Deploying Postgresql with Golang on Kubernetes - docker

Question

I'm dealing with Kubernetes. It is not possible to connect the server and the database. Tell me what I'm doing wrong and what else I need to do.
apiVersion: apps/v1
kind: Deployment
metadata:
name: testdb
spec:
replicas: 1
selector:
matchLabels:
tier: testdb
app: testapp
template:
metadata:
labels:
app: testdb
spec:
containers:
- name: testdb
image: pryby/testdbcon
env:
- name: POSTGRES_USER
value: postgres
- name: POSTGRES_PASSWORD
value: root
- name: POSTGRES_DB
value: postgres
ports:
- containerPort: 5432
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: server
spec:
replicas: 1
selector:
matchLabels:
app: server
template:
metadata:
labels:
app: server
spec:
containers:
- name: server
image: pryby/testdocker
env:
- name: LISTEN
value: 0.0.0.0:8080
- name: DB_HOST
value: testdb
- name: DB_PORT
value: "5432"
- name: DB_USER
value: postgres
- name: DB_DBNAME
value: postgres
- name: DB_PASSWORD
value: root
- name: DB_SSL
value: disable
ports:
- containerPort: 8080
What and where do I need to specify in order to get access to the database?
If possible, give an example for working with the database and api, I climbed everywhere where I can, I didn't find anything like that. Maybe I didn't search well.

Answer 1

Firstly, Here in your testDB deployment your selector's match labels and template's label need to be the same.
Secondly, You need to create a Service of Type ClusterIP.
Here is the example:
apiVersion: v1
kind: Service
metadata:
name: testdb
labels:
app: testdb
spec:
ports:
- port: 5432
name: web
clusterIP: None
selector:
app: testdb
The final yaml should look like this:
apiVersion: apps/v1
kind: Deployment
metadata:
name: testdb
spec:
replicas: 1
selector:
matchLabels:
# tier: testdb
app: testdb # <- *****changed here******
template:
metadata:
labels:
app: testdb
spec:
containers:
- name: testdb
image: pryby/testdbcon
env:
- name: POSTGRES_USER
value: postgres
- name: POSTGRES_PASSWORD
value: root
- name: POSTGRES_DB
value: postgres
ports:
- containerPort: 5432
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: server
spec:
replicas: 1
selector:
matchLabels:
app: server
template:
metadata:
labels:
app: server
spec:
containers:
- name: server
image: pryby/testdocker
env:
- name: LISTEN
value: 0.0.0.0:8080
- name: DB_HOST
value: testdb
- name: DB_PORT
value: "5432"
- name: DB_USER
value: postgres
- name: DB_DBNAME
value: postgres
- name: DB_PASSWORD
value: root
- name: DB_SSL
value: disable
ports:
- containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
name: testdb
labels:
app: testdb
spec:
ports:
- port: 5432
name: web
clusterIP: None
selector:
app: testdb

Answer 2

expose your testdb deployment with a service of type ClusterIP and port 5432.
either craft the yaml yourself, or run kubectl expose deployment testdb --port 5432 --targetPort 5432 --name testdb
you can also use the following command to generate the yaml definition file:
kubectl expose deployment testdb --port 5432 --targetPort 5432 --name testdb -dry-run=client -o yaml > service-definition.yaml