wait database is ready by simple code way

api/src/createFirstConnection.ts

@@ -0,0 +1,31 @@
+import { Connection } from 'typeorm/connection/Connection'
+import { createConnection } from 'typeorm'
+
+async function createFirstConnection(): Promise<{
+  connection: Connection | null
+  exception?: Error
+}> {
+  let i = 20
+  let lastException = null
+  while (i > 0) {
+    try {
+      return { connection: await createConnection() }
+    } catch (ex) {
+      lastException = ex
+      i--
+    }
+    await sleep(5000)
+  }
+  return {
+    connection: null,
+    exception: lastException,
+  }
+}
+
+function sleep(ms: number) {
+  return new Promise(resolve => {
+    setTimeout(resolve, ms)
+  })
+}
+
+export { createFirstConnection }

api/src/index.ts

@@ -1,10 +1,9 @@
 import { ApolloServer, makeExecutableSchema } from 'apollo-server'
-
 import 'reflect-metadata'
-import { createConnection } from 'typeorm'
 import schemaDefs from './schema/index'
 import resolvers from './resolvers'
 import { Context } from './context'
+import { createFirstConnection } from './createFirstConnection'
 
 const startServer = async () => {
   const resolversAny: any = resolvers
@@ -13,16 +12,16 @@ const startServer = async () => {
     resolvers: resolversAny,
   })
 
-  try {
-    const connection = await createConnection()
+  const result = await createFirstConnection()
+  if (result.connection) {
     const server = new ApolloServer({
       schema,
-      context: new Context(connection),
+      context: new Context(result.connection),
     })
 
     server.listen({ port: 4000 }, () => console.log(`🚀 Server ready at http://localhost:4000`))
-  } catch (ex) {
-    console.log(`Can't connect to database`, ex)
+  } else {
+    console.log(`Can't connect to database`, result.exception)
   }
 }
 

docker-compose.yml

@@ -4,8 +4,6 @@ services:
     build: './web'
     links:
       - api
-    depends_on:
-      - api
     ports:
       - "3000:3000"
     env_file:
@@ -16,8 +14,6 @@ services:
     build: './api'
     links:
       - db
-    depends_on:
-      - db
     ports:
       - "4000:4000"
     volumes: