From d0d5d97578d32a5a863b6c2789d4a492cfa2671d Mon Sep 17 00:00:00 2001
From: LUIS NOVO <lfnovo@gmail.com>
Date: Sun, 14 Dec 2025 11:39:59 -0300
Subject: [PATCH] fix: wait for API to be ready before starting frontend

Users reported "Unable to Connect to API Server" errors on startup
because the frontend started before the API finished initialization
(database migrations, etc.).

- Add wait-for-api.sh script that polls /health endpoint
- Update supervisord configs to use wait script instead of sleep 5
- Waits up to 5 minutes for API to be ready before starting frontend
- Applies to both single-container and multi-container deployments

Fixes #315
---
 Dockerfile              |  4 ++++
 Dockerfile.single       |  4 ++++
 scripts/wait-for-api.sh | 22 ++++++++++++++++++++++
 supervisord.conf        |  4 ++--
 supervisord.single.conf |  4 ++--
 5 files changed, 34 insertions(+), 4 deletions(-)
 create mode 100755 scripts/wait-for-api.sh

diff --git a/Dockerfile b/Dockerfile
index 2c6c724..c21540f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -76,6 +76,10 @@ EXPOSE 8502 5055
 
 RUN mkdir -p /app/data
 
+# Copy and make executable the wait-for-api script
+COPY scripts/wait-for-api.sh /app/scripts/wait-for-api.sh
+RUN chmod +x /app/scripts/wait-for-api.sh
+
 # Copy supervisord configuration
 COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
 
diff --git a/Dockerfile.single b/Dockerfile.single
index 47ce210..86f98b5 100644
--- a/Dockerfile.single
+++ b/Dockerfile.single
@@ -77,6 +77,10 @@ COPY --from=builder /app/frontend/public /app/frontend/public
 # Create directories for data persistence
 RUN mkdir -p /app/data /mydata
 
+# Copy and make executable the wait-for-api script
+COPY scripts/wait-for-api.sh /app/scripts/wait-for-api.sh
+RUN chmod +x /app/scripts/wait-for-api.sh
+
 # Expose ports for Frontend and API
 EXPOSE 8502 5055
 
diff --git a/scripts/wait-for-api.sh b/scripts/wait-for-api.sh
new file mode 100755
index 0000000..2848cd4
--- /dev/null
+++ b/scripts/wait-for-api.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+# Wait for the API to be healthy before starting the frontend
+# This prevents the "Unable to Connect to API Server" error during startup
+
+API_URL="${INTERNAL_API_URL:-http://localhost:5055}"
+MAX_RETRIES=60  # 60 retries * 5 seconds = 5 minutes max wait
+RETRY_INTERVAL=5
+
+echo "Waiting for API to be ready at ${API_URL}/health..."
+
+for i in $(seq 1 $MAX_RETRIES); do
+    if curl -s -f "${API_URL}/health" > /dev/null 2>&1; then
+        echo "API is ready! Starting frontend..."
+        exit 0
+    fi
+    echo "Attempt $i/$MAX_RETRIES: API not ready yet, waiting ${RETRY_INTERVAL}s..."
+    sleep $RETRY_INTERVAL
+done
+
+echo "ERROR: API did not become ready within $((MAX_RETRIES * RETRY_INTERVAL)) seconds"
+echo "Starting frontend anyway - users may see connection errors initially"
+exit 0  # Exit 0 so frontend still starts (better than nothing)
diff --git a/supervisord.conf b/supervisord.conf
index f98be12..ea4d1cf 100644
--- a/supervisord.conf
+++ b/supervisord.conf
@@ -26,7 +26,7 @@ autostart=true
 startsecs=3
 
 [program:frontend]
-command=bash -c "sleep 5 && npm run start"
+command=bash -c "/app/scripts/wait-for-api.sh && npm run start"
 directory=/app/frontend
 environment=NODE_ENV="production",PORT="8502"
 passenv=API_URL,NEXT_PUBLIC_API_URL,INTERNAL_API_URL
@@ -37,4 +37,4 @@ stderr_logfile_maxbytes=0
 autorestart=true
 priority=30
 autostart=true
-startsecs=5
+startsecs=10
diff --git a/supervisord.single.conf b/supervisord.single.conf
index afb9067..345d37b 100644
--- a/supervisord.single.conf
+++ b/supervisord.single.conf
@@ -38,7 +38,7 @@ autostart=true
 startsecs=3
 
 [program:frontend]
-command=bash -c "sleep 5 && npm run start"
+command=bash -c "/app/scripts/wait-for-api.sh && npm run start"
 directory=/app/frontend
 environment=NODE_ENV="production",PORT="8502"
 passenv=API_URL,NEXT_PUBLIC_API_URL,INTERNAL_API_URL
@@ -49,4 +49,4 @@ stderr_logfile_maxbytes=0
 autorestart=true
 priority=30
 autostart=true
-startsecs=5
\ No newline at end of file
+startsecs=10
\ No newline at end of file