This demo is part of OTC RDS Operator and deploy on a Kubernetes cluster and will use the following feature:
- Webapplication with UI
- MySQL backend (RDS OTC)
- Storage (requires default StorageClass in cluster)
Ensure existing OTC VPC,Subnet, and SecurityGroup in demoapp-rds.yaml
and deploy manifest:
kubectl apply -f demoapp-rds.yamldeploy manifest:
kubectl apply -f demoapp.yamlIf the cluster supports Ingress, adjust demoapp-ingress.yaml (e.g. hostname)
and deploy manifest:
kubectl apply -f demoapp-ingress.yamlOn Ingress endpoint in your browser should appear Golang Mysql Curd Example
Go:
import (
// ...
"k8s.io/client-go/rest"
rdsv1alpha1clientset "github.com/eumel8/otc-rds-operator/pkg/rds/v1alpha1/apis/clientset/versioned"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)Import Kubernetes Go Rest Client, OTC RDS API clientset, and Kubernetes API Metadata
// ...
for {
log.Println("LOOP: get rds " + rdsname)
rds, err := rdsclientset.McspsV1alpha1().Rdss(namespace).Get(context.TODO(), rdsname, metav1.GetOptions{})
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("KRDS: " + err.Error())
return nil, err
}
if rds.Status.Status == "ACTIVE" {
log.Println("DB ACTIVE")
for _, i := range *rds.Spec.Users {
dbUser = i.Name
dbPass = i.Password
break
}
dbDriver := "mysql"
dbHost := rds.Status.Ip
dbPort := rds.Spec.Port
dbName := rds.Spec.Databases[0]
log.Println("DB CONNECT " + dbHost)
db, err = sql.Open(dbDriver, dbUser+":"+dbPass+"@tcp("+dbHost+":"+dbPort+")/"+dbName)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("DBCONN: " + err.Error())
return nil, err
}
}
// ...
time.Sleep(5 * time.Second)
}After in-cluster authentication on K8S API, create rdsclientset, search for specific API and fetch, ip-address of RDS instance, username/password of app user and try to connect
func Index(w http.ResponseWriter, r *http.Request) {
db, err := dbConn(w)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("DB: " + err.Error())
return
}
selDB, err := db.Query("SELECT * FROM employee ORDER BY id DESC")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("INDEX: " + err.Error())
return
}
emp := Employee{}
res := []Employee{}
for selDB.Next() {
var id int
var name, city, photo string
err = selDB.Scan(&id, &name, &city, &photo)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("INDEX 2: " + err.Error())
return
}
emp.Id = id
emp.Name = name
emp.City = city
if photo != "none" {
f, err := os.Open(dataDir + "/" + photo)
if err != nil {
// http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("INDEX : photoload " + err.Error())
// return
} else {
img, _, err := image.Decode(f)
sane := resize.Resize(100, 100, img, resize.Bilinear)
var buff bytes.Buffer
png.Encode(&buff, sane)
encodedString := base64.StdEncoding.EncodeToString(buff.Bytes())
emp.Photo = encodedString
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Println("INDEX : photodecode" + err.Error())
return
}
}
defer f.Close()
} else {
emp.Photo = "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"
}
res = append(res, emp)
}
tmpl.ExecuteTemplate(w, "Index", res)
defer db.Close()Using Go text/template package to provide HTML views for the web app. Form data are stored in MySQL database. The user can upload a file, which is stored on specific data dir.
