Parse security_opts before sending them to docker daemon

Fixes #6720

Copy the parsing function from the docker CLI. Docker daemon expects to see JSON for seccomp file not a path.

drivers/docker/driver.go

@@ -1,8 +1,11 @@
 package docker
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
@@ -672,6 +675,35 @@ var userMountToUnixMount = map[string]string{
 	nstructs.VolumeMountPropagationBidirectional: "rshared",
 }
 
+// takes a local seccomp daemon, reads the file contents for sending to the daemon
+// this code modified slightly from the docker CLI code 
+// https://github.com/docker/cli/blob/8ef8547eb6934b28497d309d21e280bcd25145f5/cli/command/container/opts.go#L840 
+func parseSecurityOpts(securityOpts []string) ([]string, error) {
+	for key, opt := range securityOpts {
+		con := strings.SplitN(opt, "=", 2)
+		if len(con) == 1 && con[0] != "no-new-privileges" {
+			if strings.Contains(opt, ":") {
+				con = strings.SplitN(opt, ":", 2)
+			} else {
+				return securityOpts, fmt.Errorf("invalid security_opt: %q", opt)
+			}
+		}
+		if con[0] == "seccomp" && con[1] != "unconfined" {
+			f, err := ioutil.ReadFile(con[1])
+			if err != nil {
+				return securityOpts, fmt.Errorf("opening seccomp profile (%s) failed: %v", con[1], err)
+			}
+			b := bytes.NewBuffer(nil)
+			if err := json.Compact(b, f); err != nil {
+				return securityOpts, fmt.Errorf("compacting json for seccomp profile (%s) failed: %v", con[1], err)
+			}
+			securityOpts[key] = fmt.Sprintf("seccomp=%s", b.Bytes())
+		}
+	}
+
+	return securityOpts, nil
+}
+
 func (d *Driver) createContainerConfig(task *drivers.TaskConfig, driverConfig *TaskConfig,
 	imageID string) (docker.CreateContainerOptions, error) {
 
@@ -895,6 +927,11 @@ func (d *Driver) createContainerConfig(task *drivers.TaskConfig, driverConfig *T
 	hostConfig.SecurityOpt = driverConfig.SecurityOpt
 	hostConfig.Sysctls = driverConfig.Sysctl
 
+	hostConfig.SecurityOpt, err = parseSecurityOpts(driverConfig.SecurityOpt)
+	if (err != nil) {
+		return c, fmt.Errorf("failed to parse security_opt configuration: %v", err)
+	}
+
 	ulimits, err := sliceMergeUlimit(driverConfig.Ulimit)
 	if err != nil {
 		return c, fmt.Errorf("failed to parse ulimit configuration: %v", err)

drivers/docker/driver_test.go

@@ -978,7 +978,7 @@ func TestDockerDriver_ForcePull_RepoDigest(t *testing.T) {
 	require.Equal(t, localDigest, container.Image)
 }
 
-func TestDockerDriver_SecurityOpt(t *testing.T) {
+func TestDockerDriver_SecurityOptUnconfined(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("Windows does not support seccomp")
 	}
@@ -1004,6 +1004,34 @@ func TestDockerDriver_SecurityOpt(t *testing.T) {
 	require.Exactly(t, cfg.SecurityOpt, container.HostConfig.SecurityOpt)
 }
 
+func TestDockerDriver_SecurityOptFromFile(t *testing.T) {
+	seccompPath := "./test-resources/docker/seccomp.json"
+
+	if runtime.GOOS == "windows" {
+		t.Skip("Windows does not support seccomp")
+	}
+	if !tu.IsCI() {
+		t.Parallel()
+	}
+	testutil.DockerCompatible(t)
+
+	task, cfg, ports := dockerTask(t)
+	defer freeport.Return(ports)
+	cfg.SecurityOpt = []string{fmt.Sprintf("seccomp=%s", seccompPath)}
+	require.NoError(t, task.EncodeConcreteDriverConfig(cfg))
+
+	client, d, handle, cleanup := dockerSetup(t, task)
+	defer cleanup()
+	require.NoError(t, d.WaitUntilStarted(task.ID, 5*time.Second))
+
+	container, err := client.InspectContainer(handle.containerID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	require.Contains(t, container.HostConfig.SecurityOpt[0], "reboot")
+}
+
 func TestDockerDriver_CreateContainerConfig(t *testing.T) {
 	t.Parallel()
 

drivers/docker/test-resources/docker/seccomp.json

@@ -0,0 +1,15 @@
+{
+    "defaultAction": "SCMP_ACT_ALLOW",
+    "architectures": [
+        "SCMP_ARCH_X86_64",
+        "SCMP_ARCH_X86",
+        "SCMP_ARCH_X32"
+    ],
+    "syscalls": [
+        {
+            "name": "reboot",
+            "action": "SCMP_ACT_ERRNO",
+            "args": []
+        }
+    ]
+}