Suyash - #72
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proper readme with pics
WalkthroughThe project was updated to shift from a local Docker Compose-based Flask and MySQL setup to a Kubernetes-based deployment using KIND on AWS EC2. The Jenkins pipeline was restructured for simplicity, and comprehensive Kubernetes manifests, scripts, and documentation were added for multi-node cluster deployment, persistent storage, and service exposure. The HTML template heading was also updated. Changes
Sequence Diagram(s)sequenceDiagram
participant User
participant Jenkins
participant DockerHub
participant KIND Cluster
participant FlaskApp Pod
participant MySQL Pod
User->>Jenkins: Push code / Trigger pipeline
Jenkins->>Jenkins: Checkout code (git)
Jenkins->>Jenkins: Build Docker image
Jenkins->>Jenkins: Run tests (echo placeholder)
Jenkins->>DockerHub: Login, Tag, Push image
Jenkins->>KIND Cluster: Deploy via docker-compose (previously), now via kubectl apply
KIND Cluster->>FlaskApp Pod: Start Flask app container
KIND Cluster->>MySQL Pod: Start MySQL container with persistent volume
FlaskApp Pod->>MySQL Pod: Connect via service for DB operations
Poem
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Actionable comments posted: 10
🧹 Nitpick comments (11)
templates/index.html (1)
134-134: Remove trailing whitespace & consider proper casing in heading textThe
<h1>element currently contains a trailing space and the app name is lowercase (suyash). Removing the space prevents accidental layout glitches, and capitalising the name improves presentation consistency.- <h1>Flask + MySQL App suyash </h1> + <h1>Flask + MySQL App Suyash</h1>kub/mysql-svc.yml (1)
4-10: Add portnamefor clarity & enable future headless optionWhile optional, naming ports helps clients & tooling.
ports: - - port: 3306 + - name: mysql + port: 3306 targetPort: 3306If you ever need a headless service (
clusterIP: None) for stateful sets, adding it early avoids churn.kub/two-tier-deployment.yml (1)
17-31: Add basic pod security & health probes.The container runs as root and has no liveness/readiness probes or resource limits.
AddsecurityContext.runAsNonRoot: true, probes on/healthz(or/) and setresources.kub/mysql-deployment.yml (2)
19-20: Pin the MySQL image tag.
latestis mutable and can introduce breaking changes. Pin to a major/minor version (e.g.mysql:8.0.37) and update deliberately.
17-33: Harden the MySQL pod.Add
securityContext(runAsUser,fsGroup,allowPrivilegeEscalation: false) and resource limits.
This also satisfies the Checkov CKV_K8S_20 / CKV_K8S_23 warnings.kub/scripts.sh (1)
16-18: Inform users they must re-login for docker group membership to take effect.After
usermod -aG docker, a new shell session is required; mention this or prompt a logout.Jenkinsfile (1)
38-41:docker-compose upstage ignores the freshly pushed image.Without
docker pulland without specifying a compose file that referencestwo-tier-app:latest, the deployment won’t use the new image.
Consider replacing this with akubectl apply -f kub/stage to align with the new K8s manifests.README.md (4)
54-63: Add a language identifier to the fenced diagram block
markdownlintflags this block because it lacks a language tag.
Even if it’s an ASCII diagram, add a dummy identifier (textormermaid) to silence MD040 and unlock syntax-highlight helpers in some editors.-``` +```text
109-110: Trim the trailing colon in the headingHeading text ending with a colon violates MD026 and looks odd in rendered markdown.
-## Applied using: +## Applied using
136-143: Render thevolumeMountssnippet as YAML instead of bullet pointsThe current bullet indentation (MD007) is malformed and drops the second list item completely.
