watch a specific folder

README.md

@@ -2,30 +2,57 @@
 
 ## Setup
 
-Before running the `imap-json-fetcher`, ensure that the following environment variables are set:
+Before running the `imap-json-fetcher`, ensure that you have configured the necessary environment variables. This script uses these variables to securely connect to your IMAP server and fetch emails from a specified mailbox.
 
-- `IMAP_HOST`: Your IMAP server address (e.g., `imap.example.com:993`).
-- `IMAP_USERNAME`: Your email username.
-- `IMAP_PASSWORD`: Your email password.
+### Required Environment Variables
 
-You can set these environment variables in a Unix-like terminal as follows:
+Set the following environment variables in your system:
+
+- `IMAP_HOST`: The address of your IMAP server, including the port if necessary (e.g., `imap.example.com:993`).
+- `IMAP_USERNAME`: Your email account username.
+- `IMAP_PASSWORD`: Your email account password.
+- `IMAP_FOLDER`: The specific folder to monitor for new emails. If not specified, the script defaults to monitoring the "INBOX".
+
+You can set these variables in a Unix-like environment using the following commands:
 
 ```bash
 export IMAP_HOST="your_imap_server_address"
 export IMAP_USERNAME="your_username"
 export IMAP_PASSWORD="your_password"
+export IMAP_FOLDER="your_folder_name"  # Optional, defaults to "INBOX"
 ```
 
-## Running the Script
+### Running the Script
 
-To run the `imap-json-fetcher`, navigate to the `dist` directory where the binary is located, and use the following command:
+Navigate to the `dist` directory where the binary is compiled, and run the script using the following command:
 
 ```bash
 ./imap-json-fetcher
 ```
 
-This assumes that you have already compiled the binary and placed it in the `dist` directory.
+### Docker Container Example
+
+For running in a Docker container, you might set it up like this, passing the environment variables into your container. Replace specifics to fit your architecture and environment settings:
+
+```bash
+docker run --env IMAP_HOST=$IMAP_HOST \
+           --env IMAP_USERNAME=$IMAP_USERNAME \
+           --env IMAP_PASSWORD=$IMAP_PASSWORD \
+           --env IMAP_FOLDER=$IMAP_FOLDER \
+           --name imap-json-fetcher \
+           your_docker_image
+```
+
+This command assumes that you've built a Docker image named `your_docker_image` that encapsulates your application.
 
 ## Output
 
-The `imap-json-fetcher` will listen for new emails and output the extracted email addresses in separate JSON files, one per email, named in the format `email-seqNum.json`.
+The `imap-json-fetcher` listens for new emails arriving in the specified IMAP folder. For each new email, it extracts relevant data and saves this information in separate JSON files. The inclusion of the `IMAP_FOLDER` environment variable allows flexibility in choosing which folder to monitor, beyond just the default "INBOX".
+
+### File Naming Convention
+
+Output files are named using a timestamp to ensure uniqueness: `email-yyyyMMdd-HHmmss.json`. This format prevents overwriting files and helps in organizing data chronologically.
+
+## Flexibility in Folder Selection
+
+The `IMAP_FOLDER` environment variable provides users the flexibility to monitor various folders within their email account, such as "Sent", "Archive", or custom labels, depending on their specific requirements.

build_logs/darwin_amd64_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/darwin_arm64_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_amd64_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_amd64_static_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_arm64_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_arm64_static_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_arm_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

build_logs/linux_arm_static_build.log

@@ -0,0 +1 @@
+main.go:2:1: expected 'package', found 'import'

email-20240504-091515-0.json

@@ -0,0 +1,21 @@
+{
+  "body": "test9\r\n",
+  "date": "2024-05-04T13:15:07Z",
+  "from": [
+    {
+      "PersonalName": "",
+      "AtDomainList": "",
+      "MailboxName": "imapfetcher",
+      "HostName": "nixc.us"
+    }
+  ],
+  "subject": "test9",
+  "to": [
+    {
+      "PersonalName": "",
+      "AtDomainList": "",
+      "MailboxName": "imapfetcher",
+      "HostName": "nixc.us"
+    }
+  ]
+}

go.mod

@@ -1,14 +1,3 @@
 module imap-json-fetcher
 
 go 1.21.1
-
-require (
-	github.com/emersion/go-imap v1.2.1
-	github.com/emersion/go-message v0.15.0
-)
-
-require (
-	github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 // indirect
-	github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 // indirect
-	golang.org/x/text v0.3.7 // indirect
-)

go.sum

@@ -1,12 +0,0 @@
-github.com/emersion/go-imap v1.2.1 h1:+s9ZjMEjOB8NzZMVTM3cCenz2JrQIGGo5j1df19WjTA=
-github.com/emersion/go-imap v1.2.1/go.mod h1:Qlx1FSx2FTxjnjWpIlVNEuX+ylerZQNFE5NsmKFSejY=
-github.com/emersion/go-message v0.15.0 h1:urgKGqt2JAc9NFJcgncQcohHdiYb803YTH9OQwHBHIY=
-github.com/emersion/go-message v0.15.0/go.mod h1:wQUEfE+38+7EW8p8aZ96ptg6bAb1iwdgej19uXASlE4=
-github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 h1:OJyUGMJTzHTd1XQp98QTaHernxMYzRaOasRir9hUlFQ=
-github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
-github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 h1:IbFBtwoTQyw0fIM5xv1HF+Y+3ZijDR839WMulgxCcUY=
-github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
-golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

main.go

@@ -1,4 +1,3 @@
-package main
 
 import (
 	"encoding/json"
@@ -11,6 +10,7 @@ import (
 
 	"github.com/emersion/go-imap"
 	"github.com/emersion/go-imap/client"
+	"github.com/emersion/go-imap-idle"
 	"github.com/emersion/go-message/mail"
 )
 
