Swagger refactor/cleanup

* Remove duplicate or unused types and constants
* Move all documetation-only models and responses into swagger package
* Remove all unecessary names, go-swagger will determine names from
  struct declarations
* Use Libpod suffix to differentiate between compat and libpod models
  and responses. Taken from swagger:operation declarations.
* Models and responses that start with lowercase are for swagger use
  only while uppercase are used "as is" in the code and swagger comments
* Used gofumpt on new code

```release-note

```

Signed-off-by: Jhon Honce <jhonce@redhat.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/pkg/api/handlers/libpod/swagger_spec.go b/pkg/api/handlers/libpod/swagger_spec.go
new file mode 100644
index 000000000..8eeb041d2
--- /dev/null
+++ b/pkg/api/handlers/libpod/swagger_spec.go
@@ -0,0 +1,29 @@
+package libpod
+
+import (
+	"net/http"
+	"os"
+
+	"github.com/containers/podman/v4/pkg/api/handlers/utils"
+	"github.com/pkg/errors"
+)
+
+// DefaultPodmanSwaggerSpec provides the default path to the podman swagger spec file
+const DefaultPodmanSwaggerSpec = "/usr/share/containers/podman/swagger.yaml"
+
+func ServeSwagger(w http.ResponseWriter, r *http.Request) {
+	path := DefaultPodmanSwaggerSpec
+	if p, found := os.LookupEnv("PODMAN_SWAGGER_SPEC"); found {
+		path = p
+	}
+	if _, err := os.Stat(path); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			utils.InternalServerError(w, errors.Errorf("swagger spec %q does not exist", path))
+			return
+		}
+		utils.InternalServerError(w, err)
+		return
+	}
+	w.Header().Set("Content-Type", "text/yaml")
+	http.ServeFile(w, r, path)
+}