docs: correct README facts and document CLI options

README.md

@@ -22,35 +22,33 @@ Convert a Docker Compose file into a POSIX `sh` script that runs its services as
 
 Built for CI and test environments where you can't use `docker compose` or `podman kube play`:
 
-- **No bridge networking / netavark.** Unprivileged CI containers often have a read-only `/proc/sys`, so netavark fails to create bridge networks. A single pod shares one network namespace with no bridge: services talk over `127.0.0.1`, and names resolve via a generated `/etc/hosts` the script owns.
-- **No systemd.** Podman healthchecks are normally scheduled by systemd timers. compose2pod gates startup by polling `podman healthcheck run` directly, so `depends_on: service_healthy` works without systemd.
-- **No heavy runtime.** The core is stdlib-only — no dependencies, no compiled wheels — so it installs and runs in minimal Python images.
+- No bridge networking or netavark. Unprivileged CI containers often have a read-only `/proc/sys`, so netavark fails to create bridge networks. A single pod shares one network namespace with no bridge: services talk over `127.0.0.1`, and names resolve via a generated `/etc/hosts` the script owns.
+- No systemd. Podman healthchecks are normally scheduled by systemd timers. compose2pod gates startup by polling `podman healthcheck run` directly, so `depends_on: service_healthy` works without systemd.
+- No heavy runtime. The core is stdlib-only, with no dependencies and no compiled wheels, so it installs and runs in minimal Python images.
 
 ## Requirements
 
-**Podman 4.9 or newer.** Every form compose2pod accepts is one Podman expresses across that
-whole range, from the floor to the newest release measured (6.1): a mount option a later
-Podman adds is refused until the floor reaches it, so a document that compiles here runs on
-any supported Podman rather than only the newest one
+Podman 4.9 or newer. compose2pod accepts only forms that every Podman from 4.9 to 6.1 can
+run, so a script it generates runs on any of them
 ([ADR-0006](https://github.com/modern-python/compose2pod/blob/main/docs/adr/0006-docker-rejection-parity.md)).
 
 compose2pod's generated scripts own `/etc/hosts`: they write it to a temp
 file and bind-mount it read-only into every container under `--no-hosts`, so
 pod-internal name resolution works on any Podman version. `host.containers.internal` /
-`host.docker.internal` are not provided — add an explicit `extra_hosts`
+`host.docker.internal` are not provided; add an explicit `extra_hosts`
 entry if you need them.
 
 ## Install
 
 ```bash
 pip install compose2pod            # core: reads compose as JSON
-pip install compose2pod[yaml]      # optional: read YAML directly (adds PyYAML)
+pip install 'compose2pod[yaml]'    # optional: read YAML directly (adds PyYAML)
 ```
 
 ## Usage
 
 ```bash
-# YAML directly (needs the [yaml] extra)
+# YAML directly (needs the 'compose2pod[yaml]' extra)
 compose2pod docker-compose.yml --target app --image myimage:ci > run.sh
 
 # Or stay dependency-free by piping JSON (e.g. via yq)
@@ -59,37 +57,51 @@ yq -o=json '.' docker-compose.yml | compose2pod --target app --image myimage:ci
 sh ./run.sh
 ```
 
+Options:
+
+- `--target`: the service to run in the foreground (required).
+- `--image`: the CI image that replaces every service with a `build` section (required).
+- `--command`: a shell command overriding the target service's command.
+- `--project-dir`: the host path that relative volume and `env_file` sources resolve against (default `.`).
+- `--pod-name`: the name of the Podman pod, also used as the prefix of every container name (default `test-pod`).
+- `--format`: the input format, one of `auto`, `json`, `yaml` (default `auto`, which tries JSON, then YAML).
+- `--artifact SRC:DST`: a file to `podman cp` out of the target container after it exits (repeatable).
+- `--allow-exit-code`: a target exit code treated as success in addition to 0 (repeatable).
+
 ## Supported compose subset
 
-compose2pod refuses **every document `docker compose config` refuses** — a
-measured property, checked continuously by a differential conformance harness
-that runs the real Docker CLI and the real compose2pod pipeline over the same
-YAML. So a file that compiles is a file Docker would run; where compose2pod
-still refuses a form Docker accepts, it is because Podman genuinely cannot
-express it (each such case is documented, not guessed).
+compose2pod refuses every document `docker compose config` refuses. A test
+harness runs `docker compose config` and compose2pod over the same files to
+check this. So a file that compiles is a file Docker would run; where compose2pod
+still refuses a form Docker accepts, it is because Podman cannot express it;
+each case is documented in [`docs/adr/`](https://github.com/modern-python/compose2pod/tree/main/docs/adr/).
 
