Swagger service url behind reverse proxy
If you’re deploying apps behind a reverse proxy such as nginx you might find that the service url is incorrect. It may have redirected from http to https for example, leading to the window.location property having the scheme https and the swagger service url having the scheme http. This mismatch will cause the browser to block requests unless CORS response headers are set.
The solution :
Configure the middleware with ForwardedHeadersOptions to forward the X-Forwarded-For and X-Forwarded-Proto headers.
Forwarded Headers Middleware order
Forwarded Headers Middleware should run before other middleware. This ordering ensures that the middleware relying on forwarded headers information can consume the header values for processing. Forwarded Headers Middleware can run after diagnostics and error handling, but it must be run before calling UseHsts:
using Microsoft.AspNetCore.HttpOverrides;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();
builder.Services.Configure<ForwardedHeadersOptions>(options =>
{
options.ForwardedHeaders =
ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
});
var app = builder.Build();
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Error");
app.UseForwardedHeaders();
app.UseHsts();
}
else
{
app.UseDeveloperExceptionPage();
app.UseForwardedHeaders();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseAuthorization();
app.MapRazorPages();
app.Run();
Alternatively, call UseForwardedHeaders before diagnostics:
using Microsoft.AspNetCore.HttpOverrides;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();
builder.Services.Configure<ForwardedHeadersOptions>(options =>
{
options.ForwardedHeaders =
ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
});
var app = builder.Build();
app.UseForwardedHeaders();
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseAuthorization();
app.MapRazorPages();
app.Run();
Nginx configuration
To forward the X-Forwarded-For and X-Forwarded-Proto headers,
map $http_connection $connection_upgrade {
"~*Upgrade" $http_connection;
default keep-alive;
}
server {
listen 80;
server_name example.com *.example.com;
location / {
proxy_pass http://127.0.0.1:5000/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}
