From 19a5f291697e23225c345064b62da7a329908a7b Mon Sep 17 00:00:00 2001
From: Paulo Janotti <pjanotti@splunk.com>
Date: Wed, 12 Feb 2025 16:00:31 -0800
Subject: [PATCH] [receiver/awscontainerinsight] Add HOST_PROC env var support
 (#37694)

#### Description
Add support to HOST_PROC env var support. At this point I'm not sure if
the default should be changed or not, but, with the env var one can at
least experiment with the receiver on different images.

#### Link to tracking issue
Fixes #35862

#### Testing
Added respective unit test.

#### Documentation
Changelog
---
 ...-env-var-on-awscontainerinsightreceiver.yaml | 11 +++++++++++
 .../internal/host/nodeCapacity.go               |  9 +++++++--
 .../internal/host/nodeCapacity_test.go          | 17 +++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 .chloggen/support-host-proc-env-var-on-awscontainerinsightreceiver.yaml

diff --git a/.chloggen/support-host-proc-env-var-on-awscontainerinsightreceiver.yaml b/.chloggen/support-host-proc-env-var-on-awscontainerinsightreceiver.yaml
new file mode 100644
index 000000000000..4b86edd2ba78
--- /dev/null
+++ b/.chloggen/support-host-proc-env-var-on-awscontainerinsightreceiver.yaml
@@ -0,0 +1,11 @@
+change_type: enhancement
+
+component: awscontainerinsightreceiver
+
+note: Add support for HOST_PROC environment variable in AWS Container Insight Receiver.
+
+issues: [35862]
+
+subtext:
+
+change_logs: [user]
diff --git a/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity.go b/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity.go
index 7cf5092b77b3..ed4b84022efa 100644
--- a/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity.go
+++ b/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity.go
@@ -43,10 +43,15 @@ func newNodeCapacity(logger *zap.Logger, options ...nodeCapacityOption) (nodeCap
 		opt(nc)
 	}
 
-	if _, err := nc.osLstat(hostProc); os.IsNotExist(err) {
+	actualHostProc, ok := os.LookupEnv(string(common.HostProcEnvKey))
+	if !ok {
+		actualHostProc = hostProc
+	}
+
+	if _, err := nc.osLstat(actualHostProc); os.IsNotExist(err) {
 		return nil, err
 	}
-	envMap := common.EnvMap{common.HostProcEnvKey: hostProc}
+	envMap := common.EnvMap{common.HostProcEnvKey: actualHostProc}
 	ctx := context.WithValue(context.Background(), common.EnvKey, envMap)
 
 	nc.parseCPU(ctx)
diff --git a/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity_test.go b/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity_test.go
index d54f0dbb1f49..b574c48a7ffd 100644
--- a/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity_test.go
+++ b/receiver/awscontainerinsightreceiver/internal/host/nodeCapacity_test.go
@@ -9,6 +9,7 @@ import (
 	"os"
 	"testing"
 
+	"github.com/shirou/gopsutil/v4/common"
 	"github.com/shirou/gopsutil/v4/cpu"
 	"github.com/shirou/gopsutil/v4/mem"
 	"github.com/stretchr/testify/assert"
@@ -71,3 +72,19 @@ func TestNodeCapacity(t *testing.T) {
 	assert.Equal(t, int64(1024), nc.getMemoryCapacity())
 	assert.Equal(t, int64(2), nc.getNumCores())
 }
+
+func TestNodeCapacity_ReadsHostProcEnvVar(t *testing.T) {
+	const customHostProc = "/custom/host/proc"
+	t.Setenv(string(common.HostProcEnvKey), customHostProc)
+
+	lstatOption := func(nc *nodeCapacity) {
+		nc.osLstat = func(name string) (os.FileInfo, error) {
+			assert.Equal(t, customHostProc, name)
+			return nil, nil
+		}
+	}
+
+	nc, err := newNodeCapacity(zap.NewNop(), lstatOption)
+	assert.NoError(t, err)
+	assert.NotNil(t, nc)
+}