I have a very simple docker setup - React WebApp (admin panel) and .netCore Customer Api, they connected to bridge network. I am actually creating a health check monitor.

both containers are connected and i am able to ping via ip and container name without any issues. when i curl the health check endpoint it works fine.

However, when I do a fetch from the same url from the admin-app react code, its throwing net::ERR_NAME_NOT_RESOLVED docker. please see the code here

 async loadData() {
        try {
            fetch(')
                .then(function (response) {
                    console.log(response)
                });

        } catch (e) {
            console.log(e);
        }
    }

What i did so far -

• ensured both are in same network
• port is correct
• customer api is accessible from both external browser and container

adminapp docker

 # pull official base image
FROM node:13.12.0-alpine

# set working directory
WORKDIR /app

# add `/app/node_modules/.bin` to $PATH
ENV PATH /app/node_modules/.bin:$PATH

# install app dependencies
COPY admin-app/package.json ./
COPY admin-app/package-lock.json ./

RUN npm install --silent
RUN npm install react-scripts@3.4.1 -g --silent

# add app
COPY ./admin-app ./

# start app
CMD ["npm", "start"]

customer api docker

    #See  to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM  AS base
WORKDIR /app

ENV WEB_PORT=5000 \
    ASPNETCORE_URLS= \
    ASPNETCORE_ENVIRONMENT="Local" 

FROM  AS build
WORKDIR /src
COPY ["customerprofile/", ""]
COPY ["core/", ""]
COPY ["core/", ""]
COPY ["customerprofile/", ""]
RUN dotnet restore ""
COPY . .
WORKDIR "/src/customerprofile/Figg.Customer.Api"
RUN dotnet build "Figg.Customer.Api.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "Figg.Customer.Api.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .

EXPOSE $WEB_PORT
ENTRYPOINT ["dotnet", "Figg.Customer.Api.dll"]

any thoughts

ping works

/app # ping customer-api
PING customer-api (172.21.0.2): 56 data bytes
64 bytes from 172.21.0.2: seq=0 ttl=64 time=0.062 ms
64 bytes from 172.21.0.2: seq=1 ttl=64 time=0.049 ms
64 bytes from 172.21.0.2: seq=2 ttl=64 time=0.068 ms
64 bytes from 172.21.0.2: seq=3 ttl=64 time=0.049 ms
64 bytes from 172.21.0.2: seq=4 ttl=64 time=0.094 ms

I found the reason why its not reaching my container - but how to solve this ? please see the pic here , that would explain