Add package manager usage docs

Signed-off-by: Tihomir Jovicic <tihomir.jovicic.develop@gmail.com>

cmd/dagger/cmd/mod/file.go

@@ -158,8 +158,8 @@ func (f *file) processRequire(req *require, upgrade bool) (bool, error) {
 		return isNew, err
 	}
 
-	// the existing requirement is newer so we skip installation
-	if c > 0 {
+	// the existing requirement is newer or equal so we skip installation
+	if c >= 0 {
 		return isNew, nil
 	}
 

cmd/dagger/cmd/mod/repo_test.go

@@ -16,25 +16,25 @@ func TestClone(t *testing.T) {
 		{
 			name: "resolving shorter hash version",
 			require: require{
-				cloneRepo: "github.com/tjovicic/gcpcloudrun-cue",
-				clonePath: "",
-				version:   "d530f2ea2099",
+				cloneRepo: "github.com/tjovicic/dagger-modules",
+				clonePath: "gcpcloudrun",
+				version:   "f4a5110b86a43871",
 			},
 		},
 		{
 			name: "resolving branch name",
 			require: require{
-				cloneRepo: "github.com/tjovicic/gcpcloudrun-cue",
-				clonePath: "",
+				cloneRepo: "github.com/tjovicic/dagger-modules",
+				clonePath: "gcpcloudrun",
 				version:   "main",
 			},
 		},
 		{
 			name: "resolving tag",
 			require: require{
-				cloneRepo: "github.com/tjovicic/gcpcloudrun-cue",
-				clonePath: "",
-				version:   "v0.3",
+				cloneRepo: "github.com/tjovicic/dagger-modules",
+				clonePath: "gcpcloudrun",
+				version:   "v0.1",
 			},
 		},
 		{
@@ -74,12 +74,12 @@ func TestListTags(t *testing.T) {
 	defer os.Remove(tmpDir)
 
 	r, err := clone(&require{
-		cloneRepo: "github.com/tjovicic/gcpcloudrun-cue",
-		clonePath: "",
+		cloneRepo: "github.com/tjovicic/dagger-modules",
+		clonePath: "gcpcloudrun",
 		version:   "",
 	}, tmpDir, "", "")
 	if err != nil {
-		t.Error(err)
+		t.Fatal(err)
 	}
 
 	tags, err := r.listTags()

docs/learn/1011-package-manager.md

@@ -0,0 +1,122 @@
+---
+slug: /1011/package-manager/
+---
+
+# Manage packages using the package manager
+
+This tutorial illustrates how to install and upgrade packages using Dagger package manager.
+
+## Installing a package
+
+### Initializing workspace
+
+Create an empty directory for your new Dagger workspace:
+
+```shell
+mkdir workspace
+cd workspace
+```
+
+As described in the previous tutorials, initialize your Dagger workspace:
+
+```shell
+dagger init
+dagger new test
+```
+
+That will create 2 directories: `.dagger` and `cue.mod` where our package will reside:
+
+```shell
+.
+├── cue.mod
+│   ├── module.cue
+│   ├── pkg
+│   └── usr
+├── .dagger
+│   └── env
+│       └── test
+```
+
+### Install
+
+In our example we will use `gcpcloudrun` module from [github](https://github.com/tjovicic/dagger-modules/blob/main/gcpcloudrun/source.cue)
+Let's first add it to our `source.cue` file:
+
+```cue title="./source.cue"
+package main
+
+import (
+  "github.com/tjovicic/dagger-modules/gcpcloudrun"
+)
+
+run: gcpcloudrun.#Run
+```
+
+To install it just run 
+
+```shell
+dagger mod get github.com/tjovicic/dagger-modules/gcpcloudrun@v0.1
+```
+
+It should pull the `v0.1` version from Github, leave a copy in `cue.mod/pkg` and reflect the change in 
+`cue.mod/dagger.mod.cue` file:
+
+```shell
+cue.mod/pkg/github.com/
+└── tjovicic
+    └── dagger-modules
+        └── gcpcloudrun
+            ├── cue.mod
+            ├── README.md
+            └── source.cue
+```
+
+```cue title="./cue.mod/dagger.mod.cue"
+module: main
+
+github.com/tjovicic/dagger-modules/gcpcloudrun v0.1
+```
+
+Querying the current setup with `dagger query` should return a valid result:
+
+```json
+{
+  "run": {
+    "creds": {
+      "username": "oauth2accesstoken"
+    },
+    "deploy": {
+      "platform": "managed",
+      "port": "80"
+    },
+    "push": {
+      "auth": {
+        "username": "oauth2accesstoken"
+      },
+      "push": {}
+    }
+  }
+}
+```
+
+### Upgrading
+
+Now that you've successfully installed a package, let's try to upgrade it.
+
+```shell
+dagger mod get github.com/tjovicic/dagger-modules/gcpcloudrun@v0.2
+```
+
+You should see similar output:
+
+```shell
+12:25PM INF system | downloading github.com/tjovicic/dagger-modules:v0.2
+```
+
+And `cue.mod/dagger.mod.cue` should reflect the new version:
+
+```cue title="./cue.mod/dagger.mod.cue"
+module: main
+
+github.com/tjovicic/dagger-modules/gcpcloudrun v0.2
+```