Merge pull request #1758 from hashicorp/hugoamvieira-env-file-workertags

feat(config): Add env and file support to Worker Tags

CHANGELOG.md

@@ -6,6 +6,8 @@ Canonical reference for changes, improvements, and bugfixes for Boundary.
 
 ### New and Improved
 
+* config: Add support for reading worker tags off of environment variables
+as well as files. ([PR](https://github.com/hashicorp/boundary/pull/1758))
 * config: Add support for go-sockaddr templates to Worker and Controller
   addresses. ([PR](https://github.com/hashicorp/boundary/pull/1731))
 * host: Plugin-based host catalogs will now schedule updates for all

internal/cmd/config/config.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/rand"
 	"encoding/base64"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -157,9 +158,10 @@ type Worker struct {
 
 	// We use a raw interface for parsing so that people can use JSON-like
 	// syntax that maps directly to the filter input or possibly more familiar
-	// key=value syntax. This is trued up in the Parse function below.
-	TagsRaw interface{}         `hcl:"tags"`
+	// key=value syntax, as well as accepting a string denoting an env or file
+	// pointer. This is trued up in the Parse function below.
 	Tags    map[string][]string `hcl:"-"`
+	TagsRaw interface{}         `hcl:"tags"`
 
 	// StatusGracePeriod represents the period of time (as a duration) that the
 	// worker will wait before disconnecting connections if it cannot make a
@@ -337,12 +339,60 @@ func Parse(d string) (*Config, error) {
 		if !strutil.Printable(result.Worker.Name) {
 			return nil, errors.New("Worker name contains non-printable characters")
 		}
+
 		if result.Worker.TagsRaw != nil {
 			switch t := result.Worker.TagsRaw.(type) {
+			// We allow `tags` to be a simple string containing a URL with schema.
+			// See: https://github.com/hashicorp/go-secure-stdlib/blob/main/parseutil/parsepath.go
+			case string:
+				rawTags, err := parseutil.ParsePath(t)
+				if err != nil {
+					return nil, fmt.Errorf("Error parsing worker tags: %w", err)
+				}
+
+				var temp []map[string]interface{}
+				err = hcl.Decode(&temp, rawTags)
+				if err != nil {
+					return nil, fmt.Errorf("Error decoding raw worker tags: %w", err)
+				}
+
+				if err := mapstructure.WeakDecode(temp, &result.Worker.Tags); err != nil {
+					return nil, fmt.Errorf("Error decoding the worker's tags: %w", err)
+				}
+
 			// HCL allows multiple labeled blocks with the same name, turning it
 			// into a slice of maps, hence the slice here. This format is the
 			// one that ends up matching the JSON that we use in the expression.
 			case []map[string]interface{}:
+				for _, m := range t {
+					for k, v := range m {
+						// We allow the user to pass in only the keys in HCL, and
+						// then set the values to point to a URL with schema.
+						valStr, ok := v.(string)
+						if !ok {
+							continue
+						}
+
+						parsed, err := parseutil.ParsePath(valStr)
+						if err != nil && !errors.Is(err, parseutil.ErrNotAUrl) {
+							return nil, fmt.Errorf("Error parsing worker tag values: %w", err)
+						}
+						if valStr == parsed {
+							// Nothing was found, ignore.
+							// WeakDecode will still parse it though as we
+							// don't know if this could be a valid tag.
+							continue
+						}
+
+						var tags []string
+						err = json.Unmarshal([]byte(parsed), &tags)
+						if err != nil {
+							return nil, fmt.Errorf("Error unmarshalling env var/file contents: %w", err)
+						}
+						m[k] = tags
+					}
+				}
+
 				if err := mapstructure.WeakDecode(t, &result.Worker.Tags); err != nil {
 					return nil, fmt.Errorf("Error decoding the worker's %q section: %w", "tags", err)
 				}
@@ -374,6 +424,7 @@ func Parse(d string) (*Config, error) {
 				}
 			}
 		}
+
 		for k, v := range result.Worker.Tags {
 			if k != strings.ToLower(k) {
 				return nil, fmt.Errorf("Tag key %q is not all lower-case letters", k)

