--- title: From DNS Errors to 404s: Debugging a Redirect Bug in a... description: A subtle default behavior in Go's http.Client — automatically following HTTP redirects — silently broke redirect flows in an API Gateway, causing DNS... canonical: https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: From DNS Errors to 404s: Debugging a Redirect Bug in a Go API Gateway | daily.dev og:description: A subtle default behavior in Go's http.Client — automatically following HTTP redirects — silently broke redirect flows in an API Gateway, causing DNS... og:url: https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl og:image: https://api.daily.dev/og/posts/J7cPkzZSl.png og:image:alt: From DNS Errors to 404s: Debugging a Redirect Bug in a Go API Gateway og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # From DNS Errors to 404s: Debugging a Redirect Bug in a Go API Gateway **[ITNEXT](https://daily.dev/sources/itnext)** · 7 min read · 1 upvotes · 0 comments ## Summary A subtle default behavior in Go's http.Client — automatically following HTTP redirects — silently broke redirect flows in an API Gateway, causing DNS resolution failures inside the internal network. The fix uses http.ErrUseLastResponse to prevent the client from following redirects, returning the response as-is instead. Fixing this exposed a second hidden bug: a trailing slash mismatch between the Gateway route config and Gin's routing behavior (RedirectTrailingSlash=true), which had previously been masked by the Gateway silently following the 301 redirect internally. The post covers root cause analysis, the correct fix, and lessons about framework assumptions in distributed systems. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [A Trailing Slash Bypassed AWS API Gateway Authorization](https://daily.dev/posts/a-trailing-slash-bypassed-aws-api-gateway-authorization-xczhpumsq) · InfoQ · 1 upvotes · 0 comments - [Go and enhance your calm: demolishing an HTTP/2 interop problem](https://daily.dev/posts/go-and-enhance-your-calm-demolishing-an-http-2-interop-problem-c3u78wrxf) · Cloudflare · 10 upvotes · 0 comments - [Tracing HTTP Requests with Go's net/http/httptrace](https://daily.dev/posts/tracing-http-requests-with-go-s-net-http-httptrace-4d4noiwlv) · Blain Smith · 10 upvotes · 0 comments --- Tags: [#golang](https://daily.dev/tags/golang), [#api-gateway](https://daily.dev/tags/api-gateway) [View this post on daily.dev](https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"From DNS Errors to 404s: Debugging a Redirect Bug in a Go API Gateway","url":"https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl"},"datePublished":"2026-04-08T16:15:04.571Z","dateModified":"2026-04-08T16:15:38.766Z","description":"A subtle default behavior in Go's http.Client — automatically following HTTP redirects — silently broke redirect flows in an API Gateway, causing DNS...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/4d401d0ef7296f2ce93c12dee0cbb9bc?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/4d401d0ef7296f2ce93c12dee0cbb9bc?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"ITNEXT","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"ITNEXT","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/itnext2","url":"https://daily.dev/sources/itnext"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/from-dns-errors-to-404s-debugging-a-redirect-bug-in-a-go-api-gateway-j7cpkzzsl","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"golang,api-gateway","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"ITNEXT","item":"https://daily.dev/sources/itnext"},{"@type":"ListItem","position":3,"name":"From DNS Errors to 404s: Debugging a Redirect Bug in a Go API Gateway"}]} ```