I am new to Docker. I am trying to dockerize my Spring Boot application but getting the error
connection to localhost:5432 refused .
The Spring Boot application has a postgresql db connection and uses random port to run on Tomcat.
Please find the details below, requesting to please check and help in resolving the issue. Please give a detailed solution as I am new to Docker.
Dockerfile
FROM openjdk:8-jdk-alpine
ARG JAR_FILE=target/SpringConversionFactor-0.0.1-SNAPSHOT.jar
WORKDIR /opt/app
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","app.jar"]
Docker run
docker run springconversionfactor
Exception
Connection to localost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections
When you are running any application in docker it gets isolated from your existing environment.Here you are running spring boot application in docker and provided postgresql url as localhost:5432,because of that your spring boot application is finding postgres db inside your spring boot docker container.Please make sure where your postgres db is running.If it is running on your server give url as server_ip:5432 or if it is running in other conatiner then give it as container_name:5432 (here you can do port mapping with your server also).
Related
This question already has answers here:
From inside of a Docker container, how do I connect to the localhost of the machine?
(40 answers)
Closed 2 years ago.
I have a Spring app that connects to local Postgres db. It works fine.
I then created a Docker image from the Spring app. When running the container it throws a db connection error.
I have followed the solution suggested here, but still getting the same error.
[ERROR ] [task-1] c.z.h.p.HikariPool c.z.h.p.HikariPool.throwPoolInitializationException(HikariPool.java:593) – HikariPool-1 - Exception during pool initialization.
org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:285)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:217)
at org.postgresql.Driver.makeConnection(Driver.java:458)
at org.postgresql.Driver.connect(Driver.java:260)
I have run the docker image in several ways with the same result.
docker run app-image
docker run --network=host app-image
Dockerfile:
FROM java:8-jdk-alpine
COPY ./build/libs/runtime-0.0.1-SNAPSHOT.jar /usr/app/
WORKDIR /usr/app
ENTRYPOINT ["java", "-jar", "runtime-0.0.1-SNAPSHOT.jar"]
# Expose standard tomcat port
EXPOSE 9888
postgresql.conf:
#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*'
pg_hba.conf
# TYPE DATABASE USER ADDRESS METHOD
host postgres postgres 0.0.0.0/0 trust
host postgres postgres 172.17.0.0/16 trust
The spring application tries to connect to localhost:5432. Since the host and each container are separate network entities (i.e., the host and each container has its own network address in the docker-internal network), the container tries to connect to the database running on it. Since there is not database running, the connection cannot be established.
To fix this issue, you need to get the IP address of the host machine within the docker-internal network (see, e.g., this article at devilbox) and use this address as database server for the spring application.
I would recommend to run the postgres in a docker container aswell. You can, for example, use the official postgres image from dockerhub. Then you can reference the postgres-container from within the spring-container by the postgres-container's name.
I am deploying my boot-app's jar docker image to embedded tomcat server using jenkin and kubernetes. It is throwing an exception-
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up
App is being successfully deploy on my locale, for my local setup below are related properties-
spring.datasource.url=jdbc:mysql://localhost:3306/mydb?autoReconnect=true&useUnicode=true&CharSet=UTF-8&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=password
I just want to check on which url it is trying to connect, by which user & what password on server while deploying docker image.
Is there any way in spring boot to enable such logs while application is being deploy?