 Within that boundary it covers most of what real compose files use:
 
-- **Services** — `image`/`build`, `command`/`entrypoint`, `environment` and
+- Services: `image`/`build`, `command`/`entrypoint`, `environment` and
   `env_file` (string and long-form `{path, required, format}`), `volumes`
   (short-form and long-form `--mount`, including the `bind` and `tmpfs`
   option maps), `tmpfs`, `healthcheck`, `depends_on` (all conditions), `links`
   (read as a dependency plus a hostname alias, as Docker reads it), network
   `aliases`, `hostname`/`container_name`.
-- **Confinement & metadata** — `user`, `working_dir`, `read_only`, `init`,
+- Confinement and metadata: `user`, `working_dir`, `read_only`, `init`,
   `privileged`, `cap_add`/`cap_drop`, `security_opt`, `devices`, `group_add`,
   `platform`, `labels`, `annotations`, `pull_policy` (the quoted-boolean and
   YAML-1.1 spellings Docker accepts, too).
-- **Resources** — the legacy keys (`mem_limit`, `cpus`, `pids_limit`,
+- Resources: the legacy keys (`mem_limit`, `cpus`, `pids_limit`,
   `ulimits`, …) and the modern `deploy.resources` block.
-- **Pod-wide** — `dns`/`dns_search`/`dns_opt`, `sysctls`, `extra_hosts`.
-- **Composition** — same-file `extends`, `secrets`/`configs`, `profiles`.
+- Pod-wide: `dns`/`dns_search`/`dns_opt`, `sysctls`, `extra_hosts`.
+- Composition: same-file `extends`, `secrets`/`configs`.
+
+Accepted and ignored with a warning, since they mean nothing inside one shared pod:
+`ports`, `expose`, `restart`, `stdin_open`, `tty`, `stop_signal`,
+`stop_grace_period`, and `profiles` (every service runs regardless of profile).
 
 Compose extension fields (any `x-`-prefixed key) and YAML anchors are accepted
-as-is, so a top-level `x-*` anchor block for shared config just works.
+as-is, so a top-level `x-*` anchor block for shared config is accepted.
 `${VAR}`-style variable interpolation is left live in the generated script,
 resolved by its shell against the environment present when the script runs (no
-`.env` file support). The boundary rulings — which forms are refused, and why —
+`.env` file support). The boundary rulings, which forms are refused and why,
 are recorded in [`docs/adr/`](https://github.com/modern-python/compose2pod/tree/main/docs/adr/).
 
 ## Status

compose2pod/cli.py

@@ -21,8 +21,17 @@ def main(argv: list[str] | None = None) -> int:
     parser.add_argument("--image", required=True, help="CI image replacing services that have a build section")
     parser.add_argument("--project-dir", default=".", help="host path relative volume/env_file sources resolve to")
     parser.add_argument("--command", default="", help="shell command overriding the target service command")
-    parser.add_argument("--pod-name", default="test-pod")
-    parser.add_argument("--format", choices=("auto", "json", "yaml"), default="auto")
+    parser.add_argument(
+        "--pod-name",
+        default="test-pod",
+        help="name of the podman pod, also the container name prefix (default: test-pod)",
+    )
+    parser.add_argument(
+        "--format",
+        choices=("auto", "json", "yaml"),
+        default="auto",
+        help="input format; auto tries JSON, then YAML (default: auto)",
+    )
     parser.add_argument(
         "--artifact",
         action="append",

compose2pod/read.py

@@ -70,7 +70,7 @@ class Loader(yaml_module.SafeLoader):
 
 def _load_yaml(text: str) -> Any:  # noqa: ANN401 - returns arbitrary parsed compose data
     if _yaml is None:
-        msg = "YAML input requires the 'yaml' extra: pip install compose2pod[yaml] (or pipe JSON via yq)"
+        msg = "YAML input requires the 'yaml' extra: pip install 'compose2pod[yaml]' (or pipe JSON via yq)"
         raise UnsupportedComposeError(msg)
     try:
         return _yaml.load(text, Loader=_build_yaml_loader(_yaml))  # noqa: S506 - SafeLoader subclass, not full load

tests/test_cli.py

@@ -96,7 +96,14 @@ def test_yaml_without_pyyaml_errors(
         monkeypatch.setattr(read_module, "_yaml", None)
         rc = run_main("services: {}", ["--target", "app", "--image", "i", "--format", "yaml"], monkeypatch)
         assert rc == EXIT_USAGE_ERROR
-        assert "requires the 'yaml' extra" in capsys.readouterr().err
+        assert "pip install 'compose2pod[yaml]'" in capsys.readouterr().err
+
+    def test_help_describes_pod_name_and_format(self, capsys: pytest.CaptureFixture[str]) -> None:
+        with pytest.raises(SystemExit):
+            main(["--help"])
+        help_text = " ".join(capsys.readouterr().out.split())
+        assert "--pod-name POD_NAME name of the podman pod" in help_text
+        assert "--format {auto,json,yaml} input format" in help_text
 
     def test_invalid_yaml_returns_2(self, capsys: pytest.CaptureFixture[str], monkeypatch: pytest.MonkeyPatch) -> None:
         rc = run_main("a: [1, 2", ["--target", "app", "--image", "i", "--format", "yaml"], monkeypatch)