diff --git a/doc/howto/configuration.md b/doc/howto/configuration.md
index 5fd5cd61..112b63a7 100644
--- a/doc/howto/configuration.md
+++ b/doc/howto/configuration.md
@@ -48,7 +48,8 @@ An example manifest entry may look like
         "nextflow": {
             "enabled": true,
             "job-image-whitelist": [
-              "quay.io/cdis/*:*"
+              "quay.io/cdis/*:*",
+              "1234.ecr.aws/nextflow-approved/{{username}}:*"
             ],
             "s3-bucket-whitelist": [
               "ngi-igenomes"
@@ -98,6 +99,10 @@ An example manifest entry may look like
     * `authz` describes access rules for this container. See the [Authorization documentation](/doc/explanation/authorization.md) for more details.
     * `nextflow` is for configuration specific to Nextflow containers. See the [Nextflow workspaces documentation](/doc/explanation/nextflow.md) for more details.
       * `enabled` is false by default; if true, automatically create AWS resources required to run Nextflow workflows in AWS Batch.
-      * `job-image-whitelist` are the only images that are allowed as Nextflow workflow containers. It supports wildcards `?` for a single character and `*` for multiple characters. Warning: setting the whitelist as an empty list allows all images!
+      * `job-image-whitelist` are the only images that are allowed as Nextflow workflow containers.
+        * Supports wildcards `?` for a single character and `*` for multiple characters.
+        * `{{username}}` can be used as a placeholder for the user's actual (escaped) username.
+        * **Warning:** setting the whitelist as an empty list allows all images!
+        * **Warning:** on the ECR side, tags are ignored and users are allowed access to the whole repo.
       * `s3-bucket-whitelist` are public buckets that Nextflow jobs are allowed to get data objects from. Access to actions "s3:GetObject" and "s3:ListBucket" for `arn:aws:s3:::<bucket>` and `arn:aws:s3:::<bucket>/*` will be granted.
       * `compute-environment-type` ("EC2", "SPOT", "FARGATE" or "FARGATE_SPOT"), `instance-ami`, `instance-type` ("optimal", "g4dn.xlarge"...), `instance-min-vcpus` and `instance-max-vcpus` are AWS Batch Compute Environment settings.
diff --git a/hatchery/hatchery.go b/hatchery/hatchery.go
index a76f438a..7e49261f 100644
--- a/hatchery/hatchery.go
+++ b/hatchery/hatchery.go
@@ -63,7 +63,7 @@ func home(w http.ResponseWriter, r *http.Request) {
 func getCurrentUserName(r *http.Request) (userName string) {
 	user := r.Header.Get("REMOTE_USER")
 	if user == "" {
-		Config.Logger.Printf("Warning: No username in header REMOTE_USER!")
+		Config.Logger.Print("Warning: No username in header REMOTE_USER!")
 	}
 
 	// escape username to sanitize input from http header
diff --git a/hatchery/nextflow.go b/hatchery/nextflow.go
index 10d4f5d9..f4afbd84 100644
--- a/hatchery/nextflow.go
+++ b/hatchery/nextflow.go
@@ -250,7 +250,7 @@ func createNextflowResources(userName string, nextflowConfig NextflowConfig) (st
 	policyName = fmt.Sprintf("%s-nf-%s", hostname, userName)
 	jobImageWhitelistCondition := "" // if not configured, all images are allowed
 	if len(nextflowConfig.JobImageWhitelist) > 0 {
-		jobImageWhitelist := fmt.Sprintf(`"%v"`, strings.Join(nextflowConfig.JobImageWhitelist, "\", \""))
+		jobImageWhitelist := fmt.Sprintf(`"%v"`, strings.Join(replaceAllUsernamePlaceholders(nextflowConfig.JobImageWhitelist, userName), "\", \""))
 		jobImageWhitelistCondition = fmt.Sprintf(`,
 		"Condition": {
 			"StringLike": {
@@ -528,13 +528,10 @@ func setupVpcAndSquid(ec2Svc *ec2.EC2, userName string, hostname string) (*strin
 
 // Function to make sure launch template is created, and configured correctly
 // We need a launch template since we need a user data script to authenticate with private ECR repositories
-func ensureLaunchTemplate(ec2Svc *ec2.EC2, userName string, hostname string) (*string, error) {
+func ensureLaunchTemplate(ec2Svc *ec2.EC2, userName string, hostname string, jobImageWhitelist []string) (*string, error) {
 
 	// user data script to authenticate with private ECR repositories
-	userData, err := generateUserData(userName)
-	if err != nil {
-		return nil, err
-	}
+	userData := generateEcrLoginUserData(jobImageWhitelist, userName)
 
 	launchTemplateName := fmt.Sprintf("%s-nf-%s", hostname, userName)
 
