summaryrefslogtreecommitdiff
path: root/libpod/state.go
blob: 273e81318990a04c25b548a8f58b8d3483afb7e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
package libpod

// State is a storage backend for libpod's current state.
// A State is only initialized once per instance of libpod.
// As such, initialization methods for State implementations may safely assume
// they will be run as a singleton.
// For all container and pod retrieval methods, a State must retrieve the
// Configuration struct of the container or pod and include it in the returned
// struct. The State of the container or pod may optionally be included as well,
// but this is not a requirement.
// As such, all containers and pods must be synced with the database via the
// UpdateContainer and UpdatePod calls before any state-specific information is
// retrieved after they are pulled from the database.
// Generally speaking, the syncContainer() call should be run at the beginning
// of all API operations, which will silently handle this.
type State interface {
	// Close performs any pre-exit cleanup (e.g. closing database
	// connections) that may be required
	Close() error

	// Refresh clears container and pod states after a reboot
	Refresh() error

	// SetNamespace() sets the namespace for the store, and will determine
	// what containers are retrieved with container and pod retrieval calls.
	// A namespace of "", the empty string, acts as no namespace, and
	// containers and pods in all namespaces will be returned.
	SetNamespace(ns string) error

	// Return a container from the database from its full ID.
	// If the container is not in the set namespace, an error will be
	// returned.
	Container(id string) (*Container, error)
	// Return a container from the database by full or partial ID or full
	// name.
	// Containers not in the set namespace will be ignored.
	LookupContainer(idOrName string) (*Container, error)
	// Check if a container with the given full ID exists in the database.
	// If the container exists but is not in the set namespace, false will
	// be returned.
	HasContainer(id string) (bool, error)
	// Adds container to state.
	// The container cannot be part of a pod.
	// The container must have globally unique name and ID - pod names and
	// IDs also conflict with container names and IDs.
	// The container must be in the set namespace if a namespace has been
	// set.
	// All containers this container depends on must be part of the same
	// namespace and must not be joined to a pod.
	AddContainer(ctr *Container) error
	// Removes container from state.
	// Containers that are part of pods must use RemoveContainerFromPod.
	// The container must be part of the set namespace.
	RemoveContainer(ctr *Container) error
	// UpdateContainer updates a container's state from the backing store.
	// The container must be part of the set namespace.
	UpdateContainer(ctr *Container) error
	// SaveContainer saves a container's current state to the backing store.
	// The container must be part of the set namespace.
	SaveContainer(ctr *Container) error
	// ContainerInUse checks if other containers depend upon a given
	// container.
	// It returns a slice of the IDs of containers which depend on the given
	// container. If the slice is empty, no container depend on the given
	// container.
	// A container cannot be removed if other containers depend on it.
	// The container being checked must be part of the set namespace.
	ContainerInUse(ctr *Container) ([]string, error)
	// Retrieves all containers presently in state.
	// If a namespace is set, only containers within the namespace will be
	// returned.
	AllContainers() ([]*Container, error)

	// Accepts full ID of pod.
	// If the pod given is not in the set namespace, an error will be
	// returned.
	Pod(id string) (*Pod, error)
	// Accepts full or partial IDs (as long as they are unique) and names.
	// Pods not in the set namespace are ignored.
	LookupPod(idOrName string) (*Pod, error)
	// Checks if a pod with the given ID is present in the state.
	// If the given pod is not in the set namespace, false is returned.
	HasPod(id string) (bool, error)
	// Check if a pod has a container with the given ID.
	// The pod must be part of the set namespace.
	PodHasContainer(pod *Pod, ctrID string) (bool, error)
	// Get the IDs of all containers in a pod.
	// The pod must be part of the set namespace.
	PodContainersByID(pod *Pod) ([]string, error)
	// Get all the containers in a pod.
	// The pod must be part of the set namespace.
	PodContainers(pod *Pod) ([]*Container, error)
	// Adds pod to state.
	// The pod must be part of the set namespace.
	// The pod's name and ID must be globally unique.
	AddPod(pod *Pod) error
	// Removes pod from state.
	// Only empty pods can be removed from the state.
	// The pod must be part of the set namespace.
	RemovePod(pod *Pod) error
	// Remove all containers from a pod.
	// Used to simultaneously remove containers that might otherwise have
	// dependency issues.
	// Will fail if a dependency outside the pod is encountered.
	// The pod must be part of the set namespace.
	RemovePodContainers(pod *Pod) error
	// AddContainerToPod adds a container to an existing pod.
	// The container given will be added to the state and the pod.
	// The container and its dependencies must be part of the given pod,
	// and the given pod's namespace.
	// The pod must be part of the set namespace.
	// The pod must already exist in the state.
	// The container's name and ID must be globally unique.
	AddContainerToPod(pod *Pod, ctr *Container) error
	// RemoveContainerFromPod removes a container from an existing pod.
	// The container will also be removed from the state.
	// The container must be in the given pod, and the pod must be in the
	// set namespace.
	RemoveContainerFromPod(pod *Pod, ctr *Container) error
	// UpdatePod updates a pod's state from the database.
	// The pod must be in the set namespace.
	UpdatePod(pod *Pod) error
	// SavePod saves a pod's state to the database.
	// The pod must be in the set namespace.
	SavePod(pod *Pod) error
	// Retrieves all pods presently in state.
	// If a namespace has been set, only pods in that namespace will be
	// returned.
	AllPods() ([]*Pod, error)
}