Merge pull request #3800 from vrothberg/generate-pod

generate systemd pod

4 files changed, 36 insertions, 20 deletions

diff --git a/libpod/container_graph.go b/libpod/container_graph.go
index 5aa51bc2f..f6988e1ac 100644
--- a/libpod/container_graph.go
+++ b/libpod/container_graph.go
@@ -16,14 +16,30 @@ type containerNode struct {
 	dependedOn []*containerNode
 }
 
-type containerGraph struct {
+// ContainerGraph is a dependency graph based on a set of containers.
+type ContainerGraph struct {
 	nodes              map[string]*containerNode
 	noDepNodes         []*containerNode
 	notDependedOnNodes map[string]*containerNode
 }
 
-func buildContainerGraph(ctrs []*Container) (*containerGraph, error) {
-	graph := new(containerGraph)
+// DependencyMap returns the dependency graph as map with the key being a
+// container and the value being the containers the key depends on.
+func (cg *ContainerGraph) DependencyMap() (dependencies map[*Container][]*Container) {
+	dependencies = make(map[*Container][]*Container)
+	for _, node := range cg.nodes {
+		dependsOn := make([]*Container, len(node.dependsOn))
+		for i, d := range node.dependsOn {
+			dependsOn[i] = d.container
+		}
+		dependencies[node.container] = dependsOn
+	}
+	return dependencies
+}
+
+// BuildContainerGraph builds a dependency graph based on the container slice.
+func BuildContainerGraph(ctrs []*Container) (*ContainerGraph, error) {
+	graph := new(ContainerGraph)
 	graph.nodes = make(map[string]*containerNode)
 	graph.notDependedOnNodes = make(map[string]*containerNode)
 
@@ -78,7 +94,7 @@ func buildContainerGraph(ctrs []*Container) (*containerGraph, error) {
 // Detect cycles in a container graph using Tarjan's strongly connected
 // components algorithm
 // Return true if a cycle is found, false otherwise
-func detectCycles(graph *containerGraph) (bool, error) {
+func detectCycles(graph *ContainerGraph) (bool, error) {
 	type nodeInfo struct {
 		index   int
 		lowLink int
diff --git a/libpod/container_graph_test.go b/libpod/container_graph_test.go
index d1a52658d..38f03c59c 100644
--- a/libpod/container_graph_test.go
+++ b/libpod/container_graph_test.go
@@ -8,7 +8,7 @@ import (
 )
 
 func TestBuildContainerGraphNoCtrsIsEmpty(t *testing.T) {
-	graph, err := buildContainerGraph([]*Container{})
+	graph, err := BuildContainerGraph([]*Container{})
 	assert.NoError(t, err)
 	assert.Equal(t, 0, len(graph.nodes))
 	assert.Equal(t, 0, len(graph.noDepNodes))
@@ -24,7 +24,7 @@ func TestBuildContainerGraphOneCtr(t *testing.T) {
 	ctr1, err := getTestCtr1(manager)
 	assert.NoError(t, err)
 
-	graph, err := buildContainerGraph([]*Container{ctr1})
+	graph, err := BuildContainerGraph([]*Container{ctr1})
 	assert.NoError(t, err)
 	assert.Equal(t, 1, len(graph.nodes))
 	assert.Equal(t, 1, len(graph.noDepNodes))
@@ -49,7 +49,7 @@ func TestBuildContainerGraphTwoCtrNoEdge(t *testing.T) {
 	ctr2, err := getTestCtr2(manager)
 	assert.NoError(t, err)
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2})
 	assert.NoError(t, err)
 	assert.Equal(t, 2, len(graph.nodes))
 	assert.Equal(t, 2, len(graph.noDepNodes))
@@ -76,7 +76,7 @@ func TestBuildContainerGraphTwoCtrOneEdge(t *testing.T) {
 	assert.NoError(t, err)
 	ctr2.config.UserNsCtr = ctr1.config.ID
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2})
 	assert.NoError(t, err)
 	assert.Equal(t, 2, len(graph.nodes))
 	assert.Equal(t, 1, len(graph.noDepNodes))
@@ -99,7 +99,7 @@ func TestBuildContainerGraphTwoCtrCycle(t *testing.T) {
 	ctr2.config.UserNsCtr = ctr1.config.ID
 	ctr1.config.NetNsCtr = ctr2.config.ID
 
-	_, err = buildContainerGraph([]*Container{ctr1, ctr2})
+	_, err = BuildContainerGraph([]*Container{ctr1, ctr2})
 	assert.Error(t, err)
 }
 
