add Cache.ExternalServer configuration

internal/app/run/runner.go

@@ -52,7 +52,9 @@ func NewRunner(cfg *config.Config, reg *config.Registration, cli client.Client)
 	for k, v := range cfg.Runner.Envs {
 		envs[k] = v
 	}
-	if cfg.Cache.Enabled == nil || *cfg.Cache.Enabled {
+	if cfg.Cache.ExternalServer != "" {
+		envs["ACTIONS_CACHE_URL"] = cfg.Cache.ExternalServer
+	} else if cfg.Cache.Enabled == nil || *cfg.Cache.Enabled {
 		cacheHandler, err := artifactcache.StartHandler(
 			cfg.Cache.Dir,
 			cfg.Cache.Host,

internal/pkg/config/config.example.yaml

@@ -45,6 +45,9 @@ cache:
   # The port of the cache server.
   # 0 means to use a random available port.
   port: 0
+  # The external cache server URL. If it's specified, act_runner will use this URL as the ACTIONS_CACHE_URL rather than start a server by itself.
+  # The URL should generally end with "/".
+  external_server: ""
 
 container:
   # Specifies the network to which the container will connect.

internal/pkg/config/config.go

@@ -34,10 +34,11 @@ type Runner struct {
 
 // Cache represents the configuration for caching.
 type Cache struct {
-	Enabled *bool  `yaml:"enabled"` // Enabled indicates whether caching is enabled. It is a pointer to distinguish between false and not set. If not set, it will be true.
-	Dir     string `yaml:"dir"`     // Dir specifies the directory path for caching.
-	Host    string `yaml:"host"`    // Host specifies the caching host.
-	Port    uint16 `yaml:"port"`    // Port specifies the caching port.
+	Enabled        *bool  `yaml:"enabled"`         // Enabled indicates whether caching is enabled. It is a pointer to distinguish between false and not set. If not set, it will be true.
+	Dir            string `yaml:"dir"`             // Dir specifies the directory path for caching.
+	Host           string `yaml:"host"`            // Host specifies the caching host.
+	Port           uint16 `yaml:"port"`            // Port specifies the caching port.
+	ExternalServer string `yaml:"external_server"` // ExternalServer specifies the URL of external cache server
 }
 
 // Container represents the configuration for the container.