feat: add support for cmd directories in golang

docs/pages/docs/providers/go.md

@@ -33,8 +33,14 @@ go get
 
 ## Build
 
+If your project has multiple binaries, you can specify which one to run with the `NIXPACKS_GO_BIN` environment variable.
+Otherwise, the first binary found in the project's root directory or the project's `cmd` directory will be used.
+
 ```
 go build -o out
+# Or if there are no .go files in the root directory
+go build -o out ./cmd/{name}
+
 ```
 
 ## Start

examples/go-cmd/.gitignore

@@ -0,0 +1,15 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/

examples/go-cmd/cmd/server/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"github.com/gin-gonic/gin"
+)
+
+var Router *gin.Engine
+
+func main() {
+	r := gin.Default()
+	r.GET("/", func(c *gin.Context) {
+		c.JSON(200, gin.H{
+			"message": "Hello world!",
+		})
+	})
+	r.Run()
+}

examples/go-cmd/go.mod

@@ -0,0 +1,26 @@
+module gin
+
+go 1.18
+
+require github.com/gin-gonic/gin v1.8.1
+
+require (
+	github.com/gin-contrib/sse v0.1.0 // indirect
+	github.com/go-playground/locales v0.14.0 // indirect
+	github.com/go-playground/universal-translator v0.18.0 // indirect
+	github.com/go-playground/validator/v10 v10.10.0 // indirect
+	github.com/goccy/go-json v0.9.7 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/leodido/go-urn v1.2.1 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/pelletier/go-toml/v2 v2.0.1 // indirect
+	github.com/ugorji/go/codec v1.2.7 // indirect
+	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
+	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 // indirect
+	golang.org/x/sys v0.0.0-20210806184541-e5e7981a1069 // indirect
+	golang.org/x/text v0.3.6 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)

examples/go-cmd/go.sum

@@ -0,0 +1,75 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
+github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
+github.com/gin-gonic/gin v1.8.1 h1:4+fr/el88TOO3ewCmQr8cx/CtZ/umlIRIs5M4NTNjf8=
+github.com/gin-gonic/gin v1.8.1/go.mod h1:ji8BvRH1azfM+SYow9zQ6SZMvR8qOMZHmsCuWR9tTTk=
+github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
+github.com/go-playground/locales v0.14.0 h1:u50s323jtVGugKlcYeyzC0etD1HifMjqmJqb8WugfUU=
+github.com/go-playground/locales v0.14.0/go.mod h1:sawfccIbzZTqEDETgFXqTho0QybSa7l++s0DH+LDiLs=
+github.com/go-playground/universal-translator v0.18.0 h1:82dyy6p4OuJq4/CByFNOn/jYrnRPArHwAcmLoJZxyho=
+github.com/go-playground/universal-translator v0.18.0/go.mod h1:UvRDBj+xPUEGrFYl+lu/H90nyDXpg0fqeB/AQUGNTVA=
+github.com/go-playground/validator/v10 v10.10.0 h1:I7mrTYv78z8k8VXa/qJlOlEXn/nBh+BF8dHX5nt/dr0=
+github.com/go-playground/validator/v10 v10.10.0/go.mod h1:74x4gJWsvQexRdW8Pn3dXSGrTK4nAUsbPlLADvpJkos=
+github.com/goccy/go-json v0.9.7 h1:IcB+Aqpx/iMHu5Yooh7jEzJk1JZ7Pjtmys2ukPr7EeM=
+github.com/goccy/go-json v0.9.7/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
+github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
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+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/leodido/go-urn v1.2.1 h1:BqpAaACuzVSgi/VLzGZIobT2z4v53pjosyNd9Yv6n/w=
+github.com/leodido/go-urn v1.2.1/go.mod h1:zt4jvISO2HfUBqxjfIshjdMTYS56ZS/qv49ictyFfxY=
+github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
+github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OHLH3mGKHDcjJRFFRrJa6eAM5H+CtDdOsPc=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
+github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/pelletier/go-toml/v2 v2.0.1 h1:8e3L2cCQzLFi2CR4g7vGFuFxX7Jl1kKX8gW+iV0GUKU=
+github.com/pelletier/go-toml/v2 v2.0.1/go.mod h1:r9LEWfGN8R5k0VXJ+0BkIe7MYkRdwZOjgMj2KwnJFUo=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+github.com/rogpeppe/go-internal v1.8.0/go.mod h1:WmiCO8CzOY8rg0OYDC4/i/2WRWAB6poM+XZ2dLUbcbE=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
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+golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
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+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

