Update micromamba installation logic

* Split installation from micromamba() into micromamba_install()
* Return -1 when micromamba cannot be installed
* Add stasis.ini option "indexer.micromamba_download_url"
* Add global variable micromamba_download_url
* The installation function attempts two known-good URLs by default
*

7 files changed, 95 insertions, 12 deletions

diff --git a/src/cli/stasis_indexer/helpers.c b/src/cli/stasis_indexer/helpers.c
index 3ef96e4..bdb538d 100644
--- a/src/cli/stasis_indexer/helpers.c
+++ b/src/cli/stasis_indexer/helpers.c
@@ -172,6 +172,11 @@ int micromamba_configure(const struct Delivery *ctx, struct MicromambaInfo *m) {
     setenv("PATH", pathvar, 1);
     guard_free(pathvar);
 
+    if (micromamba_install(m)) {
+        SYSERROR("Micromamba installation failed");
+        return -1;
+    }
+
     status += micromamba(m, "config prepend --env channels conda-forge");
     if (!globals.verbose) {
         status += micromamba(m, "config set --env quiet true");
diff --git a/src/cli/stasis_indexer/stasis_indexer_main.c b/src/cli/stasis_indexer/stasis_indexer_main.c
index 45bbb6c..c13d175 100644
--- a/src/cli/stasis_indexer/stasis_indexer_main.c
+++ b/src/cli/stasis_indexer/stasis_indexer_main.c
@@ -309,6 +309,23 @@ int main(const int argc, char *argv[]) {
     printf(BANNER, version, AUTHOR);
     guard_free(version);
 
+    char *cfg_path = NULL;
+    if (asprintf(&cfg_path, "%s/stasis.ini", globals.sysconfdir) < 0) {
+        SYSERROR("Unable to allocate memory for cfg path");
+        exit(1);
+    }
+    ctx._stasis_ini_fp.cfg_path = cfg_path;
+    ctx._stasis_ini_fp.cfg = ini_open(ctx._stasis_ini_fp.cfg_path);
+    if (ctx._stasis_ini_fp.cfg) {
+        if (populate_delivery_cfg(&ctx, INI_READ_RENDER)) {
+            SYSERROR("Unable to apply stasis configuration");
+            exit(1);
+        }
+    }
+    else {
+        SYSWARN("Unable to open stasis configuration file: %s", cfg_path);
+    }
+
     indexer_init_dirs(&ctx, workdir);
 
     msg(STASIS_MSG_L1, "%s delivery root %s\n",
diff --git a/src/lib/core/conda.c b/src/lib/core/conda.c
index c9eb750..444cfaa 100644
--- a/src/lib/core/conda.c
+++ b/src/lib/core/conda.c
@@ -5,7 +5,11 @@
 #include "conda.h"
 #include "version_compare.h"
 
-int micromamba(const struct MicromambaInfo *info, char *command, ...) {
+int micromamba_install(const struct MicromambaInfo *info) {
+    if (access(info->micromamba_prefix, F_OK) == 0) {
+        SYSINFO("micromamba already installed: %s", info->micromamba_prefix);
+        return 0;
+    }
     struct utsname sys;
     uname(&sys);
 
@@ -28,23 +32,54 @@ int micromamba(const struct MicromambaInfo *info, char *command, ...) {
         return -1;
     }
 
-    char url[PATH_MAX] = {0};
-    snprintf(url, sizeof(url), "https://micro.mamba.pm/api/micromamba/%s-%s/latest", sys.sysname, sys.machine);
+    // If we ever want an exact version instead of "latest", we need to use this format instead:
+    // https://github.com/mamba-org/micromamba-releases/releases/download/${version}/micromamba-${arch}
 
-    const char installer_name[] = "mm_latest";
+    // Micromamba hosts binaries on github and on their own website. Prefer github.
+    const char *url_fmts[] = {
+        info->download_url,
+        "https://github.com/mamba-org/micromamba-releases/releases/latest/download/micromamba-%s-%s",
+        "https://micro.mamba.pm/api/micromamba/%s-%s/latest",
+    };
+    const size_t url_fmts_max = sizeof(url_fmts) / sizeof(url_fmts[0]);
+
+    char url[PATH_MAX] = {0};
     char installer_path[PATH_MAX] = {0};
-    snprintf(installer_path, sizeof(installer_path), "%s/%s", info->download_dir, installer_name);
+    const char *installer_name = "mm_latest";
+
+    size_t fail_count = 0;
+    for (size_t url_i = 0; url_i < url_fmts_max; url_i++) {
+        if (url_i == 0 && info->download_url) {
+            // If the caller supplies a download_url, use it
+            snprintf(url, sizeof(url), "%s", info->download_url);
+        } else if (url_i == 0 && isempty(info->download_url)) {
+            // No download_url has been defined, or is an empty string
+            continue;
+        } else {
+            snprintf(url, sizeof(url), url_fmts[url_i], sys.sysname, sys.machine);
+        }
 
