Wrote first docker-tcp script version

content/posts/docker-tcp.md

@@ -79,8 +79,8 @@ with the machine's public IP.
 This file can now be used to generate the actual signed certificate:
 
 ```shell
-openssl x509 -req -days 365 -sha256 -in server.csr -CA ca.pem -CAkey \
-    ca-key.pem -CAcreateserial -out server-cert.pem -extfile extfile.cnf
+openssl x509 -req -days 365 -sha256 -in server.csr -CA ca.pem \
+    -CAkey ca-key.pem -CAcreateserial -out server-cert.pem -extfile extfile.cnf
 ```
 
 Here, we can once again change the days argument to the value we want. After
@@ -151,7 +151,7 @@ encrypted connection. Let's test it by adding it to Portainer!
 
 Thankfully this is the easy part. In Portainer, add a new endpoint and choose
 the "Docker" type. Pick a name for your endpoint, fill in the endpoint URL
-including the port number (Docker's default port number is `2375`) and enable
+including the port number (Docker's default port number is `2376`) and enable
 the "TLS" switch. We choose "TLS with server and client verification", as this
 is the safest. The files to upload are `ca.pem` for the TLS CA certificate,
 `cert.pem` for the TLS certificate and `key.pem` for the TLS key. If all goes

static/scripts/docker-tcp.sh

@@ -10,9 +10,21 @@ days=365
 
 # Displays how to use the program
 function usage() {
-    echo "This script generates OpenSSL certificate pairs which can be used to expose a Docker API."
-    echo
-    echo "Usage: $0 [-h] [-d DAYS] HOST IP"
+    cat << EOF
+This script generates OpenSSL certificate pairs which can be used to expose a
+Docker API.
+
+Usage: $0 [-h] [-d DAYS] HOST IP [CERTDIR]
+
+    HOST     hostname of the machine to expose
+    IP       public IP of the machine to expose
+    CERTDIR  directory where the certificates will reside on the machine. If
+             specified, a startup_options.conf file is created for you, which
+             can then be copied over to the host.
+
+    -h       show this message
+    -d       how many days the certificate will be valid; defaults to 365
+EOF
     exit 1
 }
 
@@ -25,19 +37,99 @@ while getopts ':hd:' c; do
 done
 shift $((OPTIND - 1))
 
+host="$1"
+ip="$2"
+certdir="$3"
+
 # Check for correct amount of arguments
-[ $# -eq 2 ] || usage
+[ $# -lt 2 ] && [ $# -gt 3 ] && usage
 
 
+# =====SERVER-SIDE=====
 # Generate CA key
-openssl genrsa -aes256 -out ca-key.pem 4096
-openssl req -new -x509 -days "$DAYS" -key ca-key.pem -sha256 -out ca.pem
+openssl genrsa \
+    -aes256 \
+    -out ca-key.pem \
+    4096
+openssl req \
+    -new \
+    -x509 \
+    -days "$days" \
+    -key ca-key.pem \
+    -sha256 \
+    -out ca.pem
 
 # Generate server key
-openssl genrsa -out server-key.pem 4096
-openssl req -subj "/CN=$HOST" -sha256 -new -key server-key.pem -out server.csr
+openssl genrsa \
+    -out server-key.pem \
+    4096
+openssl req \
+    -subj "/CN=$host" \
+    -sha256 \
+    -new \
+    -key server-key.pem \
+    -out server.csr
 
 # Create extfile.cnf
-
-echo subjectAltName = "DNS:$HOST,IP:$IP,IP:127.0.0.1" > extfile.cnf
+echo subjectAltName = "DNS:$host,IP:$ip,IP:127.0.0.1" > extfile.cnf
 echo extendedKeyUsage = serverAuth >> extfile.cnf
+
+# Generate server-side certificate
+openssl x509 \
+    -req \
+    -days 365 \
+    -sha256 \
+    -in server.csr \
+    -CA ca.pem \
+    -CAkey ca-key.pem \
+    -CAcreateserial \
+    -out server-cert.pem \
+    -extfile extfile.cnf
+
+
+# =====CLIENT-SIDE=====
+# Generate key & csr
+openssl genrsa \
+    -out key.pem \
+    4096
+openssl req \
+    -subj '/CN=client' \
+    -new \
+    -key key.pem \
+    -out client.csr
+
+# Create extfile-client.cnf
+echo extendedKeyUsage = clientAuth > extfile-client.cnf
+
+# Generate certificate
+openssl x509 \
+    -req \
+    -days 365 \
+    -sha256 \
+    -in client.csr \
+    -CA ca.pem \
+    -CAkey ca-key.pem \
+    -CAcreateserial \
+    -out cert.pem \
+    -extfile extfile-client.cnf
+
+# Create startup_options.conf
+if [ -n "$certdir" ]; then
+    cat > startup_options.conf << EOF
+[Service]
+ExecStart=
+ExecStart=/usr/bin/dockerd --tlsverify --tlscacert='$certdir/ca.pem' --tlscert='$certdir/server-cert.pem' --tlskey='$certdir/server-key.pem' -H fd:// -H tcp://0.0.0.0:2376
+EOF
+
+    echo "Copy 'ca.pem', 'server-cert.pem' and 'server-key.pem' over to '$certdir' on the machine."
+    echo "'startup_options.conf' should be placed in '/etc/systemd/docker.service.d/startup_options.conf'."
+
+else
+    echo "Copy 'ca.pem', 'server-cert.pem' and 'server-key.pem' over to the chosen directory on the machine."
+    echo "Create a 'startup_options.conf' file as specified."
+
+fi
+
+echo "Now, you can restart the Docker daemon using:"
+echo "  systemctl daemon-reload"
+echo "  systemctl restart docker.service"