examples/go-gin/cmd/server/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"github.com/gin-gonic/gin"
+)
+
+var Router *gin.Engine
+
+func main() {
+	r := gin.Default()
+	r.GET("/", func(c *gin.Context) {
+		c.JSON(200, gin.H{
+			"message": "Hello world!",
+		})
+	})
+	r.Run()
+}

src/providers/go.rs

@@ -65,20 +65,46 @@ impl Provider for GolangProvider {
         setup.set_nix_archive(archive);
 
         plan.add_phase(setup);
+        let is_go_module = app.includes_file("go.mod");
 
-        if app.includes_file("go.mod") {
+        if is_go_module {
             let mut install = Phase::install(Some("go mod download".to_string()));
             install.add_cache_directory(GO_BUILD_CACHE_DIR.to_string());
             plan.add_phase(install);
         }
 
-        let mut build = if app.includes_file("go.mod") {
-            Phase::build(Some(format!("go build -o {BINARY_NAME}")))
+        let has_root_go_files = app.find_files("*.go").ok().map_or(false, |files| {
+            files
+                .iter()
+                .any(|file| file.parent() == Some(app.source.as_path()))
+        });
+
+        let build_command = if let Some(name) = env.get_config_variable("GO_BIN") {
+            Some(format!("go build -o {BINARY_NAME} ./cmd/{name}"))
+        } else if is_go_module && has_root_go_files {
+            Some(format!("go build -o {BINARY_NAME}"))
+        } else if app.includes_directory("cmd") {
+            // Try to find a command in the cmd directory
+            app.find_directories("cmd/*")
+                .ok()
+                .and_then(|dirs| {
+                    dirs.into_iter()
+                        .find(|path| path.parent().map_or(false, |p| p.ends_with("cmd")))
+                })
+                .and_then(|path| {
+                    path.file_name()
+                        .and_then(|os_str| os_str.to_str())
+                        .map(|name| format!("go build -o {BINARY_NAME} ./cmd/{name}"))
+                })
+        } else if is_go_module {
+            Some(format!("go build -o {BINARY_NAME}"))
         } else if app.includes_file("main.go") {
-            Phase::build(Some(format!("go build -o {BINARY_NAME} main.go")))
+            Some(format!("go build -o {BINARY_NAME} main.go"))
         } else {
-            Phase::build(None)
+            None
         };
+
+        let mut build = Phase::build(build_command);
         build.add_cache_directory(GO_BUILD_CACHE_DIR.to_string());
         build.depends_on_phase("setup");
         plan.add_phase(build);

tests/snapshots/generate_plan_tests__go_cmd.snap

@@ -0,0 +1,52 @@
+---
+source: tests/generate_plan_tests.rs
+expression: plan
+snapshot_kind: text
+---
+{
+  "providers": [],
+  "buildImage": "[build_image]",
+  "variables": {
+    "CGO_ENABLED": "0",
+    "NIXPACKS_METADATA": "go"
+  },
+  "phases": {
+    "build": {
+      "name": "build",
+      "dependsOn": [
+        "install",
+        "setup"
+      ],
+      "cmds": [
+        "go build -o out ./cmd/server"
+      ],
+      "cacheDirectories": [
+        "/root/.cache/go-build"
+      ]
+    },
+    "install": {
+      "name": "install",
+      "dependsOn": [
+        "setup"
+      ],
+      "cmds": [
+        "go mod download"
+      ],
+      "cacheDirectories": [
+        "/root/.cache/go-build"
+      ]
+    },
+    "setup": {
+      "name": "setup",
+      "nixPkgs": [
+        "go_1_18"
+      ],
+      "nixOverlays": [],
+      "nixpkgsArchive": "[archive]"
+    }
+  },
+  "start": {
+    "cmd": "./out",
+    "runImage": "ubuntu:jammy"
+  }
+}