From ca22cba8e41247701338142fa2057343e2a517fb Mon Sep 17 00:00:00 2001
From: Reyk Floeter <contact@reykfloeter.com>
Date: Tue, 4 Jun 2019 18:09:50 +0200
Subject: [PATCH] Allow to specify the probed cloud stacks with -c
 cloud[,cloud...]

---
 agent/azure.c       |  22 ++++---
 agent/cloud-agent.8 |  24 +++++++-
 agent/cloudinit.c   |  62 ++++----------------
 agent/main.c        | 140 ++++++++++++++++++++++++++++++++++++++------
 agent/main.h        |  32 ++++++++--
 agent/opennebula.c  |   7 ++-
 agent/openstack.c   |   8 ++-
 7 files changed, 210 insertions(+), 85 deletions(-)

diff --git a/agent/azure.c b/agent/azure.c
index 990d973..c880f9d 100644
--- a/agent/azure.c
+++ b/agent/azure.c
@@ -63,16 +63,22 @@ azure(struct system_config *sc)
 {
 	int	 ret = -1;
 
-	sc->sc_stack = "azure";
+	if (sc->sc_state == STATE_INIT) {
+		free(sc->sc_username);
+		if ((sc->sc_username = strdup("azure-user")) == NULL) {
+			log_warnx("failed to set default user");
+			return (-1);
+		}
 
-	/* Apply defaults */
-	free(sc->sc_username);
-	if ((sc->sc_username = strdup("azure-user")) == NULL) {
-		log_warnx("failed to set default user");
-		goto fail;
+		/* Apply defaults */
+		sc->sc_ovfenv = "/var/db/azure-ovf-env.xml";
+		sc->sc_priv = &az_config;
+		sc->sc_state = STATE_DHCP;
+		return (-1);
 	}
-	sc->sc_ovfenv = "/var/db/azure-ovf-env.xml";
-	sc->sc_priv = &az_config;
+
+	/* Don't try other endpoints */
+	sc->sc_state = STATE_DONE;
 
 	if (azure_getovfenv(sc) != 0) {
 		log_warnx("failed to get ovf-env.xml");
diff --git a/agent/cloud-agent.8 b/agent/cloud-agent.8
index b6990f3..5f01cf0 100644
--- a/agent/cloud-agent.8
+++ b/agent/cloud-agent.8
@@ -23,6 +23,7 @@
 .Sh SYNOPSIS
 .Nm cloud-agent
 .Op Fl nuv
+.Op Fl c Ar cloud Ns Op , Ns Ar cloud Ns ...
 .Op Fl p Ar length
 .Op Fl r Ar rootdisk
 .Op Fl t Ar timeout
@@ -32,10 +33,31 @@
 The
 .Nm
 program manages the OpenBSD provisioning and VM interaction in cloud
-environments, including Microsoft Azure and Amazon AWS.
+environments.
 .Pp
 The options are as follows:
 .Bl -tag -width Ds
+.It Fl c Ar cloud Ns Op , Ns Ar cloud Ns ...
+Probe a list of cloud stacks for provisioning in the specified order.
+If this option is not specified,
+.Nm
+tries to detect the environment and possible cloud stacks automatically.
+Supported
+.Ar cloud
+stacks are:
+.Pp
+.Bl -tag -width opennebula -offset indent -compact
+.It Ic azure
+Microsoft Azure
+.It Ic cloudinit
+Generic cloud-init
+.It Ic ec2
+Amazon AWS EC2
+.It Ic opennebula
+OpenNebula
+.It Ic openstack
+OpenStack
+.El
 .It Fl p Ar length
 Generate and set a random password for the default user.
 The password will be written in its plain form into the
diff --git a/agent/cloudinit.c b/agent/cloudinit.c
index 75b28e7..29582b4 100644
--- a/agent/cloudinit.c
+++ b/agent/cloudinit.c
@@ -31,65 +31,29 @@
 
 static int	 cloudinit_fetch(struct system_config *);
 
