fix: running HTTP status endpoint

Signed-off-by: Andrei Kvapil <[email protected]>

Author: kvaps

README.md

@@ -17,18 +17,17 @@ Set `etcd-await-election` as your command's entry point in the container or exec
 
 The relevant environment variables are:
 
-| Variable                          | Description |
+ Variable                          | Description |
 |-----------------------------------|-------------|
 | `ETCD_AWAIT_ELECTION_LOCK_NAME`   | Name of the lock within etcd used for the election process. |
 | `ETCD_AWAIT_ELECTION_IDENTITY`    | Unique identity for the instance competing for leadership. Typically set to the pod's name. |
-| `ETCD_AWAIT_ELECTION_STATUS_ENDPOINT` | Optional: HTTP endpoint to report leadership status. |
-| `ETCD_AWAIT_ELECTION_LEASE_DURATION` | Optional: Lease duration (seconds) before a leader must renew. Default: 15. |
-| `ETCD_AWAIT_ELECTION_RENEW_DEADLINE` | Optional: Time limit (seconds) for the leader to renew the lease. Default: 10. |
-| `ETCD_AWAIT_ELECTION_RETRY_PERIOD` | Optional: Time interval (seconds) to retry a failed election. Default: 2. |
+| `ETCD_AWAIT_ELECTION_STATUS_ENDPOINT` | HTTP endpoint to report leadership status, formatted as `host:port` (e.g., `127.0.0.1:1234`). Optional: If not set, no status will be reported. |
+| `ETCD_AWAIT_ELECTION_LEASE_DURATION` | Lease duration (seconds) before a leader must renew. Optional: Default is 15 seconds. |
+| `ETCD_AWAIT_ELECTION_RENEW_DEADLINE` | Time limit (seconds) for the leader to renew the lease. Optional: Default is 10 seconds. |
+| `ETCD_AWAIT_ELECTION_RETRY_PERIOD` | Time interval (seconds) to retry a failed election. Optional: Default is 2 seconds. |
 | `ETCD_AWAIT_ELECTION_ENDPOINTS` | Comma-separated list of etcd endpoints. |
 | `ETCD_AWAIT_ELECTION_CERT`, `ETCD_AWAIT_ELECTION_KEY`, `ETCD_AWAIT_ELECTION_CACERT` | TLS certificates for secure communication with etcd. |
-| `ETCD_AWAIT_ELECTION_FORCE_ACQUIRE` | Optional: Set to any non-empty value to forcefully acquire leadership by deleting existing locks. Only one instance should run with this option. |
-
+| `ETCD_AWAIT_ELECTION_FORCE_ACQUIRE` | Set to any non-empty value to forcefully acquire leadership by deleting existing locks. Optional: Use with caution as only one instance should run with this option. |
 
 ### Installation
 
@@ -45,6 +44,7 @@ ETCD_AWAIT_ELECTION_KEY=/etc/etcd/pki/etcdctl-etcd-client.key \
 ETCD_AWAIT_ELECTION_ENDPOINTS='https://127.0.0.1:2379' \
 ETCD_AWAIT_ELECTION_LOCK_NAME=test \
 ETCD_AWAIT_ELECTION_IDENTITY=$HOSTNAME \
+ETCD_AWAIT_ELECTION_STATUS_ENDPOINT=127.0.0.1:1234 \
 etcd-await-election sleep 100m
 ```
 

main.go

@@ -258,6 +258,9 @@ func (el *AwaitElection) Run() error {
 			return err
 		}
 
+		// Start the status endpoint to serve HTTP requests
+		el.startStatusEndpoint(ctx)
+
 		go el.keepLeaseAlive(ctx)
 
 		// Check current leader immediately
@@ -353,17 +356,20 @@ func (el *AwaitElection) monitorLeadership(ctx context.Context, cancel context.C
 
 func (el *AwaitElection) startStatusEndpoint(ctx context.Context) {
 	if el.StatusEndpoint == "" {
+		log.Printf("Status endpoint not configured")
 		return
 	}
 
 	serveMux := http.NewServeMux()
 	serveMux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
 		leaderResp, err := el.Election.Leader(ctx)
 		if err != nil || string(leaderResp.Kvs[0].Value) != el.LeaderIdentity {
-			http.Error(writer, "Not leader", http.StatusServiceUnavailable)
+			writer.Write([]byte("{\"status\": \"ok\", \"phase\": \"awaiting\"}\n"))
 			return
 		}
-		writer.Write([]byte("{\"status\": \"ok\"}"))
+		writer.Header().Set("Content-Type", "application/json")
+		writer.WriteHeader(http.StatusOK)
+		writer.Write([]byte("{\"status\": \"ok\", \"phase\": \"running\"}\n"))
 	})
 
 	statusServer := http.Server{
@@ -373,8 +379,12 @@ func (el *AwaitElection) startStatusEndpoint(ctx context.Context) {
 			return ctx
 		},
 	}
+
 	go func() {
-		_ = statusServer.ListenAndServe()
+		log.Printf("Starting status endpoint on %s", el.StatusEndpoint)
+		if err := statusServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Printf("Failed to start status server: %v", err)
+		}
 	}()
 }