I tried with many of the available option below-
spring.datasource.abandon-when-percentage-full
spring.datasource.access-to-underlying-connection-allowed
spring.datasource.alternate-username-allowed
spring.datasource.auto-commit
spring.datasource.catalog
spring.datasource.commit-on-return
spring.datasource.connection-customizer
spring.datasource.connection-customizer-class-name
spring.datasource.connection-init-sql
spring.datasource.connection-init-sqls
spring.datasource.connection-properties
spring.datasource.connection-test-query
spring.datasource.connection-timeout
spring.datasource.data-source
spring.datasource.data-source-class-name
spring.datasource.data-source-j-n-d-i
spring.datasource.data-source-properties
spring.datasource.db-properties
spring.datasource.default-auto-commit
spring.datasource.default-catalog
spring.datasource.default-read-only
spring.datasource.default-transaction-isolation
spring.datasource.driver-class-loader
spring.datasource.fair-queue
spring.datasource.idle-timeout
spring.datasource.ignore-exception-on-pre-load
spring.datasource.init-s-q-l
spring.datasource.initialization-fail-fast
spring.datasource.isolate-internal-queries
spring.datasource.jdbc-interceptors
spring.datasource.jdbc-url
spring.datasource.jdbc4-connection-test
spring.datasource.leak-detection-threshold
spring.datasource.log-abandoned
spring.datasource.log-validation-errors
spring.datasource.log-writer
spring.datasource.login-timeout
spring.datasource.max-age
spring.datasource.max-lifetime
spring.datasource.max-open-prepared-statements
spring.datasource.maximum-pool-size
spring.datasource.metrics-tracker-class-name
spring.datasource.minimum-idle
spring.datasource.num-tests-per-eviction-run
spring.datasource.pool-name
spring.datasource.pool-prepared-statements
spring.datasource.pool-properties
spring.datasource.propagate-interrupt-state
spring.datasource.read-only
spring.datasource.record-metrics
spring.datasource.register-mbeans
spring.datasource.remove-abandoned
spring.datasource.remove-abandoned-timeout
spring.datasource.rollback-on-return
spring.datasource.suspect-timeout
spring.datasource.test-on-connect
spring.datasource.thread-factory
spring.datasource.transaction-isolation
spring.datasource.use-disposable-connection-facade
spring.datasource.use-equals
spring.datasource.use-lock
spring.datasource.validation-interval
spring.datasource.validation-query-timeout
spring.datasource.validator
spring.datasource.validator-class-name
spring.datasource.xa
spring.datasource.xa.data-source-class-name
spring.datasource.xa.properties
I have a problem with connecting to existing remote MSSQL database from inside of a docker container running in stack.
My application consists of three modules (backend, frontend and haproxy)
Backend module is written in Java (SpringBoot app) and it's also the one that needs to connect do remote MSSQL database (by remote I mean placed on different sever, separate of docker part).
I have the following docker compose file:
I start the stack by using following command:
docker stack deploy -c docker-compose.yml myapp
The result is, all containers are up and running, but spring app reports that connection to DB is timed out:
Server seems to be configured properly, I am able to access the host from container through telnet.
When running independently (even from docker container) backend app is able to connect to database with no problems, while stacked with docker-compose however it's unable to connect to the very same db.
I've also tried to provide db server IP instead of host name - no success.
Maybe setting up networks section in docker compose would do the trick?
UPDATE
Another thing you can do is to use host.docker.internal instead of the IP address of the database. This ONLY works on docker for windows or docker for mac.
Source: I want to connect from a container to a service on the host
OLD, only works when not in swarm mode
You need to specify that docker should use the same network as the host, you can do this in the following way:
version: '3'
services:
web-app:
build:
dockerfile: web-app/something
ports:
- 8080:8080
network_mode: "host"
Reference: Use host networking
It seems that the issue was caused by networks overlapping.
Adding network configured as show below, allowed either to connect to my remote database and keep my endpoints hidden:
networks:
backend:
ipam:
driver: default
config:
- subnet: 192.168.40.0/26
I’m new to docker and I’m trying to connect my spring boot app running into my boot-example docker container to a mysql server running into my mymysql docker container on port 6603, both running on the same phisical machine.
The fact is: if I connect my spring-boot app to my mymysql docker container in order to communicate with the database, I get no errors and everything works fine.