@@ -116,7 +116,7 @@ func TestBuildContainerGraphThreeCtrNoEdges(t *testing.T) {
 	ctr3, err := getTestCtrN("3", manager)
 	assert.NoError(t, err)
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2, ctr3})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2, ctr3})
 	assert.NoError(t, err)
 	assert.Equal(t, 3, len(graph.nodes))
 	assert.Equal(t, 3, len(graph.noDepNodes))
@@ -150,7 +150,7 @@ func TestBuildContainerGraphThreeContainersTwoInCycle(t *testing.T) {
 	ctr1.config.UserNsCtr = ctr2.config.ID
 	ctr2.config.IPCNsCtr = ctr1.config.ID
 
-	_, err = buildContainerGraph([]*Container{ctr1, ctr2, ctr3})
+	_, err = BuildContainerGraph([]*Container{ctr1, ctr2, ctr3})
 	assert.Error(t, err)
 }
 
@@ -170,7 +170,7 @@ func TestBuildContainerGraphThreeContainersCycle(t *testing.T) {
 	ctr2.config.IPCNsCtr = ctr3.config.ID
 	ctr3.config.NetNsCtr = ctr1.config.ID
 
-	_, err = buildContainerGraph([]*Container{ctr1, ctr2, ctr3})
+	_, err = BuildContainerGraph([]*Container{ctr1, ctr2, ctr3})
 	assert.Error(t, err)
 }
 
@@ -190,7 +190,7 @@ func TestBuildContainerGraphThreeContainersNoCycle(t *testing.T) {
 	ctr1.config.NetNsCtr = ctr3.config.ID
 	ctr2.config.IPCNsCtr = ctr3.config.ID
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2, ctr3})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2, ctr3})
 	assert.NoError(t, err)
 	assert.Equal(t, 3, len(graph.nodes))
 	assert.Equal(t, 1, len(graph.noDepNodes))
@@ -215,7 +215,7 @@ func TestBuildContainerGraphFourContainersNoEdges(t *testing.T) {
 	ctr4, err := getTestCtrN("4", manager)
 	assert.NoError(t, err)
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
 	assert.NoError(t, err)
 	assert.Equal(t, 4, len(graph.nodes))
 	assert.Equal(t, 4, len(graph.noDepNodes))
@@ -256,7 +256,7 @@ func TestBuildContainerGraphFourContainersTwoInCycle(t *testing.T) {
 	ctr1.config.IPCNsCtr = ctr2.config.ID
 	ctr2.config.UserNsCtr = ctr1.config.ID
 
-	_, err = buildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
+	_, err = BuildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
 	assert.Error(t, err)
 }
 
@@ -280,7 +280,7 @@ func TestBuildContainerGraphFourContainersAllInCycle(t *testing.T) {
 	ctr3.config.NetNsCtr = ctr4.config.ID
 	ctr4.config.UTSNsCtr = ctr1.config.ID
 
-	_, err = buildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
+	_, err = BuildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
 	assert.Error(t, err)
 }
 
@@ -303,7 +303,7 @@ func TestBuildContainerGraphFourContainersNoneInCycle(t *testing.T) {
 	ctr1.config.NetNsCtr = ctr3.config.ID
 	ctr2.config.UserNsCtr = ctr3.config.ID
 
-	graph, err := buildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
+	graph, err := BuildContainerGraph([]*Container{ctr1, ctr2, ctr3, ctr4})
 	assert.NoError(t, err)
 	assert.Equal(t, 4, len(graph.nodes))
 	assert.Equal(t, 2, len(graph.noDepNodes))
diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index 313f67963..f51b53e85 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -788,7 +788,7 @@ func (c *Container) startDependencies(ctx context.Context) error {
 	}
 
 	// Build a dependency graph of containers
-	graph, err := buildContainerGraph(depCtrs)
+	graph, err := BuildContainerGraph(depCtrs)
 	if err != nil {
 		return errors.Wrapf(err, "error generating dependency graph for container %s", c.ID())
 	}
diff --git a/libpod/pod_api.go b/libpod/pod_api.go
index c7b0353bd..e2448e92a 100644
--- a/libpod/pod_api.go
+++ b/libpod/pod_api.go
@@ -37,7 +37,7 @@ func (p *Pod) Start(ctx context.Context) (map[string]error, error) {
 	}
 
 	// Build a dependency graph of containers in the pod
-	graph, err := buildContainerGraph(allCtrs)
+	graph, err := BuildContainerGraph(allCtrs)
 	if err != nil {
 		return nil, errors.Wrapf(err, "error generating dependency graph for pod %s", p.ID())
 	}
@@ -289,7 +289,7 @@ func (p *Pod) Restart(ctx context.Context) (map[string]error, error) {
 	}
 
 	// Build a dependency graph of containers in the pod
-	graph, err := buildContainerGraph(allCtrs)
+	graph, err := BuildContainerGraph(allCtrs)
 	if err != nil {
 		return nil, errors.Wrapf(err, "error generating dependency graph for pod %s", p.ID())
 	}