From 74ea90e4b3a2ffabc8b0faccc8cbbafe38406f43 Mon Sep 17 00:00:00 2001
From: rcourtman <courtmanr@gmail.com>
Date: Tue, 6 Jan 2026 10:56:37 +0000
Subject: [PATCH] fix: Podman sockets not prioritized when
 --docker-runtime=podman

When --docker-runtime=podman is explicitly set, the agent should try
Podman-specific sockets first before falling back to environment
defaults (which try /var/run/docker.sock).

Also adds /var/run/podman/podman.sock as a candidate socket path,
which is used by CoreOS and some Fedora configurations.

Related to #1045
---
 internal/dockeragent/agent.go               | 52 +++++++++++++++++----
 internal/dockeragent/agent_internal_test.go | 15 ++++--
 2 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/internal/dockeragent/agent.go b/internal/dockeragent/agent.go
index a3309f25b..e7f741ba4 100644
--- a/internal/dockeragent/agent.go
+++ b/internal/dockeragent/agent.go
@@ -407,7 +407,7 @@ func tryRuntimeCandidate(opts []client.Opt) (dockerClient, systemtypes.Info, err
 }
 
 func buildRuntimeCandidates(preference RuntimeKind) []runtimeCandidate {
-	candidates := make([]runtimeCandidate, 0, 6)
+	candidates := make([]runtimeCandidate, 0, 8)
 	seen := make(map[string]struct{})
 
 	add := func(candidate runtimeCandidate) {
@@ -422,6 +422,35 @@ func buildRuntimeCandidates(preference RuntimeKind) []runtimeCandidate {
 		candidates = append(candidates, candidate)
 	}
 
+	// When podman is explicitly requested, try podman-specific sockets FIRST
+	// before falling back to environment defaults (which try /var/run/docker.sock)
+	if preference == RuntimePodman {
+		if host := utils.GetenvTrim("PODMAN_HOST"); host != "" {
+			add(runtimeCandidate{
+				host:  host,
+				label: "PODMAN_HOST",
+			})
+		}
+
+		rootless := fmt.Sprintf("unix:///run/user/%d/podman/podman.sock", os.Getuid())
+		add(runtimeCandidate{
+			host:  rootless,
+			label: "podman rootless socket",
+		})
+
+		add(runtimeCandidate{
+			host:  "unix:///run/podman/podman.sock",
+			label: "podman system socket",
+		})
+
+		// Some distros (CoreOS, Fedora) use /var/run/podman instead of /run/podman
+		add(runtimeCandidate{
+			host:  "unix:///var/run/podman/podman.sock",
+			label: "podman system socket (var/run)",
+		})
+	}
+
+	// Environment defaults (uses Docker client defaults)
 	add(runtimeCandidate{
 		label:          "environment defaults",
 		applyDockerEnv: true,
@@ -442,14 +471,15 @@ func buildRuntimeCandidates(preference RuntimeKind) []runtimeCandidate {
 		})
 	}
 
-	if host := utils.GetenvTrim("PODMAN_HOST"); host != "" {
-		add(runtimeCandidate{
-			host:  host,
-			label: "PODMAN_HOST",
-		})
-	}
+	// For auto mode, check podman after environment defaults
+	if preference == RuntimeAuto {
+		if host := utils.GetenvTrim("PODMAN_HOST"); host != "" {
+			add(runtimeCandidate{
+				host:  host,
+				label: "PODMAN_HOST",
+			})
+		}
 
-	if preference == RuntimePodman || preference == RuntimeAuto {
 		rootless := fmt.Sprintf("unix:///run/user/%d/podman/podman.sock", os.Getuid())
 		add(runtimeCandidate{
 			host:  rootless,
@@ -460,6 +490,12 @@ func buildRuntimeCandidates(preference RuntimeKind) []runtimeCandidate {
 			host:  "unix:///run/podman/podman.sock",
 			label: "podman system socket",
 		})
+
+		// Some distros (CoreOS, Fedora) use /var/run/podman instead of /run/podman
+		add(runtimeCandidate{
+			host:  "unix:///var/run/podman/podman.sock",
+			label: "podman system socket (var/run)",
+		})
 	}
 
 	if preference == RuntimeDocker || preference == RuntimeAuto {
diff --git a/internal/dockeragent/agent_internal_test.go b/internal/dockeragent/agent_internal_test.go
index 9c9a8ad9e..783befc11 100644
--- a/internal/dockeragent/agent_internal_test.go
+++ b/internal/dockeragent/agent_internal_test.go
@@ -937,7 +937,7 @@ func TestBuildRuntimeCandidates(t *testing.T) {
 		{
 			name:       "podman preference includes podman sockets",
 			preference: RuntimePodman,
-			wantMin:    3, // at least env defaults + podman rootless + podman system
+			wantMin:    4, // at least podman rootless + podman system + podman (var/run) + env defaults
 		},
 	}
 
@@ -948,9 +948,16 @@ func TestBuildRuntimeCandidates(t *testing.T) {
 				t.Errorf("buildRuntimeCandidates(%v) returned %d candidates, want at least %d", tt.preference, len(candidates), tt.wantMin)
 			}
 
-			// Verify first candidate is always "environment defaults"
-			if len(candidates) > 0 && candidates[0].label != "environment defaults" {
-				t.Errorf("first candidate should be 'environment defaults', got %q", candidates[0].label)
+			// When podman is explicitly requested, podman sockets should be tried first.
+			// For auto/docker modes, environment defaults should be first.
+			if len(candidates) > 0 {
+				if tt.preference == RuntimePodman {
+					if candidates[0].label != "podman rootless socket" {
+						t.Errorf("podman preference: first candidate should be 'podman rootless socket', got %q", candidates[0].label)
+					}
+				} else if candidates[0].label != "environment defaults" {
+					t.Errorf("first candidate should be 'environment defaults', got %q", candidates[0].label)
+				}
 			}
 
 			// Verify no duplicates