internal/cmd/config/config_test.go

@@ -337,6 +337,292 @@ func TestParsingName(t *testing.T) {
 	}
 }
 
+func TestWorkerTags(t *testing.T) {
+	defaultStateFn := func(t *testing.T, tags string) {
+		t.Setenv("BOUNDARY_WORKER_TAGS", tags)
+	}
+	tests := []struct {
+		name          string
+		in            string
+		stateFn       func(t *testing.T, tags string)
+		actualTags    string
+		expWorkerTags map[string][]string
+		expErr        bool
+		expErrStr     string
+	}{
+		{
+			name: "tags in HCL",
+			in: `
+			worker {
+				tags {
+					type = ["dev", "local"]
+					typetwo = "devtwo"
+				}
+			}`,
+			expWorkerTags: map[string][]string{
+				"type":    {"dev", "local"},
+				"typetwo": {"devtwo"},
+			},
+			expErr: false,
+		},
+		{
+			name: "tags in HCL key=value",
+			in: `
+			worker {
+				tags = ["type=dev", "type=local", "typetwo=devtwo"]
+			}
+			`,
+			expWorkerTags: map[string][]string{
+				"type":    {"dev", "local"},
+				"typetwo": {"devtwo"},
+			},
+			expErr: false,
+		},
+		{
+			name: "no tags",
+			in: `
+			worker {
+				name = "testworker"
+			}
+			`,
+			expWorkerTags: nil,
+			expErr:        false,
+		},
+		{
+			name: "empty tags",
+			in: `
+			worker {
+				name = "testworker"
+				tags = {}
+			}
+			`,
+			expWorkerTags: map[string][]string{},
+			expErr:        false,
+		},
+		{
+			name: "empty tags 2",
+			in: `
+			worker {
+				name = "testworker"
+				tags = []
+			}
+			`,
+			expWorkerTags: map[string][]string{},
+			expErr:        false,
+		},
+		{
+			name: "empty str",
+			in: `
+			worker {
+				tags = ""
+			}`,
+			expWorkerTags: map[string][]string{},
+			expErr:        false,
+		},
+		{
+			name: "empty env var",
+			in: `
+			worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			expWorkerTags: map[string][]string{},
+			expErr:        false,
+		},
+		{
+			name: "not a url - entire tags block",
+			in: `
+			worker {
+				tags = "\x00"
+			}`,
+			expWorkerTags: map[string][]string{},
+			expErr:        true,
+			expErrStr:     `Error parsing worker tags: error parsing url ("parse \"\\x00\": net/url: invalid control character in URL"): not a url`,
+		},
+		{
+			name: "not a url - key's value set to string",
+			in: `
+			worker {
+				tags {
+					type = "\x00"
+				}
+			}
+			`,
+			expWorkerTags: map[string][]string{
+				"type": {"\x00"},
+			},
+			expErr: false,
+		},
+		{
+			name: "one tag key",
+			in: `
+			worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			stateFn:    defaultStateFn,
+			actualTags: `type = ["dev", "local"]`,
+			expWorkerTags: map[string][]string{
+				"type": {"dev", "local"},
+			},
+			expErr: false,
+		},
+		{
+			name: "multiple tag keys",
+			in: `
+			worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			stateFn: defaultStateFn,
+			actualTags: `
+			type = ["dev", "local"]
+			typetwo = ["devtwo", "localtwo"]
+			`,
+			expWorkerTags: map[string][]string{
+				"type":    {"dev", "local"},
+				"typetwo": {"devtwo", "localtwo"},
+			},
+			expErr: false,
+		},
+		{
+			name: "json tags - entire tags block",
+			in: `
+			worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			stateFn: defaultStateFn,
+			actualTags: `
+			{
+				"type": ["dev", "local"],
+				"typetwo": ["devtwo", "localtwo"]
+			}
+			`,
+			expWorkerTags: map[string][]string{
+				"type":    {"dev", "local"},
+				"typetwo": {"devtwo", "localtwo"},
+			},
+			expErr: false,
+		},
+		{
+			name: "json tags - keys specified in the HCL file, values point to env/file",
+			in: `
+			worker {
+				tags = {
+					type = "env://BOUNDARY_WORKER_TAGS"
+					typetwo = "env://BOUNDARY_WORKER_TAGS_TWO"
+				}
+			}`,
+			stateFn: func(t *testing.T, tags string) {
+				defaultStateFn(t, tags)
+				t.Setenv("BOUNDARY_WORKER_TAGS_TWO", `["devtwo", "localtwo"]`)
+			},
+			actualTags: `["dev","local"]`,
+			expWorkerTags: map[string][]string{
+				"type":    {"dev", "local"},
+				"typetwo": {"devtwo", "localtwo"},
+			},
+			expErr: false,
+		},
+		{
+			name: "json tags - mix n' match",
+			in: `
+			worker {
+				name = "web-prod-us-east-1"
+				tags {
+				  type = "env://BOUNDARY_WORKER_TYPE_TAGS"
+				  typetwo = "file://type_two_tags.json"
+				  typethree = ["devthree", "localthree"]
+				}
+			}
+			`,
+			stateFn: func(t *testing.T, tags string) {
+				workerTypeTags := `["dev", "local"]`
+				t.Setenv("BOUNDARY_WORKER_TYPE_TAGS", workerTypeTags)
+
+				filepath := "./type_two_tags.json"
+				err := os.WriteFile(filepath, []byte(`["devtwo", "localtwo"]`), 0o666)
+				require.NoError(t, err)
+
+				t.Cleanup(func() {
+					err := os.Remove(filepath)
+					require.NoError(t, err)
+				})
+			},
+			expWorkerTags: map[string][]string{
+				"type":      {"dev", "local"},
+				"typetwo":   {"devtwo", "localtwo"},
+				"typethree": {"devthree", "localthree"},
+			},
+			expErr: false,
+		},
+		{
+			name: "bad json tags",
+			in: `
+			worker {
+				tags = {
+					type = "env://BOUNDARY_WORKER_TAGS"
+					typetwo = "env://BOUNDARY_WORKER_TAGS"
+				}
+			}`,
+			stateFn: defaultStateFn,
+			actualTags: `
+			{
+				"type": ["dev", "local"],
+				"typetwo": ["devtwo", "localtwo"]
+			}
+			`,
+			expWorkerTags: nil,
+			expErr:        true,
+			expErrStr:     "Error unmarshalling env var/file contents: json: cannot unmarshal object into Go value of type []string",
+		},
+		{
+			name: "no clean mapping to internal structures",
+			in: `
+			worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			stateFn: defaultStateFn,
+			actualTags: `
+			worker {
+				tags {
+					type = "indeed"
+				}
+			}
+			`,
+			expErr:    true,
+			expErrStr: "Error decoding the worker's tags: 1 error(s) decoding:\n\n* '[0][worker][0]' expected type 'string', got unconvertible type 'map[string]interface {}', value: 'map[tags:[map[type:indeed]]]'",
+		},
+		{
+			name: "not HCL",
+			in: `worker {
+				tags = "env://BOUNDARY_WORKER_TAGS"
+			}`,
+			stateFn:    defaultStateFn,
+			actualTags: `not_hcl`,
+			expErr:     true,
+			expErrStr:  "Error decoding raw worker tags: At 1:9: key 'not_hcl' expected start of object ('{') or assignment ('=')",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.stateFn != nil {
+				tt.stateFn(t, tt.actualTags)
+			}
+
+			c, err := Parse(tt.in)
+			if tt.expErr {
+				require.EqualError(t, err, tt.expErrStr)
+				require.Nil(t, c)
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, c)
+			require.NotNil(t, c.Worker)
+			require.Equal(t, tt.expWorkerTags, c.Worker.Tags)
+		})
+	}
+}
+
 func TestController_EventingConfig(t *testing.T) {
 	t.Parallel()
 

