StackExchange.Redis.RedisConnectionException: No connection (requires writable - not eligible for replica) - docker

Question

I have used Redis version 2.6.66 and DotNet Core 6.0 in my project.
The prject works well in the local but after deploying it on cloud.digitalocean.com
I get an error.
How Can I solve it?
Error:
fail: API.Middleware.ExceptionMiddleware[0] No connection (requires
writable - not eligible for replica) is active/available to service
this operation: SETEX /api/products|pageIndex-1|pageSize-6|sort-name,
mc: 1/1/0, mgr: 10 of 10 >
StackExchange.Redis.RedisConnectionException: No connection (requires
writable - not eligible for replica) is active/available to service
this operation: SETEX /api/products|pageIndex-1|p> at
StackExchange.Redis.ConnectionMultiplexer.ThrowFailed[T](TaskCompletionSource`1
source, Exception unthrownException) in
/_/src/StackExchange.Redis/ConnectionMultiplexer.cs:line 1836
--- End of stack trace from previous location --- at Infrastructure.Services.ResponseCacheService.CacheResponseAsync(String
cacheKey, Object response, TimeSpan timeToLive) in
C:\Workspace\MainProjects\eshop\sigma-backend-dotnet\sigma> at
API.Helpers.CachedAttribute.OnActionExecutionAsync(ActionExecutingContext
context, ActionExecutionDelegate next) in
C:\Workspace\MainProjects\eshop\sigma-backend-dotnet\sigma\API\He> at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker
invoker, Task lastTask, State next, Scope scope,> at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed
context) at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State&
next, Scope& scope, Object& state, Boolean& isCompleted) at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|13_0(ControllerActionInvoker
invoker, Task lastTask, State next, Scope scope, Obje> at
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|20_0(ResourceInvoker
invoker, Task lastTask, State next, Scope scope, Object state, Boo> at
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Logged|17_1(ResourceInvoker
invoker) at
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Logged|17_1(ResourceInvoker
invoker) at
Microsoft.AspNetCore.Routing.EndpointMiddleware.g__AwaitRequestTask|6_0(Endpoint
endpoint, Task requestTask, ILogger logger) at
Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext
context) at
Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext
context) at
Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext
context) at
Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext
httpContext) at
Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext
httpContext, ISwaggerProvider swaggerProvider) at
API.Middleware.ExceptionMiddleware.InvokeAsync(HttpContext context) in
C:\Workspace\MainProjects\eshop\sigma-backend-dotnet\sigma\API\Middleware\ExceptionMiddleware.cs:line
47
docker-compose configuration:
services:
redis:
image: redis:latest
ports:
- 6379:6379
command: ["redis-server", "--appendonly", "yes"]
volumes:
- redis-data:/data
redis-commander:
image: rediscommander/redis-commander:latest
environment:
- REDIS_HOSTS=local:redis:6379
- HTTP_USER=XXX
- HTTP_PASSWORD=YYY
ports:
- 8081:8081
depends_on:
- redis
volumes:
redis-data:
Program.cs:
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSingleton<IConnectionMultiplexer>(c =>
{
var configuration = ConfigurationOptions.Parse(builder.Configuration.GetConnectionString("Redis"), true);
return ConnectionMultiplexer.Connect(configuration);
});

