Deploy caddy based executable on Scalingo PaaS

[Renrhaf]

Following up https://github.com/dunglas/mercure/issues/52 and https://github.com/dunglas/mercure/pull/92 :

I'm trying to deploy mercure on Scalingo, a Heruko like PaaS. The issue is that the legacy binary seems to be used when executing the application.

I can see in the logs the following messages : /!\ This Mercure binary is deprecated, use the binary based on Caddy Server instead! See https://mercure.rocks/docs/UPGRADE

How to make use of the new caddy based executable on Scalingo ? I tried using PROJECT_DIR variable to build the new executable but with no luck yet (https://doc.scalingo.com/platform/getting-started/common-deployment-errors)

[dunglas]

Where do you download the binary from?

[Renrhaf]

Here is the log of a deployment on Scalingo :

 <-- Start deployment of mercure -->
       Fetching source code
       Fetching deployment cache
-----> Fetching stdlib.sh.v8... done
-----> 
       Detected go modules via go.mod
-----> 
       Detected Module Name: github.com/dunglas/mercure
-----> 
-----> Using go1.24.0
-----> Determining packages to install
       
       Detected the following main packages to install:
       		github.com/dunglas/mercure/cmd/mercure
       
-----> Running: go install -v -tags heroku github.com/dunglas/mercure/cmd/mercure 
github.com/dunglas/mercure/common
github.com/dunglas/mercure
github.com/dunglas/mercure/cmd
github.com/dunglas/mercure/cmd/mercure
       
       Installed the following binaries:
       		./bin/mercure
 Build complete, shipping your container...
 Waiting for your application to boot... 

We can see that Scalingo uses the cmd/mercure executable to build. And here is the Procfile I use for now :

web: ADDR=":${PORT}" mercure --debug="${MERCURE_DEBUG}" --allow-anonymous --jwt-key="${MERCURE_SUBSCRIBER_JWT_KEY}" --cors-allowed-origins="${MERCURE_CORS_ALLOWED_ORIGIN}" --publish-allowed-origins="${MERCURE_PUBLISH_ALLOWED_ORIGINS}"  --write-timeout 1800s --heartbeat-interval 20s

[Renrhaf]

For information, some messages seems to be lost when using the legacy executable of Mercure. We're switching to a small server where we will deploy the Mercure docker image directly, it will be simpler.