-int
-tryendpoint(struct system_config *sc,
-    int (fetch)(struct system_config *),
-    int (next)(struct system_config *))
-{
-	int	 errfd = -1, ret;
-
-	free(sc->sc_endpoint);
-	sc->sc_endpoint = NULL;
-
-	switch (sc->sc_dhcpendpoint) {
-	case 0:
-		sc->sc_dhcpendpoint = 1;
-		if (dhcp_getendpoint(sc) == -1)
-			return tryendpoint(sc, fetch, next);
-		break;
-	case 1:
-		sc->sc_dhcpendpoint = 2;
-		if ((sc->sc_endpoint = strdup(DEFAULT_ENDPOINT)) == NULL) {
-			log_warnx("failed to set defaults");
-			return (-1);
-		}
-		break;
-	default:
-		if (next == NULL)
-			return (-1);
-		sc->sc_dhcpendpoint = 0;
-		return (*next)(sc);
-	}
-
-	errfd = disable_output(sc, STDERR_FILENO);
-	ret = (*fetch)(sc);
-	enable_output(sc, STDERR_FILENO, errfd);
-	if (ret != 0)
-		return tryendpoint(sc, fetch, next);
-
-	return (0);
-}
-
 int
 ec2(struct system_config *sc)
 {
-	free(sc->sc_username);
-	if ((sc->sc_username = strdup("ec2-user")) == NULL) {
-		log_warnx("failed to set default user");
+	if (sc->sc_state == STATE_INIT) {
+		free(sc->sc_username);
+		if ((sc->sc_username = strdup("ec2-user")) == NULL) {
+			log_warnx("failed to set default user");
+			return (-1);
+		}
+		sc->sc_state = STATE_169;
 		return (-1);
 	}
-
-	sc->sc_stack = "ec2";
-	sc->sc_dhcpendpoint = 1;
-	return tryendpoint(sc, cloudinit_fetch, NULL);
+	return cloudinit_fetch(sc);
 }
 
 int
 cloudinit(struct system_config *sc)
 {
-	sc->sc_stack = "cloudinit";
-	sc->sc_dhcpendpoint = 0;
-	return tryendpoint(sc, cloudinit_fetch, NULL);
+	if (sc->sc_state == STATE_INIT) {
+		sc->sc_state = STATE_DHCP;
+		return (-1);
+	}
+	return cloudinit_fetch(sc);
 }
 
 static int
diff --git a/agent/main.c b/agent/main.c
index 05ae3dd..ed44b3a 100644
--- a/agent/main.c
+++ b/agent/main.c
@@ -56,6 +56,7 @@ static void	 agent_unconfigure(void);
 static char	*metadata_parse(char *, size_t, enum strtype);
 
 static int	 agent_timeout;
+static char	*cloudnames[] = CLOUDNAMES;
 
 int
 shell(const char *arg, ...)
@@ -970,7 +971,8 @@ metadata(struct system_config *sc, const char *path, enum strtype type)
 	g = http_get(&sc->sc_addr, 1,
 	    sc->sc_endpoint, 80, path, NULL, 0, NULL);
 	if (g != NULL)
-		log_debug("%s: HTTP %d %s", __func__, g->code, path);
+		log_debug("%s: HTTP %d http://%s%s", __func__, g->code,
+		    sc->sc_endpoint, path);
 
 	if (g != NULL && g->code == 200 && g->bodypartsz > 0)
 		str = metadata_parse(g->bodypart, g->bodypartsz, type);
@@ -1190,20 +1192,118 @@ pwgen(size_t len, char **hash)
 	return (password);
 }
 
