSet<Todo> Todos => Set<Todo>();
}

using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Додаємо DbContext
builder.Services.AddDbContext<AppDbContext>(options =>
    options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));

var app = builder.Build();

// API endpoints
app.MapGet("/", () => "Todo API with PostgreSQL");

app.MapGet("/api/todos", async (AppDbContext db) =>
    await db.Todos.ToListAsync());

app.MapGet("/api/todos/{id}", async (int id, AppDbContext db) =>
    await db.Todos.FindAsync(id) is Todo todo
        ? Results.Ok(todo)
        : Results.NotFound());

app.MapPost("/api/todos", async (Todo todo, AppDbContext db) =>
{
    db.Todos.Add(todo);
    await db.SaveChangesAsync();
    return Results.Created($"/api/todos/{todo.Id}", todo);
});

app.MapPut("/api/todos/{id}", async (int id, Todo inputTodo, AppDbContext db) =>
{
    var todo = await db.Todos.FindAsync(id);
    if (todo is null) return Results.NotFound();

    todo.Title = inputTodo.Title;
    todo.IsCompleted = inputTodo.IsCompleted;
    await db.SaveChangesAsync();

    return Results.NoContent();
});

app.MapDelete("/api/todos/{id}", async (int id, AppDbContext db) =>
{
    var todo = await db.Todos.FindAsync(id);
    if (todo is null) return Results.NotFound();

    db.Todos.Remove(todo);
    await db.SaveChangesAsync();

    return Results.NoContent();
});

app.Run();

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Database=tododb;Username=postgres;Password=postgres"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  }
}

# Етап 1: Збірка
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src

# Копіюємо .csproj та відновлюємо залежності
COPY *.csproj .
RUN dotnet restore

# Копіюємо решту файлів та збираємо
COPY . .
RUN dotnet publish -c Release -o /app/publish

# Етап 2: Runtime
FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /app

# Копіюємо зібраний застосунок
COPY --from=build /app/publish .

# Налаштовуємо порт
ENV ASPNETCORE_URLS=http://+:8080
EXPOSE 8080

# Запускаємо застосунок
ENTRYPOINT ["dotnet", "TodoApiWithDb.dll"]

FROM mcr.microsoft.com/dotnet/sdk:8.0
WORKDIR /src

# Копіюємо .csproj та відновлюємо залежності
COPY *.csproj .
RUN dotnet restore

# Копіюємо решту файлів
COPY . .

# Встановлюємо EF Core tools
RUN dotnet tool install --global dotnet-ef
ENV PATH="${PATH}:/root/.dotnet/tools"

# Команда для виконання міграцій
ENTRYPOINT ["dotnet", "ef", "database", "update"]

apiVersion: v1
kind: Pod
metadata:
  name: postgres
  labels:
    app: postgres
spec:
  containers:
    - name: postgres
      image: postgres:16
      ports:
        - containerPort: 5432
      env:
        - name: POSTGRES_DB
          value: "tododb"
        - name: POSTGRES_USER
          value: "postgres"
        - name: POSTGRES_PASSWORD
          value: "postgres"
      resources:
        requests:
          memory: "128Mi"
          cpu: "100m"
        limits:
          memory: "256Mi"
          cpu: "500m"

apiVersion: v1
kind: Pod
metadata:
  name: todoapi
  labels:
    app: todoapi
spec:
  # Init-контейнери
  initContainers:
    # 1. Очікування доступності PostgreSQL
    - name: wait-for-postgres
      image: busybox:1.36
      command:
        - sh
        - -c
        - |
          echo "Waiting for PostgreSQL..."
          until nc -z postgres 5432; do
            echo "PostgreSQL is not ready, waiting..."
            sleep 2
          done
          echo "PostgreSQL is ready!"
    
