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|
package cluster
import (
"encoding/json"
"os"
"path/filepath"
"strings"
"github.com/moby/sys/atomicwriter"
)
// convertKVStringsToMap converts ["key=value"] to {"key":"value"}
func convertKVStringsToMap(values []string) map[string]string {
result := make(map[string]string, len(values))
for _, value := range values {
k, v, _ := strings.Cut(value, "=")
result[k] = v
}
return result
}
func loadPersistentState(root string) (*nodeStartConfig, error) {
dt, err := os.ReadFile(filepath.Join(root, stateFile))
if err != nil {
return nil, err
}
// missing certificate means no actual state to restore from
if _, err := os.Stat(filepath.Join(root, "certificates/swarm-node.crt")); err != nil {
if os.IsNotExist(err) {
clearPersistentState(root)
}
return nil, err
}
var st nodeStartConfig
if err := json.Unmarshal(dt, &st); err != nil {
return nil, err
}
return &st, nil
}
func savePersistentState(root string, config nodeStartConfig) error {
dt, err := json.Marshal(config)
if err != nil {
return err
}
return atomicwriter.WriteFile(filepath.Join(root, stateFile), dt, 0o600)
}
func clearPersistentState(root string) error {
// todo: backup this data instead of removing?
// rather than delete the entire swarm directory, delete the contents in order to preserve the inode
// (for example, allowing it to be bind-mounted)
files, err := os.ReadDir(root)
if err != nil {
return err
}
for _, f := range files {
if err := os.RemoveAll(filepath.Join(root, f.Name())); err != nil {
return err
}
}
return nil
}
func removingManagerCausesLossOfQuorum(reachable, unreachable int) bool {
return reachable-2 <= unreachable
}
func isLastManager(reachable, unreachable int) bool {
return reachable == 1 && unreachable == 0
}
|
