How to specify path for reverse proxy

Help
1

1. The problem I’m having:

I’m using docker compose with asp net app and caddy
My config:

{
  "handle": [
    {
      "handler": "subroute",
      "routes": [
        {
          "handle": [
            {
              "handler": "reverse_proxy",
              "upstreams": [
                {
                  "dial": "constests:4000/contest/examplecontest"
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "match": [
    {
      "host": [
        "examplecontest.com"
      ]
    }
  ],
  "terminal": true
}

I want that if a user goes to the examplecontest.com site it will be proxied through constests:4000/contest/examplecontest, but it doesn’t seem to work.

How can this be fixed? The point is that I need to dynamically bind domains to a specific path via the api on the site

2. Error messages and/or full log output:

"msg":"dial tcp: lookup contest/examplecontest: no such host"
"err_trace":"reverseproxy.statusError (reverseproxy.go:1248)"

3. Caddy version:

2.7.4

4. How I installed and ran Caddy:

Via Docker compose

a. System environment:

Docker

b. Command:

c. Service/unit/compose file:

d. My complete Caddy config:

{
	"admin": {
		"listen": ":2019"
	},
	"apps": {
		"http": {
			"servers": {
				"srv0": {
					"listen": [
						":443"
					],
					"routes": [
						{
							"handle": [
								{
									"handler": "subroute",
									"routes": [
										{
											"handle": [
												{
													"handler": "reverse_proxy",
													"upstreams": [
														{
															"dial": "contestgenerator:5000"
														}
													]
												}
											]
										}
									]
								}
							],
							"match": [
								{
									"host": [
										"contestcreator.com"
									]
								}
							],
							"terminal": true
						},
						{
							"handle": [
								{
									"handler": "subroute",
									"routes": [
										{
											"handle": [
												{
													"handler": "reverse_proxy",
													"upstreams": [
														{
															"dial": "contestgenerator:5000/contest/MZVPC_1234:80"
														},
													]
												}
											]
										}
									]
								}
							],
							"match": [
								{
									"host": [
										"examplecontest.com"
									]
								}
							],
							"terminal": true
						}
					]
				}
			}
		}
	}
}

5. Links to relevant resources:

2

As I said on How to specify path for reverse proxy · Issue #5817 · caddyserver/caddy · GitHub you need to use the rewrite handler.

3

I tried something like

{
  "handle": [
    {
      "handler": "subroute",
      "routes": [
        {
          "group": "group1",
          "handle": [
            {
              "handler": "rewrite",
              "uri": "contestgenerator:5000/contest/examplecontest"
            }
          ]
        }
      ]
    }
  ],
  "match": [
    {
      "host": [
        "examplecontest.com"
      ]
    }
  ],
  "terminal": true
}

But it doesn’t work, when i go to examplecontest.com it’s return 200 ok with no content

4

Rewrites don’t take a full URL, it only takes a path+query. Please read the documentation.

And you can’t only do a rewrite, you still need to proxy afterwards. Handlers are a chain.

Is there any particular reason you’re using a JSON config? You’d probably have an easier time with a Caddyfile.

Either way, you can write a Caddyfile for what you want, then run caddy adapt --pretty to get the equivalent JSON config.

5

i need to to dynamically add domains in my site. Example, i have domain contests.com, i want the content of contests.com/contest/example to be shown when navigating from another domain examplecontest.com

6

Yes, you need to use a rewrite to change the path, and the proxy to send the request to another server.