+static void
+cloud_add(enum cloudname name, struct clouds *clouds)
+{
+	struct cloud	*cloud;
+
+	TAILQ_FOREACH(cloud, clouds, cloud_entry) {
+		if (cloud->cloud_name == name)
+			fatalx("cloud %s defined twice",
+			    cloudnames[name]);
+	}
+
+	if ((cloud = calloc(1, sizeof(*cloud))) == NULL)
+		fatal("%s: calloc", __func__);
+
+	cloud->cloud_name = name;
+	switch (name) {
+	case AZURE:
+		cloud->fetch = azure;
+		break;
+	case CLOUDINIT:
+		cloud->fetch = cloudinit;
+		break;
+	case EC2:
+		cloud->fetch = ec2;
+		break;
+	case OPENNEBULA:
+		cloud->fetch = opennebula;
+		break;
+	case OPENSTACK:
+		cloud->fetch = openstack;
+		break;
+	}
+
+	TAILQ_INSERT_TAIL(clouds, cloud, cloud_entry);
+}
+
+static int
+trycloud(struct system_config *sc, struct cloud *cloud)
+{
+	int		 errfd = -1, ret = -1;
+
+	free(sc->sc_endpoint);
+	sc->sc_endpoint = NULL;
+
+	switch (sc->sc_state) {
+	case STATE_INIT:
+		if ((cloud = TAILQ_FIRST(sc->sc_clouds)) == NULL)
+			return (0);
+		sc->sc_stack = cloudnames[cloud->cloud_name];
+		log_debug("%s: %s", __func__, sc->sc_stack);
+		TAILQ_REMOVE(sc->sc_clouds, cloud, cloud_entry);
+		break;
+	case STATE_DHCP:
+		sc->sc_state = STATE_169;
+		if (dhcp_getendpoint(sc) == -1)
+			return trycloud(sc, cloud);
+		break;
+	case STATE_169:
+		sc->sc_state = STATE_DONE;
+		if ((sc->sc_endpoint = strdup(DEFAULT_ENDPOINT)) == NULL) {
+			log_warnx("failed to set defaults");
+			goto done;
+		}
+		break;
+	case STATE_DONE:
+		sc->sc_state = STATE_INIT;
+		ret = trycloud(sc, NULL);
+		goto done;
+	}
+
+	errfd = disable_output(sc, STDERR_FILENO);
+	ret = (*cloud->fetch)(sc);
+	enable_output(sc, STDERR_FILENO, errfd);
+	if (ret != 0)
+		return trycloud(sc, cloud);
+
+ done:
+	free(cloud);
+	return (0);
+}
+
 int
 main(int argc, char *const *argv)
 {
 	struct system_config	*sc;
-	int			 verbose = 0, dryrun = 0, unconfigure = 0;
+	int			 verbose = 0, dryrun = 0, unconfigure = 0, sub;
 	int			 genpw = 0, ch, ret, timeout = CONNECT_TIMEOUT;
 	const char		*error = NULL, *rootdisk = NULL;
-	char			*args, *username = NULL;
+	char			*args, *username = NULL, *options, *value;
+	struct clouds		 clouds;
+
+	/* log to stderr */
+	log_init(1, LOG_DAEMON);
 
 	if ((args = get_args(argc, argv)) == NULL)
 		fatalx("failed to save args");
 
-	while ((ch = getopt(argc, argv, "np:r:t:U:uv")) != -1) {
+	TAILQ_INIT(&clouds);
+
+	while ((ch = getopt(argc, argv, "c:np:r:t:U:uv")) != -1) {
 		switch (ch) {
+		case 'c':
+			options = optarg;
+			while (*options) {
+				if ((sub = getsubopt(&options,
+				    cloudnames, &value)) == -1)
+					fatalx("invalid cloud stack");
+				else if (value != NULL)
+					fatalx("unexpected value");
+				cloud_add(sub, &clouds);
+			}
+			break;
 		case 'n':
 			dryrun = 1;
 			break;
@@ -1238,8 +1338,6 @@ main(int argc, char *const *argv)
 	argv += optind;
 	argc -= optind;
 
-	/* log to stderr */
-	log_init(1, LOG_DAEMON);
 	log_setverbose(verbose);
 
 	if (unconfigure) {
@@ -1262,24 +1360,30 @@ main(int argc, char *const *argv)
 	if (rootdisk != NULL && growdisk(sc) == -1)
 		fatalx("failed to grow %s", rootdisk);
 
+	sc->sc_clouds = &clouds;
 	sc->sc_args = args;
 	if (username != NULL) {
 		free(sc->sc_username);
 		sc->sc_username = username;
 	}
 
-	/*
-	 * XXX Detect cloud with help from hostctl and sysctl
-	 * XXX in addition to the interface name.
-	 */
-	if (opennebula(sc) == 0)
-		ret = 0;
-	else if (strcmp("hvn0", sc->sc_interface) == 0)
-		ret = azure(sc);
-	else if (strcmp("xnf0", sc->sc_interface) == 0)
-		ret = ec2(sc);
-	else
-		ret = openstack(sc);
+	if (TAILQ_EMPTY(&clouds)) {
+		/*
+		 * XXX Auto-detect cloud with help from hostctl and
+		 * XXX sysctl in addition to the interface name.
+		 */
+		if (strcmp("hvn0", sc->sc_interface) == 0) {
+			cloud_add(AZURE, &clouds);
+		} else if (strcmp("xnf0", sc->sc_interface) == 0) {
+			cloud_add(OPENNEBULA, &clouds);
+			cloud_add(EC2, &clouds);
+		} else {
+			cloud_add(OPENNEBULA, &clouds);
+			cloud_add(OPENSTACK, &clouds);
+			cloud_add(CLOUDINIT, &clouds);
+		}
+	}
+	ret = trycloud(sc, NULL);
 
