Expand args on the HOST command so you can have dynamic hostnames (#3…

…957) fixes #1743 --------- Co-authored-by: Alex Couture-Beil <[email protected]> Co-authored-by: Alex Couture-Beil <[email protected]>
earthly · Apr 2, 2024 · 195a318 · 195a318
1 parent 9801a49
commit 195a318
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Showing 4 changed files with 61 additions and 4 deletions.
diff --git a/ast/tests/host.ast.json b/ast/tests/host.ast.json
@@ -109,6 +109,52 @@
         }
       ]
     },
+    {
+      "name": "expand-args",
+      "recipe": [
+        {
+          "command": {
+            "args": [
+              "fake_host",
+              "=",
+              "example.com"
+            ],
+            "name": "ARG"
+          }
+        },
+        {
+          "command": {
+            "args": [
+              "target_ip",
+              "=",
+              "1.2"
+            ],
+            "name": "ARG"
+          }
+        },
+        {
+          "command": {
+            "args": [
+              "$fake_host",
+              "$target_ip.3.4"
+            ],
+            "name": "HOST"
+          }
+        },
+        {
+          "command": {
+            "args": [
+              "cat",
+              "/etc/hosts",
+              "|",
+              "acbgrep",
+              "\"1.2.3.4\\W*example.com\""
+            ],
+            "name": "RUN"
+          }
+        }
+      ]
+    },
     {
       "name": "invalid-ip",
       "recipe": [

diff --git a/earthfile2llb/interpreter.go b/earthfile2llb/interpreter.go
@@ -2024,10 +2024,14 @@ func (i *Interpreter) handleHost(ctx context.Context, cmd spec.Command) error {
 	if i.local {
 		return i.errorf(cmd.SourceLocation, "HOST command not supported with LOCALLY")
 	}
-
-	host := cmd.Args[0]
-	ipStr := cmd.Args[1]
-
+	host, err := i.expandArgs(ctx, cmd.Args[0], true, false)
+	if err != nil {
+		return i.errorf(cmd.SourceLocation, "unable to expand host name for HOST: %s", cmd.Args)
+	}
+	ipStr, err := i.expandArgs(ctx, cmd.Args[1], true, false)
+	if err != nil {
+		return i.errorf(cmd.SourceLocation, "unable to expand IP addr for HOST: %s", cmd.Args)
+	}
 	ip := net.ParseIP(ipStr)
 	if ip == nil {
 		return i.errorf(cmd.SourceLocation, "invalid HOST ip %s", ipStr)

diff --git a/tests/Earthfile b/tests/Earthfile
@@ -1445,6 +1445,7 @@ host:
     DO +RUN_EARTHLY --earthfile=host.earth --target=+add-single-host
     DO +RUN_EARTHLY --earthfile=host.earth --target=+add-multiple-host
     DO +RUN_EARTHLY --earthfile=host.earth --target=+add-ipv6
+    DO +RUN_EARTHLY --earthfile=host.earth --target=+expand-args
 
 host-invalid:
     DO +RUN_EARTHLY --earthfile=host.earth --should_fail=true --target=+invalid-ip --output_contains="invalid HOST ip"

diff --git a/tests/host.earth b/tests/host.earth
@@ -16,6 +16,12 @@ add-ipv6:
     HOST cool.website dead:beef::cafe
     RUN cat /etc/hosts | grep "dead:beef::cafe\W*cool.website"
 
+expand-args:
+    ARG fake_host=example.com
+    ARG target_ip=1.2
+    HOST $fake_host $target_ip.3.4
+    RUN cat /etc/hosts | acbgrep "1.2.3.4\W*example.com"
+
 invalid-ip:
     HOST example.com 1.2.3.4.5.6.7.8.9.10