Add database credential file feature

CHANGELOG.md

@@ -1,3 +1,18 @@
+## v1.6.0 (July 2, 2025)
+
+### Added:
+- Db Credentials file feature. 
+- This feature allows a database connection to be created in cases where database credentials need to be read from a file. Currently only active on PostgreSQL.
+- It can be activated with the new config value `UseDbCredentialsFile`.
+- This feature requires a new config section called `DbCredentialsFileSettings` with the following options:
+  - `FileName`: File name containing database credentials (should be full path)
+  - `Host`: Host information of the database
+  - `Database`: Db name of the database
+  - `ApplicationName`: App name information on database connection
+  - `Port`: Port of the database
+  - `AdditionalParameters`: Additional parameters to be added on Connection. Flags such as `Pooling`, `TrustServerCertificate` can be added.
+
+
 ## v1.5.0 (March 6, 2025)
 
 ### Added:

example/Postgres/config/config.json

@@ -63,5 +63,14 @@
     "Threshold": 3,
     "DurationSc": 60,
     "HalfOpenMaxAttempts": 1
+  },
+  "UseDbCredentialsFile": true,
+  "DbCredentialsFileSettings": {
+    "FileName": "config/postgresql-test-cluster.json",
+    "Host": "10.85.240.242",
+    "Database": "test",
+    "ApplicationName": "PollingOutboxPublisher",
+    "Port": 5432,
+    "AdditionalParameters": "Pooling=true;TrustServerCertificate=true;"
   }
 }

src/ConfigOptions/DbCredentialsFileSettings.cs

@@ -0,0 +1,14 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace PollingOutboxPublisher.ConfigOptions;
+
+[ExcludeFromCodeCoverage]
+public class DbCredentialsFileSettings
+{
+    public string FileName { get; set; }
+    public string Host { get; set; }
+    public string Database { get; set; }
+    public int Port { get; set; }
+    public string ApplicationName { get; set; }
+    public string AdditionalParameters { get; set; }
+}

src/Database/Providers/PostgresConnectionProvider.cs

@@ -1,7 +1,10 @@
 using System.Data;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Options;
 using Npgsql;
+using PollingOutboxPublisher.ConfigOptions;
 using PollingOutboxPublisher.Database.Providers.Interfaces;
 using PollingOutboxPublisher.Exceptions;
 
@@ -12,15 +15,25 @@ public class PostgresConnectionProvider : IPostgresConnectionProvider
 {
     private readonly string _connectionString;
 
-    public PostgresConnectionProvider(IConfiguration configuration)
+    public PostgresConnectionProvider(IConfiguration configuration, IOptions<DbCredentialsFileSettings> databaseTbpAuthenticationCredentials)
     {
-        var connectionString = configuration.GetValue<string>("ConnectionString");
-        if (string.IsNullOrWhiteSpace(connectionString))
+        if (configuration.GetValue<bool>("UseDbCredentialsFile") is true)
         {
-            throw new MissingConfigurationException("ConnectionString");
+            ValidateTbpAuthenticationCredentials(databaseTbpAuthenticationCredentials.Value);
+            var dbCredentials = databaseTbpAuthenticationCredentials.Value;
+            var postgresqlUsernamePassword = GetPostgresqlUsernameAndPassword(dbCredentials.FileName);
+            _connectionString = GenerateConnectionString(postgresqlUsernamePassword.userName, postgresqlUsernamePassword.password, dbCredentials.Host, dbCredentials.Database, dbCredentials.Port, dbCredentials.ApplicationName,dbCredentials.AdditionalParameters);
         }
+        else
+        {
+            var connectionString = configuration.GetValue<string>("ConnectionString");
+            if (string.IsNullOrWhiteSpace(connectionString))
+            {
+                throw new MissingConfigurationException("ConnectionString");
+            }
 
-        _connectionString = connectionString;
+            _connectionString = connectionString;
+        }
     }
 
     public IDbConnection CreateConnection()
@@ -29,4 +42,58 @@ public IDbConnection CreateConnection()
     public IDbConnection CreateConnectionForReadOnly()
         => new NpgsqlConnection(_connectionString);
 
+
+    private static (string userName, string password) GetPostgresqlUsernameAndPassword(string fileName)
+    {
+        if (!File.Exists(fileName))
+        {
+            throw new FileNotFoundException($"Postgresql credentials file not found: {fileName}");
+        }
+
+        var postgresqlCredentials= new ConfigurationBuilder()
+            .AddJsonFile(fileName)
+            .Build();
+
+        var username = postgresqlCredentials["username"];
+        var password = postgresqlCredentials["password"];
+        return (username, password);
+    }
+
+    private static void ValidateTbpAuthenticationCredentials(DbCredentialsFileSettings credentialses)
+    {
+        if (string.IsNullOrWhiteSpace(credentialses.FileName))
+        {
+            throw new MissingConfigurationException("DatabaseTbpAuthenticationCredentials:FileName");
+        }
+
+        if (string.IsNullOrWhiteSpace(credentialses.Host))
+        {
+            throw new MissingConfigurationException("DatabaseTbpAuthenticationCredentials:Host");
+        }
+
+        if (string.IsNullOrWhiteSpace(credentialses.Database))
+        {
+            throw new MissingConfigurationException("DatabaseTbpAuthenticationCredentials:Database");
+        }
+
+        if (string.IsNullOrWhiteSpace(credentialses.ApplicationName))
+        {
+            throw new MissingConfigurationException("DatabaseTbpAuthenticationCredentials:ApplicationName");
+        }
+
+        if (credentialses.Port == 0)
+        {
+            throw new MissingConfigurationException("DatabaseTbpAuthenticationCredentials:Port");
+        }
+    }
+
+    private static string GenerateConnectionString(string userName, string password, string host, string database, int port, string appName, string additionalParameters)
+    {
+        var connectionString = $"User ID={userName};Password={password};Server={host};Port={port};Database={database};ApplicationName={appName};";
+
+        if (!string.IsNullOrEmpty(additionalParameters))
+            connectionString = string.Concat(connectionString, additionalParameters);;
+
+        return connectionString;
+    }
 }

src/PollingOutboxPublisher.csproj

@@ -4,7 +4,7 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net8.0</TargetFramework>
         <IsPackable>false</IsPackable>
-        <Version>1.5.0</Version>
+        <Version>1.6.0</Version>
         <RootNamespace>PollingOutboxPublisher</RootNamespace>
     </PropertyGroup>
 

src/Program.cs

@@ -103,6 +103,8 @@ private static void RegisterConfigs(IServiceCollection services, HostBuilderCont
             hostContext.Configuration.GetSection(nameof(ConfigOptions.Redis)));
         services.Configure<CircuitBreakerSettings>(
             hostContext.Configuration.GetSection(nameof(CircuitBreakerSettings)));
+        services.Configure<DbCredentialsFileSettings>(
+            hostContext.Configuration.GetSection(nameof(DbCredentialsFileSettings)));
     }
 
     private static void RegisterSerilog(IServiceCollection services)