Wrap the excerpt in a fencedyamlblock for clarity:-volumeMounts: - - name: mysql-persistent-storage - - - mountPath: /var/lib/mysql +```yaml +volumeMounts: + - name: mysql-persistent-storage + mountPath: /var/lib/mysql +```
163-163: Wrap the bare URL to satisfy MD034-## Then visit: http://localhost:5000 +## Then visit: <http://localhost:5000>
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📒 Files selected for processing (11)
Jenkinsfile(1 hunks)README.md(1 hunks)kub/cluster.yml(1 hunks)kub/mysql-deployment.yml(1 hunks)kub/mysql-pv.yml(1 hunks)kub/mysql-pvc.yml(1 hunks)kub/mysql-svc.yml(1 hunks)kub/scripts.sh(1 hunks)kub/two-tier-deployment.yml(1 hunks)kub/two-tier-svc.yml(1 hunks)templates/index.html(1 hunks)
🧰 Additional context used
🪛 Checkov (3.2.334)
kub/mysql-deployment.yml
[MEDIUM] 1-37: Containers should not run with allowPrivilegeEscalation
(CKV_K8S_20)
[MEDIUM] 1-37: Minimize the admission of root containers
(CKV_K8S_23)
kub/two-tier-deployment.yml
[MEDIUM] 1-31: Containers should not run with allowPrivilegeEscalation
(CKV_K8S_20)
[MEDIUM] 1-31: Minimize the admission of root containers
(CKV_K8S_23)
🪛 markdownlint-cli2 (0.17.2)
README.md
54-54: Fenced code blocks should have a language specified
(MD040, fenced-code-language)
109-109: Trailing punctuation in heading
Punctuation: ':'
(MD026, no-trailing-punctuation)
139-139: Unordered list indentation
Expected: 0; Actual: 2
(MD007, ul-indent)
141-141: Unordered list indentation
Expected: 0; Actual: 2
(MD007, ul-indent)
163-163: Bare URL used
(MD034, no-bare-urls)
🔇 Additional comments (2)
kub/mysql-pvc.yml (1)
5-10: PVC may fail to bind withoutstorageClassName; verify capacity is sufficient
- KIND clusters usually rely on the default
standardStorageClass (dynamic) or on a matching host-pathPersistentVolume.
• If you created a static PV (mysql-pv) make sure itsstorageClassName(or the absence of it) matches this claim – otherwise the PVC will stay in Pending.256Miis extremely small for MySQL once binary logs & ibdata grow. A minimum of1Giis typical even for demos.spec: accessModes: - ReadWriteOnce + storageClassName: standard # or match the PV’s class / leave out on hostPath PV resources: requests: - storage: 256Mi + storage: 1Gikub/two-tier-svc.yml (1)
6-12: Confirm selector label & exposure strategy
- Make sure the deployment pods carry
app: two-tier-app; a mismatch leaves the Service without endpoints.ClusterIPis perfect for in-cluster access, but if you intend to reach the app from your host you’ll still needkubectl port-forwardor change toNodePort / LoadBalancer.No code change needed if this matches your intent.
| image: kindest/node:v1.33.1 | ||
| - role: worker | ||
| image: kindest/node:v1.33.1 | ||
| - role: worker | ||
| image: kindest/node:v1.33.1 |
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Kind node image v1.33.1 does not exist – cluster creation will fail
The latest released Kind images track upstream Kubernetes; at the time of writing the highest tag is kindest/node:v1.30.x. Using an unavailable tag aborts kind create cluster.
- image: kindest/node:v1.33.1
+ image: kindest/node:v1.30.0Apply the same change to all nodes (lines 5, 7, 9).
After updating, run kind create cluster --config kub/cluster.yml to confirm.
🤖 Prompt for AI Agents
In kub/cluster.yml at lines 5, 7, and 9, the node image tag is set to
kindest/node:v1.33.1, which does not exist and will cause cluster creation to
fail. Update all these image tags to the latest available version, such as
kindest/node:v1.30.x. After making these changes, run kind create cluster
--config kub/cluster.yml to verify the cluster is created successfully.
| hostPath: | ||
| path: /home/ubuntu/two-tier-flask-app/mysqldata #This is your host path where your data will be stored. Make sure to create mysqldata directory in mentioned path |
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🛠️ Refactor suggestion
Avoid hard-coding a hostPath; use a StorageClass or Local PV instead.
hostPath ties the volume to a single node, breaks pod rescheduling, and is unsafe on managed clusters.
If you only need local storage on KIND use local + nodeAffinity; otherwise provision via a StorageClass.
- hostPath:
- path: /home/ubuntu/two-tier-flask-app/mysqldata
+ storageClassName: standard # or a dedicated RWX/RWO StorageClass
+
+# If you really need a node-local mount for KIND:
+# local:
+# path: /var/lib/kind/mysql
+# nodeAffinity:
+# required:
+# nodeSelectorTerms:
+# - matchExpressions:
+# - key: kubernetes.io/hostname
+# operator: In
+# values:
+# - <kind-worker-node-name>Committable suggestion skipped: line range outside the PR's diff.
