init containers

Author: tahsina13

build/Dockerfile

@@ -25,15 +25,5 @@ RUN apt-get update && apt-get install -y \
     strace \
     && rm -rf /var/lib/apt/lists/*
 
-# Set the working directory
-WORKDIR /usr/local/app
-
-# Copy the files into the working directory
-COPY src/ .
-
-# Set executable permissions for the trace script
-RUN chmod +x /usr/local/app/trace.sh
-
 # Default command
-CMD ["/bin/bash"]
-
+CMD ["/bin/sh"]

k8s/bpftrace.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: bpftrace-test
+spec:
+  shareProcessNamespace: true   # allow containers to see each other's processes
+  initContainers:
+  - name: bpftrace
+    image: ghcr.io/amirhnajafiz/flap:v0.0.0-beta-6
+    securityContext:
+      privileged: true                # or at least add CAP_SYS_PTRACE
+      capabilities:
+        add: ["SYS_PTRACE"]
+    command: ["sleep", "infinity"]
+  containers:
+  - name: nginx
+    image: nginx:latest
+
+

src/bpftrace/ctrace.bt src/scripts/ctrace.btsrc/bpftrace/ctrace.bt renamed to src/scripts/ctrace.bt

@@ -1,3 +1,5 @@
+#!/usr/bin/env bpftrace
+
 /* ctract.bt
  * About: Traces all file access events of a command and its subprocs and
  * outputs the total bytes read/write and access times.

src/bpftrace/ptrace.bt src/scripts/ptrace.btsrc/bpftrace/ptrace.bt renamed to src/scripts/ptrace.bt

@@ -1,3 +1,5 @@
+#!/usr/bin/env bpftrace
+
 /* ptrace.bt
  * About: Traces all file access events of a process and its subprocs and
  * outputs the total bytes read/write and access times.
@@ -10,12 +12,12 @@ BEGIN
 {
   printf("[%s] START tracing file-access events\n", strftime("%Y-%m-%d %H:%M:%S", nsecs));
 
-  @fname[cpid, 0] = "STDIN";
-  @fname[cpid, 1] = "STDOUT";
-  @fname[cpid, 2] = "STDERR";
-  @tracked[cpid] = 1;
+  @fname[$1, 0] = "STDIN";
+  @fname[$1, 1] = "STDOUT";
+  @fname[$1, 2] = "STDERR";
+  @tracked[$1] = 1;
 
-  printf("[%s] Tracking PID %d...\n", strftime("%Y-%m-%d %H:%M:%S", nsecs), cpid);
+  printf("[%s] Tracking PID %d...\n", strftime("%Y-%m-%d %H:%M:%S", nsecs), $1);
 }
 
 /* when we see a fork, if parent is tracked then also track child */

src/trace.sh

@@ -59,26 +59,26 @@ ensure_script() {
 
 # decide what to run
 if [ -n "$cmd" ]; then
-  ensure_script "bpftrace/ctrace.bt"
-  printf "Running: bpftrace -c %s bpftrace/ctrace.bt > %s\n" "'$cmd'" "$out"
+  ensure_script "scripts/ctrace.bt"
+  printf "Running: bpftrace -c %s scripts/ctrace.bt > %s\n" "'$cmd'" "$out"
   # Use exec so the shell is replaced by bpftrace (optional). We capture exit code.
   # Quoting $cmd carefully so it's passed as a single argument to -c.
-  bpftrace -c "$cmd" bpftrace/ctrace.bt > "$out"
+  bpftrace -c "$cmd" scripts/ctrace.bt > "$out"
   rc=$?
   if [ $rc -ne 0 ]; then
     printf "bpftrace exited with code %d\n" "$rc" >&2
   fi
   exit $rc
 
 elif [ -n "$pid" ]; then
-  ensure_script "bpftrace/ptrace.bt"
+  ensure_script "scripts/ptrace.bt"
   # Validate pid is numeric
   case $pid in
     ''|*[!0-9]*) printf "Error: pid must be a positive integer.\n" >&2; exit 2 ;;
   esac
 
-  printf "Running: bpftrace -p %s bpftrace/ptrace.bt > %s\n" "$pid" "$out"
-  bpftrace bpftrace/ptrace.bt "$pid" > "$out"
+  printf "Running: bpftrace -p %s scripts/ptrace.bt > %s\n" "$pid" "$out"
+  bpftrace scripts/ptrace.bt "$pid" > "$out"
   rc=$?
   if [ $rc -ne 0 ]; then
     printf "bpftrace exited with code %d\n" "$rc" >&2