    # 2. Виконання міграцій
    - name: run-migrations
      image: todoapi-migrations:1.0
      imagePullPolicy: Never
      env:
        - name: ConnectionStrings__DefaultConnection
          value: "Host=postgres;Database=tododb;Username=postgres;Password=postgres"
  
  # Основний контейнер
  containers:
    - name: api
      image: todoapi-db:1.0
      imagePullPolicy: Never
      ports:
        - containerPort: 8080
          name: http
      env:
        - name: ASPNETCORE_ENVIRONMENT
          value: "Development"
        - name: ASPNETCORE_URLS
          value: "http://+:8080"
        - name: ConnectionStrings__DefaultConnection
          value: "Host=postgres;Database=tododb;Username=postgres;Password=postgres"
      resources:
        requests:
          memory: "128Mi"
          cpu: "100m"
        limits:
          memory: "256Mi"
          cpu: "500m"

apiVersion: v1
kind: Pod
metadata:
  name: sidecar-demo
spec:
  volumes:
    - name: shared-data
      emptyDir: {}
  
  containers:
    # Основний контейнер
    - name: app
      image: myapp:1.0
      volumeMounts:
        - name: shared-data
          mountPath: /data
    
    # Sidecar контейнер
    - name: sidecar
      image: busybox:1.36
      volumeMounts:
        - name: shared-data
          mountPath: /data
          readOnly: true
      command: ["sh", "-c", "tail -f /data/app.log"]

using Microsoft.EntityFrameworkCore;
using Serilog;

var builder = WebApplication.CreateBuilder(args);

// Налаштовуємо Serilog для запису у файл
Log.Logger = new LoggerConfiguration()
    .WriteTo.Console()
    .WriteTo.File("/var/log/app/app.log", 
        rollingInterval: RollingInterval.Day,
        retainedFileCountLimit: 7)
    .CreateLogger();

builder.Host.UseSerilog();

// Додаємо DbContext
builder.Services.AddDbContext<AppDbContext>(options =>
    options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));

var app = builder.Build();

// Логуємо кожен запит
app.Use(async (context, next) =>
{
    Log.Information("Request: {Method} {Path}", context.Request.Method, context.Request.Path);
    await next();
    Log.Information("Response: {StatusCode}", context.Response.StatusCode);
});

// API endpoints (як раніше)
app.MapGet("/", () => "Todo API with Logging");
app.MapGet("/api/todos", async (AppDbContext db) => await db.Todos.ToListAsync());
// ... інші endpoints

app.Run();

# Етап 1: Збірка
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src

COPY *.csproj .
RUN dotnet restore

COPY . .
RUN dotnet publish -c Release -o /app/publish

# Етап 2: Runtime
FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /app

# Створюємо директорію для логів
RUN mkdir -p /var/log/app && chmod 777 /var/log/app

COPY --from=build /app/publish .

ENV ASPNETCORE_URLS=http://+:8080
EXPOSE 8080

ENTRYPOINT ["dotnet", "TodoApiWithDb.dll"]

apiVersion: v1
kind: Pod
metadata:
  name: todoapi-logging
  labels:
    app: todoapi
spec:
  volumes:
    # Спільний volume для логів
    - name: logs
      emptyDir: {}
  
  initContainers:
    # Очікування PostgreSQL
    - name: wait-for-postgres
      image: busybox:1.36
      command:
        - sh
        - -c
        - |
          echo "Waiting for PostgreSQL..."
          until nc -z postgres 5432; do
            sleep 2
          done
          echo "PostgreSQL is ready!"
    
    # Міграції
    - name: run-migrations
      image: todoapi-migrations:1.0
      imagePullPolicy: Never
      env:
        - name: ConnectionStrings__DefaultConnection
          value: "Host=postgres;Database=tododb;Username=postgres;Password=postgres"
  
  containers:
    # Основний контейнер - API
    - name: api
      image: todoapi-db:2.0
      imagePullPolicy: Never
      ports:
        - containerPort: 8080
          name: http
      env:
        - name: ASPNETCORE_ENVIRONMENT
          value: "Development"
        - name: ASPNETCORE_URLS
          value: "http://+:8080"
        - name: ConnectionStrings__DefaultConnection
          value: "Host=postgres;Database=tododb;Username=postgres;Password=postgres"
      volumeMounts:
        - name: logs
          mountPath: /var/log/app
      resources:
        requests:
          memory: "128Mi"
          cpu: "100m"
        limits:
          memory: "256Mi"
          cpu: "500m"
    
