hscript: Implement 'Image' script option

This option is for generating images using Horizon.  It skips most
disk-related operations, except for preparing /etc/fstab.
It also skips setting the running system's hostname.

5 files changed, 49 insertions, 40 deletions

diff --git a/hscript/disk.cc b/hscript/disk.cc
index 225148b..b0608b3 100644
--- a/hscript/disk.cc
+++ b/hscript/disk.cc
@@ -792,7 +792,7 @@ bool Mount::execute() const {
 #endif
 
     /* We have to get the filesystem for the node. */
-    if(script->options().test(Simulate)) {
+    if(script->options().test(Simulate) || script->options().test(Image)) {
         fstype = "auto";
     }
 #ifdef HAS_INSTALL_ENV
@@ -818,6 +818,9 @@ bool Mount::execute() const {
         std::cout << this->device() << " " << actual_mount << std::endl;
     }
 #ifdef HAS_INSTALL_ENV
+    else if(script->options().test(Image)) {
+        /* no-op; we don't mount during image creation (but we want fstab) */
+    }
     else {
         /* mount */
         if(!fs::exists(actual_mount, ec)) {
diff --git a/hscript/meta.cc b/hscript/meta.cc
index 2f4e4eb..e0c2b52 100644
--- a/hscript/meta.cc
+++ b/hscript/meta.cc
@@ -95,7 +95,9 @@ bool Hostname::execute() const {
         std::cout << "hostname " << actual << std::endl;
     }
 #ifdef HAS_INSTALL_ENV
-    else {
+    else if(script->options().test(Image)) {
+        /* no-op; we don't want to set the image builder's hostname */
+    } else {
         if(sethostname(actual.c_str(), actual.size()) == -1) {
             output_error("installfile:" + std::to_string(this->lineno()),
                          "hostname: failed to set host name",
diff --git a/hscript/script.cc b/hscript/script.cc
index 70381d7..cac5f3e 100644
--- a/hscript/script.cc
+++ b/hscript/script.cc
@@ -299,7 +299,7 @@ Script *Script::load(std::istream &sstream, const ScriptOptions &opts) {
         if(!the_script->internal->rootpw) {
             MISSING_ERROR("rootpw")
         }
-        if(the_script->internal->mounts.size() == 0) {
+        if(the_script->internal->mounts.size() == 0 && !opts.test(Image)) {
             MISSING_ERROR("mount")
         }
     }
diff --git a/hscript/script.hh b/hscript/script.hh
index 31e486d..5cb6db2 100644
--- a/hscript/script.hh
+++ b/hscript/script.hh
@@ -41,6 +41,8 @@ enum ScriptOptionFlags {
     Pretty,
     /*! Just print commands that would be run, for testing/debug */
     Simulate,
+    /*! Installing to an image; don't mount anything */
+    Image,
     /*! Count of flags */
     NumFlags
 };
diff --git a/hscript/script_e.cc b/hscript/script_e.cc
index 775f93a..91ebe0f 100644
--- a/hscript/script_e.cc
+++ b/hscript/script_e.cc
@@ -96,53 +96,55 @@ bool Script::execute() const {
 
     /**************** DISK SETUP ****************/
     output_step_start("disk");
+    if(!opts.test(Image)) {
 #ifdef HAS_INSTALL_ENV
-    if(opts.test(InstallEnvironment)) ped_device_probe_all();
+        if(opts.test(InstallEnvironment)) ped_device_probe_all();
 #endif /* HAS_INSTALL_ENV */
-    /* REQ: Runner.Execute.diskid */
-    for(auto &diskid : internal->diskids) {
-        EXECUTE_OR_FAIL("diskid", diskid)
-    }
+        /* REQ: Runner.Execute.diskid */
+        for(auto &diskid : internal->diskids) {
+            EXECUTE_OR_FAIL("diskid", diskid)
+        }
 
-    /* REQ: Runner.Execute.disklabel */
-    for(auto &label : internal->disklabels) {
-        EXECUTE_OR_FAIL("disklabel", label)
-    }
+        /* REQ: Runner.Execute.disklabel */
+        for(auto &label : internal->disklabels) {
+            EXECUTE_OR_FAIL("disklabel", label)
+        }
 
-    /* REQ: Runner.Execute.partition */
-    /* Ensure partitions are created in on-disk order. */
-    std::sort(internal->partitions.begin(), internal->partitions.end(),
-              [](std::unique_ptr<Partition> const &e1,
-                 std::unique_ptr<Partition> const &e2) {
-        return (e1->device() + "p" + std::to_string(e1->partno())) <
-               (e2->device() + "p" + std::to_string(e2->partno()));
-    });
-    for(auto &part : internal->partitions) {
-        EXECUTE_OR_FAIL("partition", part)
-    }
+        /* REQ: Runner.Execute.partition */
+        /* Ensure partitions are created in on-disk order. */
+        std::sort(internal->partitions.begin(), internal->partitions.end(),
+                  [](std::unique_ptr<Partition> const &e1,
+                     std::unique_ptr<Partition> const &e2) {
+            return (e1->device() + "p" + std::to_string(e1->partno())) <
+                   (e2->device() + "p" + std::to_string(e2->partno()));
+        });
+        for(auto &part : internal->partitions) {
+            EXECUTE_OR_FAIL("partition", part)
+        }
 
-    /* encrypt PVs */
+        /* encrypt PVs */
 
-    /* REQ: Runner.Execute.lvm_pv */
-    for(auto &pv : internal->lvm_pvs) {
-        EXECUTE_OR_FAIL("lvm_pv", pv)
-    }
+        /* REQ: Runner.Execute.lvm_pv */
+        for(auto &pv : internal->lvm_pvs) {
+            EXECUTE_OR_FAIL("lvm_pv", pv)
+        }
 
-    /* REQ: Runner.Execute.lvm_vg */
-    for(auto &vg : internal->lvm_vgs) {
-        EXECUTE_OR_FAIL("lvm_vg", vg)
-    }
+        /* REQ: Runner.Execute.lvm_vg */
+        for(auto &vg : internal->lvm_vgs) {
+            EXECUTE_OR_FAIL("lvm_vg", vg)
+        }
 
-    /* REQ: Runner.Execute.lvm_lv */
-    for(auto &lv : internal->lvm_lvs) {
-        EXECUTE_OR_FAIL("lvm_lv", lv)
-    }
+        /* REQ: Runner.Execute.lvm_lv */
+        for(auto &lv : internal->lvm_lvs) {
+            EXECUTE_OR_FAIL("lvm_lv", lv)
+        }
 
-    /* encrypt */
+        /* encrypt */
 
-    /* REQ: Runner.Execute.fs */
-    for(auto &fs : internal->fses) {
-        EXECUTE_OR_FAIL("fs", fs)
+        /* REQ: Runner.Execute.fs */
+        for(auto &fs : internal->fses) {
+            EXECUTE_OR_FAIL("fs", fs)
+        }
     }
 
     /* REQ: Runner.Execute.mount */