Tien Nguyen
Posted on October 8, 2023
Docker provides lightweight containers to run services in isolation from our infrastructure so we can deliver software quickly. In this tutorial, I will show you how to dockerize Spring Boot microservice and Postgres example using Docker Compose.
Related Posts:
- Spring Boot and PostgreSQL CRUD example
- Spring Boot R2DBC + PostgreSQL example
- Spring Boot, Spring Security, PostgreSQL: JWT Authentication example
- Documentation: Spring Boot Swagger 3 example
- Caching: Spring Boot Redis Cache example
Overview
Assume that we have a Spring Boot Application working with Postgres database.
The problem is to containerize a system that requires more than one Docker container:
- Spring Boot for Rest API
- Postgres for database
Docker Compose helps us setup the system more easily and efficiently than with only Docker. We're gonna following these steps:
- Create Spring Boot App working with Postgres database.
- Create Dockerfile for Spring Boot App.
- Write Docker Compose configurations in YAML file.
- Set Spring Boot Docker Compose Environment variables.
- Run the system.
Directory Structure:
Create Spring Boot App
You can read and get Github source code from one of following tutorials:
- Spring Boot and PostgreSQL CRUD example
- Spring Boot R2DBC + PostgreSQL example
- Spring Boot, Spring Security, PostgreSQL: JWT Authentication example
Using the code base above, we put the Spring Boot project in bezkoder-app folder without the need of resources/application.properties. It is because Environment variables will be exported to .env file.
Create Dockerfile for Spring Boot App
Dockerfile defines a list of commands that Docker uses for setting up the Spring Boot application environment. So we put the file in bezkoder-app folder.
Because we will use Docker Compose, we won't define all the configuration commands in this Dockerfile.
bezkoder-app/Dockerfile
# FROM maven:3.8.2-jdk-8 # for Java 8
FROM maven:3.8.5-openjdk-17
WORKDIR /bezkoder-app
COPY . .
RUN mvn clean install
CMD mvn spring-boot:run
Let me explain some points:
-
FROM: install the image of the Maven - JDK version. -
WORKDIR: path of the working directory. -
COPY: copy all the files inside the project directory to the container. -
RUN: execute a command-line inside the container:mvn clean installto install the dependencies in pom.xml. -
CMD: run scriptmvn spring-boot:runafter the image is built.
Write Docker Compose configurations
On the root of the project directory, we're gonna create the docker-compose.yml file. Follow version 3 syntax defined by Docker:
version: '3.8'
services:
postgresdb:
app:
volumes:
-
version: Docker Compose file format version will be used. -
services: individual services in isolated containers. Our application has two services:app(Spring Boot) andpostgresdb(PostgreSQL database). -
volumes: named volumes that keeps our data alive after restart.
Let's implement the details.
docker-compose.yml
version: "3.8"
services:
postgresdb:
image: postgres
restart: unless-stopped
env_file: ./.env
environment:
- POSTGRES_USER=$POSTGRESDB_USER
- POSTGRES_PASSWORD=$POSTGRESDB_ROOT_PASSWORD
- POSTGRES_DB=$POSTGRESDB_DATABASE
ports:
- $POSTGRESDB_LOCAL_PORT:$POSTGRESDB_DOCKER_PORT
volumes:
- db:/var/lib/postgres
app:
depends_on:
- postgresdb
build: ./bezkoder-app
restart: on-failure
env_file: ./.env
ports:
- $SPRING_LOCAL_PORT:$SPRING_DOCKER_PORT
environment:
SPRING_APPLICATION_JSON: '{
"spring.datasource.url" : "jdbc:postgresql://postgresdb:$POSTGRESDB_DOCKER_PORT/$POSTGRESDB_DATABASE",
"spring.datasource.username" : "$POSTGRESDB_USER",
"spring.datasource.password" : "$POSTGRESDB_ROOT_PASSWORD",
"spring.jpa.properties.hibernate.dialect" : "org.hibernate.dialect.PostgreSQLDialect",
"spring.jpa.hibernate.ddl-auto" : "update"
}'
volumes:
- .m2:/root/.m2
stdin_open: true
tty: true
volumes:
db:
-
postgresdb:
-
image: official Docker image -
restart: configure the restart policy -
env_file: specify our .env path that we will create later -
environment: provide setting using environment variables -
ports: specify ports will be used -
volumes: map volume folders
-
-
app:
-
depends_on: dependency order, postgresdb is started before app -
build: configuration options that are applied at build time that we defined in the Dockerfile with relative path -
environment: environmental variables that Spring Boot application uses -
stdin_openandtty: keep open the terminal after building container
-
You should note that the host port (LOCAL_PORT) and the container port (DOCKER_PORT) is different. Networked service-to-service communication uses the container port, and the outside uses the host port.
Docker Compose Environment variables
In the service configuration, we used environmental variables defined inside the .env file. Now we start writing it.
.env
POSTGRESDB_USER=postgres
POSTGRESDB_ROOT_PASSWORD=123456
POSTGRESDB_DATABASE=bezkoder_db
POSTGRESDB_LOCAL_PORT=5433
POSTGRESDB_DOCKER_PORT=5432
SPRING_LOCAL_PORT=6868
SPRING_DOCKER_PORT=8080
Run the Spring Boot microservice with Docker Compose
We can easily run the whole with only a single command:
docker compose up
Docker will pull the PostgreSQL and Maven images (if our machine does not have it before).