    # Sidecar контейнер - Log Reader
    - name: log-reader
      image: busybox:1.36
      volumeMounts:
        - name: logs
          mountPath: /var/log/app
          readOnly: true
      command:
        - sh
        - -c
        - |
          echo "Log reader started, waiting for log file..."
          # Чекаємо, поки з'явиться файл логів
          while [ ! -f /var/log/app/app.log ]; do
            sleep 1
          done
          echo "Log file found, starting to tail..."
          tail -f /var/log/app/app.log

apiVersion: v1
kind: Pod
metadata:
  name: init-delay-practice
spec:
  initContainers:
    - name: init-delay
      image: busybox:1.36
      command: ["sh", "-c", "echo 'Initialization started...'; sleep 5; echo 'Initialization complete!'"]
  containers:
    - name: app
      image: busybox:1.36
      command: ["sh", "-c", "echo 'Application started!'; sleep 3600"]

apiVersion: v1
kind: Pod
metadata:
  name: init-chain-practice
spec:
  volumes:
    - name: shared-data
      emptyDir: {}
  initContainers:
    - name: step-1-write
      image: busybox:1.36
      command: ["sh", "-c", "echo 'Config version 1.0' > /shared/config.txt; echo 'Step 1 complete'"]
      volumeMounts:
        - name: shared-data
          mountPath: /shared
    - name: step-2-validate
      image: busybox:1.36
      command: ["sh", "-c", "cat /shared/config.txt && echo 'Validation complete!'"]
      volumeMounts:
        - name: shared-data
          mountPath: /shared
  containers:
    - name: main-app
      image: busybox:1.36
      command: ["sh", "-c", "echo 'Main app is running!'; sleep 3600"]
      volumeMounts:
        - name: shared-data
          mountPath: /shared

apiVersion: v1
kind: ConfigMap
metadata:
  name: external-config
data:
  appsettings.json: |
    {
      "Logging": {
        "LogLevel": {
          "Default": "Debug"
        }
      },
      "AllowedHosts": "*"
    }
---
apiVersion: v1
kind: Pod
metadata:
  name: config-loader-practice
spec:
  volumes:
    - name: config-volume
      emptyDir: {}
    - name: config-source
      configMap:
        name: external-config
  initContainers:
    - name: loader
      image: busybox:1.36
      command: ["sh", "-c", "cp /source/appsettings.json /target/appsettings.json && echo 'Config copied successfully!'"]
      volumeMounts:
        - name: config-source
          mountPath: /source
        - name: config-volume
          mountPath: /target
  containers:
    - name: dotnet-app
      image: mcr.microsoft.com/dotnet/aspnet:8.0
      command: ["sh", "-c", "echo 'Dotnet reading settings:'; cat /app/config/appsettings.json; sleep 3600"]
      volumeMounts:
        - name: config-volume
          mountPath: /app/config

apiVersion: v1
kind: Pod
metadata:
  name: sidecar-poller-practice
spec:
  containers:
    # Основний контейнер (веб-сервер)
    - name: web-server
      image: nginx:1.27
      ports:
        - containerPort: 80
          name: http
    # Sidecar-контейнер для моніторингу
    - name: metrics-poller
      image: busybox:1.36
      command: ["sh", "-c", "while true; do wget -qO- http://localhost:80 > /dev/null && echo \"[$(date)] [Metrics] HTTP 200 OK - Server is healthy\"; sleep 10; done"]

apiVersion: v1
kind: Pod
metadata:
  name: resources-monitor-practice
spec:
  containers:
    - name: memory-consumer
      image: busybox:1.36
      command: ["sh", "-c", "while true; do echo 'Generating mock processing load...'; sleep 10; done"]
    - name: monitor-sidecar
      image: busybox:1.36
      command: ["sh", "-c", "while true; do if [ -f /sys/fs/cgroup/memory.current ]; then echo \"[Monitor] Memory limit status: $(cat /sys/fs/cgroup/memory.current) bytes\"; else echo \"[Monitor] Memory status: $(cat /sys/fs/cgroup/memory/memory.usage_in_bytes) bytes\"; fi; sleep 5; done"]