 	if (genpw) {
 		if (sc->sc_password_hash != NULL)
diff --git a/agent/main.h b/agent/main.h
index 93b5f92..b54b789 100644
--- a/agent/main.h
+++ b/agent/main.h
@@ -29,12 +29,30 @@
 #define DEFAULT_ENDPOINT	"169.254.169.254"
 #define CONNECT_TIMEOUT		10 /* in seconds */
 
+enum cloudname {
+	AZURE,
+	CLOUDINIT,
+	EC2,
+	OPENNEBULA,
+	OPENSTACK
+};
+#define CLOUDNAMES	{						\
+	"azure", "cloudinit", "ec2", "opennebula", "openstack", NULL	\
+}
+
 enum strtype {
 	WORD,
 	LINE,
 	TEXT
 };
 
+enum state {
+	STATE_INIT,
+	STATE_DHCP,
+	STATE_169,
+	STATE_DONE
+};
+
 struct ssh_pubkey {
 	char			*ssh_keyval;
 	char			*ssh_keyfp;
@@ -66,6 +84,14 @@ struct net_addr {
 };
 TAILQ_HEAD(net_addrs, net_addr);
 
+struct system_config;
+struct cloud {
+	enum cloudname		 cloud_name;
+	int			(*fetch)(struct system_config *);
+	TAILQ_ENTRY(cloud)	 cloud_entry;
+};
+TAILQ_HEAD(clouds, cloud);
+
 struct system_config {
 	const char		*sc_stack;
 	char			*sc_args;
@@ -77,7 +103,8 @@ struct system_config {
 	char			*sc_pubkey;
 	char			*sc_userdata;
 	char			*sc_endpoint;
-	int			 sc_dhcpendpoint;
+	enum state		 sc_state;
+	struct clouds		*sc_clouds;
 	char			*sc_instance;
 	int			 sc_timeout;
 
@@ -125,9 +152,6 @@ int	 azure(struct system_config *);
 /* cloudinit.c */
 int	 ec2(struct system_config *);
 int	 cloudinit(struct system_config *);
-int	 tryendpoint(struct system_config *,
-	    int (fetch)(struct system_config *),
-	    int (next)(struct system_config *));
 
 /* opennebula.c */
 int	 opennebula(struct system_config *);
diff --git a/agent/opennebula.c b/agent/opennebula.c
index 8395920..69d36e0 100644
--- a/agent/opennebula.c
+++ b/agent/opennebula.c
@@ -40,12 +40,15 @@ opennebula(struct system_config *sc)
 	int		 ret = -1;
 	unsigned short	 unit;
 
+	if (sc->sc_state == STATE_INIT) {
+		sc->sc_state = STATE_169;
+		return (-1);
+	}
+
 	/* Return silently without error */
 	if ((fp = fopen("/mnt/context.sh", "r")) == NULL)
 		goto done;
 
-	sc->sc_stack = "opennebula";
-
 	while ((line = fparseln(fp, &len, &lineno,
 	    delim, FPARSELN_UNESCALL)) != NULL) {
 		/* key */
diff --git a/agent/openstack.c b/agent/openstack.c
index c60acd1..9088a1a 100644
--- a/agent/openstack.c
+++ b/agent/openstack.c
@@ -31,11 +31,14 @@
 
 static int	 openstack_fetch(struct system_config *);
 
-
 int
 openstack(struct system_config *sc)
 {
-	return tryendpoint(sc, openstack_fetch, cloudinit);
+	if (sc->sc_state == STATE_INIT) {
+		sc->sc_state = STATE_DHCP;
+		return (-1);
+	}
+	return openstack_fetch(sc);
 }
 
 static int
@@ -53,7 +56,6 @@ openstack_fetch(struct system_config *sc)
 	if ((json = metadata(sc,
 	    "/openstack/latest/meta_data.json", TEXT)) == NULL)
 		goto fail;
-	sc->sc_stack = "openstack";
 
 	if ((j = json_parse(json, strlen(json))) == NULL)
 		goto fail;