Search code examples
azureazure-functionsazure-functions-runtime

Config files and retrieving in Azure-Functions

I've been experimenting with .config files in Azure-Functions.

If I write this function

using System;
using System.Configuration;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Host;


namespace GranadaCoder.AzurePoc.AzureFunctionsOne
{
    public static class AppSettingsTestOne
    {
        [FunctionName("AppSettingsTestOneFunctionName")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]HttpRequestMessage req, TraceWriter log)
        {

            try
            {

                string rootDirectory = string.Empty;
                if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("HOME")))
                {
                    /* running in azure */
                    rootDirectory = Environment.GetEnvironmentVariable("HOME") + "\\site\\wwwroot";
                }
                else
                {
                    /* in visual studio, local debugging */
                    rootDirectory = ".";
                }
                string path = rootDirectory + @"\CustomConfigFiles\CustomAppSettings.config";

                if (!System.IO.File.Exists(path))
                {
                    throw new System.IO.FileNotFoundException(string.Format("NOT FOUND!!! ('{0}')", path));
                }
                else
                {
                    log.Info(string.Format("File exists='{0}'", path));
                }

                ExeConfigurationFileMap map = new ExeConfigurationFileMap { ExeConfigFilename = path };
                Configuration config = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);

                Configuration fileConfig = ConfigurationManager.OpenExeConfiguration(path); /* does NOT work */
                string val1 = config.AppSettings.Settings["KeyOne"].Value;
                string val2 = config.AppSettings.Settings["KeyTwo"].Value;
                string val3 = config.AppSettings.Settings["KeyThree"].Value;

                string msg = string.Join(",", val1, val2, val3);

                return req.CreateResponse(HttpStatusCode.OK, msg);
            }
            catch (Exception ex)
            {
                string errorMsg = ex.Message; //  ExceptionHelper.GenerateFullFlatMessage(ex);
                log.Error(errorMsg);
                return req.CreateResponse(HttpStatusCode.BadRequest, errorMsg);
            }
        }
    }
}

with this .config file (CustomAppSettings.config)

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <appSettings>
    <add key="KeyOne" value="ValueOne" />
    <add key="KeyTwo" value="ValueTwo" />
    <add key="KeyThree" value="ValueThree" />
  </appSettings>
</configuration>

It works as anticipated.

If I use this function:

using System;
using System.Collections.Specialized;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Xml;

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Host;


namespace GranadaCoder.AzurePoc.AzureFunctionsOne
{
    public static class NameValuePairAppSettingsTest
    {
        [FunctionName("NameValuePairAppSettingsTestFunctionName")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]HttpRequestMessage req, TraceWriter log)
        {

            try
            {
                string rootDirectory = string.Empty;
                if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("HOME")))
                {
                    /* running in azure */
                    rootDirectory = Environment.GetEnvironmentVariable("HOME") + "\\site\\wwwroot";
                }
                else
                {
                    /* in visual studio, local debugging */
                    rootDirectory = ".";
                }
                string path = rootDirectory + @"\CustomConfigFiles\NameValuePairSettings.config";


                if (!System.IO.File.Exists(path))
                {
                    throw new System.IO.FileNotFoundException(string.Format("NOT FOUND!!! ('{0}')", path));
                }
                else
                {
                    log.Info(string.Format("file exists='{0}'", path));
                }

                ExeConfigurationFileMap map = new ExeConfigurationFileMap { ExeConfigFilename = path };
                Configuration config = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);

                //NameValueCollection nvc = (NameValueCollection)config.GetSection("myLittleArea"); /* does not work */

                ConfigurationSection myParamsSection = config.GetSection("myLittleArea");
                /* see https://stackoverflow.com/questions/13825323/how-do-i-get-the-values-from-a-configsection-defined-as-namevaluesectionhandler */
                string myParamsSectionRawXml = myParamsSection.SectionInformation.GetRawXml();
                XmlDocument sectionXmlDoc = new XmlDocument();
                sectionXmlDoc.Load(new StringReader(myParamsSectionRawXml));
                NameValueSectionHandler handler = new NameValueSectionHandler();
                NameValueCollection nvc = handler.Create(null, null, sectionXmlDoc.DocumentElement) as NameValueCollection;

                var items = nvc.AllKeys.SelectMany(nvc.GetValues, (k, v) => new { key = k, value = v });
                ////////foreach (var item in items)
                ////////{
                ////////    Console.WriteLine("{0} {1}", item.key, item.value);
                ////////}

                string msg = string.Join(",", items.ToList());

                return req.CreateResponse(HttpStatusCode.OK, msg);
            }
            catch (Exception ex)
            {
                string errorMsg = ex.Message; //  ExceptionHelper.GenerateFullFlatMessage(ex);
                log.Error(errorMsg);
                return req.CreateResponse(HttpStatusCode.BadRequest, errorMsg);
            }
        }
    }
}

with this .config file (NameValuePairSettings.config)

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="myLittleArea" type="System.Configuration.NameValueSectionHandler, System, Version=1.0.5000.0,Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  </configSections>

  <myLittleArea>
    <add key="color" value="red"/>
    <add key="street" value="main"/>
    <add key="month" value="july"/>
    <add key="candy" value="snickers"/>
  </myLittleArea>

</configuration>

Everything works ok.

(Drum Roll).