@@ -18,67 +18,96 @@ func main() {
 	host := os.Getenv("IMAP_HOST")
 	username := os.Getenv("IMAP_USERNAME")
 	password := os.Getenv("IMAP_PASSWORD")
+	folder := os.Getenv("IMAP_FOLDER")
+	if folder == "" {
+		folder = "INBOX"
+	}
 
 	if host == "" || username == "" || password == "" {
-		log.Fatal("Environment variables IMAP_HOST, IMAP_USERNAME, and IMAP_PASSWORD must be set")
+		log.Fatal("Required environment variables are not set")
 	}
 
 	log.Println("Connecting to server...")
-
-	// Connect to the IMAP server
 	c, err := client.DialTLS(host, nil)
 	if err != nil {
 		log.Fatalf("Failed to connect to IMAP server: %v", err)
 	}
-	log.Println("Connected")
 	defer c.Logout()
 
-	// Login
 	if err := c.Login(username, password); err != nil {
 		log.Fatalf("Failed to log in: %v", err)
 	}
-	log.Println("Logged in")
 
-	// Select INBOX
-	_, err = c.Select("INBOX", false)
+	log.Println("Logged in and authenticated")
+
+	// Ensure the selected folder is continuously monitored
+	for {
+		if err := monitorFolder(c, folder); err != nil {
+			log.Printf("Error monitoring folder %s: %v", folder, err)
+			log.Println("Attempting to reconnect in 30 seconds...")
+			time.Sleep(30 * time.Second)
+			continue
+		}
+	}
+}
+
+func monitorFolder(c *client.Client, folder string) error {
+	_, err := c.Select(folder, false)
 	if err != nil {
-		log.Fatalf("Failed to select INBOX: %v", err)
+		return fmt.Errorf("failed to select '%s': %w", folder, err)
 	}
 
-	// Set up criteria to search for new unseen emails
-	criteria := imap.NewSearchCriteria()
-	criteria.WithoutFlags = []string{imap.SeenFlag}
-	ids, err := c.Search(criteria)
-	if err != nil {
-		log.Fatalf("Failed to search emails: %v", err)
-	}
-	if len(ids) == 0 {
-		log.Println("No new emails")
-		return
-	}
+	log.Printf("Monitoring folder: %s", folder)
+	idleClient := idle.NewClient(c)
+	done := make(chan error, 1)
 
-	seqset := new(imap.SeqSet)
-	seqset.AddNum(ids...)
-
-	section := &imap.BodySectionName{}
-	items := []imap.FetchItem{section.FetchItem(), imap.FetchEnvelope}
-	messages := make(chan *imap.Message)
 	go func() {
-		if err := c.Fetch(seqset, items, messages); err != nil {
-			log.Fatalf("Failed to fetch emails: %v", err)
+		done <- idleClient.Idle(nil)
+	}()
+
+	for {
+		select {
+		case err := <-done:
+			if err != nil {
+				return fmt.Errorf("idle error: %w", err)
+			}
+			return nil
+		case <-time.After(29 * time.Minute): // Re-initiate IDLE approximately every 29 minutes
+			if err := idleClient.Terminate(); err != nil {
+				log.Printf("Error terminating IDLE: %v", err)
+			}
+			return fmt.Errorf("reinitializing IDLE")
+		}
+	}
+}
+
+func processNewMessages(c *client.Client, mbox *imap.MailboxStatus) {
+	seqset := new(imap.SeqSet)
+	seqset.AddRange(mbox.Messages, mbox.Messages)
+
+	messages := make(chan *imap.Message, 10)
+	go func() {
+		if err := c.Fetch(seqset, []imap.FetchItem{imap.FetchEnvelope, imap.FetchBody}, messages); err != nil {
+			log.Fatalf("Failed to fetch new messages: %v", err)
 		}
 	}()
 
-	counter := 0
 	for msg := range messages {
+		processMessage(msg)
+	}
+}
+
+// processMessage processes a single message, extracting data and saving to JSON
+func processMessage(msg *imap.Message) {
 	if msg == nil {
-			continue
+		log.Println("No message to process")
+		return
 	}
 
-		body := msg.GetBody(section)
+	body := msg.GetBody(&imap.BodySectionName{})
 	if body == nil {
 		log.Println("No body fetched for this message")
-			continue
+		return
 	}
 
 	r, err := mail.CreateReader(body)
@@ -122,12 +151,10 @@ func main() {
 	}
 
 	timestamp := time.Now().Format("20060102-150405")
-		fileName := fmt.Sprintf("email-%s-%d.json", timestamp, counter)
-		counter++
+	fileName := fmt.Sprintf("email-%s.json", timestamp)
 	err = os.WriteFile(fileName, emailJSON, 0644)
 	if err != nil {
 		log.Fatalf("Failed to write file %s: %v", fileName, err)
 	}
 	log.Printf("Saved %s", fileName)
-	}
 }