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| 1 | +/* |
| 2 | +Copyright 2025 The Skaffold Authors |
| 3 | +
|
| 4 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | +you may not use this file except in compliance with the License. |
| 6 | +You may obtain a copy of the License at |
| 7 | +
|
| 8 | + http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | +
|
| 10 | +Unless required by applicable law or agreed to in writing, software |
| 11 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | +See the License for the specific language governing permissions and |
| 14 | +limitations under the License. |
| 15 | +*/ |
| 16 | + |
| 17 | +package helm |
| 18 | + |
| 19 | +import ( |
| 20 | + "fmt" |
| 21 | + |
| 22 | + "github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/latest" |
| 23 | +) |
| 24 | + |
| 25 | +// DependencyGraph represents a graph of helm release dependencies |
| 26 | +type DependencyGraph struct { |
| 27 | + graph map[string][]string |
| 28 | + releases []latest.HelmRelease |
| 29 | + hasDependencies bool |
| 30 | +} |
| 31 | + |
| 32 | +// NewDependencyGraph creates a new DependencyGraph from a list of helm releases |
| 33 | +func NewDependencyGraph(releases []latest.HelmRelease) (*DependencyGraph, error) { |
| 34 | + graph := make(map[string][]string) |
| 35 | + releaseNames := make(map[string]bool) |
| 36 | + |
| 37 | + for _, r := range releases { |
| 38 | + if _, exists := releaseNames[r.Name]; exists { |
| 39 | + return nil, fmt.Errorf("duplicate release name %s", r.Name) |
| 40 | + } |
| 41 | + releaseNames[r.Name] = true |
| 42 | + } |
| 43 | + |
| 44 | + // Check for non-existent dependencies |
| 45 | + hasDependencies := false |
| 46 | + for _, r := range releases { |
| 47 | + for _, dep := range r.DependsOn { |
| 48 | + if !releaseNames[dep] { |
| 49 | + return nil, fmt.Errorf("release %s depends on non-existent release %s", r.Name, dep) |
| 50 | + } |
| 51 | + hasDependencies = true |
| 52 | + } |
| 53 | + graph[r.Name] = r.DependsOn |
| 54 | + } |
| 55 | + |
| 56 | + g := &DependencyGraph{ |
| 57 | + graph: graph, |
| 58 | + releases: releases, |
| 59 | + hasDependencies: hasDependencies, |
| 60 | + } |
| 61 | + |
| 62 | + if err := g.hasCycles(); err != nil { |
| 63 | + return nil, err |
| 64 | + } |
| 65 | + |
| 66 | + return g, nil |
| 67 | +} |
| 68 | + |
| 69 | +// GetReleasesByLevel returns releases grouped by their dependency level while preserving |
| 70 | +// the original order within each level. Level 0 contains releases with no dependencies, |
| 71 | +// level 1 contains releases that depend only on level 0 releases, and so on. |
| 72 | +func (g *DependencyGraph) GetReleasesByLevel() (map[int][]string, error) { |
| 73 | + if len(g.releases) == 0 { |
| 74 | + // For empty releases, return empty map to avoid nil |
| 75 | + return map[int][]string{}, nil |
| 76 | + } |
| 77 | + |
| 78 | + if !g.hasDependencies { |
| 79 | + // Fast path: if no dependencies, all releases are at level 0 |
| 80 | + // Preserve original order from releases slice |
| 81 | + return map[int][]string{ |
| 82 | + 0: g.getNames(), |
| 83 | + }, nil |
| 84 | + } |
| 85 | + |
| 86 | + order, err := g.calculateDeploymentOrder() |
| 87 | + if err != nil { |
| 88 | + return nil, err |
| 89 | + } |
| 90 | + |
| 91 | + return g.groupReleasesByLevel(order), nil |
| 92 | +} |
| 93 | + |
| 94 | +// hasCycles checks if there are any cycles in the dependency graph |
| 95 | +func (g *DependencyGraph) hasCycles() error { |
| 96 | + if !g.hasDependencies { |
| 97 | + return nil |
| 98 | + } |
| 99 | + |
| 100 | + visited := make(map[string]bool) |
| 101 | + recStack := make(map[string]bool) |
| 102 | + |
| 103 | + var checkCycle func(node string) error |
| 104 | + checkCycle = func(node string) error { |
| 105 | + if !visited[node] { |
| 106 | + visited[node] = true |
| 107 | + recStack[node] = true |
| 108 | + |
| 109 | + for _, dep := range g.graph[node] { |
