From a75e7709b8e0ea4d7f68b247c8c19db48666e91c Mon Sep 17 00:00:00 2001
From: Roman Dodin <dodin.roman@gmail.com>
Date: Wed, 15 Jan 2025 15:12:55 +0100
Subject: [PATCH] Added centralized magic var replacer and support replacer for
 execs (#2395)

added centralized magic var replacer and support replacer for execs
---
 clab/config.go                                | 33 ++++++++++++++---
 clab/config_test.go                           | 35 ++++++++++++++++++-
 .../clab-topo2/node1/{somefile => node1}      |  0
 clab/test_data/topo14.yml                     |  3 ++
 clab/test_data/topo2.yml                      |  2 +-
 5 files changed, 66 insertions(+), 7 deletions(-)
 rename clab/test_data/clab-topo2/node1/{somefile => node1} (100%)

diff --git a/clab/config.go b/clab/config.go
index f8c020c38..48c92990d 100644
--- a/clab/config.go
+++ b/clab/config.go
@@ -239,7 +239,7 @@ func (c *CLab) createNodeCfg(nodeName string, nodeDef *types.NodeDefinition, idx
 	if err != nil {
 		return nil, err
 	}
-	err = c.resolveBindPaths(binds, c.TopoPaths.NodeDir(nodeName))
+	err = c.resolveBindPaths(binds, nodeName)
 	if err != nil {
 		return nil, err
 	}
@@ -253,6 +253,8 @@ func (c *CLab) createNodeCfg(nodeName string, nodeDef *types.NodeDefinition, idx
 
 	nodeCfg.Config = c.Config.Topology.GetNodeConfigDispatcher(nodeCfg.ShortName)
 
+	c.processNodeExecs(nodeCfg)
+
 	return nodeCfg, nil
 }
 
@@ -261,7 +263,7 @@ func (c *CLab) createNodeCfg(nodeName string, nodeDef *types.NodeDefinition, idx
 // Returns an absolute path to the startup-config file.
 func (c *CLab) processStartupConfig(nodeCfg *types.NodeConfig) error {
 	// replace __clabNodeName__ magic var in startup-config path with node short name
-	r := strings.NewReplacer(nodeNameVar, nodeCfg.ShortName)
+	r := c.magicVarReplacer(nodeCfg.ShortName)
 	p := r.Replace(c.Config.Topology.GetNodeStartupConfig(nodeCfg.ShortName))
 
 	// embedded config is a config that is defined as a multi-line string in the topology file
@@ -498,7 +500,7 @@ func (c *CLab) verifyContainersUniqueness(ctx context.Context) error {
 // it allows host path to have `~` and relative path to an absolute path
 // the list of binds will be changed in place.
 // if the host path doesn't exist, the error will be returned.
-func (c *CLab) resolveBindPaths(binds []string, nodeDir string) error {
+func (c *CLab) resolveBindPaths(binds []string, nodeName string) error {
 	// checks are skipped when, for example, the destroy operation is run
 	if !c.checkBindsPaths {
 		return nil
@@ -513,8 +515,8 @@ func (c *CLab) resolveBindPaths(binds []string, nodeDir string) error {
 			// volume, in this case we don't need to resolve the path
 			continue
 		}
-		// replace special variable
-		r := strings.NewReplacer(clabDirVar, c.TopoPaths.TopologyLabDir(), nodeDirVar, nodeDir)
+		// replace special variables
+		r := c.magicVarReplacer(nodeName)
 		hp := r.Replace(elems[0])
 		hp = utils.ResolvePath(hp, c.TopoPaths.TopologyFileDir())
 
@@ -649,3 +651,24 @@ func addEnvVarsToNodeCfg(c *CLab, nodeCfg *types.NodeConfig) error {
 
 	return nil
 }
+
+// processNodeExecs replaces (in place) magic variables in node execs.
+func (c *CLab) processNodeExecs(nodeCfg *types.NodeConfig) {
+	for i, e := range nodeCfg.Exec {
+		r := c.magicVarReplacer(nodeCfg.ShortName)
+		nodeCfg.Exec[i] = r.Replace(e)
+	}
+}
+
+// magicVarReplacer returns a string replacer that replaces all supported magic variables.
+func (c *CLab) magicVarReplacer(nodeName string) *strings.Replacer {
+	if nodeName == "" {
+		return &strings.Replacer{}
+	}
+
+	return strings.NewReplacer(
+		clabDirVar, c.TopoPaths.TopologyLabDir(),
+		nodeDirVar, c.TopoPaths.NodeDir(nodeName),
+		nodeNameVar, nodeName,
+	)
+}
diff --git a/clab/config_test.go b/clab/config_test.go
index 6ca9b6109..31527a947 100644
--- a/clab/config_test.go
+++ b/clab/config_test.go
@@ -78,7 +78,7 @@ func TestBindsInit(t *testing.T) {
 			want: []string{
 				"node1.lic:/dst1",
 				"kind.lic:/dst2",
-				"${PWD}/test_data/clab-topo2/node1/somefile:/somefile",
+				"${PWD}/test_data/clab-topo2/node1/node1:/somefile",
 			},
 		},
 		"kind_and_node_binds": {
@@ -738,3 +738,36 @@ func TestStartupConfigInit(t *testing.T) {
 		})
 	}
 }
+
+func TestExecInit(t *testing.T) {
+	tests := map[string]struct {
+		got  string
+		node string
+		want []string
+	}{
+		"node_exec": {
+			got:  "test_data/topo14.yml",
+			node: "node1",
+			want: []string{
+				"echo \"Hello world\"",
+				"echo \"Hello node node1\"",
+			},
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			opts := []ClabOption{
+				WithTopoPath(tc.got, ""),
+			}
+			c, err := NewContainerLab(opts...)
+			if err != nil {
+				t.Error(err)
+			}
+
+			if d := cmp.Diff(c.Nodes[tc.node].Config().Exec, tc.want); d != "" {
+				t.Errorf("execs do not match %s", d)
+			}
+		})
+	}
+}
diff --git a/clab/test_data/clab-topo2/node1/somefile b/clab/test_data/clab-topo2/node1/node1
similarity index 100%
rename from clab/test_data/clab-topo2/node1/somefile
rename to clab/test_data/clab-topo2/node1/node1
diff --git a/clab/test_data/topo14.yml b/clab/test_data/topo14.yml
index 93fa6721c..41947a168 100644
--- a/clab/test_data/topo14.yml
+++ b/clab/test_data/topo14.yml
@@ -4,3 +4,6 @@ topology:
     node1:
       kind: nokia_srlinux
       startup-config: ./configs/fabric/__clabNodeName__.cfg
+      exec:
+        - echo "Hello world"
+        - echo "Hello node __clabNodeName__"
diff --git a/clab/test_data/topo2.yml b/clab/test_data/topo2.yml
index 13d2904cd..95b9b2af0 100644
--- a/clab/test_data/topo2.yml
+++ b/clab/test_data/topo2.yml
@@ -15,7 +15,7 @@ topology:
       binds:
         - node1.lic:/dst1
         - kind.lic:/dst2
-        - __clabNodeDir__/somefile:/somefile
+        - __clabNodeDir__/__clabNodeName__:/somefile
     node2:
       kind: nokia_srlinux
       type: ixr10