pod by pid

Author: koss822

Kubernetes/pod-by-pid/pod-by-pid.sh

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+#!/bin/bash
+
+# Script to find the Kubernetes pod associated with a process (PID)
+
+# Check if a PID is provided
+if [ -z "$1" ]; then
+    echo "Usage: $0 <PID>"
+    exit 1
+fi
+
+# Get the PID from the first argument
+PID=$1
+
+# Verify the process exists
+if [[ ! -d "/proc/$PID" ]]; then
+    echo "Error: Process with PID $PID does not exist."
+    exit 1
+fi
+
+# Extract the cgroup information for the process
+CGROUP_FILE="/proc/$PID/cgroup"
+if [[ ! -f $CGROUP_FILE ]]; then
+    echo "Error: Unable to access cgroup information for PID $PID."
+    exit 1
+fi
+
+# Extract the container ID (last segment of the cgroup path)
+CONTAINER_ID=$(cat "$CGROUP_FILE" | awk -F '/' '{print $NF}' | tr -d '\n')
+
+# Check if we got a valid container ID
+if [[ -z "$CONTAINER_ID" || ${#CONTAINER_ID} -lt 64 ]]; then
+    echo "Error: Unable to determine container ID for PID $PID."
+    exit 1
+fi
+
+echo "Container ID: $CONTAINER_ID"
+
+# Use kubectl to find the pod corresponding to the container ID
+POD_INFO=$(kubectl get pods --all-namespaces -o json | jq -r \
+    --arg CONTAINER_ID "$CONTAINER_ID" \
+    '.items[]
+    | select(.status.containerStatuses != null)
+    | select(.status.containerStatuses[].containerID? != null and (.status.containerStatuses[].containerID | endswith($CONTAINER_ID)))
+    | "\(.metadata.namespace) \(.metadata.name)"')
+
+# Output the result
+if [[ -z "$POD_INFO" ]]; then
+    echo "Error: No pod found for container ID $CONTAINER_ID."
+    exit 1
+else
+    echo "Pod Information:"
+    echo "Namespace: $(echo $POD_INFO | awk '{print $1}')"
+    echo "Name: $(echo $POD_INFO | awk '{print $2}')"
+fi

Kubernetes/pod-by-pid/readme.md

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+# `pod_by_pid_4microk8s`
+
+### A Script to Find the Kubernetes Pod Associated with a Process (PID) on MicroK8s
+
+`pod_by_pid.sh` is a Bash script designed specifically for environments running MicroK8s. It helps you determine which Kubernetes pod a specific process (identified by its PID) belongs to. This script extracts the container ID from the Linux process cgroup file and maps it to the corresponding pod using the `kubectl` command.
+
+---
+
+## ✨ Features
+
+- **Works exclusively with MicroK8s**:
+  - The script is tailored for MicroK8s, a lightweight Kubernetes distribution.
+- **Maps processes to pods**:
+  - Given a Linux process ID (PID), this script efficiently locates the associated pod's name and namespace.
+- **Handles Edge Cases**:
+  - Includes robust handling for processes without container IDs or when certain fields are null or incomplete.
+- **Error Handling**:
+  - Clearly notifies users of invalid PIDs, missing container IDs, or unmatched pods.
+
+---
+
+## ⚙️ How It Works
+
+1. **Provide a Process ID (PID)** as input to the script.
+2. The script inspects the process’s `/proc/<PID>/cgroup` file to extract the Kubernetes container ID.
+3. It uses the container ID to query all running Kubernetes pods via the MicroK8s `kubectl` tool.
+4. If a match is found, it outputs the namespace and name of the pod associated with the process.
+
+This script relies on the fact that MicroK8s organizes containers via `containerd` or similar runtime, and the cgroup paths include critical container metadata.
+
+---
+
+## 📜 Prerequisites
+
+1. **MicroK8s**:
+   - Ensure MicroK8s is installed and running on your system.
+   - The script assumes the `kubectl` command provided by MicroK8s is installed and available or properly aliased (e.g., `microk8s kubectl` may be aliased to `kubectl`).
+
+2. **jq**:
+   - The script requires `jq` to parse JSON output from Kubernetes API queries.
+   - Install it using:
+     ```bash
+     # On Debian/Ubuntu
+     sudo apt-get install jq
+
+     # On RHEL/CentOS
+     sudo yum install jq
+
+     # On macOS
+     brew install jq
+     ```
+
+3. **Run the Script with Sufficient Permissions**:
+   - Run the script as a user with access to the `/proc` filesystem and Kubernetes cluster configurations in MicroK8s (requires access to `kubectl`).
+
+---
+
+## 🔧 Installation
+
+1. Save the script to a file:
+   ```bash
+   nano pod_by_pid.sh

readme.md

@@ -9,6 +9,7 @@
 - [**sp500-prometheus-exporter**](https://github.com/koss822/misc/blob/master/Kubernetes/sp500exporter) - (created July/20/2023) SP500 exporter for Prometheus
 - [**slack-alarm**](https://github.com/koss822/misc/blob/master/Kubernetes/slack-alarm) - (created Feb/2024) Notification of IKEA Parasoll door/window sensor to slack
 - [**sops**](https://github.com/koss822/misc/blob/master/Kubernetes/sops) - (created Apr/2024) SOPS Git Hooks for Kubernetes Secrets Management
+- [**pod-by-pid**](https://github.com/koss822/misc/blob/master/Kubernetes/pod-by-pid) - (created Dec/2024) A Script to Find the Kubernetes Pod Associated with a Process (PID) on MicroK8s
 
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