website/content/docs/concepts/filtering/worker-tags.mdx

@@ -53,6 +53,53 @@ worker {
 
 In this format, it is not possible to have an equal sign be a part of the key.
 
+It is also possible to set the entire `tags` block or the keys' values within
+to point to an environment variable or filepath in the system, through the
+`env://` and `file://` URLs:
+
+```hcl
+worker {
+  name = "web-prod-us-east-1"
+  tags = "env://BOUNDARY_ALL_WORKER_TAGS"
+}
+```
+
+```hcl
+worker {
+  name = "web-prod-us-east-1"
+  tags {
+    type   = "env://BOUNDARY_WORKER_TYPE_TAGS"
+    region = "file://config/worker/region_tags"
+    usage  = ["admin"]
+  }
+}
+```
+
+Note that the syntax within the environment variable / file changes
+slightly depending on how the configuration file is set:
+
+For setting the entire `tags` block, both the keys and values need
+to be specified, in JSON or HCL format:
+
+```json
+{
+  "region": ["us-east-1"],
+  "type": ["prod", "webservers"]
+}
+```
+
+```hcl
+region = ["us-east-1"]
+type   = ["prod", "webservers"]
+```
+
+For setting the keys' values within the `tags` block, only a JSON
+array with the tags intended for the particular key is required:
+
+```json
+["prod", "webservers"]
+```
+
 # Target Worker Filtering
 
 Once workers have tags, it is possible to use these tags to control which

website/content/docs/configuration/worker.mdx

@@ -39,7 +39,8 @@ worker {
 - `tags` - A map of key-value pairs where values are an array of strings. Most
   commonly used for [filtering](/docs/concepts/filtering) targets a worker can
   proxy via [worker tags](/docs/concepts/filtering/worker-tags). On `SIGHUP`, the
-  tags set here will be re-parsed and new values used..
+  tags set here will be re-parsed and new values used. It can also be a string
+  referring to a file on disk (file://) or an env var (env://).
 
 ## KMS Configuration