-    if (access(installer_path, F_OK)) {
-        char *errmsg = NULL;
-        const long http_code = download(url, installer_path, &errmsg);
-        if (HTTP_ERROR(http_code)) {
-            SYSERROR("download failed: %ld: %s", http_code, errmsg);
-            guard_free(errmsg);
-            return -1;
+        snprintf(installer_path, sizeof(installer_path), "%s/%s", info->download_dir, installer_name);
+
+        if (access(installer_path, F_OK)) {
+            char *errmsg = NULL;
+            const long http_code = download(url, installer_path, &errmsg);
+            if (HTTP_ERROR(http_code)) {
+                SYSERROR("download failed: %ld: %s", http_code, errmsg);
+                guard_free(errmsg);
+                remove(installer_path);
+                fail_count++;
+                continue;
+            }
+            break;
         }
     }
 
+    if (fail_count >= url_fmts_max) {
+        SYSERROR("all download attempts failed");
+        return -1;
+    }
+
     char mmbin[PATH_MAX];
     snprintf(mmbin, sizeof(mmbin), "%s/micromamba", info->micromamba_prefix);
 
@@ -59,6 +94,16 @@ int micromamba(const struct MicromambaInfo *info, char *command, ...) {
             return -1;
         }
     }
+    return 0;
+}
+
+int micromamba(const struct MicromambaInfo *info, char *command, ...) {
+    char mmbin[PATH_MAX] = {0};
+    snprintf(mmbin, sizeof(mmbin), "%s/micromamba", info->micromamba_prefix);
+    if (access(mmbin, F_OK) < 0) {
+        SYSERROR("Unable to run micromamba. Not installed?");
+        return -1;
+    }
 
     char cmd[STASIS_BUFSIZ] = {0};
     va_list args;
diff --git a/src/lib/core/globals.c b/src/lib/core/globals.c
index b84213e..7eb1beb 100644
--- a/src/lib/core/globals.c
+++ b/src/lib/core/globals.c
@@ -29,6 +29,7 @@ struct STASIS_GLOBAL globals = {
         .verbose = false, ///< Toggle verbose mode
         .continue_on_error = false, ///< Do not stop program on error
         .always_update_base_environment = false, ///< Run "conda update --all" after installing Conda
+        .micromamba_download_url = NULL,
         .conda_fresh_start = true, ///< Remove/reinstall Conda at startup
         .conda_install_prefix = NULL, ///< Path to install Conda
         .conda_packages = NULL, ///< Conda packages to install
diff --git a/src/lib/core/include/conda.h b/src/lib/core/include/conda.h
index cc9426d..a7108ec 100644
--- a/src/lib/core/include/conda.h
+++ b/src/lib/core/include/conda.h
@@ -30,9 +30,18 @@ struct MicromambaInfo {
     char *micromamba_prefix;    //!< Path to write micromamba binary
     char *conda_prefix;         //!< Path to install conda base tree
     char *download_dir;         //!< Path to store micromamba installer
+    char *download_url;         //!< Raw URL to a remotely hosted micromamba-platform-arch file
 };
 
 /**
+ * Download and install Micromamba
+ *
+ * @param info MicromambaInfo data structure (must be populated before use)
+ * @return 0 on successful installation
+ */
+int micromamba_install(const struct MicromambaInfo *info);
+
+/**
  * Execute micromamba
  * @param info MicromambaInfo data structure (must be populated before use)
  * @param command printf-style formatter string
diff --git a/src/lib/core/include/core.h b/src/lib/core/include/core.h
index 9a2007c..ed523be 100644
--- a/src/lib/core/include/core.h
+++ b/src/lib/core/include/core.h
@@ -35,6 +35,7 @@ struct STASIS_GLOBAL {
     bool verbose; //!< Enable verbose output
     bool always_update_base_environment; //!< Update base environment immediately after activation
     bool continue_on_error; //!< Do not stop on test failures
+    char *micromamba_download_url; //!< Override download URL for micromamba
     bool conda_fresh_start; //!< Always install a new copy of Conda
     bool enable_docker; //!< Enable docker image builds
     bool enable_artifactory; //!< Enable artifactory uploads
diff --git a/src/lib/delivery/delivery_populate.c b/src/lib/delivery/delivery_populate.c
index cfa3da2..5ce11d7 100644
--- a/src/lib/delivery/delivery_populate.c
+++ b/src/lib/delivery/delivery_populate.c
@@ -99,6 +99,11 @@ int populate_delivery_cfg(struct Delivery *ctx, int render_mode) {
     }
 
     err = 0;
+    if (!globals.micromamba_download_url) {
+        globals.micromamba_download_url = ini_getval_str(cfg, "indexer", "micromamba_download_url", render_mode, &err);
+    }
+
+    err = 0;
     if (!globals.wheel_builder_manylinux_image) {
         globals.wheel_builder_manylinux_image = ini_getval_str(cfg, "default", "wheel_builder_manylinux_image", render_mode, &err);
     }