The services can be run on the background with command:
docker compose up -d
$ docker compose up -d
[+] Running 14/14
✔ postgresdb 13 layers [⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿] 0B/0B Pulled 30.0s
✔ a803e7c4b030 Pull complete
✔ 009c876521a0 Pull complete
✔ 9c412905cca2 Pull complete
✔ 6463d4bf467a Pull complete
✔ bd8b983728ed Pull complete
✔ febc167f3560 Pull complete
✔ d73c81c4ade3 Pull complete
✔ 34b3b0ac6e9e Pull complete
✔ 9bd86d074f4e Pull complete
✔ 406f63329750 Pull complete
✔ ec40772694b7 Pull complete
✔ 7d3dfa1637e9 Pull complete
✔ e217ca41159f Pull complete
[+] Building 2.9s (9/9) FINISHED
=> [app internal] load build definition from Dockerfile
=> => transferring dockerfile: 231B
=> [app internal] load .dockerignore
=> => transferring context: 2B
=> [app internal] load metadata for docker.io/library/maven:3.8.5-openjdk-17
=> [app 1/4] FROM docker.io/library/maven:3.8.5-openjdk-17@sha256:3a9c30b3af6278a8ae0007d3a3bf00fff80ec3ed7ae4eb9bfa1772853101549b
=> [app internal] load build context
=> => transferring context: 1.94kB
=> [app 2/4] WORKDIR /bezkoder-app
=> [app 3/4] COPY . .
=> [app 4/4] RUN mvn clean install
=> [app] exporting to image
=> => exporting layers
=> => writing image sha256:bb65745b652009fa4bf508b771c9abc5e90f257f9efde63251df8c0a74c672d7
=> => naming to docker.io/library/spring-boot-postgres-app
[+] Running 2/1
✔ Container spring-boot-postgres-postgresdb-1 Created
✔ Container spring-boot-postgres-app-1 Created
Attaching to spring-boot-postgres-app-1, spring-boot-postgres-postgresdb-1
...
spring-boot-postgres-postgresdb-1 | PostgreSQL init process complete; ready for start up.
spring-boot-postgres-postgresdb-1 |
spring-boot-postgres-postgresdb-1 |
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.102 UTC [1] LOG: starting PostgreSQL 16.0 (Debian 16.0-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.102 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.102 UTC [1] LOG: listening on IPv6 address "::", port 5432
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.105 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.109 UTC [64] LOG: database system was shut down at 2023-10-03 03:35:18 UTC
spring-boot-postgres-postgresdb-1 | 2023-10-03 03:35:18.113 UTC [1] LOG: database system is ready to accept connections
spring-boot-postgres-app-1 | [INFO] Scanning for projects...
spring-boot-postgres-app-1 | [INFO]
spring-boot-postgres-app-1 | [INFO] --------------< com.bezkoder:spring-boot-jpa-postgresql >---------------
spring-boot-postgres-app-1 | [INFO] Building spring-boot-jpa-postgresql 0.0.1-SNAPSHOT
spring-boot-postgres-app-1 | [INFO] --------------------------------[ jar ]---------------------------------
spring-boot-postgres-app-1 | [INFO]
spring-boot-postgres-app-1 | [INFO] >>> spring-boot-maven-plugin:3.1.0:run (default-cli) > test-compile @ spring-boot-jpa-postgresql >>>
...
spring-boot-postgres-app-1 | 2023-10-03T03:41:46.545Z INFO 59 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
spring-boot-postgres-app-1 | 2023-10-03T03:41:46.551Z INFO 59 --- [ main] s.j.p.SpringBootJpaPostgresqlApplication : Started SpringBootJpaPostgresqlApplication in 2.188 seconds (process running for 2.354)
Now you can check the current working containers:
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9c3d10422b09 spring-boot-postgres-app "/usr/local/bin/mvn-…" 2 minutes ago Up 2 minutes 0.0.0.0:6868->8080/tcp, :::6868->8080/tcp spring-boot-postgres-app-1
ed0b41f7f1c8 postgres "docker-entrypoint.s…" 2 minutes ago Up 2 minutes 0.0.0.0:5433->5432/tcp, :::5433->5432/tcp spring-boot-postgres-postgresdb-1
And Docker images:
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
spring-boot-postgres-app latest bb65745b6520 5 minutes ago 962MB
postgres latest 2d74f8a2591c 6 minutes ago 417MB
Send a HTTP request to the Spring Boot - Postgres system:
Check Postgres Database:
$ docker exec -ti spring-boot-postgres-postgresdb-1 /bin/bash
root@8869979fbd27:/# psql bezkoder_db postgres
psql (16.0 (Debian 16.0-1.pgdg120+1))
Type "help" for help.
bezkoder_db=# SELECT * FROM tutorials;
id | description | published | title
----+-------------------+-----------+--------------------------------------
1 | Tut#1 Description | f | bezkoder Docker Spring Boot Postgres
(1 row)
Stop the Application
Stopping all the running containers is also simple with a single command:
docker compose down
$ docker compose down
✔ Container spring-boot-postgres-app-1 Removed
✔ Container spring-boot-postgres-postgresdb-1 Removed
✔ Network spring-boot-postgres_default Removed
If you need to stop and remove all containers, networks, and all images used by any service in docker-compose.yml file, use the command:
docker compose down --rmi all
Conclusion
Today we've successfully created Docker Compose file for Spring Boot application and Postgres. Now we can connect Spring Boot to PostgreSQL with Docker on a very simple way: docker-compose.yml.
You can apply this way to one of following project:
- Spring Boot and PostgreSQL CRUD example
- Spring Boot R2DBC + PostgreSQL example
- Spring Boot, Spring Security, PostgreSQL: JWT Authentication example
If you want to deploy the system on AWS, please visit:
Deploy Spring Boot App on AWS – Elastic Beanstalk
Happy Learning! See you again.
Source Code
The source code for this tutorial can be found at Github.
Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)
Caching: Spring Boot Redis Cache example
Posted on October 8, 2023
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