Skip to main content

Dockerize a dotnet core application with SQL connectivity


Before reading this article, I am assuming that you know Docker, Dotnet core and have a dotnet core application which is trying to connect to SQL server. Read how to build aspnet core app, docker and run the docker container.

If docker container is running and you are not able to connect to database, this blog should help you fix it. 

Prerequisite - 
  • Make sure code is working via running aspnet core locally via visual studio or command line.
  • Port 1433 is opened for connecting to SQL server.

Solution

If you have Docker file ready, it should somewhat look like below file - 

FROM
mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
WORKDIR /app

# Copy csproj and restore as distinct layers
COPY /SampleAPI/*.csproj ./
RUN dotnet restore

# Copy everything else and build
COPY . .
WORKDIR /app/SampleAPI
RUN dotnet publish -c Production -o publish

# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1

WORKDIR /app/SampleAPI
COPY --from=build-env /app/SampleAPI .
WORKDIR /app/SampleAPI/bin/Production/netcoreapp3.1

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



Add following lines to make database connectivity  

#To connect to database
RUN sed -i 's/MinProtocol = TLSv1.2/MinProtocol = TLSv1/g' /etc/ssl/openssl.cnf
RUN sed -i 's/MinProtocol = TLSv1.2/MinProtocol = TLSv1/g' /usr/lib/ssl/openssl.cnf
RUN sed -i 's/DEFAULT@SECLEVEL=2/DEFAULT@SECLEVEL=1/g' /etc/ssl/openssl.cnf
RUN sed -i 's/DEFAULT@SECLEVEL=2/DEFAULT@SECLEVEL=1/g' /usr/lib/ssl/openssl.cnf

The above lines invoke 'sed'(stream Editor) to open file and edit it. 
  • Line 1 is modfying '/etc/ssl/openssl.conf' file and replacing MinProtocal = TLSv1.2 to MinProtocol = TLSv1. 
  • Line 2 is modifying same protocol in another file. 
  • Line 3 is setting the security level from DEFAULT@SECLEVEL=2 to DEFAULT@SECLEVEL=1. 
  • Line 4 is modifying the same in another file.
Note: You can add first 2 OR last 2 OR all lines depending upon connection issue with database.

Final Docker file will look something like that - 
FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
WORKDIR /app

# Copy csproj and restore as distinct layers
COPY /SampleAPI/*.csproj ./
RUN dotnet restore

# Copy everything else and build
COPY . .
WORKDIR /app/SampleAPI
RUN dotnet publish -c Production -o publish

# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1

#To connect to database
RUN sed -i 's/MinProtocol = TLSv1.2/MinProtocol = TLSv1/g' /etc/ssl/openssl.cnf
RUN sed -i 's/MinProtocol = TLSv1.2/MinProtocol = TLSv1/g' /usr/lib/ssl/openssl.cnf
RUN sed -i 's/DEFAULT@SECLEVEL=2/DEFAULT@SECLEVEL=1/g' /etc/ssl/openssl.cnf
RUN sed -i 's/DEFAULT@SECLEVEL=2/DEFAULT@SECLEVEL=1/g' /usr/lib/ssl/openssl.cnf

WORKDIR /app/SampleAPI
COPY --from=build-env /app/SampleAPI .
WORKDIR /app/SampleAPI/bin/Production/netcoreapp3.1

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



Build Docker image

docker build -t sampleapi:latest .


Run Docker container 

docker run -rm -p 5000:80 sampleapi:latest

where 80 is default port of docker container and 5000 port to expose to internet. 

Browse the API and it should respond with successful database connection. 

Alternatively

bionic version of aspnet core image can be used - 
FROM mcr.microsoft.com/dotnet/core/sdk:3.1-bionic AS build-env
WORKDIR /app

# Copy csproj and restore as distinct layers
COPY /DPRR-API/*.csproj ./
RUN dotnet restore

# Copy everything else and build
COPY . .
WORKDIR /app/DPRR-API
RUN dotnet publish -c Production -o publish

# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-bionic

WORKDIR /app/DPRR-API
COPY --from=build-env /app/DPRR-API .
WORKDIR /app/DPRR-API/bin/Production/netcoreapp3.1

ENTRYPOINT ["dotnet", "DPRR-API.dll"]

By using bionic image of aspnet core(mcr.microsoft.com/dotnet/core/sdk:3.1-bionic), there should not be any need of modifying the TLS or default settings.

Please share your feedback if it works for you. 

Comments

  1. Thanks for sparing out time to write comment on post. Please elaoborate more on what you would like to advice.

    ReplyDelete
  2. cool stuff you have and you keep redesign all of us
    HRDF training

    ReplyDelete
  3. This is such a great resource that you are providing and you give it away for free.
    digital marketing courses in hyderabad with placements

    ReplyDelete

  4. If you don"t mind proceed with this extraordinary work and I anticipate a greater amount of your magnificent blog entries
    Digital Marketing Training Institutes in Hyderabad

    ReplyDelete
  5. All things considered I read it yesterday however I had a few considerations about it and today I needed to peruse it again on the grounds that it is very elegantly composed.
    data scientist course

    ReplyDelete

Post a Comment

Popular posts from this blog

Nutch crawler and integration with Solr

Before moving ahead with this article, I assume you have Solr installed and running. If you would like to install Solr on windows, mac or via docker, please read Setup a Solr instance . There are several ways to install nutch which you can read from Nutch tutorial , however I have written this article for those who would like to install nutch using docker. I tried finding help on google but could not find any help for nutch installation using docker and spent good amount of time fixing issues specific to it. Therefore I have written this article to help and save time of other developers. Install nutch using docker- 1. Pull docker image of nutch using below command,      > docker pull apache/nutch 2. Once image is pulled, run the container,      > docker run -t -i -d --name nutchcontainer apache/nutch /bin/bash 3. You should be able to enter in the container and see bash prompt,      > bash-5.1#  Let's setup few important setting...

AJAX Progrraming

Ajax , shorthand for Asynchronous JavaScript and XML , is a web development technique for creating interactive web applications. The intent is to make web pages feel more responsive by exchanging small amounts of data with the server behind the scenes, so that the entire web page does not have to be reloaded each time the user requests a change. This is meant to increase the web page's interactivity, speed, and usability. The Ajax technique uses a combination of: XHTML (or HTML) and CSS, for marking up and styling information. The DOM accessed with a client-side scripting language, especially JavaScript and JScript, to dynamically display and interact with the information presented. The XMLHttpRequest object is used to exchange data asynchronously with the web server. In some Ajax frameworks and in certain situations, an IFrame object is used instead of the XMLHttpRequest object to exchange data with the web server, and in other implementations, dynamically added tags may be used. ...

Call a custom Script from Excel

  It is quite common that we receive the data in Excel and several times we have to remove unwanted characters from columns or modify the data as per the requirement. To avoid manual fixes of these kind of requirements, we may use Macro to automate the process which not only increase productivity but also avoid manual errors. We can easily create Macro to quickly fix it. Here are the steps to create Macro and run it. Open Excel Goto View tab on Main menu Click on 'View Macros'. This should open a Macro popup. Enter Macro Name and click on + icon. Clicking on + icon should open Macro Coding screen(as shown below). Add your code in the function. Click on Save icon to save the file with Macro. Click on Run icon to run the Macro code. The above code should remove additional line breaks from columns. Reference Code(to remove line breaks from columns): Sub MyCustomMacro () Dim MyRange As Range Application . ScreenUpdating = False Application . Calculation = xlCa...