func main() {
log.Println("Server started on: :8080")
http.HandleFunc("/", Index)
http.HandleFunc("/show", Show)
http.HandleFunc("/new", New)
http.HandleFunc("/edit", Edit)
http.HandleFunc("/insert", Insert)
http.HandleFunc("/update", Update)
http.HandleFunc("/delete", Delete)
http.ListenAndServe(":8080", nil)
}Routing of http handler to different function. Service web app on port :8080
---
apiVersion: apps/v1
kind: StatefulSet
spec:
template:
spec:
containers:
- image: ghcr.io/eumel8/demoapp:1.0.0
name: demoapp
ports:
- containerPort: 8080
env:
- name: MYSQL_NAME
valueFrom:
fieldRef:
fieldPath: spec.serviceAccountName
- name: MYSQL_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: DATA_DIR
value: "/data" # external pvc
volumeMounts:
- mountPath: /data
name: demoapp-volume
serviceAccountName: demoapp
volumes:
- name: demoapp-volume
persistentVolumeClaim:
claimName: demoapp-volumeUse K8S metadata for MYSQL_NAME and MYSQL_NAMESPACE,
Attach external PVC to the web app container, and expose containerPort 8080
FROM mtr.devops.telekom.de/mcsps/golang:1.18 as builder
WORKDIR /app
ADD . /app
RUN go mod download && go mod tidy && go build -o main main.go
FROM gcr.io/distroless/base
LABEL org.opencontainers.image.authors="f.kloeker@telekom.de"
LABEL version="1.0.0"
LABEL description="Create DemoApp for OTC RDS Operator"
WORKDIR /
USER nonroot:nonroot
COPY --from=builder --chown=nonroot:nonroot /app/main /
COPY --from=builder --chown=nonroot:nonroot /app/kodata /var/run/ko
ENV KO_DATA_PATH=/var/run/ko
EXPOSE 8080
ENTRYPOINT ["/main"]
A Dockerfile to compile to Go binary and copy the result in a distroless images
name: Build
# https://github.com/marketplace/actions/cosign-installer
on:
push:
branches:
- "**"
pull_request:
branches: [ master ]
release:
types: [created]
env:
IMAGE_NAME: oro-demoapp/demoapp
jobs:
build:
runs-on: ubuntu-latest
steps:
- name: Setup Go
uses: actions/setup-go@v2
with:
go-version: 1.18
- name: Checkout Repo
uses: actions/checkout@v2
- name: Setup ko
uses: imjasonh/setup-ko@v0.6
- name: Install Cosign
uses: sigstore/cosign-installer@main
- name: Log in to ghcr registry
run: |
echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
echo "${{ secrets.GITHUB_TOKEN }}" | ko login ghcr.io -u ${{ github.actor }} --password-stdin
- name: Build the image with ko
run: |
ko build -t ko --sbom none --bare
env:
KO_DOCKER_REPO: ghcr.io/${{ github.repository_owner }}/oro-demoapp/demoapp
- name: Build the image with docker
run: docker build . --file Dockerfile --tag $IMAGE_NAME --label "runnumber=${GITHUB_RUN_ID}"
- name: Push & Sign image
run: |
IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
# Change all uppercase to lowercase
IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
# Strip git ref prefix from version
VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
# Strip "v" prefix from tag name
[[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
# Use Docker `latest` tag convention
[ "$VERSION" == "master" ] && VERSION=latest
echo IMAGE_ID=$IMAGE_ID
echo VERSION=$VERSION
echo "{{ github.ref.type }}"
docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
docker push $IMAGE_ID:$VERSION
cosign sign --key env://COSIGN_KEY $IMAGE_ID:$VERSION
cosign sign --key env://COSIGN_KEY ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME:ko
env:
COSIGN_KEY: ${{secrets.COSIGN_KEY}}
COSIGN_PASSWORD: ${{secrets.COSIGN_PASSWORD}}
- name: Push & Sign image release
if: github.ref.type == 'tag'
run: |
IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
VERSION=${GITHUB_REF_NAME}
docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
docker push $IMAGE_ID:$VERSION
cosign sign --key env://COSIGN_KEY $IMAGE_ID:$VERSION
env:
COSIGN_KEY: ${{secrets.COSIGN_KEY}}
COSIGN_PASSWORD: ${{secrets.COSIGN_PASSWORD}}Github Action build the image with docker and with ko which don't need a Dockerfile definition. Both images are signed with cosign to verify with the pubkey
Using the Github Registry
Frank Kloeker f.kloeker@telekom.de
Life is for sharing. If you have an issue with the code or want to improve it, feel free to open an issue or an pull request.
Go Crud Example is adapted from www.golangprograms.com