1 files changed, 103 insertions, 0 deletions
diff --git a/client/client.go b/client/client.go
new file mode 100644
index 000000000..ad717b970
--- /dev/null
+++ b/client/client.go
@@ -0,0 +1,103 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"syscall"
+	"time"
+
+	"github.com/kubernetes-incubator/cri-o/types"
+)
+
+const (
+	maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
+)
+
+// CrioClient is an interface to get information from crio daemon endpoint.
+type CrioClient interface {
+	DaemonInfo() (types.CrioInfo, error)
+	ContainerInfo(string) (*types.ContainerInfo, error)
+}
+
+type crioClientImpl struct {
+	client         *http.Client
+	crioSocketPath string
+}
+
+func configureUnixTransport(tr *http.Transport, proto, addr string) error {
+	if len(addr) > maxUnixSocketPathSize {
+		return fmt.Errorf("Unix socket path %q is too long", addr)
+	}
+	// No need for compression in local communications.
+	tr.DisableCompression = true
+	tr.Dial = func(_, _ string) (net.Conn, error) {
+		return net.DialTimeout(proto, addr, 32*time.Second)
+	}
+	return nil
+}
+
+// New returns a crio client
+func New(crioSocketPath string) (CrioClient, error) {
+	tr := new(http.Transport)
+	configureUnixTransport(tr, "unix", crioSocketPath)
+	c := &http.Client{
+		Transport: tr,
+	}
+	return &crioClientImpl{
+		client:         c,
+		crioSocketPath: crioSocketPath,
+	}, nil
+}
+
+func (c *crioClientImpl) getRequest(path string) (*http.Request, error) {
+	req, err := http.NewRequest("GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	// For local communications over a unix socket, it doesn't matter what
+	// the host is. We just need a valid and meaningful host name.
+	req.Host = "crio"
+	req.URL.Host = c.crioSocketPath
+	req.URL.Scheme = "http"
+	return req, nil
+}
+
+// DaemonInfo return cri-o daemon info from the cri-o
+// info endpoint.
+func (c *crioClientImpl) DaemonInfo() (types.CrioInfo, error) {
+	info := types.CrioInfo{}
+	req, err := c.getRequest("/info")
+	if err != nil {
+		return info, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return info, err
+	}
+	defer resp.Body.Close()
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return info, err
+	}
+	return info, nil
+}
+
+// ContainerInfo returns container info by querying
+// the cri-o container endpoint.
+func (c *crioClientImpl) ContainerInfo(id string) (*types.ContainerInfo, error) {
+	req, err := c.getRequest("/containers/" + id)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	cInfo := types.ContainerInfo{}
+	if err := json.NewDecoder(resp.Body).Decode(&cInfo); err != nil {
+		return nil, err
+	}
+	return &cInfo, nil
+}