57 lines
1.7 KiB
Markdown
57 lines
1.7 KiB
Markdown
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# manhole
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An opinionated HTTP manhole into Go processes.
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## Assumptions This Package Makes
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- Make each server instance have a unique HTTP port that is randomized by default.
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This makes it very hard to accidentally route this manhole to the outside world.
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If more assurance is required I personally suggest using [yubikey totp][yktotp],
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but do research.
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- Application code does not touch [`http.DefaultServeMux`][default-servemux]'. This is so that
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administative control rods can be dynamically flipped in the case they are
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needed.
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- [pprof][pprof] endpoints added to `http.DefaultServeMux`. This allows easy
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access to [pprof runtime tracing][pprof-tracing] to debug issues on long-running
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applications like HTTP services.
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- Make the manhole slightly inconvenient to put into place in production. This
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helps make sure that this tool remains a debugging tool and not a part of a
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long-term production rollout.
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## Usage
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Compile this as a plugin:
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```console
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$ go get -d github.com/Xe/gopreload/manhole
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$ go build -buildmode plugin -o manhole.so github.com/Xe/gopreload/manhole
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```
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Then add [`gopreload`][gopreload] to your application:
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```go
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// gopreload.go
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package main
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/*
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This file is separate to make it very easy to both add into an application, but
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also very easy to remove.
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*/
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import _ "github.com/Xe/gopreload"
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```
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And at runtime add the `manhole.so` file you created earlier to the target system
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somehow and add the following environment variable to its run configuration:
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```sh
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GO_PRELOAD=/path/to/manhole.so
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```
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---
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[pprof]: https://godoc.org/net/http/pprof
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[default-servemux]: https://godoc.org/net/http#pkg-variables
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[yktotp]: https://github.com/GeertJohan/yubigo
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[gopreload]: https://github.com/Xe/gopreload
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