🤖 Prompt for AI Agents
In kub/mysql-pv.yml at lines 12 to 13, avoid using a hard-coded hostPath as it
restricts pod rescheduling and is unsafe for managed clusters. Replace the
hostPath volume with a PersistentVolume that uses a StorageClass or a Local
PersistentVolume with nodeAffinity to ensure proper scheduling and safer storage
management. Update the YAML to define a StorageClass or configure a local PV
with appropriate node affinity instead of directly referencing the hostPath.
| env: | ||
| - name: MYSQL_HOST | ||
| value: "10.96.163.109" # Replace with your MySQL Service ClusterIP | ||
| - name: MYSQL_PASSWORD | ||
| value: "admin" | ||
| - name: MYSQL_USER | ||
| value: "root" | ||
| - name: MYSQL_DB | ||
| value: "mydb" |
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🛠️ Refactor suggestion
Do not embed credentials in plain-text env vars; use Secrets.
Move MYSQL_USER, MYSQL_PASSWORD, and MYSQL_DB to a Secret and reference it with envFrom or individual valueFrom.
🤖 Prompt for AI Agents
In kub/two-tier-deployment.yml around lines 22 to 30, the environment variables
MYSQL_USER, MYSQL_PASSWORD, and MYSQL_DB are currently set with plain-text
values, which is insecure. Create a Kubernetes Secret containing these
credentials and update the deployment to reference this Secret using envFrom or
individual valueFrom fields instead of hardcoding the values directly in the env
section.
| env: | ||
| - name: MYSQL_HOST | ||
| value: "10.96.163.109" # Replace with your MySQL Service ClusterIP | ||
| - name: MYSQL_PASSWORD | ||
| value: "admin" |
There was a problem hiding this comment.
Hard-coding a ClusterIP will break on every new deploy.
Inside the cluster prefer DNS (mysql or mysql-svc.default.svc.cluster.local).
A static IP will change when the Service is recreated.
- - name: MYSQL_HOST
- value: "10.96.163.109" # Replace with your MySQL Service ClusterIP
+ - name: MYSQL_HOST
+ value: "mysql" # Kubernetes service DNS🤖 Prompt for AI Agents
In kub/two-tier-deployment.yml around lines 22 to 26, the MYSQL_HOST environment
variable is hard-coded with a ClusterIP, which will break on redeployments
because the IP can change. Replace the hard-coded IP with the MySQL service DNS
name, such as "mysql" or "mysql-svc.default.svc.cluster.local", to ensure stable
connectivity within the cluster.
| env: | ||
| - name: MYSQL_ROOT_PASSWORD | ||
| value: "admin" | ||
| - name: MYSQL_DATABASE | ||
| value: "mydb" | ||
| - name: MYSQL_USER | ||
| value: "admin" | ||
| - name: MYSQL_PASSWORD | ||
| value: "admin" |
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🛠️ Refactor suggestion
Credentials should be mounted from a Secret, not hard-coded.
Storing DB passwords in the manifest is a security risk and leaks to anyone with read access to the repo/cluster.
🤖 Prompt for AI Agents
In kub/mysql-deployment.yml around lines 20 to 28, the MySQL credentials are
hard-coded as environment variables, which is a security risk. Replace these
hard-coded values by creating a Kubernetes Secret containing the credentials,
then reference this Secret in the env section using valueFrom with secretKeyRef
for each variable. This ensures credentials are securely managed and not exposed
in the manifest.
| if ! command -v kubectl &>/dev/null; then | ||
| echo "📦 Installing kubectl (latest stable version)..." | ||
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| curl -LO "https://dl.k8s.io/release/$(curl -Ls https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl" | ||
| sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl | ||
| rm -f kubectl | ||
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| echo "✅ kubectl installed successfully." | ||
| else | ||
| echo "✅ kubectl is already installed." | ||
| fi |
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kubectl download ignores architecture – breaks on ARM.
You already detect ARCH for Kind; reuse it here to fetch the correct kubectl binary.
-if ! command -v kubectl &>/dev/null; then
+if ! command -v kubectl &>/dev/null; then
@@
- curl -LO "https://dl.k8s.io/release/$(curl -Ls https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
+ ARCH=$(uname -m)
+ if [ "$ARCH" = "x86_64" ]; then
+ PLATFORM="amd64"
+ elif [ "$ARCH" = "aarch64" ]; then
+ PLATFORM="arm64"
+ else
+ echo "❌ Unsupported architecture: $ARCH"
+ exit 1
+ fi
+ curl -LO "https://dl.k8s.io/release/$(curl -Ls https://dl.k8s.io/release/stable.txt)/bin/linux/${PLATFORM}/kubectl"🤖 Prompt for AI Agents
In kub/scripts.sh around lines 50 to 60, the kubectl download URL does not
consider the system architecture, causing failures on ARM systems. Modify the
script to reuse the existing ARCH variable to dynamically construct the download
URL for the correct kubectl binary matching the system architecture. This
ensures the script fetches the appropriate binary for the current platform.
| git url: "https://github.com/suyash700/two-tier-flask-app.git", branch: "master" | ||
| } |
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Pipeline clones a different repository – likely a copy-paste mistake.
git url: "https://github.com/suyash700/two-tier-flask-app.git" will fetch a fork, not the main repo being built by CI. Confirm intent.