If I create a custom configuration section.

using System.Configuration;

namespace GranadaCoder.AzurePoc.ConfigurationLibrary.MyCustomConfigurationSettings
{
    public static class MyCustomConfigurationSettingsConfigurationRetriever
    {
        public static readonly string ConfigurationSectionName = "MyCustomConfigurationSettingsConfigurationSectionName";

        /*
        public static MyCustomConfigurationSettingsConfigurationSection GetMyCustomConfigurationSettings()
        {
            MyCustomConfigurationSettingsConfigurationSection returnSection = (MyCustomConfigurationSettingsConfigurationSection)ConfigurationManager.GetSection(ConfigurationSectionName);
            if (returnSection != null)
            {
                return returnSection;
            }

            return null;
        }
        */

        public static MyCustomConfigurationSettingsConfigurationSection GetMyCustomConfigurationSettings(System.Configuration.Configuration cfg)
        {
            MyCustomConfigurationSettingsConfigurationSection returnSection = (MyCustomConfigurationSettingsConfigurationSection)cfg.GetSection(ConfigurationSectionName);
            if (returnSection != null)
            {
                return returnSection;
            }

            return null;
        }
    }
}

and

using System.Configuration;

namespace GranadaCoder.AzurePoc.ConfigurationLibrary.MyCustomConfigurationSettings
{
    public class MyCustomConfigurationSettingsConfigurationSection : ConfigurationSection
    {
        private const string FavoriteNumberPropertyName = "FavoriteNumber";
        private const string FavoriteColorPropertyName = "FavoriteColor";

        [ConfigurationProperty(FavoriteNumberPropertyName, IsRequired = true, DefaultValue = 100)]
        public int FavoriteNumber
        {
            get
            {
                return (int)this[FavoriteNumberPropertyName];
            }
        }

        [ConfigurationProperty(FavoriteColorPropertyName, IsRequired = true, DefaultValue = ",")]
        public string FavoriteColor
        {
            get
            {
                return (string)this[FavoriteColorPropertyName];
            }
        }
    }
}

and .config (MyCustomConfigurationSettings.config)

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name ="MyCustomConfigurationSettingsConfigurationSectionName" type="GranadaCoder.AzurePoc.ConfigurationLibrary.MyCustomConfigurationSettings.MyCustomConfigurationSettingsConfigurationSection, GranadaCoder.AzurePoc.ConfigurationLibrary" />
  </configSections>
  <MyCustomConfigurationSettingsConfigurationSectionName
    FavoriteNumber="333"
    FavoriteColor="Green"
  >
  </MyCustomConfigurationSettingsConfigurationSectionName>
</configuration>

and azure function code

using System;
using System.Configuration;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Host;

using GranadaCoder.AzurePoc.ConfigurationLibrary.MyCustomConfigurationSettings;



namespace GranadaCoder.AzurePoc.AzureFunctionsOne
{
    public static class CustomConfigurationTest
    {
        [FunctionName("CustomConfigurationTestFunctionName")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]HttpRequestMessage req, TraceWriter log)
        {
            try
            {
                string rootDirectory = string.Empty;
                if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("HOME")))
                {
                    /* running in azure */
                    rootDirectory = Environment.GetEnvironmentVariable("HOME") + "\\site\\wwwroot";
                }
                else
                {
                    /* in visual studio, local debugging */
                    rootDirectory = ".";
                }
                string path = rootDirectory + @"\CustomConfigFiles\MyCustomConfigurationSettings.config";

                log.Info(string.Format("CustomConfigurationTestFunctionName HostingEnvironment.ApplicationPhysicalPath='{0}'", System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath));

                if (!System.IO.File.Exists(path))
                {
                    throw new System.IO.FileNotFoundException(string.Format("NOT FOUND!!! ('{0}')", path));
                }
                else
                {
                    log.Info(string.Format("File exists='{0}'", path));
                }

                ExeConfigurationFileMap map = new ExeConfigurationFileMap { ExeConfigFilename = path };
                Configuration config = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);

                MyCustomConfigurationSettingsConfigurationSection customSection = MyCustomConfigurationSettingsConfigurationRetriever.GetMyCustomConfigurationSettings(config);

                string msg = string.Join(",", customSection.FavoriteNumber.ToString(), customSection.FavoriteColor);

                return req.CreateResponse(HttpStatusCode.OK, msg);
            }
            catch (Exception ex)
            {
                string errorMsg = ex.Message; //  ExceptionHelper.GenerateFullFlatMessage(ex);
                log.Error(errorMsg);
                return req.CreateResponse(HttpStatusCode.BadRequest, errorMsg);
            }
        }
    }
}

The above does not work.

I get an error

"An error occurred creating the configuration section handler for MyCustomConfigurationSettingsConfigurationSectionName: Could not load file or assembly 'GranadaCoder.AzurePoc.ConfigurationLibrary' or one of its dependencies. The system cannot find the file specified. (C:\blah\blah\blah\bin\Debug\net461\CustomConfigFiles\MyCustomConfigurationSettings.config line 4)"

The file IS THERE (see image)

Any idea why the custom configuration does not work?

enter image description here

Solution

  • After printed out the BaseDirectory of current domain in the Azure Function, I found that the function is ran by fun.exe. It will look for the assembly in "AppData\Local\Azure.Functions.Cli\1.0.1\" folder. After copied the "GranadaCoder.AzurePoc.ConfigurationLibrary" to the folder, the function will work fine.

    Code:

    string friendlyName = AppDomain.CurrentDomain.FriendlyName;
string baseDirectory = AppDomain.CurrentDomain.BaseDirectory;

    Output:

    BaseDirectory = "C:\\Users\\myusername\\AppData\\Local\\Azure.Functions.Cli\\1.0.1\\"
FriendlyName = "func.exe"