@@ -585,7 +582,7 @@ func createBatchComputeEnvironment(userName string, hostname string, tagsMap map
 	}
 
 	// the launch template for the compute envrionment must be user-specific as well
-	launchTemplateName, err := ensureLaunchTemplate(ec2Svc, userName, hostname)
+	launchTemplateName, err := ensureLaunchTemplate(ec2Svc, userName, hostname, nextflowConfig.JobImageWhitelist)
 	if err != nil {
 		return "", err
 	}
@@ -1553,13 +1550,33 @@ workDir = '%s'`,
 	return configContents, nil
 }
 
+func replaceAllUsernamePlaceholders(strArray []string, userName string) []string {
+	var result []string
+	for _, str := range strArray {
+		result = append(result, strings.Replace(str, "{{username}}", userName, -1))
+	}
+	return result
+}
+
 // function to generate user data
-func generateUserData(userName string) (string, error) {
-	// TODO: read repo from config
-	approvedRepo := "143731057154.dkr.ecr.us-east-1.amazonaws.com/nextflow-approved"
+func generateEcrLoginUserData(jobImageWhitelist []string, userName string) string {
+	var ecrRepos []string
+	for _, image := range replaceAllUsernamePlaceholders(jobImageWhitelist, userName) {
+		if strings.Contains(image, ".ecr.") {
+			// NOTE: on the ECR side, tags are ignored and users are allowed access to the whole repo.
+			repo := strings.Split(image, ":")[0]
+			ecrRepos = append(ecrRepos, repo)
+		}
+	}
 
 	// TODO: read region from config
-	userData := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf(`MIME-Version: 1.0
+	runCmd := ""
+	for _, approvedRepo := range ecrRepos {
+		runCmd += fmt.Sprintf(`
+- aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin %s`, approvedRepo)
+	}
+
+	userData := fmt.Sprintf(`MIME-Version: 1.0
 Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="
 
 --==MYBOUNDARY==
@@ -1567,8 +1584,8 @@ Content-Type: text/cloud-config; charset="us-ascii"
 
 packages:
 - aws-cli
-runcmd:
-- aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin %s/%s
---==MYBOUNDARY==--`, approvedRepo, userName)))
-	return userData, nil
+runcmd:%s
+--==MYBOUNDARY==--`, runCmd)
+
+	return base64.StdEncoding.EncodeToString([]byte(userData))
 }
diff --git a/hatchery/nextflow_test.go b/hatchery/nextflow_test.go
new file mode 100644
index 00000000..1c824f5e
--- /dev/null
+++ b/hatchery/nextflow_test.go
@@ -0,0 +1,51 @@
+package hatchery
+
+import (
+	"encoding/base64"
+	"fmt"
+	"testing"
+)
+
+func TestReplaceAllUsernamePlaceholders(t *testing.T) {
+	defer SetupAndTeardownTest()()
+
+	initialArray := []string{"quay.io/cdis/*:*", "1234.ecr.aws/nextflow-repo/{{username}}"}
+	userName := "test-escaped-username"
+	replacedArray := replaceAllUsernamePlaceholders(initialArray, userName)
+	expectedOutput := []string{"quay.io/cdis/*:*", fmt.Sprintf("1234.ecr.aws/nextflow-repo/%s", userName)}
+
+	errMsg := fmt.Sprintf("The 'replaceUsernamePlaceholder' function should have returned the expected output '%v', but it returned: '%v'", expectedOutput, replacedArray)
+	if len(replacedArray) != len(expectedOutput) {
+		t.Error(errMsg)
+	}
+	for i := range replacedArray {
+		if replacedArray[i] != expectedOutput[i] {
+			t.Error(errMsg)
+		}
+	}
+}
+
+func TestGenerateEcrLoginUserData(t *testing.T) {
+	defer SetupAndTeardownTest()()
+
+	jobImageWhitelist := []string{"1234.ecr.aws/repo1:tagA", "1234.ecr.aws/repo/without/tag", "quay.io/cdis/*:*", "1234.ecr.aws/nextflow-repo/{{username}}:tagB"}
+	userName := "test-escaped-username"
+	userData := generateEcrLoginUserData(jobImageWhitelist, userName)
+	expectedOutput := `MIME-Version: 1.0
+Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="
+
+--==MYBOUNDARY==
+Content-Type: text/cloud-config; charset="us-ascii"
+
+packages:
+- aws-cli
+runcmd:
+- aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 1234.ecr.aws/repo1
+- aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 1234.ecr.aws/repo/without/tag
+- aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 1234.ecr.aws/nextflow-repo/test-escaped-username
+--==MYBOUNDARY==--`
+
+	if userData != base64.StdEncoding.EncodeToString([]byte(expectedOutput)) {
+		t.Errorf("The 'generateEcrLoginUserData' function should have returned the expected output '%v', but it returned: '%v'", expectedOutput, userData)
+	}
+}