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Objective-C on Miren

Objective-C isn't auto-detected, so you deploy it with a Dockerfile.miren that compiles your app with GNUstep. This guide uses SOPE (the SKYRiX Object Publishing Environment — the Objective-C web framework that SOGo is built on), whose WOApplication and WOHttpAdaptor give you a real HTTP server, WebObjects-style.

Let your agent do this

Ask your AI coding agent to "set up this Objective-C app on Miren" after installing the Miren agent skills. It adds the Dockerfile.miren and GNUstep build, and deploys — using this page as its reference.

Do you need a Dockerfile?​

Yes. Add a Dockerfile.miren to your project root. Miren builds from it instead of guessing the stack — see Using Dockerfile.miren.

Want native support?

Miren auto-detects and builds common stacks (Python, Node, Bun, Go, Ruby, Rust) without a Dockerfile. This language isn't one of them yet — if you'd like first-class support, request it.

The app​

Subclass WOApplication and override dispatchRequest: to return a WOResponse. WOApplicationMain starts the app and its built-in HTTP adaptor:

#import <NGObjWeb/WOApplication.h>
#import <NGObjWeb/WOResponse.h>
#import <NGObjWeb/WORequest.h>
#import <NGObjWeb/WOCoreApplication.h>

@interface HelloApp : WOApplication
@end

@implementation HelloApp
- (WOResponse *)dispatchRequest:(WORequest *)_request {
    WOResponse *r = [WOResponse responseWithRequest:_request];
    [r setStatus:200];
    [r setHeader:@"text/plain" forKey:@"content-type"];
    [r appendContentString:@"Hello from Objective-C on Miren!\n"];
    return r;
}
@end

int main(int argc, const char *argv[]) {
    return WOApplicationMain(@"HelloApp", argc, argv);
}

Bind to the injected port​

SOPE's HTTP adaptor takes its listen address from the WOPort default, which you pass on the command line. Miren injects PORT, so start the app with -WOPort 0.0.0.0:$PORT:

web: sh -c '. /usr/share/GNUstep/Makefiles/GNUstep.sh && exec /app/obj/app -WOPort 0.0.0.0:$PORT'
Give WOPort an explicit 0.0.0.0

-WOPort 8080 alone makes the adaptor bind the wildcard address (*:8080), which fails on this stack with NGCouldNotBindSocketException … Address family not supported. Pass the address explicitly — -WOPort 0.0.0.0:$PORT — so it binds IPv4 on all interfaces. The sh -c '. GNUstep.sh && exec …' wrapper sources the GNUstep environment so the app finds its frameworks at runtime.

The Dockerfile​

Build with GNUstep's makefile system. gnustep-make provides only the makefiles, so install GNU make too; libsope-dev provides SOPE's headers and libraries. A single-stage image keeps the GNUstep runtime and SOPE libraries available at run time:

FROM debian:12
RUN apt-get update -y \
    && apt-get install -y make gobjc gnustep-make gnustep-base-runtime libgnustep-base-dev libsope-dev libsope1 \
    && rm -rf /var/lib/apt/lists/*
WORKDIR /app
COPY main.m GNUmakefile ./
RUN . /usr/share/GNUstep/Makefiles/GNUstep.sh && make
EXPOSE 8080

The GNUmakefile builds a plain tool linked against the SOPE libraries (SOPE's own woapp.make bundle fragment is too old for current gnustep-make, so link them directly):

include $(GNUSTEP_MAKEFILES)/common.make

TOOL_NAME = app
app_OBJC_FILES = main.m
app_TOOL_LIBS += -lNGObjWeb -lNGExtensions -lEOControl -lNGStreams -lNGMime -lSaxObjC -lDOM

include $(GNUSTEP_MAKEFILES)/tool.make

The compiled binary lands at obj/app.

.dockerignore​

.git

Deploy​

Create .miren/app.toml naming your app and deploy from your project root:

name = "objc-bench"
miren deploy
The Procfile is required

Even with a Dockerfile.miren, Miren needs at least one service defined — the web: line above. Without it the deploy stops with no services defined.

Agent quick reference​

  • Detection: none — requires Dockerfile.miren
  • Framework: SOPE (libsope-dev) — WOApplication + WOHttpAdaptor; override dispatchRequest:
  • Build: GNUstep makefiles as a plain tool linking -lNGObjWeb … (install make); binary at obj/app
  • Port: -WOPort 0.0.0.0:$PORT — the explicit 0.0.0.0 avoids a wildcard bind failure
  • Runtime: source GNUstep.sh before exec so the app finds its frameworks
  • Service is required: the web: Procfile line — the image CMD is not used

Next steps​