Add --requires flag to podman run/create

Podman has, for a long time, had an internal concept of
dependency management, used mainly to ensure that pod infra
containers are started before any other container in the pod. We
also have the ability to recursively start these dependencies,
which we use to ensure that `podman start` on a container in a
pod will not fail because the infra container is stopped. We have
not, however, exposed these via the command line until now.

Add a `--requires` flag to `podman run` and `podman create` to
allow users to manually specify dependency containers. These
containers must be running before the container will start. Also,
make recursive starting with `podman start` default so we can
start these containers and their dependencies easily.

Fixes #9250

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

2 files changed, 18 insertions, 0 deletions

diff --git a/pkg/specgen/generate/container_create.go b/pkg/specgen/generate/container_create.go
index 1d724ffb0..ef9975021 100644
--- a/pkg/specgen/generate/container_create.go
+++ b/pkg/specgen/generate/container_create.go
@@ -364,6 +364,17 @@ func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen.
 	if len(s.Secrets) != 0 {
 		options = append(options, libpod.WithSecrets(s.Secrets))
 	}
+	if len(s.DependencyContainers) > 0 {
+		deps := make([]*libpod.Container, 0, len(s.DependencyContainers))
+		for _, ctr := range s.DependencyContainers {
+			depCtr, err := rt.LookupContainer(ctr)
+			if err != nil {
+				return nil, errors.Wrapf(err, "%q is not a valid container, cannot be used as a dependency", ctr)
+			}
+			deps = append(deps, depCtr)
+		}
+		options = append(options, libpod.WithDependencyCtrs(deps))
+	}
 	return options, nil
 }
 
diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index c10dc5ef5..28111f96d 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -160,10 +160,17 @@ type ContainerBasicConfig struct {
 	// to 0, 1, 2) that will be passed to the executed process. The total FDs
 	// passed will be 3 + PreserveFDs.
 	// set tags as `json:"-"` for not supported remote
+	// Optional.
 	PreserveFDs uint `json:"-"`
 	// Timezone is the timezone inside the container.
 	// Local means it has the same timezone as the host machine
+	// Optional.
 	Timezone string `json:"timezone,omitempty"`
+	// DependencyContainers is an array of containers this container
+	// depends on. Dependency containers must be started before this
+	// container. Dependencies can be specified by name or full/partial ID.
+	// Optional.
+	DependencyContainers []string `json:"dependencyContainers,omitempty"`
 }
 
 // ContainerStorageConfig contains information on the storage configuration of a