🤖 Prompt for AI Agents
In Jenkinsfile around lines 7 to 8, the git URL points to
"https://github.com/suyash700/two-tier-flask-app.git", which appears to be a
fork and not the main repository intended for the CI pipeline. Verify the
correct repository URL for the main project and update the git url field to
point to that repository to ensure the pipeline clones the correct source code.
| stage("PUSH TO DOCKERHUB") { | ||
| steps { | ||
| withCredentials([usernamePassword( | ||
| credentialsId: "dockerhubId", | ||
| usernameVariable: "dockerhubuser", | ||
| passwordVariable: "dockerHubpass" | ||
| )]) { | ||
| sh "docker login -u ${env.dockerhubuser} -p ${env.dockerHubpass}" | ||
| sh "docker image tag my-flask-app:latest ${env.dockerhubuser}/two-tier-app:latest" | ||
| sh "docker push ${env.dockerhubuser}/two-tier-app:latest" | ||
| } |
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🛠️ Refactor suggestion
Environment variable usage in docker login is incorrect.
withCredentials exposes vars directly ($dockerhubuser, $dockerHubpass).
${env.dockerhubuser} resolves to an empty string.
- sh "docker login -u ${env.dockerhubuser} -p ${env.dockerHubpass}"
- sh "docker image tag my-flask-app:latest ${env.dockerhubuser}/two-tier-app:latest"
- sh "docker push ${env.dockerhubuser}/two-tier-app:latest"
+ sh "docker login -u $dockerhubuser -p $dockerHubpass"
+ sh "docker image tag my-flask-app:latest $dockerhubuser/two-tier-app:latest"
+ sh "docker push $dockerhubuser/two-tier-app:latest"📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| stage("PUSH TO DOCKERHUB") { | |
| steps { | |
| withCredentials([usernamePassword( | |
| credentialsId: "dockerhubId", | |
| usernameVariable: "dockerhubuser", | |
| passwordVariable: "dockerHubpass" | |
| )]) { | |
| sh "docker login -u ${env.dockerhubuser} -p ${env.dockerHubpass}" | |
| sh "docker image tag my-flask-app:latest ${env.dockerhubuser}/two-tier-app:latest" | |
| sh "docker push ${env.dockerhubuser}/two-tier-app:latest" | |
| } | |
| stage("PUSH TO DOCKERHUB") { | |
| steps { | |
| withCredentials([usernamePassword( | |
| credentialsId: "dockerhubId", | |
| usernameVariable: "dockerhubuser", | |
| passwordVariable: "dockerHubpass" | |
| )]) { | |
| sh "docker login -u $dockerhubuser -p $dockerHubpass" | |
| sh "docker image tag my-flask-app:latest $dockerhubuser/two-tier-app:latest" | |
| sh "docker push $dockerhubuser/two-tier-app:latest" | |
| } |
🤖 Prompt for AI Agents
In Jenkinsfile lines 24 to 34, the docker login command incorrectly uses
environment variables via ${env.dockerhubuser} and ${env.dockerHubpass}, which
are empty. Instead, use the variables directly as $dockerhubuser and
$dockerHubpass without the env prefix in the shell commands inside
withCredentials to correctly access the credentials.
| kubectl apply -f two-tier-deployment.yaml | ||
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| kubectl apply -f two-tier-svc.yaml | ||
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| kubectl apply -f mysql-svc.yaml | ||
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🛠️ Refactor suggestion
Fix manifest names & stray double-space in the apply sequence
two-tier-deployment.yaml/two-tier-svc.yamlshould match the earlier rename suggestion (flask-deployment.yamlvstwo-tier-deployment.yaml).- Extra space before
mysql-svc.yamlbreaks neat copy-paste.
-kubectl apply -f two-tier-deployment.yaml
-kubectl apply -f two-tier-svc.yaml
-kubectl apply -f mysql-svc.yaml
+kubectl apply -f two-tier-deployment.yaml # or: 04-flask-deployment.yaml
+kubectl apply -f two-tier-svc.yaml
+kubectl apply -f mysql-svc.yamlVerify the actual filenames in kub/ and keep the list 1-to-1.
📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| kubectl apply -f two-tier-deployment.yaml | |
| kubectl apply -f two-tier-svc.yaml | |
| kubectl apply -f mysql-svc.yaml | |
| kubectl apply -f two-tier-deployment.yaml # or: 04-flask-deployment.yaml | |
| kubectl apply -f two-tier-svc.yaml | |
| kubectl apply -f mysql-svc.yaml |
🤖 Prompt for AI Agents
In README.md lines 119 to 126, the manifest filenames used in the kubectl apply
commands do not match the earlier suggested renames and there is an extra space
before mysql-svc.yaml. Update the filenames to exactly match those in the kub/
directory, replacing two-tier-deployment.yaml and two-tier-svc.yaml with
flask-deployment.yaml and flask-svc.yaml respectively, and remove the extra
space before mysql-svc.yaml to ensure clean copy-pasting.
| ├── 01-mysql-pv.yaml | ||
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| 2. Access the Flask app in your web browser: | ||
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| - Frontend: http://localhost | ||
| - Backend: http://localhost:5000 | ||
| ├── 02-mysql-pvc.yaml | ||
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| 3. Create the `messages` table in your MySQL database: | ||
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| - Use a MySQL client or tool (e.g., phpMyAdmin) to execute the following SQL commands: | ||
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| ```sql | ||
| CREATE TABLE messages ( | ||
| id INT AUTO_INCREMENT PRIMARY KEY, | ||
| message TEXT | ||
| ); | ||
| ``` | ||
| ├── 03-mysql-deployment.yaml | ||
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| 4. Interact with the app: | ||
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| - Visit http://localhost to see the frontend. You can submit new messages using the form. | ||
| - Visit http://localhost:5000/insert_sql to insert a message directly into the `messages` table via an SQL query. | ||
| ├── 04-flask-deployment.yaml | ||
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| ## Cleaning Up | ||
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| To stop and remove the Docker containers, press `Ctrl+C` in the terminal where the containers are running, or use the following command: | ||
| ├── kind-config.yaml |
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🛠️ Refactor suggestion
Align file names with the actual manifests to avoid confusion
The file-structure section lists numbered manifest files (01-*.yaml, 02-*.yaml, etc.) whereas the subsequent kubectl apply commands reference the un-prefixed names. This mismatch will break copy-paste workflows and confuse readers.
-├── 01-mysql-pv.yaml
-├── 02-mysql-pvc.yaml
-├── 03-mysql-deployment.yaml
-├── 04-flask-deployment.yaml
+├── mysql-pv.yaml
+├── mysql-pvc.yaml
+├── mysql-deployment.yaml
+├── two-tier-deployment.yamlKeep the naming consistent in both the tree and the apply commands (or vice-versa).
📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| ├── 01-mysql-pv.yaml | |
| 2. Access the Flask app in your web browser: | |
| - Frontend: http://localhost | |
| - Backend: http://localhost:5000 | |
| ├── 02-mysql-pvc.yaml | |
| 3. Create the `messages` table in your MySQL database: | |
| - Use a MySQL client or tool (e.g., phpMyAdmin) to execute the following SQL commands: | |
| ```sql | |
| CREATE TABLE messages ( | |
| id INT AUTO_INCREMENT PRIMARY KEY, | |
| message TEXT | |
| ); | |
| ``` | |
| ├── 03-mysql-deployment.yaml | |
| 4. Interact with the app: | |
| - Visit http://localhost to see the frontend. You can submit new messages using the form. | |
| - Visit http://localhost:5000/insert_sql to insert a message directly into the `messages` table via an SQL query. | |
| ├── 04-flask-deployment.yaml | |
| ## Cleaning Up | |
| To stop and remove the Docker containers, press `Ctrl+C` in the terminal where the containers are running, or use the following command: | |
| ├── kind-config.yaml | |
| ├── mysql-pv.yaml | |
| ├── mysql-pvc.yaml | |
| ├── mysql-deployment.yaml | |
| ├── two-tier-deployment.yaml | |
| ├── kind-config.yaml |
🤖 Prompt for AI Agents
In README.md around lines 33 to 45, the file names listed in the file-structure
section include numeric prefixes (e.g., 01-mysql-pv.yaml), but the kubectl apply
commands later reference the files without these prefixes. To fix this, update
either the file-structure listing to remove the numeric prefixes or modify the
kubectl apply commands to include the numeric prefixes, ensuring consistent
naming between the two sections to avoid confusion and broken workflows.
1 participant
Did it via CLUSTER-ip for simplicity
do mention it for sake of reference..
Thank you..
Summary by CodeRabbit
New Features
Documentation
Refactor
Style