Podman CRI

This project is an attempt to create a Podman-like API to control CRI-O. This will enable any client compatible with the Podman API to control CRI-O, or possibly any other CRI-compatible runtime.

Podman API client ---( Podman API )---> This project ---( CRI API )---> CRI-O

Only a selection of the API endpoints will be available.

Image endpoints are proxied to Podman. Podman and CRI-O share the same storage for images, so CRI-O can access transparently any image that Podman pulls or builds. Just make sure that CRI-O and Podman are both running as the root user. See containers-storage.conf(5).

Build

Install dependencies:

sudo dnf install -y gcc protobuf-devel

Install Rust: see the website rustup.rs.

Build:

cargo build

Test and demo

To test and demo this project, use a Podman machine.

See machine/README.md.

Configuration

Environment variables:

• PODMAN_ENDPOINT
• PODMAN_CRI_ENDPOINT
• CONTAINER_RUNTIME_ENDPOINT

Podman API

What is the Podman API? See https://docs.podman.io/en/latest/_static/api.html.

Podman usually listens on:

/run/user/1000/podman/podman.sock

OpenAPI source:

• https://storage.googleapis.com/libpod-master-releases/swagger-latest.yaml

Endpoints to implement in this project:

GET /containers/{id}/json
DELETE /libpod/pods/{id}
GET /containers/json?all=true
GET /events
GET /_ping
GET /libpod/containers/json?all=true
GET /libpod/images/json
GET /libpod/info
GET /libpod/pods/json
GET /volumes
POST /build?dockerfile=&labels=
POST /containers/{id}/stop?abortSignal=
POST /libpod/containers/create
POST /libpod/pods/{id}/start
POST /libpod/pods/{id}/stop
POST /libpod/pods/create

CRI API

What is the CRI API? See https://kubernetes.io/docs/concepts/architecture/cri/.

CRI-O usually listens on:

/run/crio/crio.sock

Proto files sources:

• https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.proto
• https://github.com/gogo/protobuf/blob/v1.3.2/gogoproto/gogo.proto
• https://github.com/protocolbuffers/protobuf/raw/v27.1/src/google/protobuf/descriptor.proto

Development utils

Inspect Podman API calls:

$ podman system info | grep podman.sock
path: /run/user/1000/podman/podman.sock
$ mv /run/user/1000/podman/podman.sock /run/user/1000/podman/podman2.sock
$ socat -t100 -v UNIX-LISTEN:/run/user/1000/podman/podman.sock,mode=777,reuseaddr,fork UNIX-CONNECT:/run/user/1000/podman/podman2.sock 2>&1 | grep -E 'GET|PUT|POST|DELETE'

Generate Rust code from the OpenAPI spec:

podman run --rm -v $(pwd):/workspace:z openapitools/openapi-generator-cli generate -i /workspace/podman-peerpods/swagger-latest.yaml -g rust-axum -o /workspace/podman-api --additional-properties=disableValidator=true,packageName=podman-api --skip-validate-spec

Patch models to fix missing type:

diff --git a/podman-api/src/models.rs b/podman-api/src/models.rs
index 1af1dde..d58b6b2 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -3,6 +3,9 @@
 use http::HeaderValue;
 use validator::Validate;

+// TODO this is a workaround for cargo error[E0412]: cannot find type `integer` in this scope
+/// synonym of u32
+type integer = u32;

 #[cfg(feature = "server")]
 use crate::header;