| 110 | + if !visited[dep] { |
| 111 | + if err := checkCycle(dep); err != nil { |
| 112 | + return err |
| 113 | + } |
| 114 | + } else if recStack[dep] { |
| 115 | + return fmt.Errorf("cycle detected involving release %q", node) |
| 116 | + } |
| 117 | + } |
| 118 | + } |
| 119 | + recStack[node] = false |
| 120 | + return nil |
| 121 | + } |
| 122 | + |
| 123 | + for node := range g.graph { |
| 124 | + if !visited[node] { |
| 125 | + if err := checkCycle(node); err != nil { |
| 126 | + return err |
| 127 | + } |
| 128 | + } |
| 129 | + } |
| 130 | + return nil |
| 131 | +} |
| 132 | + |
| 133 | +// getNames returns a slice of release names in their original order |
| 134 | +func (g *DependencyGraph) getNames() []string { |
| 135 | + names := make([]string, len(g.releases)) |
| 136 | + for i, release := range g.releases { |
| 137 | + names[i] = release.Name |
| 138 | + } |
| 139 | + return names |
| 140 | +} |
| 141 | + |
| 142 | +// calculateDeploymentOrder returns a topologically sorted list of releases, |
| 143 | +// ensuring that releases are deployed after their dependencies while maintaining |
| 144 | +// the original order where possible |
| 145 | +func (g *DependencyGraph) calculateDeploymentOrder() ([]string, error) { |
| 146 | + visited := make(map[string]bool) |
| 147 | + order := make([]string, 0, len(g.releases)) |
| 148 | + |
| 149 | + // Create a mapping of release name to its index in original order |
| 150 | + originalOrder := make(map[string]int, len(g.releases)) |
| 151 | + for i, release := range g.releases { |
| 152 | + originalOrder[release.Name] = i |
| 153 | + } |
| 154 | + |
| 155 | + var visit func(node string) error |
| 156 | + visit = func(node string) error { |
| 157 | + if visited[node] { |
| 158 | + return nil |
| 159 | + } |
| 160 | + visited[node] = true |
| 161 | + |
| 162 | + // Sort dependencies based on original order |
| 163 | + deps := make([]string, len(g.graph[node])) |
| 164 | + copy(deps, g.graph[node]) |
| 165 | + if len(deps) > 1 { |
| 166 | + // Sort dependencies by their original position |
| 167 | + for i := 0; i < len(deps)-1; i++ { |
| 168 | + for j := i + 1; j < len(deps); j++ { |
| 169 | + if originalOrder[deps[i]] > originalOrder[deps[j]] { |
| 170 | + deps[i], deps[j] = deps[j], deps[i] |
| 171 | + } |
| 172 | + } |
| 173 | + } |
| 174 | + } |
| 175 | + |
| 176 | + // Visit dependencies in original order |
| 177 | + for _, dep := range deps { |
| 178 | + if err := visit(dep); err != nil { |
| 179 | + return err |
| 180 | + } |
| 181 | + } |
| 182 | + order = append(order, node) |
| 183 | + return nil |
| 184 | + } |
| 185 | + |
| 186 | + // Process releases in their original order |
| 187 | + for _, release := range g.releases { |
| 188 | + if err := visit(release.Name); err != nil { |
| 189 | + return nil, err |
| 190 | + } |
| 191 | + } |
| 192 | + |
| 193 | + return order, nil |
| 194 | +} |
| 195 | + |
| 196 | +// groupReleasesByLevel groups releases by their dependency level while preserving |
| 197 | +// the original order within each level |
| 198 | +func (g *DependencyGraph) groupReleasesByLevel(order []string) map[int][]string { |
| 199 | + levels := make(map[int][]string) |
| 200 | + releaseLevels := make(map[string]int) |
| 201 | + |
| 202 | + // Calculate level for each release |
| 203 | + for _, release := range order { |
| 204 | + level := 0 |
| 205 | + for _, dep := range g.graph[release] { |
| 206 | + if depLevel, exists := releaseLevels[dep]; exists { |
| 207 | + if depLevel >= level { |
| 208 | + level = depLevel + 1 |
| 209 | + } |
| 210 | + } |
| 211 | + } |
| 212 | + releaseLevels[release] = level |
| 213 | + if levels[level] == nil { |
| 214 | + levels[level] = make([]string, 0) |
| 215 | + } |
| 216 | + levels[level] = append(levels[level], release) |
| 217 | + } |
| 218 | + |
| 219 | + return levels |
| 220 | +} |
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