When I move my spring boot application into my boot-example container and try to communicate (through Hibernate) to my mymysql container, then I get this error:
2018-02-05 09:58:38.912 ERROR 1 --- [ main] o.a.tomcat.jdbc.pool.ConnectionPool : Unable to create initial connections of pool.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_111]
My spring boot application.properties are:
server.port=8083
spring.jpa.hibernate.ddl-auto=create-drop
spring.datasource.url=jdbc:mysql://localhost:6603/mydockerdb
spring.datasource.username=root
spring.datasource.password=mypassword
It works fine until my spring boot app runs in a docker container on port 8082, (after the docker image is correctly built):
docker run -it -p 8082:8083 boot-example
You cannot use localhost inside the container, it's the container itself. Hence, you will always get the connection refused error.
You can do below things -
Add your host machine IP in application.properties file of your spring boot application. (Not recommended since it breaks docker portability logic)
In case you want to use localhost, use --net=host while starting the container. (Not recommended for Production since no logical network layer exists)
Use --links for container communication with a DNS name. (deprecated/legacy)
Create a compose file & call your DB from spring boot app with the service name since they will be in same network & highly integrated with each other. (Recommended)
PS - Whenever you need to integrate multiple containers together, always go for docker-compose version 3+. Use docker run|build to understand the fundamentals & performing dry/test runs.
As #vivekyad4v suggested - the easiest way to achieve your desire, is to use docker-compose which has better container communication integration.
Docker-compose is a tool for managing single or multiple docker container/s. It uses single configuration file called docker-compose.yml.
For better information about docker-compose, please take a look at documentation and compose file reference
In my experience, it is good practice to follow SRP (single responsibility principle), thus - creating one container for your database and one for your application. Both of them are communicating using network you specify in your configuration.
Following example of docker-compose.yml might help you:
version: '2'
networks:
# your network name
somename:
driver: bridge
services:
# PHP server
php:
image: dalten/php5.6-apache
ports:
- 80:80
volumes:
- .application_path:/some/application/path
# your container network name defined at the beggining
networks:
- somename
# Mysql server for backend
mysql:
image: dalten/mysql:dev
ports:
- 3306:3306
# The /var/lib/mysql volume MUST be specified to achieve data persistence over container restart
volumes:
- ./mysql_data:/var/lib/mysql
environment:
MYSQL_ROOT_PASSWORD: root
MYSQL_DATABASE: backend
# your container network name defined at the beggining
networks:
- somename
Note: Communication between containers inside network can be achieved by calling the service name from inside container.
The connection parameters to MySQL container from PHP, would in this example be:
hostname: mysql
port: 3306
database: backend
user: root
password: root
As per above suggestion, Docker-compose is a way but if you don't want to go with compose/swarm mode.
Simply create your own network using docker network create myNet
Deploy your containers listening on a created network --network myNet
Change your spring.datasource.url to jdbc:mysql://mymysql:6603/mydockerdb
By using DNS resolution of docker demon, containers can discover each other and hence can communicate.
[DNS is not supported by default bridge. A user-defined network using bridge does.]
For more information: https://docs.docker.com/engine/userguide/networking/
I new using spring boot and docker and I faced a problem running the docker containers.
On debug mode, there is no problem on applications boot, but when I run them as a container, there is something wrong.
For example, I have my server config with all the yml files, also eureka properties.
The config server boot perfectly, but not the eureka server, it must look for it`s configuration to the config server becouse of these:
uri: ${vcap.services.config-service.credentials.uri:http://127.0.0.1:8888}
In the eureka`s log I can found:
Could not locate PropertySource: I/O error on GET request for
"http://127.0.0.1:8888/server-eureka/default":Connection refused;
nested exception is java.net.ConnectException: Connection refused
So I see that eureka cant connect to the config server for a reason I cant understund.
Maybe I miss something in my docker file.
If you are not using docker linked containers you'll have to use only the public ip addresses. Docker will assign every running container an own ip address which is per default not accessible. Only when you start to expose ports there will be an entry to iptables that is linking the hosts public ip address and given port to the internal used port and (dynamically assigned) ip address of the docker container. This is also why 127.0.0.1 does not work cause it would look into the containers local context but tgere the service is not running.