Answer 1

I deployed the project according to the instructions below:
Deploy to Linux using Docker - for use with .Net 6.0
Create a new droplet with Digital Ocean using the Docker 19.03.12 on Ubuntu 20.04
IP address: Your IP address
Password for root user: YourPassword
Login to the droplet using either the terminal or Powershell:
ssh root#ipaddress
You will be asked for your password. Enter this.
Create a new docker-compose file using the following command:
sudo nano docker-compose.yml
Copy and paste in the docker-compose configuration:
Run the following command to start the docker services
docker-compose up -d
Install and configure apache by running the following commands:
sudo apt update
sudo apt install apache2
a2enmod proxy proxy_http proxy_html rewrite
systemctl restart apache2
sudo ufw app list
sudo ufw allow 'Apache Full'
sudo systemctl status apache2
Optional - allow the ports through the firewall to allow you to manage PostGreSQL and Redis via the ports.
sudo ufw allow 8080/tcp
sudo ufw allow 8081/tcp
Test you can access the default apache page by browsing to: http://ipaddress
Create a new directory that will contain our published dotnet app and assign rights to the user:
sudo mkdir /var/skinet
sudo chown -R $USER:$USER /var/skinet
Create a new config file for the skinet app:
sudo nano /etc/apache2/sites-available/skinet.conf
Paste in the following configuration which will set up a reverse proxy with the Kestrel server:
<VirtualHost *:80>
ServerAdmin webmaster#localhost
ProxyPreserveHost On
ProxyPass / http://127.0.0.1:5000/
ProxyPassReverse / http://127.0.0.1:5000
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
Enable the skinet site by running the following commands:
a2ensite skinet
ls /etc/apache2/sites-enabled
a2dissite 000-default
systemctl reload apache2
Install the deploy reloaded extension. Create a settings.json file in the .vscode directory and update the IP address and password for your server:
{
"deploy.reloaded": {
"packages": [
{
"name": "Version 1.0.0",
"description": "Package version 1.0.0",
"files": [
"publish/**"
]
}
],
"targets": [
{
"type": "sftp",
"name": "Linux",
"description": "SFTP folder",
"host": "ipaddress", "port": 22,
"user": "root", "password": "your password",
"dir": "/var/skinet",
"mappings": {
"publish/**": "/"
}
}
]
}
}
Optional - Change the logging level for the appsettings.json to information for the Microsoft logging level:
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft": "Information",
"Microsoft.Hosting.Lifetime": "Information"
}
},
}
Republish the app with changes by running the following command in VS Code terminal:
dotnet publish -c Release -o publish skinet.sln
Deploy the files by using the command pallette -> deploy reloaded -> deploy package
Add an endpoint to stripe for to point to the IP address of the server and select the 2 events we want to listen to: payment_intent.succeeded, payment_intent.payment_failed. Note the web hook MY_SECRET_PASSWORD as we will need this soon.
http://ipaddress/api/payments/webhook
Back on the linux server create a service config for the kestrel server:
sudo nano /etc/systemd/system/skinet-web.service
Update the configuration for your API keys where it says REPLACEME and then paste the config into the nano editor
[Unit]
Description=Kestrel service running on Ubuntu 20.04
[Service]
WorkingDirectory=/var/skinet
ExecStart=/usr/bin/dotnet /var/skinet/API.dll
Restart=always
RestartSec=10
SyslogIdentifier=skinet
User=www-data
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment='Token__Key=CHANGE ME TO SOMETHING SECURE'
Environment='Token__Issuer=http://REPLACEME'
Environment='StripeSettings__PublishibleKey=REPLACEME'
Environment='StripeSettings__SecretKey=REPLACEME'
Environment='StripeSettings__WhSecret=REPLACEME'
Environment='ConnectionStrings__DefaultConnection=Server=localhost;Port=5432;User Id=appuser;Password=MY_SECRET_PASSWORD; Database=skinet'
Environment='ConnectionStrings__IdentityConnection=Server=localhost;Port=5432;User Id=appuser;Password=MY_SECRET_PASSWORD; Database=identity'
Environment='ConnectionStrings__Redis=localhost'
Environment='ApiUrl=http://ipaddress/Content/'
[Install]
WantedBy=multi-user.target
Install the .Net runtime using the instructions here: https://learn.microsoft.com/en-gb/dotnet/core/install/linux-ubuntu#2004-
Restart the journal service by running the following command:
systemctl restart systemd-journald
Start the kestrel service by running the following command:
sudo systemctl start skinet-web.service
Check it is started by running:
netstat -ntpl
Check the journal by running:
journalctl -u skinet-web.service --since "5 min ago"
Make sure there are no errors and then test you can browse to the published app on http://ipaddress